JP5862955B2 - Customer voltage stabilization system in distribution system - Google Patents

Description

  The present invention relates to a voltage stabilization system for a distribution system, and is particularly useful when applied to stabilization of a consumer voltage in a distribution system in which power obtained by solar cell power generation from a customer is supplied as surplus power. It is. Moreover, it is useful when applied to stabilization of consumer voltage in an overloaded power distribution system by charging an electric vehicle.

  The introduction of photovoltaic power generation systems is being actively promoted as one of the means for reducing carbon dioxide emissions to suppress global warming. The voltage fluctuation of the existing power system is expected to increase with the introduction of this solar power generation system in large quantities. This is because the electric power obtained by the solar power generation from the customer is supplied as surplus power through the distribution system, and as a result, the voltage of the distribution system rises. In connection with this, the problem that the case where the electric power of solar power generation cannot be supplied to a system | strain at the time of a light load state occurs in the daytime arises. This is because the upper limit value of the consumer voltage is determined according to the regulations, and power cannot be supplied in a system that has reached the upper limit value. In addition, there arises a problem that the voltage rapidly changes depending on the amount of solar radiation and it becomes difficult to maintain the stability of the customer voltage. In addition, when charging to electric vehicles at the same time, such as at night, the load suddenly increases, and as a result, the consumer voltage may fall below the lower limit of the regulations. There is also a problem that it is difficult to maintain.

  In order to suppress such fluctuations in consumer voltage, introduction of a reactive power compensator (STATCOM) that uses reactive power to suppress fluctuations in voltage is being studied. Such a STATCOM introduction plan is generally studied in a distribution system of 6600 V or more in consideration of compensation for the entire system and ease of voltage control.

  FIG. 15 is an explanatory diagram conceptually showing a power distribution system in which a reactive power compensator is installed. As shown in the figure, a feeder 2 is connected to the secondary side of the distribution substation 1, and a low-voltage distribution line 4 (lead-in wire) is connected to the feeder 2 via the secondary side of each transformer 3. The same applies hereinafter), and a load group 5 of the final consumer is connected to each distribution line 4. Here, the primary side of the feeder 2 and the transformer 3 is normally a high voltage of about 6600 V, and the voltage is stepped down so that the secondary side has a low voltage of about 200 V. The load group 5 is a household load for 4 to 5 houses, for example, distributed from one transformer 3, and surplus power such as a solar cell (PV) paired with a power conditioner (PCS), for example. The load which supplies to the distribution line 4 is also included.

  In such a distribution system, the reactive power compensator I for stabilizing the voltage is generally connected to the terminal side of the feeder 2 of 6600 V, and compensates for voltage fluctuations generated in each of many distribution lines 4 in a lump. It is supposed to be. In this case, the final customer has a large scale of about 500 houses, for example.

  In the case of constructing a compensation system using this type of reactive power compensator in a high voltage system of 6600 V, the number of loads to be compensated is large, so that not only the capacity is increased, but also the semiconductor element constituting the reactive power compensator Technical problems remain in terms of reliability, that is, withstand voltage and life. In addition, it is necessary to provide redundancy from the viewpoint of compensation for the entire distribution system. However, reactive power compensators for high-voltage systems cause an increase in capacity and size more than necessary by considering redundancy. It will be. As a result, the cost increases and becomes a harmful effect of the spread of the voltage stabilization system.

JP 2005-34168 A

  Therefore, in constructing a system for stabilizing the consumer voltage in the distribution system, the withstand voltage of the semiconductor element can be reduced, and an inexpensive invalidity that can guarantee sufficient reliability even with an inexpensive semiconductor element. The emergence of a voltage stabilization system with redundancy in power compensation devices is awaited.

  In view of the above problems, the present invention provides a consumer voltage stabilization system in a distribution system that can stabilize the voltage of the distribution system by using a reactive power compensator with a small withstand voltage load of a semiconductor element and also has redundancy. For the purpose.

The first aspect of the present invention for achieving the above object is as follows:
Each reactive power compensator for performing reactive power compensation is distributed and arranged for each load group connected to each distribution line on the low voltage side of the transformer in the distribution system. In the distribution system, which is controlled to perform reactive power compensation by a control means such that the voltage value at the installed location is within the range of the regulation value until the maximum output of In the customer voltage stabilization system.

  According to the present aspect, the first means is to perform compensation only for the necessary part at the location of the cause that causes the voltage fluctuation by changing the idea, that is, in the immediate vicinity of the load group. That is, a system capable of performing predetermined reactive power compensation on the low voltage side is constructed. As a result, it is possible to cope with only spots where voltage stabilization is a problem. In addition, since the reactive power compensator is distributed on the low-voltage side, it is possible to use parts with a small rated voltage and rated current, and because consumer parts can be used, elements that make up the reactive power compensator, etc. Inexpensive ones can be used. Further, the capacity to be compensated for by the apparatus need only be a capacity corresponding to a voltage variation caused by a load group to which the apparatus is connected. As a result, it is possible not only to reduce the size and cost of the reactive power compensator, but also to improve the flexibility of facility planning in the distribution system and reduce the installation and introduction cost to the distribution system. In addition, since many reactive power compensators are distributed in locations where compensation is required, not only the customer voltage is stabilized, but the redundancy of the entire distribution system is increased, and the robustness of the entire distribution system is improved. Can contribute.

The second aspect of the present invention is:
Each reactive power compensator for performing reactive power compensation is distributed and arranged for each load group connected to each distribution line on the low voltage side of the transformer in the distribution system. A control means for estimating a system state which is a state of a distribution system at a connection position of the compensation device to the distribution line and a load state which is a state of each load group, and a compensation amount which is a voltage variation due to each load group It is determined and controlled so as to compensate the compensation amount for each reactive power compensator, and there is a consumer voltage stabilization system in a distribution system.

  According to this aspect, since the reactive power compensator is arranged on the low voltage side, it is possible to use even a component having a small rated voltage or rated current, and the reactive power compensator is configured with a consumer semiconductor element and a passive component. be able to. Further, the capacity to be compensated for by the apparatus need only be a capacity corresponding to a voltage variation caused by a load group to which the apparatus is connected. As a result, it is possible not only to reduce the size and cost of the reactive power compensator, but also to improve the flexibility of facility planning in the distribution system and to reduce the installation and introduction cost to the distribution system. At the same time, the reactive power compensator is distributed and arranged corresponding to each load group, and the system state at the connection position of each reactive power compensator to the distribution line and the load state of each load group are estimated to Since the compensation amount, which is the voltage fluctuation due to the load group, is determined, it is possible to perform an appropriate autonomous control by the reactive power compensator according to the necessary compensation amount for each load group. Further, the plurality of reactive power compensators arranged in a distributed manner not only stabilizes the consumer voltage, but also increases the redundancy of the entire distribution system, which can contribute to the improvement of the robustness of the entire distribution system.

