JP4628386B2 - Distributed power supply operating status detection device, watt-hour meter, and distribution system control device - Google Patents

Description

  The present invention relates to a distributed power supply operating state detection device, a watt hour meter, and a power meter for detecting the operation of a distributed power supply in a consumer having a distributed power supply connected to the power distribution system by measuring current and voltage at the customer entrance. The present invention relates to a control device.

Conventionally, private power generation facilities are generally installed in large consumers, and their operating status has been grasped by electric utilities of the connected power system. However, in recent years, with the progress of electric power liberalization and the like, installation of small power generation facilities powered by an internal combustion engine or the like has become widespread mainly in small-lot establishments such as shops connected to the power distribution system.
The power source of such a power generation facility is called a distributed power source, but various problems have occurred in the operation of the power distribution system as such a distributed power source is connected to the power distribution system.

An example of the above problem will be described with reference to FIG. A distribution line (feeder) F is drawn from the substation through the circuit breaker CB. Division switches S1 to S5 are inserted in the distribution lines in order to classify loads to be supplied with power, and the loads in each section are divided so as to be substantially equal.
In the figure, the division switches S1 to S4 are always turned on, and S5 is opened to divide the distribution system, and shows an example divided into five sections (D1 to D5).
L1 to L5 indicate loads, and G1 to G3 indicate generators of distributed power sources. Here, it is assumed that customers of the load L2 and the loads L3 and L4 have installed distributed power sources G1, G2, and G3.

  As indicated by the arrows in the figure, power is supplied, and consumers of the loads L2 and L5 supply power to the loads (L2, L5) by generating power from the distributed power source and transmit surplus generated power to the distribution lines. . The consumer of the load L3 is supplied with power from the distributed power source G2 and the system. L1 and L4 are normal consumer loads.

  FIG. 13 shows an example of the substation and sections D1 to D3 in FIG. The substation 10 steps down the extra high voltage received from the power transmission line 20 by the transformer 11 (usually 6 kv) and passes through the bus 14 and the circuit breaker 14 to a plurality of feeders F1 and F2 (two feeders are illustrated in the figure). Is withdrawn to supply power to a given area. Each feeder is provided with a wattmeter 13 to measure the feeding power of the feeder.

  A customer A who does not have a distributed power source and a customer B who has a distributed power source are connected to the distribution line. In each consumer, a load L (L1 to L3 in the figure) consumes power, and a watt-hour meter M for measuring power consumption is installed as equipment of the electric utility. When the generator G (G1, G2 in the figure) of the customer B in which the distributed power source is installed is not generating power, the measured value of the electricity meter is the power consumption of the load L of each customer. The total power consumption of these loads coincides with the feed power of the feeder F1 measured by the power meter 13 of the substation.

In a state where the generator G installed at the consumer is generating power, the measured value of the watt-hour meter M is the difference between the power consumption of the load L and the generated power of the generator G. Further, when the generated power is larger than the power consumption of the load as in the sections D2 and D5 shown in FIG. 12, the measured value of the power consumption of the wattmeter M is negative, that is, the measured value of the power transmitted to the distribution system. Become.
Thus, when the distributed power source of the consumer is in an operating state, the power supply value of the feeder F1 measured by the power meter 13 of the substation does not match the total power consumption value of the load of the distribution system.

In such a state, for example, when the power supplied to the substation is stopped for some reason such as an accident of the transmission line 20, the power supply to the distribution line F is stopped, and at the same time, connected to the distribution line. The distributed power sources G1 to G3 are disconnected (shut off) from the system by the operation of the protection device (distributed power source isolated operation prevention device). And the distributed power supply cannot resume power generation immediately due to its characteristics and put it into the system.
Therefore, the power supply at the time of power recovery of the system is supplied in a state where there is no generated power of the distributed power source. In the case of the above example, the power distribution line is used when power is supplied to the sections D1 to D5 as before the accident. There is a concern that the (feeder F1) will be overloaded, and it becomes necessary to operate the segment switch to switch the load of some sections to another system.
In that case, in order to switch the load appropriately, it is necessary to accurately grasp the loads L1 to L5 of the sections D1 to D5.

