JP5833338B2 - Low voltage distribution line impedance calculation device - Google Patents

Description

  The present invention relates to an impedance calculation device for a low-voltage distribution line that calculates the impedance of the low-voltage distribution line necessary for a voltage adjustment device that adjusts the voltage of the low-voltage distribution line that distributes AC power to a load.

  When the low-voltage distribution line from the distribution system power supply (post transformer) to the load is long, the voltage fluctuation (line voltage fluctuation) of the low-voltage distribution line also increases according to the load weight. For this reason, the voltage regulator provided in the system power supply side regulates the voltage of a low voltage distribution line, and stabilizes the voltage in power supply.

  This voltage adjusting device calculates the voltage drop of the low-voltage distribution line and adjusts the voltage from the power transmission end to the end of the low-voltage distribution line. In calculating the voltage drop of the low-voltage distribution line, it is necessary to investigate and input the impedance of the low-voltage distribution line in advance.

  Moreover, patent document 1 is known as a prior art. The simple impedance measuring apparatus described in Patent Document 1 includes a load circuit connected to a low-voltage distribution line in an energized state, current supply means for supplying a preset input current to the load circuit, and a low-voltage distribution line and a load circuit. And a power factor meter that calculates a power factor from the detected voltage, current, and power, and an arithmetic means that obtains an absolute value of the impedance of the low-voltage distribution line based on the power factor calculated by the power factor meter.

JP-A-9-304453

  However, in the conventional voltage regulator, since the impedance of the low voltage distribution line is investigated and input in advance, there is a problem that it takes much time.

  An object of the present invention is to provide an impedance calculation device for a low-voltage distribution line that can calculate the impedance of the low-voltage distribution line by a simple method without taking time and effort.

The invention of claim 1 is required for a voltage regulator in which an output terminal is connected to a power transmission end of a low voltage distribution line in which an input terminal is connected to a power distribution system power source and a load is connected to a plurality of points between a power transmission end and a terminal. An impedance calculation device for calculating the impedance of the low-voltage distribution line, wherein the transformer capacity, the maximum load capacity that is the ratio of the sum of the maximum capacities of the loads and the transformer capacity, and the maximum load capacity According to the voltage drop of the low-voltage distribution line, the load power factor, the input unit for inputting the ratio of the resistance and reactance of the low-voltage distribution line, the maximum load capacity, and the connection method of each load calculating the end maximum load capacity corresponding value from the count determined Te calculates a distal maximum load capacity converted value, the output voltage of the transformer, the active current and a load power factor at the time of maximum load capacity, maximum the low pressure at the time of load capacity And the voltage drop of the wire, the ratio between the resistance component and reactance component of the low-voltage distribution line, and a load power factor at the time of maximum load capacity, the impedance calculation unit for calculating the impedance of the active current Toka et the low-voltage distribution lines It is characterized by providing.

  According to a second aspect of the present invention, the voltage regulator includes a current detector that detects a current flowing through a power transmission end of the low-voltage distribution line, a voltage detector that detects a voltage at the power transmission end of the low-voltage distribution line, and the current. Based on the detected current from the detector, the detected voltage from the voltage detector, and the impedance of the low-voltage distribution line calculated by the impedance calculator, the voltage from the transmission end to the end of the low-voltage distribution line is within a specified value. And a voltage adjusting device main body for adjusting the voltage at the power transmission end of the low-voltage distribution line by adjusting the compensation amount.

According to the present invention, the resistance of the maximum load capacity of the sum and the transformer capacity of the voltage drop of the maximum load capacity at a low-voltage distribution line is the ratio and the maximum load capacity at a load power factor and low-voltage distribution line of each load Since the impedance of the low-voltage distribution line is calculated from the ratio of the minutes and reactances and the effective current, the impedance of the low-voltage distribution line can be calculated by a simple method with little effort.

