JP5056188B2 - Method for determining optimum arrangement of voltage regulator - Google Patents

Description

  The present invention relates to a method for determining an optimum arrangement of a voltage regulator, and more particularly, to a method for determining an optimum arrangement of a voltage regulator installed in a power distribution system.

Conventionally, a voltage regulator is used as a device that compensates for a drop in line voltage due to load fluctuations occurring in a distribution system. This voltage regulator is a voltage regulator having a tap winding, an instrument transformer to which the system voltage is input to the primary side, and the secondary voltage of the instrument transformer is higher than the set value. A voltage relay that outputs a tap lowering command and outputs a tap raising command when it is low, and a load tap switching device that switches the tap of the voltage adjusting transformer according to the tap lowering command and the tap raising command. (For example, refer to Patent Document 1). Such a voltage regulator is installed at a predetermined position of the system so that the voltage drop of the system is equal in anticipation of future increase in power demand.
Japanese Patent Laid-Open No. 11-273972

  By the way, the distribution system is formed radially from the distribution substation toward the end of the load, and system planning, operation, and control have been performed on the premise that the power flow flows in one direction. However, with the progress of deregulation in recent years, it is expected that a large number of distributed power sources will be connected to the distribution system. As a result, reverse power flow will occur in the distribution system, and voltage fluctuations will not occur in existing voltage regulators. Compensation is not possible, and the system voltage may deviate from the specified range.

  Therefore, a main object of the present invention is to provide an optimum arrangement determining method for a voltage regulator capable of determining an optimum arrangement of the voltage regulator in a distribution system in which a reverse power flow occurs.

  An optimum arrangement determination method for a voltage regulator according to the present invention is a method for determining an optimum arrangement of a voltage regulator to be installed in a distribution system, wherein a system state is set using power flow calculation, and particle swarm optimization ( PSO) is used to search for the optimum state, and minimizing the installation cost of the voltage regulator is used as an evaluation index for determining the optimum state.

  Preferably, the tap change of the voltage regulator is handled as a continuous value in the search process for optimizing the set value of the voltage regulator.

  Preferably, the range of change of the system state is given as a time series change of the load power, and the optimum arrangement is determined so that the system voltage can always be maintained within the specified range within the state change range.

  Preferably, the optimum state is determined through the state change range so that the total distribution loss is minimized.

  Preferably, the optimum state is determined so that the control margin of the voltage regulator is maximized through the state change range.

  In the method for determining the optimum arrangement of the voltage regulator according to the present invention, the system state is set using power flow calculation, the optimum state is searched using PSO, and the installation cost of the voltage regulator is minimized. Is an evaluation index for determining the optimum state. Therefore, in order to maintain the voltage of the system in which the reverse power flow caused by the distributed power supply occurs within the voltage management range, it is possible to obtain information on which position of the distribution system the voltage regulator should be installed.

(1) Overall overview There is tidal current calculation as a calculation method to obtain the voltage and current distribution from the distribution substation to the load end. Power flow calculation is a parameter that sets the voltage at a point some distance away from the voltage regulator, the output voltage of the distribution substation, the load (including the distributed power generator), the installation position of the voltage regulator and the set value ) Is an initial condition, and the voltage at each load installation point and the current flowing between two adjacent load points are obtained.

  What is to be searched now is the installation position of the voltage regulator. As a method of searching for this, there is a method of searching for an installation position where the power flow calculation is repeated by trial and error and the system voltage or current value can be maintained within a specified range. However, with this method, the number of searches increases, and depending on the search start position, there is a possibility that the installation position that is not the optimal installation position is taken as a solution.

  In order to solve this problem, there is a plurality of minimum values in the target function (objective function), and PSO (Particle Swarm Optimization) which is an effective method when searching for the smallest minimum value among them with a small number of searches. ) Is used. The installation function of the voltage regulator is included in the objective function of the PSO because the installation cost differs depending on whether the voltage regulator is newly installed or moved. Also, distribution line loss is included from the viewpoint of energy saving. Further, in order to cope with a future increase in load without moving the voltage control device as much as possible, the control margin amount is equalized so that the tap of the voltage adjustment device is as close as possible to the center tap. While maintaining the system voltage and current values at specified values, the installation position of the voltage regulator that minimizes this objective function is obtained.