In addition, even when the accident is not recovered, for example, when the section D4 is set to work outage due to electrical work, the load in the section D5 must be switched to another system. At this time, the switch S5 (loop switch) for connection is first turned on to form a loop with another system for switching the load in the section D5, and then the switches S3 and S4 in the section D4 where the work is interrupted are opened. , The load in the section D5 is switched to another system.
At this time, the power flow (current) in each section cannot be grasped only by the measured value of the power sent from the feeder F1 measured at the substation during the operation of the distributed power source. The phase difference in the loop switch cannot be calculated. For this reason, when the phase difference exceeds a predetermined value (usually about 10 degrees), there is a risk that the system may be shaken by the cross current (loop cross current) flowing through the loop formation and the distributed power supply may be disconnected, which causes the distribution line to be overloaded. Etc. are concerned.

As a countermeasure, Patent Document 1 discloses an actual power distribution of each section based on the measured value of the power transmitted from the distribution line immediately before the accident measured at the substation and the generated power of the distributed power sources G1 to G3 immediately before the accident. It is disclosed that the load is calculated and thereby the power flow in each section is grasped.
However, the distributed power source installed at the customer is the customer's equipment for the electric power company, and all the customers who have installed the distributed power source have extra measuring equipment for the electric power company for the convenience of the electric power company. It is difficult to request installation.
Thus, the actual control of the power distribution system is not limited to the above, and various inconveniences occur. For example, when a fault occurs in a specific section of the power distribution system, the current delivered to the distribution line is excessive during an accident recovery operation such as re-injection of the circuit breaker CB and sequential throwing of the switch S1, S2, S3, etc. The breaker CB is interrupted, and even in a normal supply state, depending on the section of the distribution line, there is a problem that the voltage drops or rises above a specified value.
JP 2003-61247 A

  In order to eliminate the inconveniences described above, the present invention provides a detection device or a distributed power source for grasping the operating status of a distributed power source installed at a customer entrance that is a connection point between a customer who has installed a distributed power source and a distribution system. A watt-hour meter having a function of detecting an operating state of Furthermore, the detection device or watt hour meter is installed at the entrance of the customer where each distributed power source is installed, and the power flow for each section of the distribution line feeder divided by the division switch based on the detection result information And the actual load electric power value of the said consumer is estimated, Based on this estimated value, control of the distribution system which avoided the said inconvenience is implement | achieved.

  The first technical means of the present invention detects a power factor of power flowing into or out of a consumer having a distributed power source from a commercial system, compares the detected power factor with a preset threshold value, and the detected value is a threshold value. It is characterized by a distributed power source detection device that determines that the distributed power source of the consumer is in a power generation state when the power is lower.

  The second technical means detects the electric power flowing into or out of the consumer and the power factor thereof, and the detected value of the electric power when detecting that the distributed power source of the consumer is in the power generation state based on the detected power factor. Based on the above, the generated power of the distributed power source of the consumer is estimated.

  The third technical means is characterized in that, when it is detected that the distributed power source is in a power generation state, the generated power of the distributed power source is estimated from the difference between the detected power values detected before and after the detection.

  The fourth technical means estimates an average load power of a consumer based on the detected value of the power when the power generation state of the distributed power source is not detected, and calculates the power when the distributed power source is operating. It is characterized in that the generated power of the distributed power source is estimated in real time based on the difference from the detected value.

  A fifth technical means is characterized in that the load power estimation is an average value of the detected power values within a predetermined time.

  The sixth technical means is characterized in that the detected value of the power factor is an average value of the power factor measured values within a predetermined time.

  A seventh technical means is characterized in that the distributed power supply operating state detecting device has a communication function.

  The eighth technical means is characterized by an watt-hour meter provided with the distributed power supply operating state detecting device.

  The ninth technical means installs the distributed power supply operating state detection device of the seventh technical means at a connection point between each customer having a distributed power source connected to the power distribution system and the system, Collects information on the generated power of the distributed power source, and based on the information and at least the power sent out of the distribution system, the power in each supply section divided by the division switch that divides the power supply section inserted into the distribution system The tidal current is estimated and the switching of the section switch is controlled.

  A tenth technical means is characterized in that, based on the estimation of the power flow, the phase difference of the system in the section switch to be inserted when the distribution system is connected in a loop is detected to determine whether or not the loop connection is possible. To do.

  According to the present invention, the operation of the distributed power supply according to the present invention is performed at the connection point between the customer and the grid where the watt hour meter managed by the electric utility is installed without requesting the installation of a special measuring device in the customer facility. It is possible to detect the presence / absence of power generation of the distributed power source of the consumer and / or the operation status such as the generated power by installing the detection device or installing the device in the watt-hour meter.