It is a circuit block diagram of the impedance calculation apparatus and voltage regulator of the low voltage distribution line of Example 1 of this invention. It is a figure which shows the voltage regulator which compensates a terminal voltage. It is a figure which shows the method of calculating the impedance of a low voltage distribution line. It is a figure which shows the method of dividing the low-voltage distribution line into three and calculating the impedance of a low-voltage distribution line by 1/3 impedance and 1/3 load. It is a figure which shows the input data used when calculating the impedance of a low voltage distribution line. It is a figure which shows the voltage calculation of the terminal voltage of the low voltage distribution line by the voltage regulator of Example 1. FIG. It is a whole block diagram of the specific example of the voltage regulator of Example 1. FIG. It is a detailed block diagram of the specific example of the voltage regulator of Example 1 shown in FIG. It is a figure which shows the relationship between ON / OFF of a triac and the compensation voltage of the voltage regulator of Example 1 shown in FIG. It is a flowchart which shows the impedance calculation method and voltage adjustment method which are implement | achieved by the impedance calculation apparatus and voltage regulator of the low voltage distribution line of Example 1.

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

  1 is a circuit configuration diagram of an impedance calculation device and a voltage adjustment device for a low-voltage distribution line according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating a voltage regulator for compensating for the terminal voltage.

  In FIG. 2, the RN phase secondary voltage of the pole transformer TF (for example, 6.6 kV / 200 V (100 × 2)) is VR-J, and the NT phase secondary voltage is VT-J. . The distribution line impedance is RL and XL, the terminal voltage of the RN phase distribution line is VR-M, and the terminal voltage of the NT phase distribution line is VT-M. Let the R-phase load current be IR and the T-phase load current be IT.

  In designing a low-voltage distribution line, a maximum load capacity (MVA), a voltage drop (ΔV), and a load power factor (PF) are determined in advance. As shown in FIG. 3, the voltage drop due to the impedances RL and XL of the low-voltage distribution line when the load is the maximum load capacity (MVA) is assumed to be ΔV. Further, it is assumed that the ratio between the R component and the X component of the low-voltage distribution line is known.

  The distribution line impedance calculation device 5 includes a data input unit 51 and an impedance calculation unit 52. The data input unit 51 includes the maximum load capacity (MVA), the voltage drop (ΔV) of the low voltage distribution line at the maximum load capacity (MVA), the load power factor (PF), the R component and the X component of the low voltage distribution line. And the ratio.

  The impedance calculation unit 52 includes a maximum load capacity (MVA), a voltage drop (ΔV) of the low voltage distribution line at the maximum load capacity (MVA), a load power factor (PF), and an R component and an X component of the low voltage distribution line. Based on the ratio, the impedance (RL (resistance), XL (reactance)) of the low-voltage distribution line is calculated, and the calculated impedances RL, XL of the low-voltage distribution line are output to the voltage regulator 2.

  The voltage adjustment device 2 adjusts the voltage so that the terminal voltage of the low-voltage distribution line falls within a specified value using the impedances RL and XL of the low-voltage distribution line calculated by the distribution line impedance calculation device 5.

  In FIG. 4, assuming that the load is distributed and connected in the middle of the low-voltage distribution line, the low-voltage distribution line is divided into three parts, and 1/3 impedance RL / 3, XL / 3 and 1/3 load. Shows a method of calculating the impedance of the low-voltage distribution line.

  FIG. 5 shows input data used when calculating the impedance of the low-voltage distribution line. As shown in FIG. 5A, as input items, the transformer capacity TVA has an initial setting value of 50 KVA, the maximum load capacity MVA is 100%, and the voltage drop ΔV of the low-voltage distribution line at the maximum load capacity. Is 6V, the average load power factor PF is fixed at 95%, and the wire diameter of the low-voltage distribution line is 60 mm 2. FIG. 5B shows the calculated impedance value of the pole transformer TF.

  FIG.5 (c) has shown the calculated value of RKL (resistance part) and XKL (reactance part) of the impedance per km of a low voltage distribution line. The wire type is CU-OW, the wire diameter is 60 mm, RKL is 313 mΩ, and XKL is 267 mΩ. The impedance when the low voltage distribution line is L (m) is RL and XL.

  First, as shown in FIG. 4, the load of the low-voltage distribution line is divided into three, for example, and the terminal maximum load capacity when the low-voltage distribution line has a load of each 1/3 load capacity at a position of every 1/3 of the total length. A conversion value (AVA) is calculated by the following formula. Here, it is assumed that the three-house equal wiring division equal load capacity.

AVA = (1 × MVA / 3 + 2/3 × MVA / 3 + 1/3 × MVA / 3) × TVA = 0.667 × TVA × MVA
In this case, the coefficient KA is 0.67.

Further, when the load is concentrated at the end of the low-voltage distribution line, the coefficient KA is 1. If KA is 1,
AVA = TVA × MVA / 100 = 50 (kVA)
It becomes.

