JPWO2019111292A1 - POWER CONDITIONER SYSTEM, POWER SYSTEM WITH THE SAME, AND ACCIDENT POINT LOCATION METHOD - Google Patents

Abstract

The power conditioner system includes an inverter circuit connected to a power system via a power transmission line, an ammeter that measures an output current of the inverter circuit, and a control device that is connected to the ammeter and controls the inverter circuit. . The control device, when receiving a predetermined input signal determined in advance, the inverter circuit receives a first AC voltage signal having a first frequency and a first voltage value and a second AC voltage signal having a second frequency and a second voltage value. It is constructed to control an inverter circuit to output a signal to a power line. The control device is constructed to obtain a first output current of the inverter circuit according to the first AC voltage signal measured by the ammeter and a second output current of the inverter circuit according to the second AC voltage signal. There is. The control device is constructed to calculate the DC resistance and the inductance based on the first impedance, the second impedance, the first complex number, and the second complex number.

Description

  The present invention relates to a power conditioner system, a power system including the same, and an accident point locating method.

  2. Description of the Related Art Conventionally, as described in, for example, Japanese Patent No. 3053119, there has been known an accident situation identification device improved so that a distance to an accident point can be located with high accuracy. “Orientation” is to specify the position of the accident point. 2. Description of the Related Art Conventionally, a technique of locating a fault point in a power system using the amount of electricity in the power system has been generally used, and the fault point is estimated from the amount of electricity before the accident.

Japanese Patent No. 3053119

  The above-described conventional technique has a problem that an expensive and dedicated accident situation identification device that executes complicated calculations is required. Even in a power system using renewable energy, which has become popular in recent years, it is also possible to locate an accident point by using a conventional method. However, the inventor of the present application has conducted intensive research and found a novel technique of locating an accident point using a power conditioner system installed in a renewable energy power system.

  The present invention has been made in order to solve the above-described problems, and provides a power conditioner system having a function of specifying an accident point, an electric power system having the same, and an accident point locating method. Aim.

The power conditioner system according to the first invention,
An inverter circuit connected to the transmission line,
An ammeter that measures an output current that the inverter circuit outputs to the transmission line;
A control device that is connected to the ammeter and controls the inverter circuit;
With
The control device, when receiving a predetermined input signal predetermined, a first AC voltage signal having a first frequency and a first voltage value and a second frequency and a second voltage value different from the first frequency. And output the second AC voltage signal to the inverter circuit. The first output current of the inverter circuit according to the first AC voltage signal and the second output current of the inverter circuit according to the second AC voltage signal. And is configured to measure with the ammeter,
The control device has a first impedance determined by the first voltage value and the first output current, a second impedance determined by the second voltage value and the second output current, a DC resistance, the first frequency and an inductance. A first complex number representing the first impedance and a second complex number representing the second impedance with the DC resistance, the second frequency and the inductance are configured to calculate the DC resistance and the inductance. Have been.

The power system according to the second invention,
A DC power supply that outputs DC power,
A power conditioner system that converts the DC power from the DC power supply into AC power and outputs the AC power to a transmission line,
With
The power conditioner system includes:
An inverter circuit connected to the transmission line,
An ammeter that measures an output current that the inverter circuit outputs to the transmission line;
A control device that is connected to the ammeter and controls the inverter circuit;
With
The control device, when receiving a predetermined input signal predetermined, a first AC voltage signal having a first frequency and a first voltage value and a second frequency and a second voltage value different from the first frequency. And output the second AC voltage signal to the inverter circuit. The first output current of the inverter circuit according to the first AC voltage signal and the second output current of the inverter circuit according to the second AC voltage signal. And is configured to measure with the ammeter,
The control device has a first impedance determined by the first voltage value and the first output current, a second impedance determined by the second voltage value and the second output current, a DC resistance, the first frequency and an inductance. A first complex number representing the first impedance and a second complex number representing the second impedance with the DC resistance, the second frequency and the inductance are configured to calculate the DC resistance and the inductance. Have been.

The accident point locating method according to the third invention,
A power conditioner comprising: an inverter circuit connected to a transmission line; an ammeter for measuring an output current output from the inverter circuit to the transmission line; and a control device connected to the ammeter and controlling the inverter circuit. An accident point locating method for locating an accident point of the transmission line using
Causing the inverter circuit to output a first AC voltage signal having a first frequency and a first voltage value and a second AC voltage signal having a second frequency and a second voltage value different from the first frequency; Measuring the first output current of the inverter circuit according to the AC voltage signal and the second output current of the inverter circuit according to the second AC voltage signal with the ammeter;
The first impedance is determined by the first voltage value and the first output current, the second impedance and the DC resistance determined by the second voltage value and the second output current, and the first impedance is represented by the first frequency and the inductance. Calculating the DC resistance and the inductance based on a first complex number and the DC resistance, a second complex number representing the second impedance at the second frequency and the inductance,
Calculating a distance from the power conditioner to the accident point based on the DC resistance and the inductance;
Is provided.