The third aspect of the present invention is:
In the consumer voltage stabilization system in the power distribution system described in the second aspect,
The reactive power compensator is controlled by control means for determining the compensation amount,
The control means includes
A state in which the reactive power compensator is stopped as viewed from the connection position, and a state in which a fixed current value that is an existing current is supplied by the reactive power compensator or a known load impedance in the reactive power compensator Calculate the voltage fluctuation value caused by the load group based on each impedance of the distribution system in the inserted state,
In the consumer voltage stabilization system in the distribution system, the compensation amount of the reactive power compensator is determined so that the calculated voltage fluctuation value is canceled.

  According to this aspect, the control means estimates the system state and the load state of the load group at the connection position to the low-voltage distribution line of the reactive power compensator, and is appropriate for each load group that performs reactive power compensation. A compensation amount can be determined.

The fourth aspect of the present invention is:
In the consumer voltage stabilization system in the power distribution system described in the third aspect,
The control means includes
A stopped state calculation unit that generates a first circuit equation based on an equivalent circuit representing the power distribution system in a state where the reactive power compensator is stopped, as viewed from the connection position;
A connection state calculation unit for generating a second circuit equation based on an equivalent circuit representing the power distribution system in a state in which a fixed current that is an existing value is supplied by the reactive power compensator as viewed from the connection position;
A compensation amount computing unit that computes a voltage variation value caused by the load group based on the first and second circuit equations and computes a compensation amount of the reactive power compensator based on the voltage variation value. ,
The first circuit equation is a voltage V _{g of} an equivalent voltage source on the distribution system side, a voltage V ₁ that is an actual measurement voltage at the connection position, and an actual measurement current that flows from the distribution system toward the connection position. Current I ₁ , current I _L which is an actually measured current flowing from the load group toward the connection position, impedance Z _{1 of the} distribution system, impedance Z _{L of} the load group, equivalent of a distributed power source installed in the load group Using the voltage V _pcs of a typical voltage source, it is expressed by the following equations (1), (2), (3),

The second circuit equation generated by the connection state calculation unit is the voltage V _g , the voltage V ₁ ′ that is the actual measurement voltage at the connection position, and the actual measurement current that flows from the distribution system toward the connection position. A current I ₁ ′, a current I _L ′ that is an actually measured current flowing from the load group toward the connection position, the impedance Z ₁ , the impedance Z _L , the voltage V _pcs , and a current I _st that is the fixed current are used. And expressed by the following equations (4), (5), (6),

The compensation amount computing unit computes the impedance Z ₁ and the voltage V _g of the distribution system from the first and second circuit equations based on the equations (7) and (8), and the voltage fluctuation value Δ | V | is calculated by equation (9),

Further, the combined impedance Z _i obtained by collectively looking at the distribution side and the load side from the previous connection position is calculated based on the equation (10), and the combined impedance Z _i is expressed as r + jx divided into a real part r and an imaginary part x. Then, the compensation amount _xst to be compensated by the reactive power compensator is calculated by the equation (11) or the equation (12) so as to cancel the voltage fluctuation value Δ | V |.

In the customer voltage stabilization system in the distribution system, which is characterized by being.

  According to this aspect, based on a predetermined calculation result of the connection state calculation unit by insertion of the stop state calculation unit and the current source, the system state and load at the connection position to the low-voltage distribution line in the compensation amount calculation unit A specific amount of compensation can be determined for each load group that performs reactive power compensation by specifically estimating the load state of the group.

According to a fifth aspect of the present invention,
In the consumer voltage stabilization system in the power distribution system described in the third aspect,
The control means includes
A stop state calculation unit for generating the first circuit equation;
A connection state calculation unit for generating a third circuit equation based on an equivalent circuit representing the power distribution system in a state where an existing load impedance is inserted in the reactive power compensator as seen from the connection position;
A compensation amount computing unit that computes a voltage variation value caused by the load group based on the first and third circuit equations and computes a compensation amount of the reactive power compensator based on the voltage variation value. ,
The first circuit equation is expressed by equations (13), (14), (15), as in the fourth aspect,

The third circuit equation generated by the connection state calculation unit is the voltage V _g , the voltage V ₁ ′ that is the actual measurement voltage at the connection position, and the actual measurement current that flows from the distribution system toward the connection position. Using the current I ₁ ′, the current I _L ′ which is an actually measured current flowing from the load group toward the connection position, the impedance Z ₁ , the impedance Z _L , and the voltage V _pcs , the following equations (16) and (17 )

The compensation amount calculation unit, the first and third the distribution system from the circuit equation of the impedance Z ₁ and the voltage V _g Equation (18), as well as calculated based on (19), the voltage fluctuation value delta | V | is calculated by equation (20),

Further, the combined impedance Z _i obtained by collectively looking at the distribution side and the load side from the previous connection position is calculated based on the equation (21), and the combined impedance Z _i is expressed as r + jx divided into a real part r and an imaginary part x. Then, the compensation amount _xst to be compensated by the reactive power compensator is calculated by the equation (22) or the equation (23) so as to cancel the voltage fluctuation value Δ | V |.

In the customer voltage stabilization system in the distribution system, which is characterized by being.

  According to this aspect, based on a predetermined calculation result of the connection state calculation unit by inserting the stop state calculation unit and the load impedance, the system state and load at the connection position to the low-voltage distribution line in the compensation amount calculation unit A specific amount of compensation can be determined for each load group that performs reactive power compensation by specifically estimating the load state of the group.

The sixth aspect of the present invention is:
In the consumer voltage stabilization system in the power distribution system described in the second aspect,
The reactive power compensator is controlled by control means for determining the compensation amount,
The control means includes
An inter-order harmonic current I _{st — n} that is a current corresponding to a frequency other than an integral multiple of the commercial frequency is output from the reactive power compensator, and the inter-order harmonic voltage measured at both ends of the reactive power compensator is V 1 — _n. And the inter-order harmonic current flowing from the connection position toward the distribution system side as I _{1_n} and the inter-order harmonic current flowing from the connection position toward the load side as I _{L_n} , the impedance on the distribution system side in the inter-order harmonics Z 1 — _n is _obtained by Equation (24), and the impedance on the load side in the inter-order harmonic is obtained by Equation (25).