Then, the effective current IP is calculated by the following formula using the calculated terminal maximum load capacity conversion. When the load power factor is 95% as in the example shown in FIG.
IP = 0.95 × AVA / 0.2 kV = 4.75 × AVA
IP = 4.75 × KA × TAV × MVA
Next, a method for calculating the resistance component RL and reactance component XL of the impedance of the low-voltage distribution line will be described.

  Distribution line voltage drop ΔV (terminal load capacity conversion) at the time of maximum load capacity MVA at the time of single-phase three-wire load equilibrium is calculated by the following equation.

ΔV = RL × IP + XL × IQ
IQ is a reactive current, RL is in Ω, XL = (XKL / RKL) × RL, and IQ = (0.312 / 0.95) × IP.

In addition, 0.312 is calculated | required by SIN (cos < ^-1 > 0.95).

  When the voltage drop ΔV of the low-voltage distribution line is expressed using this equation, the following equation is obtained.

ΔV = RL × (1+ (XKL / RKL) × (0.312 / 0.95)) × IP
= RL * (1+ (XKL / RKL) * (0.312 / 0.95)) * 4.75 * AVA
From this equation, RL is expressed by the following equation.

RL = ΔV / ((1+ (XKL / RKL) × (0.312 / 0.95)) × 4.75 × AVA)) × 1000
In this equation, ΔV is 6V as in the example shown in FIG. 5A, and XKL / RKL is 267/313 as shown in FIG. 5C. Since AVA is represented by TVA and MVA shown in FIG. 5A, RL becomes 19.73 mΩ by substituting these data into the above equation.

  Since XL = (XKL / RKL) × RL, XL is 16.83 mΩ.

  Next, the terminal voltage of the low voltage distribution line is calculated. First, in the single-phase three-wire system shown in FIG. 2, the RN phase terminal voltage (V) is obtained by the following formula.

VR−M = (VR−J) −KA × (RK × (IR effective current component) + XK × (IR reactive current component)) − KA × (RK × ((IR−IT) effective current component) + XK × (Reactive current of (IR-IT)))
The TN phase terminal voltage (V) is obtained by the following equation.

VT−M = (VT−J) −KA × (RK × (IT active current) + XK × (IT reactive current)) − KA × (RK × ((IT−IR) effective current) + XK × (Reactive current of (IT-IR)))
Here, RT and XT are based on the data in the example of FIG. RK = RT + RL, XK = XT + XL.

Thus, according to the distribution line impedance calculation apparatus 5 of Example 1, the maximum load capacity (MVA) known in the distribution line basic design and the voltage drop (ΔV) of the low-voltage distribution line at the maximum load capacity (MVA). Since the impedance (RL, XL) of the low voltage distribution line is calculated based on the load power factor (PF), the ratio of the R component and the X component of the low voltage distribution line, and the effective current, it does not take time and effort. The impedance of the low voltage distribution line can be calculated by a simple method.

  Next, details of the voltage adjustment device 2 that adjusts the voltage so that the terminal voltage of the low-voltage distribution line falls within the specified value using the data of the impedances RL and XL of the low-voltage distribution line calculated by the distribution line impedance calculation device 5. Will be explained.

  The voltage regulator 2 shown in FIG. 1 has an input terminal connected to a system power source 1 (for example, a single-phase three-wire AC power source) via a first distribution line 2a (power supply line), and is connected from the power transmission end to the end. Second distribution line 2b (power supply line) in which a plurality of loads 3-1 to 3-5 and a plurality of photovoltaic power generation devices (PV) 4-1 to 4-5 are connected to a plurality of points Pt1 to Pt5 The output terminal is connected to the power transmission end.

  In the distribution line impedance Z of the second distribution line 2b, the resistance calculated from the above is% R, and the reactance is% X. The load 3-1 and the solar power generation device 4-1 are connected to the point Pt1 of the second distribution line 2b, the load 3-2 and the solar power generation device 4-2 are connected to the point Pt2, and the point Pt3 Are connected to the load 3-3 and the solar power generation device 4-3, the point Pt4 is connected to the load 3-4 and the solar power generation device 4-4, and the point Pt5 is connected to the load 3-5 and A solar power generation device 4-5 is connected.

  Note that the solar power generation device does not have to be provided at all of the points Pt1 to Pt5, and may be provided, for example, at at least one of the points Pt1 to Pt5.