  According to the power conditioner system, the power system, and the fault point locating method described above, the power conditioner system can exhibit the fault point locating function, and thus has an advantage that it is not necessary to use a dedicated fault point locating device. is there.

FIG. 1 is a system configuration diagram illustrating a power conditioner system according to a first embodiment and a power system including the power conditioner system. FIG. 2 is a circuit diagram of the power conditioner system according to the first embodiment. 5 is a flowchart illustrating a work procedure executed in the power system according to the first embodiment; 3 is a flowchart of a routine executed in the power conditioner system according to the first embodiment; 5 is a graph for explaining the principle of the method for locating an accident point according to the first embodiment. 9 is a flowchart of a routine executed in the power conditioner system according to the modification of the first embodiment. FIG. 2 is a system configuration diagram illustrating a power conditioner system according to a modification of the first embodiment and a power system including the same. FIG. 2 is a system configuration diagram illustrating a power conditioner system according to a modification of the first embodiment and a power system including the same. FIG. 2 is a system configuration diagram illustrating a power conditioner system according to a modification of the first embodiment and a power system including the same. FIG. 2 is a system configuration diagram illustrating a power conditioner system according to a second embodiment and a power system including the power conditioner system. FIG. 2 is a system configuration diagram illustrating a power conditioner system according to a second embodiment and a peripheral configuration thereof; FIG. 9 is a diagram for explaining map information created by the power conditioner system according to the second embodiment. FIG. 9 is a diagram for explaining map information created by the power conditioner system according to the second embodiment. 9 is a flowchart of a routine executed in the power conditioner system according to the second embodiment. FIG. 13 is a circuit diagram showing a power conditioner system according to a modification of the second embodiment and a peripheral configuration thereof.

  FIG. 1 is a system configuration diagram showing a power conditioner system 12 and a power system 1 including the power conditioner system 12 according to the first embodiment. The power system 1 includes a grid-connected power generation unit 2, a first bus 6 receiving power generated by the grid-connected power generation unit 2, a power transmission network 7 connected to the first bus 6, and power via the power transmission network 7. It has a second bus 9 to receive and a load 8 connected to the second bus 9.

  The system interconnection power generation unit 2 includes a rotating machine generator 4, a first circuit breaker 5, a solar cell array 3, and a power conditioner system 12 that is a power conversion device. “Power conditioner system” is also abbreviated as “PCS”.

  The rotating machine generator 4 is connected to the first bus 6 via the first circuit breaker 5. The rotating machine generator 4 supplies power to the transmission line 70 through the first bus 6. The rotating machine generator 4 is a rotating machine generator mounted on a fossil energy generator or a nuclear power generator. The rotating machine generator 4 performs a system interconnection operation together with the solar power system including the solar cell array 3 and the PCS 12.

  The PCS 12 includes an inverter circuit 22 and a power conversion control device 40, as shown in FIG. The PCS 12 is a power converter that converts DC power to AC power. Inverter circuit 22 converts DC power from solar cell array 3 to AC power. The AC power output from the inverter circuit 22 is supplied to the transmission line 70 via the first bus 6.

  The power conversion control device 40 controls the operation of the inverter circuit 22, and specifically controls the switching operation of the switching elements included in the inverter circuit 22. The power conversion control device 40 is configured to be able to execute “current limit control” separately from the steady-state control. The “current limiting control” according to the first embodiment suppresses or stops the output current of the inverter circuit 22 when the voltage on the output side of the inverter circuit 22 meets a predetermined condition. The detailed structure of the PCS 12 will be described later with reference to FIG.

  The power system 1 includes an instrument current transformer 69, a second circuit breaker 71, a relay 73, and an instrument transformer 75. The power transmission network 7 includes a power transmission line 70 and a third circuit breaker 72. One end of the transmission line 70 is connected to the first bus 6, and the other end of the transmission line 70 is connected to the third circuit breaker 72. The third circuit breaker 72 mediates the other end of the transmission line 70 and the second bus 9. An instrument current transformer 69 and an instrument transformer 75 are provided near the connection between the power transmission line 70 and the first bus 6. The current I measured by the instrument current transformer 69 and the voltage V measured by the instrument transformer 75 are input to the relay 73. Reference numeral 76 schematically shows a situation where the ground fault 76 has occurred in the transmission line 70. The location where the ground fault 76 has occurred is treated as the accident point Q.

  The relay 73 is a distance relay as an example. The relay 73 can detect an accident of the transmission line 70 based on whether or not the impedance of the transmission line 70 meets a predetermined impedance condition.

  The first bus 6 is connected to the rotary generator 4, the power transmission line 70 of the power transmission network 7, and the PCS 12. The rotating machine generator 4 and the PCS 12 are connected in parallel to the first bus 6, and the transmission line 70 receives the output power of these power generating facilities. The first bus 6 is a bus of a substation.