In addition, the detected generated power is collected at a control station that controls the distribution system such as a sales office, and the power flow status of each supply section divided by the distribution switch of the distribution system, the actual load power of the customer It is possible to grasp the situation, and it is possible to prevent a voltage drop / rise at the end or midway of the system.
In addition, distribution system circuit breakers and switches due to unexpected overloads in system control operations such as re-insertion of substation circuit breakers when the distributed power source is disconnected, such as during accident recovery operations, and sequential throwing of divisional switches Can be avoided.
In addition, since the power flow can be estimated, it is possible to accurately grasp the phase difference in the loop switch to be inserted in the loop operation of the system when switching the load of the distribution system, etc. It is possible to avoid disconnection of distributed power sources.

  FIG. 1 is a diagram showing a part of a power distribution system in which the present invention is implemented. FIG. 1 shows a watt-hour meter 1 having a built-in operating state detection device for a distributed power source having a communication function according to the present invention installed in a consumer B in which a distributed power source is installed in the distribution system illustrated in FIG. A control station 15 such as a business office of an electric power company collects the operation status such as the generated power of the distributed power source detected by the watt-hour meter and the power sent from each feeder measured by the power meter 13 from the substation. An example of controlling the power distribution system is shown.

FIG. 2 is a diagram illustrating the operation principle of the distributed power supply according to the present invention, in order to verify the generated power of the distributed power supply and the power supplied from the system to the consumer and the power factor thereof. It is a figure explaining the measurement condition. As shown in the figure for each of the four customers, a measuring instrument for the power supplied to the customer and its power factor is installed at the connection point (customer entrance) between the customer and the grid. A measuring device for generated power and power factor was installed at the connection point of the generator, which is a distributed power source.
The customer receives power at a low voltage (voltage) through a pole transformer, has a plurality of load devices, and supplies power to these loads by the power generated by the system and the generator.
The distributed power source is a power generation facility that drives a synchronous generator with a rated output of 0.8 kW, and hot water supply that uses heated cooling water (hot water) for hot water supply by cooling the engine with cooling water during power generation. It is a power generation facility with facilities.

FIG. 3 is a diagram showing a record of a measuring instrument installed in the consumer. FIG. 3A shows the active power at the customer entrance, FIG. 3B shows a record in which instantaneous values of the power factor of the same power are detected at intervals of 1 minute, FIG. 3C shows an average value of the power factor measurement values for 10 minutes, and FIG. This is the power generated by the generator (distributed power supply).
In the record of the generated power of the generator, a state in which negative power is consumed is recorded. As described above, the power generation equipment is provided with the hot water supply equipment, and the heater for preventing freezing of the hot water supply equipment is used. The power consumption and the power consumption for equipment control are recorded. (This record is for December).

In FIG. 3A, many needle-like peaks are recorded in the measured value of the active power at the customer entrance, which is caused by the instantaneous start-up current at the time of the intermittent operation of the motor load. Correspondingly, a similar acicular peak is recorded in the power factor measurement value of FIG. 3B.
In the 10-minute average power factor measurement value of FIG. 3C, the acicular peak of the instantaneous value is removed.
Note that the power factor measurement value of the generated power of the generator G of the distributed power source was approximately 100%. As can be understood from the record in FIG. 3D, since the generator installed in the consumer is operated with high efficiency, in most cases, it is operated near the rated output with high efficiency. In the case of a machine, since it operates at high efficiency near the rated output, the power factor is necessarily operated at 100%.
In addition, in a power generation facility that generates direct-current power such as a fuel cell, it is supplied via a DC / AC converter, and in the case of a power generation facility using an induction generator, it is also supplied via an AC / AC converter. Electric power is also supplied from the power generation facility at a normal power factor of 100%.

The following facts can be observed by comparing the record of the power factor measurement value in FIG. 3B or FIG. 3C with the record of the generated power of the generator G in FIG. 3D.
That is, the record of the power factor fluctuation of the power factor measurement value in FIG. 3B or FIG. 3C corresponds to the record of the operation / stop of the generator.
In addition to the above items, the type / characteristics of the customer's load is considered to be substantially constant even if there is some variation in load power, that is, the power factor of the customer's load is considered to be substantially constant.