  For details on PSO, see “Particle Swarm Optimization” by J. Kennedy and R. Eberhart (Proc. Of IEEE International Conference on Neural Networks, Vol. IV, pp.1942-1948, Perth, Australia, 1995. And “A Modified Particle Swarm Optimizer” (Proc. Of IEEE International Conference on Evolutionary Computation, Anchorage, May 1998) by Y. Shi, and R. Eberhart.

(2) Preconditions for the optimal placement problem of the voltage regulator As shown in FIG. 1, in the optimum placement / settling problem of the voltage regulator, it takes a long time to search for the installation position and the set value of the voltage regulator, which are state variables. . Therefore, we will divide it into an optimal placement problem and an optimal settling problem. However, the optimal placement and settling problems for voltage regulators are the system conditions that are auxiliary variables (distribution substation voltage, load, system configuration, system impedance, etc.) and the voltage regulator installation locations and settings that are state variables. As an inverse problem to obtain the installation position and settling value of the voltage regulator from the voltage and current distribution to obtain the best evaluation, as opposed to the forward problem to obtain the voltage and current distribution that is the basis for evaluation of optimality from the value Can be defined.

  In addition, the placement problem and the settling problem are closely related, and it is assumed that the placement is determined in order to obtain the optimum settling value, and the control of the voltage regulator is required to obtain the optimum placement. It is assumed that the state, that is, the settling value has been determined. Therefore, it is difficult to consider the optimal placement problem and the optimal settling problem of the voltage regulator as separate problems. However, as shown in FIG. 1, since the distribution of the voltage and current to be evaluated for optimality is ultimately determined by the tap position obtained as a result of the control of the voltage regulator, the state variables in the target problem The object to be evaluated is related through an intermediate parameter called the tap position.

  In other words, in the optimal placement problem of the voltage regulator, it is possible to treat it separately from the optimal settling problem if only the tap position obtained as a result of the control of the voltage regulator is taken into account. The optimal placement problem is handled considering only the tap position. In addition, since the tap position of a voltage regulator changes with load conditions or a set value, in the optimal arrangement | positioning problem of a voltage regulator, the tap position of a voltage regulator is also handled as a state variable.

(3) Evaluation items for optimality in the optimal placement problem of voltage regulators The evaluation items are the following three items: minimization of installation cost, equalization of control margin of voltage regulator, and minimization of line loss. It is possible to evaluate at least one item. For minimizing the installation cost, a search is performed to minimize the number of newly installed voltage regulators in the target system or the number of voltage regulators to be rearranged.

  Regarding the equalization of the control margin of the voltage regulator, if it is necessary to install multiple devices in the target system, all the installed devices are considered in consideration of future increases in load and distributed power sources. A search for maximizing the control margin of the tap of the voltage regulator is performed. That is, instead of setting the taps separately for each voltage regulator as shown in FIG. 2 (a), the tap positions of all the voltage regulators are made equal as shown in FIG. 2 (b). 2 (a) and 2 (b), as voltage regulators, a distribution substation LDC (Line Drop Compensator) and an SVR (Step Voltage Regulator) are used. It is shown. For minimizing the line loss, a search for minimizing the line loss of the entire system is performed.

(4) State variable The distance from the distribution substation to each voltage regulator is treated as a continuous value, which is used as a state variable. That is, as the parameter in the optimal problem, the position (discrete value) of the power pole where the voltage regulator can be installed is considered, but it is difficult to set the position data of all the power poles in the target distribution system, and the actual power pole Since the intervals are also different, the distance (continuous value) from the distribution substation to each voltage regulator is used as a parameter. The final installation position is an installation position that can be installed close to the value obtained as a continuous value.

  Moreover, the tap position of each voltage regulator is handled as a continuous value, which is used as a state variable. Here, when the voltage regulator is an SVR or a fixed booster, the tap position is a positive integer and is a discrete value. Further, when the voltage regulator is a UPFC (Unified Power Flow Controller), the tap position is a continuous value. Therefore, even when the voltage regulator is an SVR or a fixed booster, the tap position is handled as a continuous value, and the final tap position is determined by searching for the optimum set value with the installation position of the voltage regulator fixed. Find the optimal settling value for the adjustment device.