FIG. 2 is a circuit diagram illustrating the PCS 12 of the power system 1 according to the first embodiment. The PCS 12 includes an inverter circuit 22, which is a power conversion unit, an interconnection transformer 23, a capacitor 24, a DC reactor 25, a DC voltage detector 26, a DC current detector 27, an AC voltage detector 28, an AC It includes a current detector 29 and a power conversion control device 40. When turning on the PCS12 power switch (not shown), the power-on signal _{S ON} to the PCS12 is input.

  The main circuit 21 is a circuit that supplies the power generated by the solar cell array 3 to the first bus 6. The main circuit 21 includes an inverter circuit 22, an interconnection transformer 23, a capacitor 24, and a DC reactor 25.

  The inverter circuit 22 converts DC power supplied from the solar cell array 3 into AC power synchronized with the AC power supply of the first bus 6. Inverter circuit 22 outputs the converted AC power to supply it to first bus 6.

  The interconnection transformer 23 is provided on the output side (AC side) of the inverter circuit 22. Interconnection transformer 23 transforms the AC voltage output from inverter circuit 22 into a voltage for supplying to first bus 6.

  The capacitor 24 and the DC reactor 25 form an AC filter. The AC filter is provided on the AC side of the interconnection transformer 23. The AC filter suppresses a harmonic current flowing from the inverter circuit 22 to the first bus 6.

  The DC voltage detector 26 is provided on the input side (DC side) of the inverter circuit 22. DC voltage detector 26 detects a DC voltage input from solar cell array 3. The DC voltage detector 26 outputs the detected DC voltage to the power conversion control device 40.

  The DC current detector 27 is provided on the input side of the inverter circuit 22. DC current detector 27 detects a DC current input from solar cell array 3. DC current detector 27 outputs the detected DC current to power conversion control device 40.

  The AC voltage detector 28 is provided on the output side (AC side) of the DC reactor 25. The AC voltage detector 28 detects an AC voltage output from the inverter circuit 22. The AC voltage detector 28 outputs the detected AC voltage to the power conversion control device 40.

  The AC current detector 29 is provided on the output side of the DC reactor 25. The AC current detector 29 detects an AC current output from the inverter circuit 22. The AC current detector 29 outputs the detected AC current to the power conversion control device 40.

  The power conversion control device 40 is a control device that controls the inverter circuit 22. The power conversion control device 40 includes a DC voltage measurement unit 41, a DC current measurement unit 42, an AC voltage measurement unit 43, an AC current measurement unit 44, a power control unit 45, a PWM (Pulse Width Modulation) control unit 46, , An input / output interface 47.

  The DC voltage measurement unit 41 measures the DC voltage input from the solar cell array 3 based on the DC voltage detected by the DC voltage detector 26. The DC voltage measurement unit 41 outputs the measured DC voltage to the power control unit 45.

  The DC current measurement unit 42 measures the DC current input from the solar cell array 3 based on the DC current detected by the DC current detector 27. The DC current measurement unit 42 outputs the measured DC current to the power control unit 45.

  The AC voltage measuring unit 43 measures the system voltage of the first bus 6 (the output voltage of the inverter circuit 22) based on the AC voltage detected by the AC voltage detector 28. The AC voltage measurement unit 43 outputs the measured AC voltage to the power control unit 45.

  The AC current measuring unit 44 measures the AC current output from the inverter circuit 22 based on the AC current detected by the AC current detector 29. The AC current measurement unit 44 outputs the measured AC current to the power control unit 45.

  The power control unit 45 measures the DC voltage measured by the DC voltage measurement unit 41, the DC current measured by the DC current measurement unit 42, the AC voltage measured by the AC voltage measurement unit 43, and the AC current measurement by the AC current measurement unit 44. An arithmetic process for controlling the amount of electricity (current, voltage, power, etc.) output from the inverter circuit 22 is performed based on the obtained alternating current. The power control unit 45 outputs the calculated amount of electricity to the PWM control unit 46 as an output command value for the inverter circuit 22.

  The PWM control unit 46 generates a gate signal for performing PWM control of the inverter circuit 22 based on the output command value input from the power control unit 45. The PWM control unit 46 controls the drive of the inverter circuit 22 by the generated gate signal. Thus, AC power having a desired frequency can be output from the inverter circuit 22.

The input / output interface 47 can exchange signals with the outside of the PCS 12. The input / output interface 47 is connected to the power control unit 45 and an accident point locating unit 50 described later. Output interface 47 may enter the fault point locating process execution command S ₀ for executing the fault point locating program fault point locating unit 50.

The power conversion control device 40 includes an accident point locating unit 50. The accident point locating unit 50 includes a calculation unit 51, a storage unit 52, and an internal bus 53. The storage unit 52 stores a program in which an accident point locating process according to FIG. 4 described later is described. An accident point locating process execution instruction S ₀ is input to the input-output interface 47, the arithmetic unit 51 executes the storage unit 52 reads the fault point locating program.