Further, by _{calculating the} combined impedance Z _{i — n} in the inter-order harmonics when the distribution side and the load side are collectively viewed from the connection position by Equation (26), and further converting the combined impedance Z _{i — n} to a value corresponding to the commercial frequency The synthetic impedance Z _i is obtained, the synthetic impedance Z _i is divided into a real part r and an imaginary part x and expressed as r + jx, and the reactive power compensator compensates to cancel the voltage fluctuation value Δ | V |. The power compensation amount x _st is calculated by the equation (27) or the equation (28).

  In the customer voltage stabilization system in the distribution system, which is characterized by being.

  According to this aspect, using the inter-order harmonic injection method, the system state at the connection position to the distribution line on the low voltage side of the reactive power compensator and the load state of the load group that performs reactive power compensation are appropriately determined. An appropriate amount of compensation can be determined for each load group that performs estimation and reactive power compensation.

The seventh aspect of the present invention is
Each reactive power compensator for performing reactive power compensation is distributed and arranged for each load group connected to each distribution line on the low voltage side of the transformer in the distribution system. In a consumer voltage stabilization system in a distribution system, which is controlled by a control means to compensate for the compensation amount for each reactive power compensator, by determining a compensation amount for the voltage fluctuation due to
The control means includes
Sending voltage V _g to the distribution system side, impedance (R + jX) of the distribution system, voltage in a state where the reactive power compensator is stopped at the connection position of the load group and the reactive power compensator in each distribution line based on V _1, it calculates the reactive power compensator should compensate compensation amount as reactive current I _STC having a phase difference of 90 degrees with respect to the voltage by the following equation (29),

A consumer voltage stabilization system in a power distribution system is configured to cancel a voltage fluctuation by controlling the reactive power compensator so as to output the reactive current I _STC .

According to this aspect, the amount of compensation to be compensated by the reactive power compensator can be accurately obtained as the reactive current I _STC , and control is performed so as to supply such reactive current I _STC for each load group. Appropriate reactive power compensation can be performed.

The eighth aspect of the present invention is
In the consumer voltage stabilization system in the power distribution system described in the seventh aspect,
The voltage V _g , the resistance component R and the reactance component X of the impedance of the distribution system are stored in a memory as known parameters, and the calculation of the above equation (29) includes data representing each parameter read from the memory; in consumer voltage stabilization system in the power distribution system, which comprises using the data representative of the voltages V ₁ was measured.

According to this aspect, it is possible to easily obtain data relating to the voltage V _g , the resistance component R of the impedance of the distribution system, and the reactance component X necessary for the calculation of Expression (29).

The ninth aspect of the present invention provides
In the customer voltage stabilization system in the distribution system described in the seventh or eighth aspect,
The voltage V ₁ is expressed by the following equation (30) based on a current I flowing from the connection position toward the load group in a state where the reactive power compensator is stopped.

  It is in the consumer voltage stabilization system in the distribution system characterized by calculating by.

According to this aspect, the voltage V ₁ necessary for the calculation of Expression (29) can be calculated based on the actually measured current I.

The tenth aspect of the present invention provides
In the consumer voltage stabilization system in the power distribution system according to any one of the seventh to ninth aspects,
The resistance component R and reactance component X of the impedance of the distribution system use the values of the real part and the imaginary part of the impedance estimated by the equation (7). is there.

  According to this aspect, it is possible to obtain information on the desired resistance component R and reactance component X using the impedance estimated based on Equation (7).

The eleventh aspect of the present invention is
In the consumer voltage stabilization system in the power distribution system according to any one of the seventh to ninth aspects,
The resistance component R and reactance component X of the impedance of the distribution system use the values of the real part and the imaginary part of the impedance estimated by the equation (18). is there.

  According to this aspect, it is possible to obtain information on the desired resistance component R and reactance component X using the impedance estimated based on Expression (18).

The twelfth aspect of the present invention provides
In the consumer voltage stabilization system in the power distribution system according to any one of the seventh to ninth aspects,
In the power distribution system, the resistance component R and reactance component X of the impedance of the power distribution system use values obtained by converting the real part and imaginary part values of the impedance estimated by the equation (24) into commercial frequencies. In the customer voltage stabilization system.

  According to this aspect, it is possible to obtain information on the desired resistance component R and reactance component X using the impedance estimated based on Equation (24).

The thirteenth aspect of the present invention provides
In the consumer voltage stabilization system in the power distribution system according to any one of the first to twelfth aspects,
The load group includes a load to which a power conditioner that converts DC power generated by a distributed power source into predetermined AC power is connected.

  According to this aspect, it is possible to achieve stabilization of consumer voltage by appropriate reactive power compensation even in a distribution system in which an unstable element of system voltage exists.

The fourteenth aspect of the present invention provides
In the consumer voltage stabilization system in the power distribution system according to any one of the first to thirteenth aspects,
Consumer voltage stabilization in a distribution system using leakage reactance of each transformer, reactance of a low-voltage distribution line, reactance of a lead-in line, etc. as all or part of a reactor for interconnection in each reactive power compensator In the system.

  According to this aspect, since the reactor for interconnection necessary for exhibiting the predetermined function of the reactive power compensator is used for the leakage reactance on the secondary side of the transformer, the device configuration is rational for that. It will be a thing.

  According to the present invention, since it is possible to take measures immediately in the vicinity of the location causing the voltage fluctuation, it is possible to realize spot correspondence to the problematic location. In addition, by disposing the reactive power compensator on the distribution line on the low voltage side for each load group, the breakdown voltage performance of the semiconductor elements constituting the reactive power compensator can be reduced and the overall cost can be reduced. It is possible to improve the flexibility of facility planning in the power distribution system and reduce the installation and introduction cost to the power distribution system. In addition, due to the effect of the distributed arrangement, it is possible to provide sufficient redundancy of the entire distribution system. Furthermore, since the reactive power compensator arranged in a distributed manner can perform autonomous control for each load group, predetermined compensation can also be performed appropriately. As a result, even when a distributed power source such as a solar cell system that causes voltage fluctuation is connected to the load side, it is possible to stabilize the consumer voltage in the distribution system at a low cost.