FIG. 4 is a diagram for explaining the above points. The load L of the consumer must be supplied with active power Pl and reactive power Ql. When the generator G of the distributed power source is in a stopped state, the active power Pl and the reactive power Ql are all supplied from the system.
When the generator G starts generating power at the output Pg, the active power supplied from the system becomes Ps = Pl−Pg, but the generator G is controlled to have a power factor of 100%, that is, reactive power Q = 0 as described above. (Cue zero control) Since the reactive power is not supplied, the total reactive power Qs = Ql of the load is supplied from the system, so that the power factor measurement value at the customer entrance decreases.

From the above facts, when the power factor measurement value at the customer entrance falls below a predetermined threshold value, it can be detected that the distributed power source installed in the consumer is in the power generation state.
It can be seen that the load power of the consumer is a stable value of about 1 to 10 kw on average and the measured value of power factor is approximately 70 to 95% from the measured value of FIG. 3A. On the other hand, the output of the generator of the distributed power supply is about 0.8 kw of the rated output, which is 80% of the load power. In this situation, when the distributed power source starts power generation, if the reactive power supply from the distributed power source is zero, the calculated power factor is reduced to about 10% to 30%.
In FIGS. 3B and 3C, it fluctuates by 10% to more than 60%. This is because the synchronous generator of the distributed power supply temporarily supplies reactive power in accordance with the fluctuation of the system voltage and the fluctuation of the generator voltage. it is conceivable that. However, basically, as described above, the power generation equipment of the distributed power source performs zero cue control, so the power factor measurement value at the customer entrance is greatly reduced.
As a result of setting and determining the threshold value to 65% in FIGS. 3B and 3C, the correct answer rate of the determination in each customer is as shown in FIG. This threshold value is a design value that is appropriately set in consideration of load characteristics.

FIG. 6 is an illustration of the above items. In the figure, W1 and W2 indicate the measured power at the customer entrance, Pg indicates the measured value of the generated power of the generator G of the distributed power source, and Pl and Ql indicate the active power and reactive power of the load. As illustrated, when the generator G of the distributed power source starts operation, the power factor measurement value at the customer entrance decreases from Cos θ1 to Cos θ2.
Pg ′, W2 ′, and Ps ′ indicated by broken lines indicate a state where the generated power of the distributed power source exceeds the load of the customer and a part of the generated power is transmitted to the grid (reverse tide), and the customer entrance The measured value of the wattmeter indicates a case where a negative value is measured. In this case, it is clear that the distributed power source is in operation.

As shown in FIG. 6, by detecting the operation of the distributed power source from the measured value of the power factor, the generated power of the distributed power source is estimated from the difference between the measured power values at the customer entrance before and after detecting the start of the operation. Can do.
In addition, when the operation of the distributed power source is confirmed from the power factor measurement value, the rated output of the generator is estimated as the generated power, assuming that it is operating near the rated output of the generator from the normal operating status of the distributed power source. It can be fully utilized for system operation considering overloading of distribution lines.

Furthermore, the actual average load power of the customer can be obtained from the measured power value at the customer entrance when the operating state of the distributed power source is not detected, and the operation of the distributed power source is detected based on the average value. The power generation output of the distributed power source can be estimated in real time from the difference from the measured value of the inlet power at the time.
In this way, the generated power of the distributed power source can be estimated, so these detected values can be collected to grasp the actual load power and current state of the customer in each section of the system, accident recovery, load switching, etc. In this case, the system can be controlled accurately.

FIG. 7 is a diagram showing an example of the distributed power supply operating condition detection device 30 of the present invention. In the figure, 31 is a voltage detection unit at a power receiving end of a consumer, 32 is a current detection unit supplied to the consumer, 33 is a power calculation unit supplied to the consumer, and 34 is a consumer based on the phase difference of the voltage / current. The power factor calculation unit 35 of the power to be supplied, 35 is a power factor comparison unit that compares the calculation result of the power factor with a preset threshold value and detects the presence or absence of the operation of the distributed power source, and 36 is a distributed power source. An average load calculation unit that averages power calculation values for a predetermined period during which no operation is detected and estimates an average load power, 37 estimates the output of the distributed power source when the power factor comparison unit detects the operation of the distributed power source The distributed power supply output calculation unit 38 inputs various settings such as setting of the average time in power factor calculation, threshold setting of the power factor comparison unit, period setting in average load calculation, and setting of a method for estimating the distributed power output. A setting operation unit 39 is provided for each detection unit and calculation unit. Storage unit for storing output values, calculated values, and various set values; 40, a communication unit for communicating various detection values, calculation results, etc .; 41, a display unit for displaying various detection values, etc. as necessary; It is a control part to control.
If the generated power of the distributed power source is not estimated, the power calculation unit 33, the average load calculation unit 36, and the distributed power output calculation unit 37 can be omitted.
Moreover, it can also be comprised as a watt-hour meter which has a distributed power supply operating condition detection function by adding an electric energy calculating part to a present Example. Or it can comprise as a similar watt-hour meter by adding the said distributed power supply operating condition detection function to the control software of an electronic watt-hour meter.