  FIG. 3 is a flowchart illustrating a work procedure performed in the power system 1 according to the first embodiment. First, a worker knows that an accident may have occurred in the power system (step S100).

  Next, the worker arrives at a power plant connected to the power transmission network 7 where an accident may have occurred (step S102). It is assumed that the PCS 12 is installed in this power plant. The worker closes the second circuit breaker 71, which should have been cut off at the power plant, and makes the PCS 12 and the transmission line 70 communicate with each other (step S104).

  Next, the operator turns on the power of the PCS 12 by operating the power switch of the PCS 12 (step S106). In the first embodiment, since it is assumed that the PCS 12 is temporarily shut down after the occurrence of the accident, the power of the PCS 12 is turned on again. As a modified example, if the PCS 12 enters the standby mode when an accident occurs, a return operation from the standby mode may be performed instead of turning on the power again.

Then, the operator gives a fault point locating process execution instruction _{S 0} with respect PCS12 (step S108). Fault point locating process execution command S ₀ is a predetermined input signal to a predetermined. Fault point locating process execution instruction S ₀ in the first embodiment, the worker by performing some operation outside the PCS12, a signal input from the outside to the PCS12. Fault point locating process execution command _{S 0} may be entered by a manual operation through the GUI on the operation screen of the operation buttons or PCS12 of PCS12. Alternatively, fault point locating process execution command S _0, by using the communication functions of the PCS12, it may be input via the operation terminal connected by PCS12 wired or wireless. In any case, the accident point locating process in the first embodiment requires an external input signal as a condition for starting execution, and is not automatically executed only by the internal processing of the PCS 12.

FIG. 4 is a flowchart of a routine executed in the PCS 12 according to the first embodiment. The routine shown in FIG. 4 is a program in which the accident point locating process according to the first embodiment is described, and is stored in the storage unit 52. Routine of Figure 4, if the fault point locating process execution instruction S ₀ is input to PCS12, executed by the computation unit 51 of the accident point locating unit 50.

In the routine of FIG. 4, first, the arithmetic unit 51 causes the inverter circuit 22 to output the first AC voltage signal (Step S110). Next, the arithmetic unit 51 measures the first output current I ₁ of the inverter circuit 22 in response to the first alternating voltage signal with an alternating current measurement unit 44 (step S112). Next, the arithmetic unit 51 causes the inverter circuit 22 to output the second AC voltage signal (Step S114). Calculation unit 51 is constructed of the second output current I ₂ of the inverter circuit 22 in response to the second alternating voltage signal to measure an alternating current measurement unit 44 (step S116).

In the series of processes in steps S110 to S116, the PCS 12 outputs two types of AC voltage signals having different frequencies from each other by controlling the inverter circuit 22. The first AC voltage signal has a first frequency f _1, a signal having a first voltage value V _1. Second AC voltage signal has a second frequency f _2, a signal having a second voltage value V _2. For example, f ₁ <f ₂ and V ₁ <V ₂ may be satisfied. Note that the magnitudes of the voltage values V ₁ and V ₂ may be sufficiently smaller than the system voltage. While the system voltage is a high voltage of 6000 V to 60,000 V, V ₁ and V ₂ may be voltages within a range of, for example, about 100 V to ₂₀₀ V. The first output current I ₁ flowing according to the output of the first AC voltage signal and the second output current I ₂ flowing according to the output of the second AC voltage signal are measured by the AC current detector 29. .

Specific value of the first frequency f ₁ and the second frequency f ₂ is stored in advance in the storage unit 52. The basic frequency f ₀ of the AC power output from the PCS 12 is set. The basic frequency f ₀ is a commercial power supply frequency that is the basis of a system interconnection system including the PCS 12. The commercial power frequency is set to 50 Hz or 60 Hz depending on the country and region.

The first frequency f ₁ and the second frequency f ₂ may be defined as a relationship between the fundamental frequency f ₀ example below.
f ₁ = f ₀ (1)
f ₂ = 2f ₀ = 2f ₁ (2)

f ₂ is a 2-fold harmonic of the fundamental wave. f ₂ may be any frequency different from the _{f 1.} For example it can be an integral multiple of the frequency of f _1. More specifically, if f ₁ = f ₀ is 50 Hz, f ₂ = 2 × f ₁ = 100. f ₂ may be greater than _{f 1,} it may be smaller than _{f 1.} For example a value obtained by multiplying the coefficients of 1/2, etc. _{f 1} may be _{f 2.} Further, _{f 1} may not be the same value as _{f 0.} f ₁ may even larger than _{f 0,} may even smaller than _{f 0.}

Calculation unit 51, the following equation (3), according to (4), a first impedance Z ₁ determined by the first voltage value V ₁ and the first output current I _1, the second voltage value V ₂ and the second output current a second impedance _{Z 2} determined from I _2, to calculate the (step S118).
Z ₁ = V ₁ / I ₁ (3)
Z ₂ = V ₂ / I ₂ (4)

Processing unit 51, a first complex number, and a second complex number, it calculates a DC resistance R ₁ and an inductance L ₁ on the basis of. The “first complex number” is a complex number representing the first impedance Z ₁ , the DC resistance R ₁ being a real part, and the product of the first angular frequency ω ₁ and the inductance L _{1 being} an imaginary part. However, ω ₁ = 2πf ₁ . "Second complex" is a complex number representing the second impedance Z _2, a DC resistance R ₁ and the real part, the second angular frequency omega ₂ and the product of the inductance L ₁ and the imaginary part. However, ω ₂ = 2πf ₂ .