It is explanatory drawing which shows notionally the power distribution system which installed the reactive power compensation apparatus which concerns on embodiment of this invention. It is a block diagram which shows the control apparatus of the reactive power compensation apparatus which concerns on 1st Example of this invention. It is a circuit diagram which shows the equivalent circuit in a current source insertion system. It is a circuit diagram which shows the equivalent circuit in a current source insertion system. It is a circuit diagram which shows the equivalent circuit in a current source insertion system. It is a circuit diagram which shows the equivalent circuit in a current source insertion system. It is a circuit diagram which shows the equivalent circuit in a current source insertion system. It is a circuit diagram which shows the equivalent circuit of the power distribution system in a load impedance insertion system. It is a circuit diagram which shows the equivalent circuit of the power distribution system in a load impedance insertion system. It is a circuit diagram which shows the equivalent circuit of the power distribution system in a load impedance insertion system. It is a circuit diagram which shows the equivalent circuit of the power distribution system in a load impedance insertion system. It is a circuit diagram which shows the equivalent circuit of the power distribution system in an interharmonic injection system. It is explanatory drawing for demonstrating the calculation principle of the reactive current which should be compensated with the reactive power compensation apparatus which concerns on the 4th Example of this invention. It is a block diagram which shows the control apparatus of the reactive power compensation apparatus which concerns on the said 4th Example. It is explanatory drawing which shows notionally the power distribution system which installed the reactive power compensation apparatus which concerns on a prior art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram conceptually showing a power distribution system in which a reactive power compensator according to this embodiment is installed. As shown in the figure, a feeder 2 is connected to the secondary side of the distribution substation 1, and a low-voltage side distribution line 4 is connected to the feeder 2 via each transformer 3. The load group 5 of the end customer is connected to the electric wire 4. This is the same as the conventional system shown in FIG.

  In this embodiment, the reactive power compensator II is arranged on the secondary side (200 V) of the transformer 3 so as to correspond to each load group 5. That is, the reactive power compensator II is distributed to each distribution line 4 by being connected to each distribution line 4 at the connection position 6. Thus, each reactive power compensator II is distributed to each reactive power compensator II distributed and arranged for each load group 5 distributed from one transformer 3 via each distribution line 4 on the low voltage (200V) side. It is configured to perform predetermined compensation control. Here, the load group 5 is, for example, 4 to 5 household loads. In the case of this embodiment, the load group 5 includes a solar battery PV and a power conditioner PCS that converts its output into predetermined AC power.

  As described above, the reactive power compensator II in the present embodiment is separately distributed on the secondary side of each transformer 3, so that even a component having a small rated voltage or rated current can be used, and reactive power compensation is performed. Inexpensive elements can be used for the elements constituting the apparatus II. As a result, the reactive power compensator II can be reduced in size and cost. Moreover, since the consumer voltage can be stabilized by inserting the reactive power compensator at the location of the load group 5 having the PCS, it is possible to cope with the load group 5 in a spot manner. . Thereby, the flexibility of the facility plan in a power distribution system and the installation introduction cost to a power distribution system can be reduced. Furthermore, since a large number of reactive power compensators are distributed and arranged, the redundancy is increased and the robustness of the entire power distribution system can be improved.

  Here, each reactive power compensator II has a built-in control device. Such a control device compensates for reactive power by supplying predetermined reactive power to the distribution line 4 by the reactive power compensator II in which the control device is incorporated when the voltage of each distribution line 4 is out of the regulation range. To do. Here, most primitively, when reactive power compensation is performed within the range of the supply capacity of the reactive power compensator II so that the voltage at the connection position is within the specified range, the limit of the supply capacity is reached. It is sufficient to perform control to apply a limiter.

  On the other hand, more appropriate compensation operation can be performed by appropriately autonomously controlling each reactive power compensator II. In this case, it is necessary to provide a function for estimating the system state at the connection position to the distribution line 4 to be supplied with compensation power and the load state of the load group 5 and determining the compensation amount for each load group 5.

  Some specific examples in the case of performing such autonomous control will be described as examples. In each of the embodiments described below, each reactive power compensator II distributed and arranged for each load group 5 autonomously compensates for the amount of compensation required only in accordance with the state of the load group 5 corresponding to itself. The system voltage is stabilized.

<First embodiment>
FIG. 2 is a block diagram showing a control device of the reactive power compensator according to the first embodiment. As shown in the figure, the control device in this example includes a detection circuit 11, a stop state calculation unit 12, a connection state calculation unit 13, and a compensation amount calculation unit 14.

The detection circuit 11 detects the values of the actually measured predetermined voltages V ₁ and V ₁ ′, currents I ₁ and I ₁ ′, currents I _L and I _L ′.

Stop state calculating unit 12 generates a first circuit equation detailing voltages V ₁ in the detection circuit _11, a current I _1, with reference to the measured value of the current I _L, after on the basis of the equivalent circuit (see FIG. 3) To do. The equivalent circuit shown in FIG. 3 represents the distribution system in a state where the reactive power compensator II is stopped, as viewed from the connection position 6 of the reactive power compensator II to the distribution line 4. The equivalent circuit will be described in detail later.

The connection state calculation unit 13 refers to the actually measured values of the voltage V ₁ ′, the currents I ₁ ′, and I _L ′ in the detection circuit 11 and based on an equivalent circuit (see FIG. 4), a second circuit equation that will be described in detail later. Is generated. The equivalent circuit shown in FIG. 4 represents a power distribution system in a state in which a reactive current compensator II supplies an existing current _Ist as viewed from the connection position 6 of the reactive power compensator II to the distribution line 4. The equivalent circuit will be described in detail later.

The compensation amount calculation unit 14 calculates the voltage fluctuation value Δ | V | (voltage increase value in this example) caused by the load group 5 based on the first and second circuit equations, and the voltage fluctuation value Δ Based on | V |, the compensation amount x _st by the reactive power compensator II is calculated. In the case of this example, the value of the reactor that should bring about a predetermined voltage drop is obtained, and the main circuit control signal 16 is supplied via the PWM generation circuit 15 so that a current component equivalent to this reactor is output from the reactive power generation circuit. Control.

Next, a method for determining the compensation amount _xst based on the estimation of the system state of the distribution system and the estimation of the load state of the load group 5 when controlling the reactive power compensator II according to the present embodiment by autonomous decentralization will be described in more detail. In this example, the system state when the reactive power compensator II is viewed from the connection position to the distribution line 4 is set as a Thevenin equivalent circuit divided into the load side and the distribution side, and the equivalent parameters are calculated by calculating the parameters in this state. The distribution system status is estimated.

