JP4895735B2 - How to build a microgrid system - Google Patents

Description

  The present invention relates to a method for constructing a microgrid system having a configuration in which a plurality of types of distributed power sources are networked.

  As is well known, various distributed power sources such as natural gas cogeneration and fuel cells have been developed in recent years. By adopting such a distributed power source as an in-house power generation facility in a building, it is possible to obtain excellent overall energy efficiency by supplying thermoelectric power, and to reduce greenhouse gas emissions. Power) and the cost reduction by simplifying the distribution facilities, and there are various advantages such as easy to ensure independence stability in the event of an earthquake or fire. Therefore, a power distribution system using a distributed power source is likely to be widely used in the future. For example, a system in which a distributed power source is interchanged among a plurality of consumers has been proposed (for example, see Patent Document 1).

By the way, in the power distribution system using the above-described distributed power source, when the distributed power source is used in a base load operation by using the distributed power source and a commercial system (electric power company's power network) together, the electric power company can change voltage and frequency. The ancillary function will be undertaken, and the commercial system will only be required to compensate for load fluctuations, increasing the burden on the power company. Therefore, in recent years, a technique for performing load following operation of a distributed power source has been proposed. For example, a technique has been proposed in which an entire microgrid system formed by networking a plurality of distributed power sources and a plurality of customers is collectively controlled so as to follow load fluctuations. According to such a technique, not only the load fluctuation compensation burden on the commercial system can be reduced, but also the load fluctuation compensation does not depend on the commercial system. ) Can be realized. (For example, refer to Patent Document 2).
JP 2002-238168 A JP 2005-160286 A

  However, in order to perform the load following operation by connecting the above-described microgrid system to a commercial system, it is required that the balance between power generation and load (demand) is always consistent. In addition, when a microgrid system is operated independently from a commercial system, it is required to stably supply power of stable quality within the range of the system. It is required that the balance is always consistent. In a system constituted by a small-scale distributed power source such as a microgrid system, there is a risk that the power quality may be greatly impaired due to an imbalance of power supply and demand. In other words, in order to realize load following operation during commercial grid connection and stable quality power supply during independent operation, the balance between power generation and load must always be matched.

  The present invention takes the above-described conventional problems into consideration, and considers that the operation suitable for the performance of each distributed power source can be realized from the stage of selecting the distributed power source and determining the configuration. It aims at providing the construction method of the microgrid system which can make the balance of load and load correspond.

The present invention, in a construction method of a microgrid system that constructs a network that controls and operates a plurality of types of distributed power sources in an integrated manner and supplies power to a specific area, measures load fluctuations in the specific area, Based on the frequency analysis of the measurement data and the frequency response characteristics of each distributed power source, the shared frequency assigned to each distributed power source is determined, and the load analysis frequency analysis result is determined based on the shared frequency. Assigning to each distributed power source and obtaining the capacity of each distributed power source, and creating a transition probability distribution of load change amount and / or a transition probability distribution of load change rate The load fluctuation measurement period is determined .

  Because of these features, load fluctuation measurement data is frequency-analyzed, so load fluctuations in specific areas that are configured by overlapping load fluctuations at various speeds from very slow load fluctuations to instantaneous load fluctuations. The frequency components are decomposed and grasped. In addition, different types of distributed power supplies have different load following characteristics (response characteristics), but the shared frequency assigned to each distributed power supply is determined based on each frequency response characteristic. Since the frequency analysis result (resolved frequency components) is assigned to each distributed power source based on the shared frequency, each distributed power source is responsible for a frequency band suitable for each. Furthermore, since the capacity | capacitance of each distributed power supply is each calculated by the above-mentioned frequency analysis result and shared frequency, a distributed power supply becomes an appropriate capacity | capacitance.

Also , if you look at the transition probability distribution of the load change amount and load change rate, you can visualize how much load fluctuation can be captured by the measurement cycle, so measurement required to properly compensate for load fluctuation The period can be clarified.

  Further, the present invention evaluates the fuel efficiency characteristics of a distributed power source that uses fuel together with the power generation efficiency during steady operation and the power generation efficiency during transient operation, and based on the evaluation result, The operation of the distributed power source may be determined.