As described above, the setting of the distributed power output calculation unit 37 is, for example, the rated output of the generator or the operation of the distributed power source by the power factor comparison unit 35 according to the characteristics and operation mode of the distributed power source installed in the consumer. A method of estimating a power generation output in real time as a difference between power calculation values of the power calculation unit 33 before and after detection, or as a difference between an average load power value calculated by the average load calculation unit and a power value calculated by the power calculation unit One or more can be set.
The setting of the average load calculation unit 36 can be set in accordance with the time zone for estimating the average load power because the problems that occur in system operation differ between light load and heavy load.
The setting of the power factor comparison unit 35 is set to 65% in the actual measurement example, but an optimum value is set corresponding to the load characteristic of the consumer. The same applies to the time for obtaining the average value in the power factor calculation, and the optimum value is set according to the load characteristics of the consumer. For example, when the main load is a resistance load, it may not be necessary to calculate an average value.

FIG. 8 is a flowchart for explaining the operation of this embodiment. In S1, voltage / current detection values are acquired. In S2, the voltage / current phase difference θ is detected and the power factor (Cosθ) is detected. It is determined whether or not the instantaneous value of the power factor detected in S3 is averaged, and when averaging is performed (YES), the averaging time set in advance in S4 is acquired, the averaging process is performed in S5, and in S6 It is determined whether or not the power factor value is equal to or less than a preset threshold value. If the power factor value is equal to or less than a set value (YES), it is determined in S7 that the distributed power source is generating power. If it is not less than the predetermined value (NO), it is determined that the distributed power supply is stopped.
If the power factor detection value is not averaged in S3 (NO), the process skips to S6 and is compared with the threshold value.

Next, when it is determined in S7 that the distributed power source is generating power, if the generated power of the distributed power source is estimated, the process proceeds to the next step.
In S8, it is determined whether or not power calculation is being performed. As described above, depending on the installation status of the distributed power supply in the system, if it is estimated that the distributed power supply is operating at the rated output by confirming the operation of the distributed power supply, the power calculation is not necessarily performed. S16 shows this case.
In S9, it is determined whether or not to obtain a calculated value of average load power. As described above, if it is not necessary to estimate the generated power of the distributed power source in real time, it is not always necessary to calculate the average load power.
If it is acquired in S9 (YES), the average load power calculation value P10 is acquired in S10, the real-time power calculation value (measured value) Ps is acquired in S11, and Pg = P10-Ps is calculated in S12 and real time. Estimated power generation output of distributed power source.
If the average load power is not calculated or the calculation result is not acquired in S9, the power calculation value Pl immediately before detecting the operation of the distributed power source is acquired in S13, and the power calculation value Ps immediately after the detection is acquired in S14. In S15, Pg = P1-Ps is estimated as the power generation output of the distributed power source.

FIG. 9 shows the distributed power supply operation status detection apparatus shown in the first embodiment installed at each customer entrance (connected to the grid) where the distributed power supply is installed, and at least the detection information of the distributed power supply operation status of the detection apparatus. It is a figure which shows an example of the control apparatus which collects and controls a power distribution system based on the said information.
The power distribution system control device 50 includes the distributed power supply operating state detection device of the distributed power supply operating state detection device via a communication function together with the detected power and voltage / current values of each feeder installed in the substation at a control station such as a business office of an electric power company. Collect detection information.