First, the reactive power compensator II is stopped. FIG. 3 shows an equivalent circuit of the system state in the stopped state. In FIG. 3, V _g is the voltage of the equivalent voltage source on the distribution system side, and V ₁ is the connection position of the reactive power compensator II (see FIG. 1; the same applies hereinafter) to the distribution line 4 (see FIG. 1; the same applies hereinafter). actually measured voltage at 6, I ₁ is the current actually measured flows from the power distribution line 4 at the connection position 6, I _L is the load group 5; actually measured current flows (see Figure 1 hereinafter) at the connection position 6 , Z ₁ is the impedance of the distribution system, Z _L is the impedance of the load group 5, and V _pcs is the voltage of an equivalent voltage source that is a distributed power source installed in the load group 5.

As described above, when the voltage V ₁ , the current I ₁ , and the current _IL are measured, the first circuit equations of Expressions (1-1) to (1-3) are established.

Next, the reactive power compensator II outputs a current _Ist . An equivalent circuit in this state is shown in FIG. In FIG. 4, V ₁ ′ is a measured voltage at the connection position 6 to the distribution line 4 of the reactive power compensator II, I ₁ ′ is a measured current flowing from the distribution line 4 toward the connection position 6, and I _L ′. Is a measured current flowing from the load group 5 toward the connection position 6, and I _st is a fixed current supplied by the reactive power compensator II. Note that V _g , Z ₁ , Z _L , and V _pcs are the same parameters as in FIG.

  Here, equations (1-4) to (1-6) are derived based on the equivalent circuit of FIG.

When the above equations (1-1) to (1-6) are used, four parameters (V _g , Z ₁ , Z _L , V _pcs ) can be obtained, but what is required here is impedance Z ₁ and voltage V _g. It is. These are given by the following equations (1-7) and (1-8).

  Therefore, the voltage fluctuation value Δ | V | by the load group 5 is expressed as the following equation (1-9).

  This voltage fluctuation value Δ | V | is a voltage to be compensated by the reactive power compensator II. Here, the amount of reactive power injection required to suppress the voltage fluctuation value Δ | V | is calculated using a Thevenin equivalent circuit.

5 and 6 are equivalent circuits in which all of the load side and the distribution side are viewed from the connection position 6 of the reactive power compensator II. FIG. 5 shows a state in which the reactive power compensator II is stopped. _Shows a state in which a predetermined current _Ist is supplied from the reactive power compensator II.

Here, since it is E = V _1, the combined impedance Z _i viewed collectively distribution side and the load side from the connecting position 6 is expressed by the following equation (1-10).

The combined impedance Z _i given by the above equation (1-10) is set as Z _i = r (real part) + jx (imaginary part) as shown in FIG. Then, in order to simplify the calculation of the reactive power output from the reactive power compensator II, the reactive power compensator II is simulated as a reactor (jx _st ), and the current flowing through the reactor is obtained. Insertion of the reactor (jx _st), the voltage V _{1 ',} the voltage change value Δ than the voltage V ₁ | is because it is possible to perform a predetermined reactive power compensator be reduced by the amount | V.

Here, there is a relationship of the formula (1-11) between the voltages V ₁ and V ₁ ′ and the voltage fluctuation value Δ | V |, and the voltage V ₁ ′ is expressed by the formula (1-12).

  Therefore, the voltage fluctuation value Δ | V | can be expressed as in Expression (1-13).

As a result, in the case of this example, the compensation amount x _st expressed as reactance is as shown in Expression (1-14).

Or when calculating _| requiring the compensation amount _xst , Formula (1-15) is formed approximately.

As a result, the compensation amount x _st expressed as reactance is as shown in equation (1-16).

  Based on the above formula (1-14) or (1-16), the value of the reactor that should bring about a predetermined voltage fluctuation (in this example, a drop) was found. Therefore, by controlling the main circuit control signal 16 (see FIG. 2) of the reactive power compensator II so that the reactive power compensator II outputs a current component equivalent to the reactor, the predetermined voltage fluctuation can be suppressed. Can be realized.

  In the above description, the load is a case where the voltage of the distribution line 4 is increased. However, in the case where the load is decreased, the same appropriate effect can be obtained by applying a capacitor instead of the reactor in the compensation of the reactive power as described above. Can be compensated.

<Second embodiment>
In the first embodiment, while the reactive power compensator II is stopped, the voltage V ₁ , the current I ₁ , and the current _IL are measured, and a predetermined current I _st is output from the reactive power compensator II. In this state, a predetermined parameter is obtained by measuring the voltage V ₁ ′, the current I ₁ ′, and the current I _L ′. In contrast, in the present embodiment, the former state is the same, but in the latter state, a known impedance Z is inserted into the connection position 6 while the reactive power compensator II is stopped, and the voltage V ₁ ′, current I ₁ ′, and current I _L ′ are measured. Thus, a predetermined parameter is obtained based on changes in voltage and current between the former and the latter.

More specifically, FIG. 8 shows the voltage V ₁ at the connection position 6, the current I ₁ flowing from the low-voltage distribution line 4 toward the connection position 6, and the load group 5 toward the connection position 6 in this embodiment. equivalent circuit in the case of measuring the current I _L flowing through (be the same circuit as FIG. 3, providing a first circuit equations), 9 connected by inserting a predetermined impedance Z while stopping the power compensator II Equivalent circuit for measuring voltage V ₁ ′ at position 6, current I ₁ ′ flowing from low-voltage distribution line 4 toward connection position 6, and current I _L ′ flowing from load group 5 toward connection position 6 It is. The third circuit equation is generated based on the equivalent circuit shown in FIG.

  As is apparent from FIG. 8, the equations constituting the first circuit equation are the same as the equations (1-1) to (1-3) in the first embodiment.

  On the other hand, from the equivalent circuit shown in FIG. 9, the third circuit equations shown in equations (2-4) and (2-5) are derived.

Thus, the impedance Z ₁ and the voltage V _g are derived from the relations of the expressions (2-1) to (2-5), and are given by the following expressions (2-6) and (2-7).

As a result, as shown in FIGS. 10 and 11, the combined impedance Z _{i when the} distribution side and the load side are collectively viewed from the connection position 6 is expressed by the equation (2-9) using the relationship of the equation (2-8). ).