(5) Objective function Evaluation of optimality in the target problem is based on the premise that the system voltage falls within the specified value range. Also, considering the minimization of equipment costs and operation costs, it is necessary to minimize the number of newly installed or relocated units and minimize the power distribution loss. In consideration of future increases in load, when a plurality of voltage regulators are installed, it is necessary to maximize the control margin so that control is not concentrated on one voltage regulator. Specifically, it is considered that the control tap (tap position in the target load state) of each voltage regulator is close to the center tap.

  An objective function for comprehensively evaluating these is expressed by the following equation (1). In addition, because the target is a severe state of voltage and power flow, the load state is two states of heavy load and light load, the output of the distributed power source is heavy load and light load when the distributed power connection A total of four states, each of which is a combination of a state that varies from 0 [kW] to the maximum output and a state in which it varies from the maximum output to 0 [kW], are targeted.

Here, l is the number of system states to be considered, and l = 2 (two types of heavy load and light load) when the output is constant distributed power connection, and l = 4 (heavy load when distributed power connection) 4 types in total, 2 types of load and light load and 2 types of distributed power supply output fluctuation state). M is the number of branches, n is the number of voltage regulators, Cost _k is the cost of the _k-th voltage regulator (new installation cost, relocation cost), and Loss _i is the effective power loss of branch i. , Margin _j is the control margin of the jth voltage regulator, w _i is the weighting factor of each term of the objective function, and g (V, I) is the sum of absolute values of voltage / current constraint deviation (penalty function) ) Respectively.

  Further, the control margin of the voltage regulator is expressed by the following equation (2).

Here, Tap _{Control j} indicates the control tap of the _jth voltage regulator, and Tap _{Center j} indicates the center tap of the jth voltage regulator.

  Further, the sum of absolute values of voltage / current constraint deviation is expressed by the following equation (3).

Here, if V _h > voltage specified value upper limit value, Vupper _h = V _h -voltage specified value upper limit value, otherwise Vupper _h = 0. If V _h <voltage specified value lower limit value, Vlower _h = V _h -voltage specified value upper limit value, otherwise Vlower _h = 0. If I _i > maximum allowable current, then Iupper _i = I _i -maximum allowable current, otherwise Iupper _i = 0. If | Tap _{Control j} −Tap _{Center j} |> int (total taps / 2), then Tap _j = Tap _{Center j} −Tap _{Control j} , otherwise Tap _j = 0. Also, r is the number of nodes, V _h is the voltage at node h, I _i is the current passing through branch i, Vupper _h is the amount of deviation from the voltage upper limit constraint at node h, and Vlower _h is the deviation from the voltage lower limit constraint at node h. Iupper _i indicates the current upper limit deviation of the branch i. In addition, regarding the numerical values of the weight coefficients w1, w2, w3, and w4 in the objective function, each evaluation item is relatively evaluated and set to a value between 0 and 1.

(6) Constraint conditions The following constraint conditions must be satisfied for system operation. First, it is necessary to satisfy the voltage upper and lower limit constraints, that is, the voltage at each node does not exceed the specified range. Second, it is necessary to satisfy the current upper limit constraint, that is, the current passing through the line, CB, and switch does not always exceed the maximum allowable current for a short time. Thirdly, it is necessary to satisfy the restrictions of the installation area, that is, to exclude areas where the voltage regulator cannot be installed due to surrounding buildings, environment, landscape, and the like. Fourthly, it is necessary that the tap position is satisfied, that is, the tap position of the voltage regulator is between center taps ± int (total number of taps / 2).

  For the first, second, and fourth constraint conditions, the constraint deviation amount is added to the objective function as a penalty value, and for the third constraint condition, the installation position of the voltage regulator that is a state variable is set. When setting, exclude areas where installation is not possible.

  As described above, in the optimum arrangement problem, the optimum arrangement of the voltage regulator that minimizes Equation (1) within a range satisfying all the first to fourth constraint conditions is obtained.