  The voltage regulator 2 includes a detection solar cell 21, a current detector 22, a voltage detector 23, and a voltage regulator main body 24.

  The solar cell for detection 21 is provided to predict each power generation capacity of each of the solar power generation devices 4-1 to 4-5, generates power by receiving sunlight, and adjusts the voltage using the power generation amount as the solar cell power generation amount. The data is output to the apparatus main body 24. Here, the solar cell for detection 21 and each solar cell of each of the solar power generation devices 4-1 to 4-5 are arranged so that the amount of solar radiation from the sun reaches almost equally. In addition, the rated power generation capacities of the solar power generation devices 4-1 to 4-5 at the respective points Pt1 to Pt5 are input to the voltage adjustment device 2 in advance.

  The current detector 22 detects a current flowing through the power transmission end of the second distribution line 2b. The voltage detector 23 detects the voltage at the power transmission end of the second distribution line 2b. The voltage adjustment device main body 24 is based on the amount of solar cell power generated from the solar cell for detection 21, the detected current from the current detector 22, and the detected voltage from the voltage detector 23, from the power transmission end to the end of the second distribution line 2b. Adjust the voltage within the specified value.

  More specifically, the voltage regulator 2 preliminarily calculates the calculated distribution line impedance Z (% R,% X) from the apparatus 2 (the power transmission end of the second distribution line 2b) to the end of the second distribution line 2b. While being inputted as a calculated value, the effective current and the reactive current are calculated based on the detection current of the current detector 22 and the detection voltage of the voltage detector 23, and the second distribution by the solar power generation devices 4-1 to 4-5. The voltage rise of the terminal voltage of the electric wire 2b is calculated.

Moreover, the voltage regulator 2 is based on the solar cell power generation amount from the solar cell 21 for detection, and each photovoltaic power generator 4-1 to 4-5 attached between the power transmission end of the 2nd distribution line 2b to the terminal. Predict and calculate each generation capacity. Specifically, the voltage regulator 2 determines how much the solar cell power generation amount from the detection solar cell 21 is relative to the rated solar cell power generation amount (100%). This is Ao%. Further, when the rated power generation capacities (rated currents) of the solar power generation devices 4-1 to 4-5 at the points Pt1 to Pt5 input in advance to the voltage adjusting device 2 are Ipv1T to Ipv5T, The effective current Ipv1 (or Ipv2, Ipv3, Ipv4, Ipv5) by the actual power generation of the power generation devices 4-1 to 4-5 is
Ipv1 (or Ipv2, Ipv3, Ipv4, Ipv5) = Ipv1T (or Ipv2T, Ipv3T, Ipv4T, Ipv5T) × Ao
It is calculated for each point.

  FIG. 6 is a diagram illustrating voltage calculation of the terminal voltage of the distribution line by the voltage regulator 2 according to the first embodiment. Here, for simplicity of explanation, only the points Pt0, Pt1, and Pt2 are assumed, the point Pt0 is the position of the output terminal of the voltage regulator 2 at the power transmission end of the second distribution line 2b, and the point Pt2 is the second distribution line. Corresponds to the end of 2b.

  P1 is the active power of the load 3-1 at the point Pt1, Q1 is the reactive power, Ip1 is the active current, Iq1 is the reactive current, PV1 is the active power of the solar power generation device 4-1, and Ipv1 is the active current. P2 is the active power of the load 3-2 at the point Pt2, Q2 is the reactive power, Ip2 is the active current, Iq2 is the reactive current, PV2 is the active power of the solar power generation device 4-2, and Ipv2 is the active current. The distribution line impedance between the calculated points Pt0 and Pt1 is resistance r1, reactance x1, and the distribution line impedance between the points Pt1 and Pt2 is resistance r2 and reactance x2.

  The voltage adjustment device 2 is installed on the power transmission end side of the second distribution line 2b, and the voltage adjustment device 2 detects the current flowing through the power transmission end of the second distribution line 2b and the voltage at the power transmission end of the second distribution line 2b. The terminal voltage of the second distribution line 2b is calculated, and the output voltage (transmission end voltage) of the voltage regulator 2 is set so that the voltage from the transmission end voltage to the end voltage of the second distribution line 2b is within the specified value. adjust.