Solving a binary linear equation defined for the first impedance Z ₁ and the second impedance Z ₂ to calculate a DC resistance R ₁ and an inductance L ₁ according to a transmission line distance from the power plant to the accident point Q. Can be. Specifically, R ₁ and L ₁ are calculated by solving simultaneous equations according to the following equations (5) and (6).
Z ₁ = R ₁ + jω ₁ L ₁ (5)
Z ₂ = R ₁ + jω ₂ L ₁ (6)
In the above formula, j is a symbol representing an imaginary number.

When ω ₁ and ω ₂ are represented by f ₀ , the following equations (7) and (8) are obtained.
Z ₁ = R ₁ + j (2πf ₀ ) L ₁ (7)
Z ₂ = R ₁ + j (2π × 2f ₀ ) L ₁ (8)
By solving the equations (7) and (8) for R1 and L1, the following equations (9) and (10) are obtained.
R ₁ = 2Z ₁ −Z ₂ (9)
ω ₁ L ₁ = | Z ₁ −Z ₂ | (10)

In Equation (10), L ₁ is multiplied by an angular frequency coefficient, and here, ω ₁ is multiplied. Coefficient of L ₁ can be represented by either the first frequency f ₁ and the second frequency f _2. ω ₁ = 2πf ₁ , and expressed as ω ₂ based on equations (1) and (2), is as shown in the following equation (11).
_{ω 1 = 2π (f 2/} 2) = (2πf 2) × 1/2 = ω 2/2 ··· (11)

  The calculation unit 51 is actually configured to execute a calculation process including at least equations (3), (4), (7), and (8).

Next, the calculation unit 51 calculates a distance D between the power plant and the accident point Q (Step S120). In the first embodiment, the installation location of the PCS 12 is regarded as the location of the power plant for simplification. FIG. 5 is a graph for explaining the principle of the method for locating the accident point Q according to the first embodiment. R and L correspond to a resistance component and an inductance component between the PCS 12 and the accident point Q. The distance D shown in FIG. 1 can be obtained from the distance between the origin O and the coordinates Q determined by R ₁ and ω ₁ L ₁ on the complex plane shown in FIG.

That is, the distance D can be calculated according to the following equation (12). Since the distance has a relationship proportional to the impedance, in the equation (12), the distance D on the left side is proportional to the impedance value on the right side ((R ₁ ) ² + (ω ₁ L ₁ ) ² ) − ^辺. I have.

  Next, the calculation unit 51 outputs the distance D from the input / output interface 47 (Step S122). Then, the current routine ends.

According to the accident point locating process according to the first embodiment described above, to measure a first output current I ₁ and the second output current I ₂ corresponding to the first alternating voltage signal and the second alternating voltage signal from PCS12 it is thus possible to calculate in accordance with such calculation formula (1) to (11), the DC resistance R ₁ and inductance L ₁ used for orientation of the fault point Q. When there is an accident in the electric power system to which the electric power system 1 using renewable energy is connected, the accident point Q can be located by outputting an AC voltage from the PCS 12. Thus, when an accident occurs in the power system, the PCS 12 can locate the accident point Q. By accurately locating the accident point Q on the transmission line 70, it is possible to eliminate the accident in a short time.

  FIG. 6 is a flowchart of a routine executed in PCS 12 according to the modification of the first embodiment. In the flowchart of FIG. 6, steps S118 to S122 in FIG. 4 are omitted, and instead, step S130 is added.

  In step S130, the calculation unit 51 outputs information on the first AC voltage signal and the second AC voltage signal and a current measurement value corresponding to these signals to the outside of the PCS 12 via the input / output interface 47. Thereby, the worker can obtain information necessary for the calculation using the above equations (1) to (10). Therefore, the worker can calculate the actual distance D on his own terminal. According to the modification of FIG. 6, the development cost of the PCS 12 can be minimized.

  FIGS. 7 to 9 are system configuration diagrams illustrating the PCS 12 according to the modification of the first embodiment and the power systems 101 to 103 including the same. The power system 101 of FIG. 7 differs from the power system 1 of FIG. 1 in the following two points. The first difference is that the power system 1 is a system interconnection system and the power system 101 is an independent power system. That is, in the power system 101, the rotary generator 4 is not connected to the first bus 6, and only the series circuit of the PCS 12 and the solar cell array 3 is connected to the first bus 6.