  In the above method, when searching for an optimal solution using an optimization method, it is possible to reach the region where the optimal solution exists by passing through the constraint deviation region, in order to increase the search efficiency of the optimal solution. The first, second, and fourth constraint deviation amounts are added to the objective function as penalty functions. However, by adding a penalty function to the objective function, there is a possibility that a solution having a constraint deviation is searched as an optimal solution. Therefore, it is confirmed that the penalty function is zero in the final optimal solution.

(7) Formulation of Optimal Arrangement Problem of Voltage Regulator Using PSO Here, an outline algorithm using PSO, which is one of the modern heuristic (MH) techniques, is shown. First, in procedure 1, parameters such as weighting coefficients in a search formula for a solution space by PSO are set. Next, in step 2, state quantities are randomly generated by the number of agents for the state variables defined as described above. Also, the initial speed is randomly generated. In procedure 3, the tidal current calculation is executed for each state quantity, and the objective function of Equation (1) is calculated.

  In procedure 4, the evaluation value of the initial state is set as pbest of each agent. Also, gbest is the smallest evaluation value of pbest. In step 5, the speed is calculated. In step 6, the search point and speed of the agent having a poor evaluation value with respect to the current search point are replaced with the value of the agent having a good evaluation value. At this time, the information of the search point (pbest) with the highest evaluation that has been searched so far for each agent remains.

  In step 7, a new state is calculated. At this time, the upper and lower limit constraints of each agent are considered. In step 8, the tidal current calculation is executed for the new state of each agent, and the evaluation value is calculated. In step 9, if the evaluation value of the new state is better than pbest for each agent, pbest is changed. If the smallest evaluation value of the current pbest is better than gbest, gbest is changed. In step 10, when the maximum number of iterations has been reached, the process ends. Otherwise, the process returns to step 5. The best solution is gbest when the maximum number of iterations has passed.

(8) Specific Relocation of Voltage Regulator and Search Method for New Installation The evaluation item that places the most emphasis on the optimal placement problem of voltage regulator is the installation cost of the voltage regulator, that is, the relocation cost of the existing voltage regulator, It is to obtain the arrangement of the voltage regulator that minimizes the installation cost of the new voltage regulator. Below, those search methods are demonstrated.

  First, a search method in a system in which no voltage regulator is installed will be described. For such systems, it is not known in advance how many voltage regulators should be installed for the target system to satisfy the voltage / current constraints. However, if optimal placement search is performed by randomly changing the number of installed voltage regulators, if three voltage regulators are installed for the target system, four or more will be installed if the voltage / current constraints are satisfied. If the optimum arrangement search is performed, a long time is required for the search. Therefore, in this method, in order to eliminate unnecessary searching in the number of installed voltage regulators and shorten the search time, the initial number of voltage regulators is set to one, and if there is a deviation, the number is increased, and the deviation from the restriction The optimal arrangement search is repeated until there is no more, and the number of installations and the optimal arrangement that minimize the installation cost are searched.

  Next, the search method in a system with an existing voltage regulator is described. For such systems, new installation costs and relocation costs may be considered. Although it depends on the number of existing voltage regulators to be rearranged, it is generally cheaper to relocate one voltage regulator than to newly install one voltage regulator, so the priority is to rearrange existing voltage regulators. When the voltage / current constraint is not satisfied, the optimum arrangement of the new voltage regulator is searched.

  Also, considering the cost, when considering the optimal placement of the new voltage regulator, it is necessary to return the existing voltage regulator to the initial state (installation position before relocation study). If the voltage / current constraint is not satisfied even if a new device is installed, it is necessary to perform a search that combines the rearrangement of the existing voltage regulators and the optimum arrangement of the new voltage regulators before increasing the number of newly installed devices. Therefore, the final search order is as follows. The following search order is based on the premise that the cost of rearranging all the existing voltage regulators is lower than the unit price of the new voltage regulator and the installation cost thereof.

  First, in procedure 1, a rearrangement search for the existing voltage regulator is performed. Next, in procedure 2, the existing voltage regulator is placed in the initial arrangement state, and the optimum arrangement search for one new voltage regulator is performed. In the procedure 3, the rearrangement search for the existing voltage regulator and the optimum placement search for one new voltage regulator are performed. In step 4, the existing voltage regulator is placed in the initial arrangement state, and an optimum arrangement search for two new voltage regulators is performed. In the procedure 5, the rearrangement search for the existing voltage regulators and the optimum layout search for the two new voltage regulators are performed. Thereafter, the number of new voltage regulators is increased, and the search is repeated until the voltage / current constraints are satisfied.