  As a result, a distributed power source using fuel can be operated efficiently, the fuel consumption of the distributed power source can be reduced, and the operation of the microgrid system can be realized in consideration of economy.

In addition, the present invention evaluates system frequency fluctuations with respect to load fluctuations for a distributed power source composed of a rotary generator, and based on the evaluation result, outputs the power output value of the distributed power source composed of the generator. The range may be determined.

  Thereby, at the time of the independent operation which supplies electric power only from a distributed power source, the fluctuation of the system frequency can be kept within a predetermined deviation, and a desired power quality can be ensured.

  Furthermore, the present invention constructs a simulated virtual system by connecting a dummy load for inspection to the distributed power source composed of the generator, and evaluates the system frequency variation with respect to the load variation using the virtual system. It is preferable.

  As a result, when an evaluation is performed using an actual load such as an electric device, there is a risk of causing a failure in the actual load due to low-quality power. The system frequency level can be evaluated.

  According to the construction method of the microgrid system according to the present invention, the microgrid system is constructed based on the speed of load fluctuation (frequency component) and the response performance of the distributed power supply. Thus, efficient compensation for load fluctuations can be performed, the capacity of the distributed power supply can be optimized, and the capacity shortage and excess facilities of the distributed power supply can be prevented. As described above, since the operation suitable for the performance of each distributed power source can be realized from the stage of selecting the distributed power source and determining the configuration, the balance between the power generation and the load in the microgrid system is matched. be able to.

  Embodiments of a method for constructing a microgrid system according to the present invention will be described below with reference to the drawings. In the present embodiment, a case where a certain facility is a specific area and the microgrid system 1 is built in the facility will be described as an example.

  First, the microgrid system 1 in the present embodiment will be described.

FIG. 1 is a schematic diagram showing a schematic configuration of a microgrid system 1 in the present embodiment.
As shown in FIG. 1, the microgrid system 1 in the present embodiment constructs a network in which a plurality of types of distributed power sources 2 to 5 are integratedly controlled by a control means 6 to operate and load 9 in a specific area. ... A system that supplies power to (electrical equipment, etc.). The microgrid system 1 is connected to a commercial system 7 via a power receiving point P. The power receiving point P is provided with a switch 8. By switching the switch 8, the microgrid system 1 can be freely connected to the commercial system 7 or disconnected from the commercial system 7. Therefore, when the microgrid system 1 is connected to the commercial system 7 by the switch 8, the load 9 in the entire specific area (facility) is obtained by the power purchase from the commercial system 7 and the power generation by the respective distributed power sources 2-5. Driving (interconnected operation). On the other hand, when the microgrid system 1 is disconnected from the commercial system 7, the operation (self-sustained operation) is to cover the load 9 of the entire specific area only by the power generation by the respective distributed power sources 2-5.

  Next, a procedure for constructing the microgrid system 1 having the above-described configuration will be described.

[Investigation of the nature of load fluctuation]
First, since it is necessary to determine the total capacity of the distributed power sources 2 to 5 when constructing the microgrid system 1, a step of measuring the load fluctuation in a specific area is performed.

The process of measuring the load fluctuation will be described in detail. A power measuring instrument (not shown) is installed at each of the loads 9... At the planned construction location of the microgrid system 1 and the planned receiving location P to be connected to the commercial system 7. The daily load fluctuation in the year is measured with the measuring instrument. Then, the total capacity of the distributed power sources 2 to 5 is determined based on the measured power value.
FIG. 2 is a daily load curve showing a specific example of the measurement result of daily load fluctuation. As shown in FIG. 2, as a specific example of daily load fluctuation, when there is a load power of about 600 kW at the maximum, this is defined as the total capacity of the distributed power sources 2 to 5.

  In addition, in order to realize load following operation at the time of interconnection operation and stable power supply at the time of independent operation, it is necessary to perform fluctuation compensation by the distributed power sources 2 to 5 for a steep load fluctuation. It is necessary to clarify how much time fluctuation means "steepness". Therefore, a process of determining a load fluctuation measurement period is performed.

  The process of determining the load fluctuation measurement cycle will be described in detail. The load fluctuation measurement cycle is determined by creating a transition probability distribution of the load change amount and a transition probability distribution of the load change rate. As a result, it is possible to employ a measurement cycle necessary for appropriately performing load fluctuation compensation. The transition probability distribution is a plot of how the measurement value and the rate of change of the measurement value change from one measurement time to the next, and how much fluctuation can be captured by the measurement cycle. Visualized.