Therefore, the compensation amount x _st that should cause a predetermined voltage fluctuation (voltage drop) based on the equation (2-9) also by the method of this example is set to the reactor value according to the equation (2-10) or the equation (2-11). Can be obtained as

  Therefore, also in this example, as in the first embodiment, the main circuit control signal 16 (see FIG. 2) of the reactive power compensator II is output so that the reactive power compensator II outputs a current component equivalent to the reactor. In the same manner, it is possible to achieve a predetermined voltage fluctuation suppression.

<Third embodiment>
Similar to the first and second embodiments, the estimation of the system state and the load state and the calculation of the compensation amount can also be realized by applying the inter-order harmonic injection method. In other words, interharmonic current that is a current corresponding to a frequency other than an integral multiple of the commercial frequency is injected from the reactive power compensator II, and the distribution system and load impedance are estimated based on the fluctuation of the interharmonic current. Then, the system state and the load state are estimated based on such estimation.

  FIG. 12 shows an equivalent circuit when the inter-order harmonic injection method is applied. The equivalent circuit shown in the figure is a Thevenin equivalent circuit, and power supplies having different frequencies are ignored. Therefore, the current source, the distribution impedance, and the load impedance of the interharmonic current output from the reactive power compensator II are obtained.

The current source from which the inter-order harmonic current is output from the reactive power compensator II is I _{st — n} , the inter-order harmonic component voltage measured at both ends of the reactive power compensator II is V 1 — _n , and the order detected on the system side the harmonic current _{I 1_n,} when the interharmonics current detected by the load and _{I L_n} following formula (3-1), (3-2) by between distribution line impedance _{Z 1_n} and order in interharmonic The load impedance Z _{L — n at the} harmonic is obtained.

Further, the combined impedance Z _{i — n} in the inter-order harmonic viewed from the connection position on the power distribution side and the load side is given by Expression (3-3).

Here, the synthetic impedance Z _i at the commercial frequency is obtained by conversion.

Thus, also by the method of this example, the value of the compensation amount x _st that should bring about a predetermined voltage (voltage drop) based on the formula (3-3) is obtained by the formula (3-4) or the formula (3-5). Can do.

Therefore, the reactive power compensator II controls the main circuit control signal 16 (see FIG. 2) of the reactive power compensator II so as to output a current component equivalent to the reactor that gives the compensation amount _xst . Similar to the first and second embodiments, it is possible to realize the suppression of a predetermined voltage fluctuation.

  Similar compensation control can be performed by acquiring parameters related to these from the upper command center instead of using the system state estimation and the load state estimation shown in the first to third embodiments.

<Fourth embodiment>
FIG. 13 is an explanatory diagram for explaining the calculation principle of the reactive current to be compensated by the reactive power compensator according to the fourth embodiment of the present invention. In the distribution system shown in the figure, the distribution line IV between the distribution substation 1 and the customer III is composed of a feeder (high voltage distribution line) 2, (on the pole) transformer 3, (low voltage side) distribution line 4, The reactive power generator II is connected with the load group 5 to the connection position 6 which is the end of the lead-in line 4A. The load group 5 in this embodiment includes a normal load 5A, a PV (solar cell) 5B, and an EV (electric vehicle) 5C. Here, the normal load 5A is an electric product such as a lighting and a refrigerator in the consumer III, and is a device in which current flows from the system together with the EV 5C. In contrast, PV5C is a device that supplies current to the grid.

Here, the impedance of the distribution line IV is R + jX, the supply voltage from the distribution substation 1 is the voltage V _g , the voltage at the connection position 6 is the voltage V ₁ , and the current flowing from the connection position 6 toward the customer III is the current and I _1. Further, regarding the current I ₁ , if the component in phase with the voltage V ₁ is I _1d and the orthogonal component is I _1q , the normal load 5A and EV 5C consume active power, and the output of PV 5B is also active power. The current I ₁ in a state before the compensator II is installed (stopped state) is given by the following equation (4-1).

Therefore, the relationship between the voltages _{V 1} and the voltage _{V g} is expressed by the following equation (4-2).

Next, a state where the reactive power compensator II is installed (operating state) will be considered. Since the reactive power compensator II outputs reactive power, it may be considered that the reactive power compensator II outputs only the reactive current I _1q . From this, the relationship between the voltage V _g and the voltage V ₁ ′ (the voltage at the connection position 6 during the operation of the reactive power compensator II) is expressed by the following equation (4-3).

Here, the reactive power compensator II may make the magnitude of the voltage V ₁ equal to the magnitude of the voltage V _g by the reactive current I _1q .

Therefore, the reactive power compensator II in this embodiment may be controlled so as to flow the reactive current I _STC given by the following equation (4-4).

Referring to the equation (4-4), the voltage V _g , the impedance of the distribution line IV (R + jX), and the voltage V ₁ in a state where the reactive power compensator II at the connection position 6 of the reactive power compensator II is stopped. It can be seen that the reactive current _ISTC, which is the compensation amount to be compensated by the reactive power compensator II, can be accurately obtained.

FIG. 14 shows this embodiment in which the reactive current I _STC to be compensated is generated based on the equation (4-4). As shown in the figure, the compensation amount calculation unit 24 in this embodiment includes a memory 24A and a reactive current calculation unit 24B. Here, the memory 24A, the value of the impedance (R + jX) of the voltage V _g and distribution line IV delivery to feeders 2 of the distribution system are stored in advance. On the other hand, a voltage detector 25, measures the voltages V ₁ at the connection position 6 in a state of stopping the reactive power compensator II.

Compensation amount calculation unit 24 performs calculation on equation (4-4) based on the stored contents and a voltage detector 25 is voltages _{V 1} detected information in the memory 24A, obtains the reactive current _{I STC.}

As a result, the main circuit control signal 16 is formed via the PWM generation circuit 15 so that the reactive current _ISTC is supplied.

Thus, according to the present embodiment, the reactive current I _STC to be compensated for by the reactive power compensator II can be accurately obtained, and the load group 5 is controlled by supplying such reactive current I _STC. Appropriate reactive current compensation can be performed every time.

In the fourth embodiment, the voltage V ₁ detected by the voltage detector 25 is directly used for the calculation of the expression (4-4). However, the load from the connection position 6 in a state where the reactive power compensator II is stopped is used. The voltage V ₁ can also be detected by measuring the current I ₁ flowing into the group 5. That is, a predetermined calculation may be performed by substituting the values of the voltage V _g , impedance (R + jX), and current I ₁ (= I _d ) stored in the memory 24A into the previous equation (4-2).