  FIG. 3 is a flowchart showing an arrangement determination method when a voltage regulator is newly installed for a system in which no voltage regulator is installed. In step S1, a system configuration, a load state, a system facility, etc. are set. At this time, it is examined whether system configuration and load state data necessary for optimal placement are available. As system configuration data, data of n cases with high switching frequency, that is, data at normal time (i = 1) and data at system switching (i = 2, 3,..., N) are necessary. As load state data, data in a heavy load state (j = 1) and data in a light load state (j = 2) are required.

  In step S2, it is determined whether or not there is an existing voltage regulator (SVR). If there is not, an initial setting of the number k of new voltage regulators is performed in step S3. That is, k = 1. The case where there is an existing voltage regulator will be described with reference to FIG. In step S4, the optimum arrangement of the voltage regulator is searched using HPSO (Hybrid PSO), and in step S5, the power flow calculation is executed for the installable power pole position (discrete value).

  In step S6, it is determined whether or not there is a deviation of the voltage / current constraint. If there is a deviation, a new voltage regulator is added in step S7 (k = k + 1), the process returns to step S4, and the deviation is made in step S6. If NO, in step S8, the number and arrangement of voltage regulators that obtain the best evaluation are selected as the optimum arrangement result of the voltage regulator.

  HPSO is a hybrid method that combines the mechanism of PSO and the concept of natural selection used in GA (Genetic Algorithm) and the like. Details of this HPSO are described in “Using Selection to Improve Particle Swarm Optimization” by Prof. Angeline (Proc. Of IEEE International Conference on Evolutionary Computation, Anchorage, May 1998).

  FIG. 4 is a flowchart illustrating an arrangement determination method in the case where the voltage regulator is rearranged with respect to the system in which the voltage regulator is installed. In step S11, an initial setting is made for the number L of rearranged existing voltage regulators (L = 1). In step S12, a combination of existing voltage regulators to be examined for rearrangement is generated. Set the combination of existing voltage regulators to be considered for placement.

  In step S14, the optimum arrangement of the voltage regulator is searched using HPSO, and in step S15, power flow calculation is performed on the installable power pole position (discrete value). In step S16, it is determined whether or not the examination has been completed for all combinations. If not completed, the process returns to step S13. If completed, the process proceeds to step S17.

  In step S17, it is determined whether or not there is a combination that does not deviate from the voltage / current constraint. If there is no combination, it is determined in step S18 whether or not the existing number has been reached, and the existing number has not been reached. In this case, in step S19, the number of rearranged voltage regulators is increased (L = L + 1), and the process returns to step S12. The case where the existing number is reached in step S18 will be described with reference to FIG. If there is a combination that does not deviate from the voltage / current constraints in step S17, in step S20, the rearranged number and arrangement of the existing voltage regulators that obtain the best evaluation from the combinations that do not deviate from the constraint are selected as the optimum arrangement result. To do.

  FIG. 5 is a flowchart showing an arrangement determination method when the voltage regulator is rearranged and newly installed in a system in which the voltage regulator is installed. In step S21, the number L of rearranged existing voltage regulators is reset (L = 0). In step S22, the number k of newly installed voltage regulators is initialized (k = 1). A combination of the existing and new voltage regulators to be examined for placement / optimum placement is generated, and in step S24, a combination of the existing and new voltage regulators to be examined for rearrangement / optimum placement is set.

  In step S25, the optimum arrangement of the voltage regulator is searched using HPSO, and in step S26, power flow calculation is performed on the installable power pole position (discrete value). In step S27, it is determined whether or not the examination has been completed for all combinations. If not completed, the process returns to step S24, and if completed, the process proceeds to step S28.