  As in the power system 102 shown in FIG. 8, a storage battery 13 may be connected to the PCS 12 instead of the solar cell array 3. As in the power system 103 shown in FIG. 9, a wind power system 14 may be connected to the PCS 12 instead of the storage battery 13. The wind power system 14 includes a wind power generator 15 and a power converter 16. The AC power generated by the wind power generator 15 depends on the strength of the wind. Since the intensity of the wind changes every moment, the AC power generated by the wind power generator 15 is difficult to stabilize. Therefore, it is preferable that the AC converter 16 converts the AC power from the wind power generator 15 into a constant DC voltage, and further converts the DC voltage into a stable AC power with the PCS 12. As another modification, two or more DC power supply systems may be selected from a DC power supply system group including the solar cell array 3, the storage battery 13, and the wind power system 14, and the selected DC power supply system may be selected via a plurality of PCSs 12. Each of the power supply systems may be connected to the first bus 6. Thereby, a plurality of DC power supply systems may be operated in parallel.

Embodiment 2 FIG.
FIG. 10 is a system configuration diagram illustrating the PCS 112 according to the second embodiment and the power system 201 including the same. The difference between the PCS 112 according to the second embodiment and the PCS 12 according to the first embodiment is a difference in the control content executed by the fault point locating unit 50 of the power conversion control device 40. In the second embodiment, a program different from that of the first embodiment is executed by the arithmetic unit 51.

  In the second embodiment, the communication terminal of the worker and the PCS 112 can communicate via the network 80. FIG. 10 illustrates a notebook PC 82 having a monitor 82a and a mobile phone terminal 89 having a display unit 89a as communication terminals owned by the worker. The network 80 is connected to a map information service system 90 constructed on the Internet. The map information service system 90 may be a so-called cloud computing system. In the following description, configurations that are the same as or correspond to those of the first embodiment will be denoted by the same reference numerals, and differences from the first embodiment will be mainly described. Omitted.

  FIG. 11 is a system configuration diagram illustrating the PCS 112 according to the second embodiment and a peripheral configuration thereof. The accident point locating unit 50 built in the PCS 112 according to the second embodiment basically has the same hardware configuration as the accident point locating unit 50 according to the first embodiment. Although the illustration is simplified in FIG. 11, the accident point locating unit 50 according to the second embodiment actually has the same configuration as the circuit diagram of the PCS 112 shown in FIG. The fault point locating unit 50 according to the second embodiment is different in that the transmission line laying diagram M1 and the local geographic data M01 are stored in the storage unit 52 and that the control process according to the flowchart of FIG. This is different from the first embodiment.

  FIG. 11 also shows the configuration of the map information service system 90. The map information service system 90 includes a database 94 storing geographic data M0, and a map server 92 for transmitting desired map information according to a user's request. It is preferable that the PCS 112 automatically acquire the latest transmission line installation diagram M1 via the network 80 at regular intervals. Further, the accident point locating unit 50 of the PCS 112 is configured to store, based on the geographic data M0, local geographic data M01 of at least the area including the transmission line laying diagram M1. It is preferable that the local geographic data M01 is also automatically updated at regular intervals based on the latest geographic data M0.

  FIGS. 12 and 13 are diagrams for explaining map information created by the PCS 112 according to the second embodiment. As shown in FIG. 12, a first layer composed of local geographic data M01, a second layer composed of a transmission line laying diagram M1, and a location where the accident point Q is located on the transmission line are calculated. One composite map M2 is created by overlapping the third layer.

  The composite map M2 is displayed on the monitor 82a of the notebook PC 82. As shown in FIG. 13, the composite map M2 includes a solar cell array 3 installation location, a PCS 112 installation location, a substation 220, roads 221, 222, 223, 224, building information 227, 228, a river 225, and a forest 226. , The towers Tw1 to Tw10, the azimuth icon 232, the scale display 234, and the scaling icon 235 are illustrated.

  Further, the composite map M2 according to the second embodiment includes a current position icon 230 indicating the current position of the worker, an accident point display icon 231 indicating the accident point Q, and route information Nv indicating a path connecting these with a broken arrow. And Since these may be realized by cooperating with a known GPS map information navigation system, detailed description will be omitted.

  FIG. 14 is a flowchart of a routine executed in the PCS 112 according to the second embodiment. The routine shown in FIG. 14 is a program in which the accident point locating process according to the second embodiment is described, and is stored in the storage unit 52. The processing in steps S110 to S120 is the same as in the first embodiment, and a description thereof will not be repeated.