51 is a communication unit that communicates with the substation and / or the distributed power supply operation state detection device, 52 is a distributed power supply operation state acquisition unit, for example, information of detection results of each detection unit or calculation results of each calculation unit of the first embodiment To get.
53 is an acquisition unit for feeder power / voltage / current detected by the substation, and 54 is for estimating the power flow in each section of each feeder based on the generated power information of the distributed power source and the power / current sent from the substation. Similarly, the power flow calculation unit 55 is a parallel power flow calculation unit that estimates a power flow in each section when the distributed power supply is disconnected.
As an example of calculation of power flow estimation at the time of disconnection 55, the power generation output of each distributed power source acquired by the distributed power source operation status acquisition unit 52 and the power / current of the feeder acquired by the feeder delivery power acquisition unit 53 Is estimated by equally dividing each section. Based on the estimated tidal current value of each section at the time of the separation, the tidal current calculation unit 54 subtracts the power generation output of each distributed power source in the section acquired in 52 to estimate the current state of the tidal current.
56 is a phase calculation unit that obtains characteristic information (resistance / reactance) of the feeder to be looped at the time of load switching and the like, and an estimated current flow of the feeder, and 57 calculates a phase difference in the loop switch. 57 is the phase difference This is a loop determination unit that allows a loop to be entered when it is within a preset reference value. The reference value is a design item determined according to the characteristics of the distributed power supply of the feeder. However, when the phase difference is usually about 10 degrees or more, there are cases where the distributed power supply is disconnected due to the fluctuation of the system due to the cross current caused by the loop connection. It has been reported.

Similarly, reference numeral 58 denotes a voltage calculation unit that calculates a voltage value in each section (section switch) based on the flow of the feeder and the characteristic information. 59 is a setting operation unit for various setting values such as reference values and data, and 60 is a variety of system statuses that have been collected in the past other than those related to the operation status of distributed power sources (switching information of classification switches, accident information, protection device It is a system information acquisition part about an operation condition, an accident area, a work blackout schedule, load switching, etc.).
61 is a storage unit for various information such as each calculation result, set value, and collection information, and 62 is a command for operating the circuit breaker CB and the section switch S of each feeder based on these calculations, determination results, and various information. An operation commanding unit 63, a display unit 63 indicating a system state such as an open / closed state of the segment switch, and a control unit 64 for controlling these units.

Here, a supplementary description will be given of the phase calculation unit 56 and the loop determination unit 57 that determines whether or not the loop is possible in the loop switch according to the embodiment.
FIG. 10A is a diagram showing the phase relationship between the delivery voltage Vs of the distribution line (feeder) and the voltage Vr at the end (loop switch). The voltage drop due to the resistance R and reactance X of the feeder is caused by the current I flowing through the feeder. It shows that a phase difference φ occurs in Vr. FIG. 10B is a diagram showing a case in which a loop connection is made in order to switch a part of the load between the feeder F1 of the load current IF1 and the feeder F2 of the IF2, and the loop point switch (loop switch) St is To form a loop.
FIG. 10C is a diagram illustrating a phase relationship between the voltages Vr1 and Vr2 in the switch St that is a loop point of the feeders F1 and F2. As shown in the figure, a phase difference φ is generated between Vr1 and Vr2 at the loop point, thereby generating a voltage difference of Vr1−Vr2, and a loop cross current flows when the switch St is turned on. This loop cross current becomes large when the phase difference becomes large, and the system is shaken by the influence of the loop cross current, and the generator of the distributed power source cannot follow and may be disconnected.
Note that FIG. 10 is a diagram for explaining that a phase difference occurs between the sending voltage and the terminal voltage, and a difference in current value or the like is not reflected in each feeder section.

FIG. 11 is a flowchart for explaining the loop operation of the loop switch St according to the embodiment.
In S20, information on the switch St and the feeders F1 and F2 that are the loop operation target selected by the operation command unit 62 is acquired. In S21, the feed power / current of each feeder F1, F2 is acquired, in S22, the estimated value of the power generation output of the customer's distributed power source in the feeder F1, F2 is acquired, and in S23, each section at the time of the distributed power source disconnection is acquired. A tidal current is estimated (displacement tidal current calculation unit 55). In S24, the estimated power generation output value of the distributed power source is subtracted from the estimated value to estimate the current state of the tidal current in each section (tidal current calculation unit 56). In S25, based on the estimated value and the resistance / reactance of the feeder, FIG. The phase difference in the loop switch shown in FIG. It is determined whether or not the phase difference calculated in S26 is within the reference value. If it is within the reference value (YES), the switch is turned on (loop determination unit 57). If it is not within the reference value (NO), another loop point (switch) is selected by the operation command unit 62 based on the information indicating that the loop is not possible.