  In step S28, it is determined whether or not there is a combination that does not deviate from the voltage / current constraint. If there is no combination, it is determined in step S29 whether or not the existing number has been reached, and the existing number has not been reached. In this case, the number of existing voltage regulators rearranged is increased in step S30 (L = L + 1), and the process returns to step S23. If the number of existing voltage regulators has been reached in step S29, the number L of rearranged existing voltage regulators is reset in step S31 (L = 0), and the number k of newly installed voltage regulators is increased in step S32 (k = k + 1), the process returns to step S23. If there is a combination that does not deviate from the voltage / current constraint in step S28, the number and arrangement of the existing voltage regulators that obtain the best evaluation from the combinations that do not deviate from the constraints and the new voltage regulators are obtained in step S33. Select the number and placement as the optimum placement results.

  6 and 7 are flowcharts showing a method for searching for the optimum arrangement of the voltage regulator using HPSO. In step S41, the number of search iterations is initialized (iter = 1), and in step S42, initial search points for each agent are randomly generated. That is, the initial arrangement (initial search point) of the voltage regulator is set based on the normal time (i = 1).

  In step S43, the system configuration is initialized (i = 1). In step S44, the load state is initialized (j = 1). In step S45, the evaluation values in the target system configuration and the target load state are calculated. To do. In step S46, it is determined whether or not the evaluation has been completed for all loads. If not, the load state is updated in step S47 (j = j + 1), and the process returns to step S45.

  If the evaluation for all loads is completed in step S46, the sum of evaluation values for each load state in the target system configuration is calculated in step S48. In step S49, it is determined whether or not the evaluation has been completed for all the system configurations. If not, the system configuration is updated in step S50 (i = i + 1), and the process returns to step S44.

  If the evaluation for all system configurations is completed in step S49, the sum of evaluation values for each system configuration at the search point (target voltage adjustment device) is calculated in step S51. In step S52, the pbest (best evaluation value in the search process for each agent) of each agent that obtained a good result and the gbest (best evaluation value in the search process of all agents) of all agents are updated.

  In step S53, selection is performed for each search point. That is, the search point and speed of an agent with a poor evaluation value are replaced with the value of an agent with a good evaluation value. In step S54, the speed and search point of each agent are corrected. That is, the speed is corrected using the current speed, pbest, and gbest, and the search point is corrected using the corrected speed. In step S55, it is determined whether or not the maximum number of iterations has been reached. If not, the number of iterations is increased in step S56 (iter = iter + 1), and the process returns to step S43. To do.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure for demonstrating the precondition of the optimal arrangement | positioning determination method of the voltage regulator by one Embodiment of this invention. It is a figure for demonstrating equalization of the control margin of a voltage regulator. It is a flowchart which shows the arrangement | positioning determination method in the case of newly installing a voltage regulator with respect to the system | system in which the voltage regulator is not installed. It is a flowchart which shows the arrangement | positioning determination method in the case of rearranging a voltage regulator with respect to the system | strain in which the voltage regulator is installed. It is a flowchart which shows the arrangement | positioning determination method in the case of rearranging and newly installing a voltage regulator with respect to the system | strain in which the voltage regulator is installed. It is a part of flowchart which shows the search method of the optimal arrangement | positioning of the voltage regulator which uses HPSO. It is the remaining part of the flowchart which shows the search method of the optimal arrangement | positioning of the voltage regulator which uses HPSO.

Explanation of symbols

  LDC line voltage drop compensator, SVR voltage regulator.

Claims (10)