  When the distance D is calculated in step S120, the calculation unit 51 refers to the local geographic data M01 stored in the storage unit 52 (step S200). In parallel with step S200, the arithmetic unit 51 refers to the transmission line installation diagram M1 stored in the storage unit 52 (step S202). The transmission line laying diagram M1 shows the laying position of the transmission line 70 and the length of the transmission line 70 on a map. The transmission line installation diagram M1 may take in a transmission line map held by a power company or the like, or may take in a transmission line map provided by various map information services on the Internet.

  The calculation unit 51 sets the accident point Q at a position at a distance D from the PCS 112 following the transmission line 70 (step S204). As shown in FIG. 12, even if the transmission line 70 is bent and laid, the sections D1 to D4 may be added and the accident point Q may be at the position where the distance D is reached. .

  Next, the calculation unit 51 creates the composite map M2 (Step S206). The calculation unit 51 matches the local geographic data M01 and the scale of the transmission line laying diagram M1 with each other based on the address and the address, and then compares the local geographic data M01 and the transmission line laying diagram M1 as shown in FIG. Overlap. The calculation unit 51 writes the accident point Q specified in step S204 on the composite map M2 (step S208). The arithmetic unit 51 writes route information Nv indicating a route from the current position icon 230 to the accident point Q in the composite map M2 by cooperating with a known GPS map information navigation system (step S210). Then, the current routine ends.

  FIG. 15 is a system configuration diagram illustrating the PCS 112 according to a modification of the second embodiment and its peripheral configuration. The notebook PC 82 includes a monitor 82a, a processor 84, a memory 85, a user interface 86, and an input / output interface 87. An application program 88 is installed in the memory 85. The application program 88 is constructed so that steps S200 to S210 of the routine shown in FIG. 14 can be executed. Thus, the creation of the composite map M2 may be shared between the PCS 112 and the notebook PC 82. The application program 88 may be installed in the mobile phone terminal 89, whereby the mobile phone terminal 89 can also execute the processing according to the flowchart of FIG.

  In Embodiment 2, a large amount of information is included in the composite map M2, but a composite map M2 having simpler contents may be provided. As an example of a modification, a composite map M2 in which only the accident point Q is displayed on the transmission line installation diagram M1 by omitting the layer of the local geographic data M01 may be provided. This is because even if there is no local geographic data M01, the worker can reach the accident point Q by using the towers Tw1 to Tw10 near the accident point Q as clues. As another modification, some pieces of information other than the roads 221, 222, 223, and 224 in the local geographic data M01 may be omitted from the composite map M2. As another modification, the steel towers Tw1 to Tw10 may be omitted. As another modification, the current position icon 230 and the route information Nv may be omitted, and instead, the towers Tw6 and Tw7 nearest to the accident point Q are made more prominent than the other towers Tw1 to Tw5 and Tw8 to Tw10. May be displayed. Specific methods of highlighting display include various methods for a particular tower, such as changing the color or transparency, increasing the size, and blinking.

  Modifications similar to the modification of the first embodiment may be made in the second embodiment, and the power system 201 of the second embodiment can be modified in the same manner as the modifications of FIGS. 7 to 9.

  In the first and second embodiments, the accident point locating unit 50 is configured so that the arithmetic unit 51 and the storage unit 52 execute the accident point locating program. The arithmetic unit 51 is also called a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a DSP. The storage unit 52 corresponds to, for example, a nonvolatile or volatile semiconductor memory such as a RAM, a ROM, a flash memory, an EPROM, and an EEPROM. Thus, the function of the accident point locating unit 50 is realized by software, firmware, or a combination of software and firmware. However, the accident point locating unit 50 is not limited to such a specific structure. At least a part of the accident point locating unit 50 may be constructed with dedicated hardware. In this case, the dedicated hardware constituting at least a part of the accident point locating unit 50 is, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. It may be. As described above, the accident point locating unit 50 may be configured to execute the accident point locating process described with reference to FIG. 4, FIG. 6, or FIG. 14 by hardware, software, firmware, or a combination thereof.

  The control operations of the PCS 12 and the power systems 1, 101 to 103, 201 according to the first and second embodiments may be provided as an accident point locating method. The accident point locating method according to the first and second embodiments may be performed by adding the accident point locating unit 50 to the conventional PCS and the electric power system afterward and executing the accident point locating process.