FIG. 3 is a diagram showing a method of creating a transition probability distribution of load change amount, and FIG. 4 is a diagram showing a method of creating a transition probability distribution of load change rate.
As shown in FIG. 3, the transition probability distribution of the load change amount has the previous measured value (P [n]) measured at a predetermined period as the horizontal axis and the subsequent measured value (P [n + 1]). Is a graph with the vertical axis representing each measurement cycle (I to V) from the previous measurement value (P [n]) and the subsequent measurement value (P [n + 1]) in each measurement cycle (I to V). ) Is created by plotting each. Further, as shown in FIG. 4, the transition probability distribution of the load change rate has a subsequent measured value change rate (dP) with the horizontal axis representing the previous measured value change rate (dP [n]) measured at a predetermined period. [N + 1]) is a graph with the vertical axis representing each measurement from the previous measurement value change rate (dP [n]) and the subsequent measurement value change rate (dP [n + 1]) in each measurement cycle. Created by plotting each period.

FIG. 5 and FIG. 6 are graphs showing specific examples of the transition probability distribution of the load change amount and the transition probability distribution of the load change rate, and FIG. 5A shows the transition of the load change amount when measured at a cycle of 10 seconds. FIG. 5B is a transition probability distribution of the load change rate when measured at a cycle of 10 seconds, and FIG. 6A is a transition probability distribution of the load change amount measured at a cycle of 1 second. FIG. 6B shows a transition probability distribution of the load change rate when measured at a cycle of 1 second.
As shown in FIGS. 5 (a) and 5 (b), when measured at a cycle of 10 seconds, the characteristics of the transition probability distribution of the load change amount and the load change rate cannot be grasped vaguely. As shown in a) and FIG. 6B, when the measurement is performed at a cycle of 1 second, the features of the transition probability distribution of the load change amount and the load change rate appear clearly in the shape. Therefore, it can be seen that in the microgrid system 1 in this specific example, it is necessary to measure the load at a period of 1 second to compensate for the variation.

  Next, a step of performing frequency analysis on the measured load variation as described above is performed. Specifically, the active power data measured at a predetermined cycle is subjected to frequency analysis by Fourier transform. Thereby, the measured data is decomposed | disassembled into each frequency component.

FIG. 7 is a graph showing a specific example of the load analysis frequency analysis result.
As shown in FIG. 7, since it can be confirmed that load fluctuations in various frequency bands are included, it is understood that it is necessary to select distributed power sources 2 to 5 suitable for compensation of each frequency band. In this specific example, since measurement is performed at a cycle of 1 second, the frequency analysis result is decomposed only into fluctuation components slower than 0.5 Hz (2-second cycle).

[Power supply performance evaluation]
It is necessary to know which type of distributed power source 2 to 5 has a response performance that can be followed in the frequency band described above. Therefore, the output response characteristics from the time when each of the distributed power sources 2 to 5 receives the output command until it actually reaches the output is measured, and the frequency response characteristics are evaluated. In order to evaluate the response performance, the sine wave response characteristics when the output command changes from the maximum to the minimum in each of the distributed power sources 2 to 5 are measured.

FIG. 8 shows a response characteristic when the command value is changed in a sine wave shape, FIG. 8A shows a case where the response characteristic is the limit, and FIG. 8B shows a case where the response characteristic is the limit. The case where it is 2 times is shown.
As shown in FIGS. 8A and 8B, when the frequency of the sine wave command value is increased, the output (Pout) cannot follow the command (Pref). As a result, the amplitude of the sine wave of the output (Pout) decreases, and the phase difference between the sine wave of the command (Pref) and the sine wave of the output (Pout) increases. Therefore, for each of the distributed power sources 2 to 5, the amplitude ratio of the sine wave output value to the sine wave command value when the command frequency is changed, or the sine wave to the sine wave command value when the command frequency is changed. The frequency response characteristics of each of the distributed power sources 2 to 5 can be evaluated from the phase difference between the output values.