When the loads and the power generation capacities of the solar power generation devices are evenly arranged with respect to the second distribution line 2b and the load is a power factor load, the distribution line impedance (% R,% X) <<Under the condition of load impedance (RL, XL), per distribution line (one equivalent),
Distribution line voltage drop = effective current × distribution line resistance r + reactive current × distribution line reactance x. For this reason, the terminal voltage of the second distribution line 2b is
Terminal voltage = transmission end voltage−coefficient K × (active current × distribution line resistance% R + reactive current × distribution line reactance% X)
Is required.

  The coefficient K is obtained from conversion for obtaining a load amount arranged from equality of% R and resistance value,% X and reactance value, distribution line impedance, and effective current flowing through the transmission end of the distribution line.

  Next, calculation of distribution line voltage drop and terminal voltage will be described more specifically. Each distribution line voltage drop is as follows per distribution line (corresponding to one) under the condition of distribution line impedance (% R,% X) << load impedance (RL, XL).

The voltage drop V1-2 between points Pt1 and Pt2 is
V1-2 = r2 * (Ip2-Ipv2) + x2 * Iq2
It becomes.

The voltage drop V0-1 between points Pt0 and Pt1 is
V0-1 = r1 * (Ip1 + Ip2-Ipv1-Ipv2) + x1 * (Iq1 + Iq2)
It becomes.

The voltage drop V0-2 between points Pt0 and Pt2 is
When r1 = r2 and x1 = x2, V0-2 = r1 * (Ip1 + 2 * Ip2-Ipv1-2-2 * Ipv2) + x1 * (Iq1 + 2 * Iq2).

Assuming P1 = P2 and Q1 = Q2,
V0-2 = r1 * (3 * Ip2-Ipv1-2-2Ipv2) + x1 * (3 * Iq2)
The voltage (terminal voltage) V2 at the point Pt2 is
Assuming P1 = P2 and Q1 = Q2, V2 = V0−r1 × (3 × Ip2−Ipv1-2 × Ipv2) + x1 × (3 × Iq2)
Furthermore, assuming PV1 = PV2, V0-2 = r1 × (3 × Ip2-3 × Ipv2) + x1 × (3 × Iq2)
The voltage at the point Pt2 is V2 = V0−r1 × (3 × Ip2−3 × Ipv2) + x1 × (3 × Iq2)
Furthermore, when the load power factor is 100%,
V0-2 = r1 * (3 * Ip2-3 * Ipv2)
The voltage at the point Pt2 is VPt2 = V0−r1 × (3 × Ip2−3 × Ipv2)
It becomes.

  FIG. 7 is an overall configuration diagram of a specific example of the voltage regulator according to the first embodiment. FIG. 8 is a detailed configuration diagram of a specific example of the voltage regulator of Embodiment 1 shown in FIG.

  In the voltage regulator 2 shown in FIG. 7, in a single-phase three-wire distribution line, single-phase three-wire AC is input to input terminals R1, N1, and T1, and single-phase three-wires are output from output terminals R2, N2, and T2. Formula AC is output. The voltage regulator 2 includes a detection solar cell 21, a current detector 22a that detects a current flowing through the power transmission end of the distribution line connected to the output terminal R2, and a current flowing through the power transmission end of the distribution line connected to the output terminal T2. Current detector 22b for detecting voltage, voltage detector 23 for detecting the voltage at output terminals R2, N2, and T2, voltage adjusting sections 24a and 24b, control circuit 25, and gate circuits 26a and 26b. The control circuit 25 has a memory 25a.

  The memory 25a stores the calculated distribution line impedance between the points and the rated power generation capacities (rated currents) of the solar power generation devices 4-1 to 4-5 at the points. The control circuit 25 is configured to detect the detection solar cell 21, the current detectors 22a and 22b, the voltage detector 23, the distribution line impedance between the points from the memory 25a, and the photovoltaic power generators 4-1 at each point. The terminal voltage of the second distribution line 2b is calculated based on each rated power generation capacity (each rated current) of -4-5.

  Based on the terminal voltage from the control circuit 25, the gate circuits 26a and 26b send gate signals to the voltage adjusting units 24a and 24b.

  The voltage adjustment unit 24a is provided on the RN phase side, and the voltage adjustment unit 24b is provided on the NT phase side. Based on the gate signals from the gate circuits 26a and 26b, the voltage adjusting units 24a and 24b turn on or off the triacs TRC1 to TRC5 including the AC semiconductor switches so that the terminal voltage of the second distribution line 2b is within the specified value. Therefore, the compensation voltage is changed to take measures against voltage rise and voltage drop of the terminal voltage.