  As described above, based on the acquisition of the operating status of the distributed power supply installed in the consumer that could not be acquired conventionally by the present invention, the current / voltage and power flow in each section of each feeder of the distribution system are calculated, and further the loop By calculating the phase difference at the point (switch) and determining information such as whether or not the loop switch can be turned on, the operation command unit 62 of the circuit breaker / segment switch is Operation commands for substation circuit breakers, feeder switches, loop switches, and so on. Unexpected overload sections, voltage drops / rises, and operation of distributed power sources during operation. Occurrence of abnormal situations such as disconnection can be avoided.

It is explanatory drawing of the power distribution system to which this invention is applied. It is explanatory drawing of the measurement of the electric power of the consumer which installed the distributed power supply, a power factor, and the generated electric power of a distributed power supply. It is a figure which shows the measurement result of FIG. It is explanatory drawing of the electric power generation of a distributed power supply. It is a graph which shows the relationship between a power factor fluctuation | variation and the power generation of a distributed power supply. It is a vector diagram explaining a power factor fluctuation | variation. It is a block diagram of Example 1 of the present invention. 3 is a flowchart for explaining the operation of the first embodiment. It is a block diagram of Example 2 of the present invention. It is explanatory drawing of the phase difference of a loop switch. 10 is a flowchart illustrating an example of an operation according to the second embodiment. It is explanatory drawing of the problem of a prior art. It is explanatory drawing of the conventional power distribution system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Substation, 14 ... Substation bus, 15 ... Control station, F ... Distribution line feeder, CB ... Circuit breaker, S ... Section switch, L ... Load, G ... Generator, Pl ... Load active power, Ql ... Load reactive power, Pg ... distributed power generation output, 30 ... distributed power supply operating state detection device, 31 ... voltage detection unit, 32 ... current detection unit, 33 ... power calculation unit, 34 ... power factor calculation unit, 35 ... power factor comparison , 36 ... Average load calculation unit, 37 ... Distributed power output calculation unit, 50 ... Distribution system control device, 52 ... Distributed power supply operating status acquisition unit, 53 ... Feeder feed power acquisition unit, 54 ... Power flow calculation unit, 55 disconnection Time flow calculation unit, 56 ... phase calculation unit, 57 ... loop determination unit, 58 ... loop calculation unit.

Claims (10)

  A power factor of power flowing into or out of a consumer having a distributed power source from a commercial system is detected, the power factor detection value is compared with a preset threshold value, and when the detected value is lower than the threshold value, the distributed power source of the consumer It is determined that is in a power generation state.   The electric power flowing into or out of the consumer and the power factor thereof are detected, and based on the detected value of the electric power when the distributed power source of the consumer is detected to be in the power generation state by the power factor detection value, The distributed power supply operating state detection apparatus according to claim 1, wherein the generated power of the distributed power supply is estimated.   3. The distributed power supply according to claim 2, wherein when it is detected that the distributed power supply is in a power generation state, the generated power of the distributed power supply is estimated from a difference between detection values of the power detected before and after the detection. Driving status detection device.   The average load power of the consumer is estimated based on the detected value of the power when the power generation state of the distributed power source is not detected, and real time is determined by the difference from the detected value of the power when the distributed power source is operating. 3. The distributed power supply operating state detection apparatus according to claim 2, wherein the generated power of the distributed power supply is estimated.   The distributed power supply operating state detection device according to claim 4, wherein the estimation of the load power is an average value of detection values of the power within a predetermined time.   The distributed power supply operating state detection device according to claim 1, wherein the detected value of the power factor is an average value of the detected power factor within a predetermined time.   The distributed power supply operating state detection device according to claim 1, further comprising a communication function.   A watt-hour meter comprising the distributed power supply operating state detection device according to claim 1.   A distributed power source detection device according to claim 7 is installed at a connection point between each customer having a distributed power source connected to the power distribution system and the system, and information on the generated power of the distributed power source of each customer is collected. , Based on the information and at least the delivery power of the distribution system, estimate the power flow in each supply section divided by the division switch for dividing the power supply section inserted in the distribution system, Distribution system control device characterized by controlling opening and closing.   10. The system according to claim 9, wherein based on the estimation of the power flow, a phase difference of the system in the section switch to be inserted when the distribution system is loop-connected is detected to determine whether or not the loop connection is possible. Distribution system controller.

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