Furthermore, in the fourth embodiment has been to perform the calculation of Expression (4-4) by using the information of the pre-impedance has been stored in the memory 24A (R + jX) and the voltage V _g, of For example, the information may be supplied by communication from an upper control station, or impedance (R + jX) information obtained by the estimation method described in detail in the first to third embodiments, or impedance (R + jX). and it may be using the information of the voltage V _g.

Further details are as follows.
1) As the resistance component R and the reactance component X of the impedance, the values of the real part and the imaginary part of the impedance estimated by the equation (1-7) are used.

As the voltage V _g, an estimated value of Expression (1-8) is used.
2) As the resistance component R and reactance component X of the impedance, the values of the real part and the imaginary part of the impedance estimated by the equation (2-6) are used.

The voltage V _g uses the estimated value of the equation (2-7).
3) As the resistance component R and reactance component X of impedance, values obtained by converting the values of the real part and imaginary part of the impedance estimated by the equation (3-3) into commercial frequencies are used. Here, the voltage V _g uses the value obtained by the equation (13) using the impedance.

  INDUSTRIAL APPLICABILITY The present invention can be effectively used in an industrial field where an electric power distribution system is operated and maintained, and an industrial field where an electric appliance used in the industrial field is manufactured and sold.

II Reactive power compensator 1 Distribution substation 2 Feeder 3 Transformer 4 Distribution line (low voltage side)
5 Load group 6 Connection position

Claims (12)

Each reactive power compensator for performing reactive power compensation is distributed and arranged for each load group connected to each distribution line on the low voltage side of the transformer in the distribution system. A control means for estimating a system state which is a state of a distribution system at a connection position of the compensation device to the distribution line and a load state which is a state of each load group, and a compensation amount which is a voltage variation due to each load group Determined and controlled to compensate the compensation amount for each reactive power compensator ,
The reactive power compensator is controlled by control means for determining the compensation amount,
The control means includes
A state in which the reactive power compensator is stopped as viewed from the connection position, and a state in which a fixed current value that is an existing current is supplied by the reactive power compensator or a known load impedance in the reactive power compensator Calculate the voltage fluctuation value caused by the load group based on each impedance of the distribution system in the inserted state,
A consumer voltage stabilization system in a distribution system , wherein a compensation amount of the reactive power compensator is determined so that the calculated voltage fluctuation value is canceled . In the consumer voltage stabilization system in the power distribution system according to claim 1 ,
The control means includes
A stopped state calculation unit that generates a first circuit equation based on an equivalent circuit representing the power distribution system in a state where the reactive power compensator is stopped, as viewed from the connection position;
A connection state calculation unit for generating a second circuit equation based on an equivalent circuit representing the power distribution system in a state in which a fixed current that is an existing value is supplied by the reactive power compensator as viewed from the connection position;
A compensation amount computing unit that computes a voltage variation value caused by the load group based on the first and second circuit equations and computes a compensation amount of the reactive power compensator based on the voltage variation value. ,
The first circuit equation is a voltage V _{g of} an equivalent voltage source on the distribution system side, a voltage V ₁ that is an actual measurement voltage at the connection position, and an actual measurement current that flows from the distribution system toward the connection position. Current I ₁ , current I _L which is an actually measured current flowing from the load group toward the connection position, impedance Z _{1 of the} distribution system, impedance Z _{L of} the load group, equivalent of a distributed power source installed in the load group Using the voltage V _pcs of a typical voltage source, it is expressed by the following equations (1), (2), (3),

The second circuit equation generated by the connection state calculation unit is the voltage V _g , the voltage V ₁ ′ that is the actual measurement voltage at the connection position, and the actual measurement current that flows from the distribution system toward the connection position. A current I ₁ ′, a current I _L ′ that is an actually measured current flowing from the load group toward the connection position, the impedance Z ₁ , the impedance Z _L , the voltage V _pcs , and a current I _st that is the fixed current are used. And expressed by the following equations (4), (5), (6),

The compensation amount computing unit computes the impedance Z ₁ and the voltage V _g of the distribution system from the first and second circuit equations based on the equations (7) and (8), and the voltage fluctuation value Δ | V | is calculated by equation (9),

Further well as calculated based on equation (10) the combined impedance Z _i viewed collectively distribution side and the load side from the front Symbol connection position, and r + jx divides the combined impedance Z _i to the real part r and the imaginary part x Then, the compensation amount _xst to be compensated by the reactive power compensator is calculated by the equation (11) or the equation (12) so as to cancel the voltage fluctuation value Δ | V |.

A customer voltage stabilization system in a power distribution system characterized by being a thing. In the consumer voltage stabilization system in the power distribution system according to claim 1 ,
The control means includes
A stopped state calculation unit that generates a first circuit equation based on an equivalent circuit representing the power distribution system in a state where the reactive power compensator is stopped, as viewed from the connection position ;
A connection state calculation unit for generating a third circuit equation based on an equivalent circuit representing the power distribution system in a state where an existing load impedance is inserted in the reactive power compensator as seen from the connection position;
A compensation amount computing unit that computes a voltage variation value caused by the load group based on the first and third circuit equations and computes a compensation amount of the reactive power compensator based on the voltage variation value. ,
The first circuit equation is a voltage V _{g of} an equivalent voltage source on the distribution system side , a voltage V ₁ that is an actual measurement voltage at the connection position, and an actual measurement current that flows from the distribution system toward the connection position. Current I ₁ , current I _L which is an actually measured current flowing from the load group toward the connection position, impedance Z _{1 of the} distribution system , impedance Z _{L of} the load group, equivalent of a distributed power source installed in the load group Using the voltage V _pcs of a typical voltage source, it is expressed by equations (13), (14), (15),

The third circuit equation generated by the connection state calculation unit is the voltage V _g , the voltage V ₁ ′ that is the actual measurement voltage at the connection position, and the actual measurement current that flows from the distribution system toward the connection position. Using the current I ₁ ′, the current I _L ′ which is an actually measured current flowing from the load group toward the connection position, the impedance Z ₁ , the impedance Z _L , and the voltage V _pcs , the following equations (16) and (17 )

The compensation amount calculation unit, the first and third the distribution system from the circuit equation of the impedance Z ₁ and the voltage V _g Equation (18), as well as calculated based on (19), the voltage fluctuation value delta | V | is calculated by equation (20),

Further, the combined impedance Z _i obtained by collectively looking at the distribution side and the load side from the previous connection position is calculated based on the equation (21), and the combined impedance Z _i is expressed as r + jx divided into a real part r and an imaginary part x. Then, the compensation amount _xst to be compensated by the reactive power compensator is calculated by the equation (22) or the equation (23) so as to cancel the voltage fluctuation value Δ | V |.