In a method of determining the optimum arrangement of voltage regulators in a distribution system with existing N voltage regulators (where N is a natural number) ,
A first step of generating a plurality of combinations of (N + k) voltage regulators by adding k (where k is a natural number) voltage regulators to the N voltage regulators;
A second step of determining an optimal installation position of the (N + k) voltage regulators in each of the plurality of combinations set in the first step using particle swarm optimization (PSO);
Based on the optimum installation position obtained in the second step in each of the plurality of combinations, the (N + k) voltage regulators are respectively installed on the (N + k) power poles of the distribution system to calculate the power flow. A third step to perform;
A fourth step of determining whether or not there is a combination that does not deviate from the voltage / current constraint in the power flow calculation performed in the third step,
The initial value of k is 1,
If there is no combination without voltage / current deviation in the fourth step, k is incremented by 1 and the process returns to the first step.
In the case where there are one or more combinations in which there is no voltage / current deviation in the fourth step, the best evaluation combination of the one or more combinations is determined as the optimum arrangement of the voltage regulators;
In the PSO, characterized by an evaluation index of order seeking the optimal placement to the minimum necessary installation costs of the voltage regulator, the optimal arrangement determination method of the voltage regulator. In a method for determining the optimum arrangement of voltage regulators in a distribution system with existing N voltage regulators (where N is an integer greater than or equal to 2),
Of the N voltage regulators, L voltage regulators (where L is an integer greater than or equal to 1 and less than or equal to N) are rearranged to generate a plurality of combinations of the N voltage regulators. A first step;
A second step of determining an optimum installation position of the N voltage regulators in each of the plurality of combinations set in the first step using particle swarm optimization (PSO);
In each of the plurality of combinations, based on the optimum installation position obtained in the second step, the N voltage regulators are respectively installed on the N power poles of the distribution system, and a power flow calculation is performed. And the steps
A fourth step of determining whether or not there is a combination that does not deviate from the voltage / current constraint in the power flow calculation performed in the third step,
The initial value of L is 1,
If there is no combination without voltage / current deviation in the fourth step, L is incremented by 1 and the process returns to the first step.
In the case where there are one or more combinations in which there is no voltage / current deviation in the fourth step, the best evaluation combination of the one or more combinations is determined as the optimum arrangement of the voltage regulators;
In the PSO, a method for determining the optimum arrangement of the voltage regulator, wherein the installation cost of the voltage regulator is minimized as an evaluation index for obtaining the optimum installation position. In a method for determining the optimal arrangement of voltage regulators in a distribution system without existing voltage regulators,
A first step of determining an optimal installation position of k voltage regulators (where k is a natural number) using particle swarm optimization (PSO);
A second step of performing the power flow calculation by installing the k voltage regulators on the k power poles of the distribution system based on the optimum installation position obtained in the first step;
And a third step of determining whether or not there is a deviation of the voltage / current constraint in the power flow calculation performed in the second step,
The initial value of k is 1,
If there is a voltage / current deviation in the third step, k is incremented by 1 and the process returns to the first step.
If there is no voltage / current deviation in the third step, the optimum installation position of the k voltage regulators obtained in the second step is determined as the optimum arrangement of the voltage regulators,
In the PSO, a method for determining the optimum arrangement of the voltage regulator, wherein the installation cost of the voltage regulator is minimized as an evaluation index for obtaining the optimum installation position. In the search process of optimizing the set value of the voltage regulator, and wherein the handling tap change of the voltage regulator as a continuous value, the voltage regulating device according to any one of claims 1 to 3 Optimal placement determination method. Given variation range of the system state as a time series change in load power, characterized Rukoto always looking for the optimum installation position location so as to maintain the system voltage within a specified range in the state variable range, according to claim 1 optimal arrangement determination method of the voltage regulator device according to any one of up to claim 4. The through state change range, the sum of the power distribution loss, characterized in Rukoto seeking the optimal placement to minimize the optimum arrangement determination method of the voltage regulator of claim 5. The through state variation range, the control allowance of the voltage regulator is characterized Rukoto seeking the optimal placement to maximize the optimum arrangement determination method of the voltage regulator of claim 5. In the method of determining the optimal arrangement of the voltage regulator installed in the distribution system,
The system state is set using power flow calculation, the optimum state is searched using particle swarm optimization (PSO), and the installation state of the voltage regulator is minimized. As an evaluation index to determine,
The change range of the system state is given as a time series change of the load power, the system voltage can always be maintained within the specified range within the state change range, and the total distribution loss is minimized through the state change range. In this way, the optimum state of the voltage regulator is determined. In the method of determining the optimal arrangement of the voltage regulator installed in the distribution system,
The system state is set using power flow calculation, the optimum state is searched using particle swarm optimization (PSO), and the installation state of the voltage regulator is minimized. As an evaluation index to determine,
The change range of the system state is given as a time series change of the load power, the system voltage can always be maintained within the specified range within the state change range, and the voltage control device tap control margin can be maintained through the state change range. A method for determining an optimum arrangement of a voltage regulator, wherein the optimum state is determined so that the amount is maximized. The optimal arrangement determination of the voltage regulator according to claim 8 or 9, wherein a tap change of the voltage regulator is treated as a continuous value in a search process for optimizing a set value of the voltage regulator. Method.

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