  FIG. 8 shows a detailed configuration of the voltage adjustment unit 24a. The voltage adjustment unit 24b has the same configuration as the voltage adjustment unit 24a. Here, the configuration of the voltage adjustment unit 24a will be described.

  In FIG. 8, the primary winding T1ap of the transformer T1a is connected between the input terminal R1 and the output terminal R2, and one end of the secondary winding T1as of the transformer T1a is connected to one end of the triacs TRC1 and TRC2. . The other end of the secondary winding T1as of the transformer T1a is connected to one end of the triacs TRC3, TRC4, and TRC5 via the reactor L1.

  The other end of the triac TRC1 is connected to the other end of the triac TRC5 and one end of the secondary winding T3s of the transformer T3. The other end of the triac TRC2 is connected to the other end of the triac TRC3, and is connected to the other end of the secondary winding T3s of the transformer T3 via the fuse F1. The other end of the triac TRC4 is connected to the midpoint end of the secondary winding T3s of the transformer T3 via the fuse F2. One end of the primary winding T3p of the transformer T3 is connected to one end of the primary winding T1ap of the transformer T1a. The transformer T3 prevents damage to the semiconductor element due to induced lightning.

  FIG. 9 is a diagram showing a relationship between on / off of the triacs TRC1 to TRC5 and the compensation voltage. The gate circuit 26a outputs a gate signal to the gate terminals of the triacs TRC1 to TRC5.

  The triacs TRC1 to TRC5 are turned on or off as shown in the table of FIG. 9 based on the gate signal, for example, by setting the compensation voltage to + 5V, + 2.5V, 0V, −2.5V, −5V, The voltage across the primary winding T1ap of the transformer T1a is compensated.

  If the terminal voltage of the second distribution line 2b is equal to or higher than the specified voltage, the compensation voltage is first set to -2.5V, and if the terminal voltage is still higher than the specified voltage, the compensation voltage is set to -5V. If the terminal voltage is less than the specified voltage, the compensation voltage is first set to + 2.5V, and if the terminal voltage is still less than the specified voltage, the compensation voltage is set to + 5V.

  Also, for example, as shown in FIG. 1B, when the terminal voltage of the second distribution line 2b rises from the 200V line, the compensation voltage becomes −5V by turning on the triacs TRC2 and TRC5. Since the AC input is 200V and the compensation voltage is -5V, the AC output, that is, the voltage at the point (power transmission end) Pt0 becomes 195V, and falls from the 200V line.

  Similarly, TRIACs TRC6 to TRC10 are provided in the TN phase voltage adjustment unit 24b, and by turning on or off the TRIACs TRC6 to TRC10, the RN phase and the TN phase can be controlled independently, and unbalanced. Load countermeasures can also be performed.

  FIG. 10 is a flowchart illustrating a distribution line impedance calculation method and a voltage adjustment method realized by the distribution line impedance calculation apparatus and the voltage adjustment apparatus 2 according to the first embodiment. A distribution line impedance calculation method and a voltage adjustment method will be described with reference to FIG.

  First, in the distribution line impedance calculation device 5, the maximum load capacity (MVA) of the target distribution line and the voltage drop (ΔV) of the low-voltage distribution line at that time are input (step S10).

  Next, in the distribution line impedance calculation device 5, the known load power factor and the ratio of R and X of the low-voltage distribution line are input, and the maximum load capacity (MVA) and the voltage drop (ΔV) of the low-voltage distribution line at that time Based on the load power factor and the ratio of R and X of the low-voltage distribution line, impedances RL and XL of the low-voltage distribution line are calculated (step S11).

  Next, the current detector 22 and the voltage detector 23 detect the current and voltage at the point Pt0 of the second distribution line 2b which is the power transmission end. Moreover, the solar cell power generation amount is detected by the detection solar cell 21 (step S12).

  The control circuit 25 in the voltage adjusting device main body 24 is configured so that each solar power is generated from the solar cell power generation amount from the detection solar cell 21 and each rated power generation capacity (each rated current) of each solar power generation device 4-1, 4-2. The effective currents Ipv1, Ipv2 due to actual power generation of the photovoltaic power generators 4-1, 4-2 are calculated (step S13).