A customer voltage stabilization system in a power distribution system characterized by being a thing. In the consumer voltage stabilization system in the power distribution system according to claim 1 ,
The reactive power compensator is controlled by control means for determining the compensation amount,
The control means includes
An inter-order harmonic current I _{st — n} that is a current corresponding to a frequency other than an integral multiple of the commercial frequency is output from the reactive power compensator, and the inter-order harmonic voltage measured at both ends of the reactive power compensator is V 1 — _n. And the inter-order harmonic current flowing from the connection position toward the distribution system side as I _{1_n} and the inter-order harmonic current flowing from the connection position toward the load side as I _{L_n} , the impedance on the distribution system side in the inter-order harmonics seeking Z _{1_n} in equation (24) determines a load of the impedance Z _{L_n} in interharmonic by formula (25),

Further, by _{calculating the} combined impedance Z _{i — n} in the inter-order harmonics when the distribution side and the load side are collectively viewed from the connection position by Equation (26), and further converting the combined impedance Z _{i — n} to a value corresponding to the commercial frequency The combined impedance Z _i obtained by collectively viewing the distribution side and the load side from the connection position is obtained, the combined impedance Z _i is divided into a real part r and an imaginary part x and expressed as r + jx, and the voltage fluctuation value Δ | The compensation amount _xst to be compensated by the reactive power compensator is calculated by the equation (27) or the equation (28) so as to cancel V |.

A customer voltage stabilization system in a power distribution system characterized by being a thing. Each reactive power compensator for performing reactive power compensation is distributed and arranged for each load group connected to each distribution line on the low voltage side of the transformer in the distribution system. In a consumer voltage stabilization system in a distribution system, which is controlled by a control means to compensate for the compensation amount for each reactive power compensator, by determining a compensation amount for the voltage fluctuation due to
The control means includes
Sending voltage V _g to the distribution system side, impedance (R + jX) of the distribution system, voltage in a state where the reactive power compensator is stopped at the connection position of the load group and the reactive power compensator in each distribution line Based on V ₁ , a compensation amount to be compensated by the reactive power compensator is calculated as a reactive current I _STC having a phase difference of 90 degrees with respect to the voltage V ₁ by the following equation (29):

A consumer voltage stabilization system in a distribution system, wherein the reactive power compensator is controlled so as to output the reactive current I _STC so as to cancel a voltage fluctuation. In the consumer voltage stabilization system in the power distribution system according to claim 5 ,
The voltage V _g , the resistance component R and the reactance component X of the impedance of the distribution system are stored in a memory as known parameters, and the calculation of the above equation (29) includes data representing each parameter read from the memory; consumer voltage stabilization system in the power distribution system, which comprises using the data representative of the voltages V ₁ was measured. In the consumer voltage stabilization system in the power distribution system according to claim 5 or claim 6 ,
The voltage V ₁ is expressed by the following equation (30) based on a current I flowing from the connection position toward the load group in a state where the reactive power compensator is stopped.

A customer voltage stabilization system in a power distribution system, characterized by: In the consumer voltage stabilization system in the power distribution system according to any one of claims 5 to 7 ,
The resistance component R and reactance X of the impedance of the power distribution system, consumer voltage stabilization system in the power distribution system, which comprises using the value of the real and imaginary part of the impedance estimated by the following equation (7).

( Where Z ₁ is the impedance of the distribution system, V ₁ is the actually measured voltage at the connection position when the reactive power compensator is stopped , and I ₁ is the state where the reactive power compensator is stopped) the distribution system measured current flowing toward the connecting position from, I _L is the measured current which flows toward the connecting position from the load group in a state of stopping the reactive power compensator, V 1 _'is the invalid The actually measured voltage at the connection position when the current _Ist is output from the power compensator , and I ₁ ′ is the actual voltage flowing from the distribution system toward the connection position when the current _Ist is output from the reactive power compensator. Current, I _L ′ is an actually measured current flowing from the load group toward the connection position when the current I _st is output from the reactive power compensator ) In the consumer voltage stabilization system in the power distribution system according to any one of claims 5 to 7 ,
The resistance component R and reactance X of the impedance of the power distribution system, consumer voltage stabilization system in the power distribution system, which comprises using the value of the real and imaginary part of the impedance estimated by the following equation (18).

( Where Z ₁ is the impedance of the distribution system, V ₁ is the actually measured voltage at the connection position when the reactive power compensator is stopped , and I ₁ is the state where the reactive power compensator is stopped) The measured current flowing from the distribution system toward the connection position, V ₁ ′ is the measured voltage at the connection position when the current I _st is output from the reactive power compensator , and I ₁ ′ is the reactive power compensator. This is the measured current that flows from the distribution system toward the connection position when the current _Ist is output from In the consumer voltage stabilization system in the power distribution system according to any one of claims 5 to 7 ,
Resistance component R and reactance X of the impedance of the power distribution system, in the power distribution system, characterized by using the value obtained by converting the values of the real and imaginary parts of the estimated impedance commercial frequency by the following formula (24) Customer voltage stabilization system.

(The expression obtains the impedance Z 1 — _n on the distribution system side in the inter-order harmonic when the inter- order harmonic current I _{st — n} that is a current corresponding to a frequency other than an integer multiple of the commercial frequency is output from the reactive power compensator. The inter-order harmonic voltage measured at both ends of the reactive power compensator is V 1 — _n and the inter-order harmonic current flowing from the connection position toward the distribution system side is I 1 — _n ) In the consumer voltage stabilization system in the power distribution system according to any one of claims 1 to 10 ,
A consumer voltage stabilization system in a distribution system, wherein the load group includes a load connected to a power conditioner that converts DC power generated by a distributed power source into predetermined AC power. In the consumer voltage stabilization system in the power distribution system according to any one of claims 1 to 11 ,
Consumer voltage stabilization in the distribution system, wherein the using the reactance of the transformer leakage reactance and low-voltage distribution line, reactance of drop lines as all or part of the interconnection reactor in each reactive power compensator system.

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