1, 101 to 103, 201 power system, 2 grid-connected power generation unit, 3 solar cell array, 4 rotating generator, 5 first circuit breaker, 6 first bus, 7 power grid, 8 load, 9 second bus , 12, 112 Power Conditioner System (PCS), 13 Storage Battery, 14 Wind Power System, 15 Wind Generator, 16 Power Converter, 21 Main Circuit, 22 Inverter Circuit, 23 Interconnection Transformer, 24 Capacitor, 25 DC Reactor, 26 DC voltage detector, 27 DC current detector, 28 AC voltage detector, 29 AC current detector, 40 power conversion control device, 41 DC voltage measurement unit, 42 DC current measurement unit, 43 AC voltage measurement unit, 44 AC Current measurement unit, 45 power control unit, 46 PWM control unit, 47 input / output interface, 50 accident point locating unit, 51 calculation unit, 52 storage unit, 53 Internal bus, 69 current transformer for instrument, 70 transmission line, 71 second circuit breaker, 72 third circuit breaker, 73 relay, 75 instrument transformer, 76 ground fault, 80 network, 82 notebook PC, 82a monitor, 84 processor, 85 memory, 86 user interface, 87 input / output interface, 88 application program, 89 mobile phone terminal, 89a display unit, 90 map information service system, 92 map server, 94 database, 220 substation, 221 road, 225 river , 226 forest, 227 building information, 230 current position icon, 231 accident point display icon, 232 azimuth icon, 234 scale display, 235 scale icon, Q accident point, R ₁ DC resistance, ω ₁ first angular frequency, L ₁ inductance, D distance, _{S 0} accident point locating processing Execution _{command, S ON} power on signal, M0 geographic data, M01 local geographic data, M1 power lines laying view, M2 composite map, Nv route information, Tw1～Tw10 tower

Claims (6)

An inverter circuit connected to the transmission line,
An ammeter that measures an output current that the inverter circuit outputs to the transmission line;
A control device that is connected to the ammeter and controls the inverter circuit;
With
The control device, when receiving a predetermined input signal predetermined, a first AC voltage signal having a first frequency and a first voltage value and a second frequency and a second voltage value different from the first frequency. And output the second AC voltage signal to the inverter circuit. The first output current of the inverter circuit according to the first AC voltage signal and the second output current of the inverter circuit according to the second AC voltage signal. And is configured to measure with the ammeter,
The control device has a first impedance determined by the first voltage value and the first output current, a second impedance determined by the second voltage value and the second output current, a DC resistance, the first frequency and an inductance. A first complex number representing the first impedance and a second complex number representing the second impedance with the DC resistance, the second frequency and the inductance are configured to calculate the DC resistance and the inductance. Power conditioner system. The controller is configured to output AC power having a commercial power frequency and a third voltage value to the inverter circuit when not receiving the predetermined input signal,
At least one of the first frequency and the second frequency is a frequency different from the commercial power frequency,
The power conditioner system according to claim 1, wherein the first voltage value and the second voltage value are smaller than the third voltage value. The control device is configured to determine the DC resistance R, the inductance L, and an angular frequency coefficient ω determined by the first frequency or the second frequency.

The power conditioner system according to claim 1, wherein the power conditioner system is configured to calculate a distance from a power conditioner installation location to an accident point according to the following formula. The control device is configured to calculate a distance from a power conditioner installation location to an accident point based on the value of the DC resistance and the value of the inductance,
The control device is configured to store a transmission line laying diagram indicating a place where the transmission line is laid and a power conditioner installation location,
The power supply according to claim 1, wherein the control device is configured to notify that the accident point is located at the distance from the power conditioner installation location by following the power transmission line in the power line installation diagram. Conditioner system. A DC power supply that outputs DC power,
A power conditioner system that converts the DC power from the DC power supply into AC power and outputs the AC power to a transmission line,
With
The power conditioner system includes:
An inverter circuit connected to the transmission line,
An ammeter that measures an output current that the inverter circuit outputs to the transmission line;
A control device that is connected to the ammeter and controls the inverter circuit;
With
The control device, when receiving a predetermined input signal predetermined, a first AC voltage signal having a first frequency and a first voltage value and a second frequency and a second voltage value different from the first frequency. And output the second AC voltage signal to the inverter circuit. The first output current of the inverter circuit according to the first AC voltage signal and the second output current of the inverter circuit according to the second AC voltage signal. And is configured to measure with the ammeter,
The control device has a first impedance determined by the first voltage value and the first output current, a second impedance determined by the second voltage value and the second output current, a DC resistance, the first frequency and an inductance. A first complex number representing the first impedance and a second complex number representing the second impedance with the DC resistance, the second frequency and the inductance are configured to calculate the DC resistance and the inductance. Power system. A power conditioner comprising: an inverter circuit connected to a transmission line; an ammeter for measuring an output current output from the inverter circuit to the transmission line; and a control device connected to the ammeter and controlling the inverter circuit. An accident point locating method for locating an accident point of the transmission line using
Causing the inverter circuit to output a first AC voltage signal having a first frequency and a first voltage value and a second AC voltage signal having a second frequency and a second voltage value different from the first frequency; Measuring the first output current of the inverter circuit according to the AC voltage signal and the second output current of the inverter circuit according to the second AC voltage signal with the ammeter;
The first impedance is determined by the first voltage value and the first output current, the second impedance and the DC resistance determined by the second voltage value and the second output current, and the first impedance is represented by the first frequency and the inductance. Calculating the DC resistance and the inductance based on a first complex number and the DC resistance, a second complex number representing the second impedance at the second frequency and the inductance,
Calculating a distance from the power conditioner to the accident point based on the DC resistance and the inductance;
Accident point localization method equipped with.

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