  The control circuit 25 obtains an effective current and a reactive current from the detection current from the current detector 22 and the detection voltage from the voltage detector 23, and determines each load 3-1 and 3-by the difference from each effective current Ipv1, Ipv2. 2 effective currents Ip1, Ip2 and reactive currents Iq1, Iq2 are obtained (step S15).

  Next, the control circuit 25 calculates the terminal voltage of the 2nd distribution line 2b by predetermined voltage calculation using the data of distribution line impedance (r, x) (step S17). The predetermined voltage calculation is a calculation formula when the load connected to the second distribution line 2b is a power factor load. The gate circuits 26 a and 26 b generate a gate signal based on the terminal voltage from the control circuit 25.

  Next, based on the gate signals from the gate circuits 26a and 26b, the voltage adjustment units 24a and 24b turn on or off the triacs TRC1 to TRC10 so that the terminal voltages are within a specified value, thereby providing a compensation amount (compensation voltage). Are adjusted and determined (step S19).

  The gate circuits 26a and 26b determine whether or not the terminal voltage and the power transmission end voltage from the control circuit 25 are within the specified values. If the terminal voltage and the power transmission end voltage are not within the specified values, the gate circuits 26a and 26b generate a gate signal to perform the step. Return to S19.

On the other hand, when the terminal voltage and the power transmission end voltage are within the specified values, the voltage adjustment device 2 compensates for the compensation amount determined in step S19 (step S23), and the compensation result at the point Pt0 is confirmed (step S23). S25).
Thus, according to the voltage regulator 2 of Example 1, for example, when the amount of photovoltaic power generation exceeds the amount of load and the terminal voltage increases, the amount of photovoltaic power generation at a plurality of points is calculated and transmitted. Detects the current and voltage at the end, calculates the active power and reactive power including reverse power flow, calculates the terminal voltage from these and distribution line impedance, and the power transmission end voltage, terminal voltage and each point voltage are within the specified value Thus, the voltage of the voltage adjusting device 2 can be adjusted.

  In addition, the connection position of the voltage regulator 2 may be not only the power transmission end but also an intermediate point and a plurality of points.

  The present invention can be applied to power distribution facilities and the like.

DESCRIPTION OF SYMBOLS 1 Power distribution system power supply 2 Voltage regulator 3-1 to 3-5 Load 4-1 to 4-5 Photovoltaic power generation device (PV)
5 Distribution Line Impedance Calculation Device 21 Detection Solar Cells 22, 22a, 22b Current Detector 23 Voltage Detector 25 Control Circuits 26a, 26b Gate Circuit 25a Memory 51 Data Input Unit 52 Impedance Calculation Unit Z Distribution Line Impedance

Claims (2)

The impedance of the low-voltage distribution line required for the voltage regulator in which the output terminal is connected to the power transmission end of the low-voltage distribution line whose input terminal is connected to the power distribution system power source and the load is connected to multiple points between the transmission end and the terminal end An impedance calculation device for calculating
A transformer capacity, a maximum load capacity that is a ratio of the sum of the maximum capacity of each load and the transformer capacity, a voltage drop of the low-voltage distribution line at the maximum load capacity, a load power factor, and the low-voltage distribution An input unit for inputting the ratio of the resistance and reactance of the wire;
The terminal maximum load capacity conversion value is calculated from the maximum load capacity and the count determined according to the connection method of each load, the terminal maximum load capacity conversion value, the output voltage of the transformer, and the maximum load The effective current is calculated from the load power factor at the capacity , the voltage drop of the low-voltage distribution line at the maximum load capacity , the ratio of the resistance and reactance of the low-voltage distribution line, and the load force at the maximum load capacity an impedance calculating unit that calculates a ratio, the impedance of the active current Toka et the low-voltage distribution lines,
An impedance calculating device for a low-voltage distribution line, comprising: The voltage regulator is
A current detector for detecting a current flowing through a power transmission end of the low-voltage distribution line;
A voltage detector for detecting a voltage at a power transmission end of the low-voltage distribution line;
Based on the detected current from the current detector, the detected voltage from the voltage detector, and the impedance of the low-voltage distribution line calculated by the impedance calculation unit, the voltage from the transmission end to the end of the low-voltage distribution line is a specified value. A voltage adjusting device main body for adjusting the voltage at the power transmission end of the low-voltage distribution line by adjusting the compensation amount so as to be within,
The impedance calculation device for a low-voltage distribution line according to claim 1.

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