  In this embodiment, as the distributed power sources 2 to 5, a gas engine 2 and a gas engine 3 that can follow a slow fluctuation, a nickel metal hydride battery 4 that can follow a fast fluctuation, and an electric double layer capacitor 5. Selected. In this case, the ratio of the amplitude of the sine wave output value to the sine wave command value when the command frequency is changed is as shown in the graph of FIG. Further, the phase difference of the sine wave output value with respect to the sine wave command value when the command frequency is changed is as shown in the graph of FIG. 9B.

  As shown in FIGS. 9 (a) and 9 (b), the gas engine 2 has an amplitude ratio (gain) of 0 (dB) up to about 0.01 Hz, but the amplitude exceeds about 0.01 Hz. The ratio (gain) decreases. This means that the gas engine 2 can respond appropriately to the command within a range up to about 0.01 Hz. 9A and 9B, the gas engine 3 can respond up to about 0.03 Hz, and the nickel-metal hydride battery 4 can respond up to about 0.1 Hz. Furthermore, it can be seen that the electric double layer capacitor 5 can respond even at 0.1 Hz or higher.

  Subsequently, the shared frequency of each of the distributed power sources 2 to 5 is determined based on the frequency response characteristics of each of the distributed power sources 2 to 5 evaluated as described above. Specifically, the gas engine 2 is in charge of frequencies lower than 0.01 Hz, the gas engine 3 is in charge of frequencies from 0.01 to 0.03 Hz, and the nickel metal hydride battery 4 is 0.03 to 0.10 Hz. The electric double layer capacitor 5 is assigned a frequency higher than 0.1 Hz.

  Further, each distributed power source 2 to 5 needs to compensate for all the load fluctuations in the shared frequency band each of which is in charge, but if the capacity of the distributed power sources 2 to 5 is too small, the load fluctuations in the shared frequency band It becomes impossible to compensate all of. On the other hand, when the capacity | capacitance of the distributed power sources 2-5 is too large, it will become an excess installation of a power source and will become uneconomical. Therefore, the frequency analysis result of the load fluctuation is assigned to each of the distributed power sources 2 to 5 based on the shared frequency of each of the distributed power sources 2 to 5, and the optimum capacity of each of the distributed power sources 2 to 5 is obtained. Specifically, the optimum capacity of the distributed power sources 2 to 5 is calculated by integrating the intensity of the shared frequency band of each distributed power source 2 to 5.

FIG. 10 is a graph showing the frequency analysis of the load fluctuation handled by the nickel metal hydride battery 4 in the above example.
Taking the nickel-metal hydride battery 4 as an example, as shown in FIG. 10, the optimum capacity of the nickel-metal hydride battery 4 can be calculated by integrating the intensity of the frequency band assigned to the nickel-metal hydride battery 4.

  By the way, for load fluctuations with a long period of time, it is desirable to determine the output in consideration of economy as in the case of the commercial system. However, in the microgrid system 1 having a small power source parameter, the distributed power source 2 can be operated with a constant output. 5 is very low. Therefore, for the gas engines 2 and 3 that use fuel, the fuel efficiency characteristics of the gas engines 2 and 3 are evaluated together with the power generation efficiency during steady operation and the power generation efficiency during transient operation, and based on the evaluation results, The operation of engines 2 and 3 is determined. The power generation efficiency during steady operation is calculated from the amount of electricity generated and the amount of fuel consumed with the output of each power source kept constant. On the other hand, the power generation efficiency during transient operation is calculated from the amount of electricity generated and the amount of fuel consumed when a sine wave output command is given with the maximum amplitude for each frequency.

FIG. 11A is a graph showing the power generation efficiency during steady operation, and FIG. 11B is a graph showing the power generation efficiency during transient operation.
As shown in FIG. 11A, the gas engines 2 and 3 during steady operation can generate power with higher efficiency as the output is higher. On the other hand, the gas engines 2 and 3 during the transient operation show that the power generation efficiency does not depend on the output change speed. This indicates that the power generation efficiency of the gas engines 2 and 3 depends only on the average output. Therefore, the gas engines 2 and 3 are operated so that a high output can be maintained on average without any problem even if the output is frequently changed during operation.

  By the way, when at least one of the distributed power sources 2 to 5 described above is a rotating machine type generator, the rotation speed of the generator changes according to the load fluctuation during the self-sustained operation, so that fluctuation occurs in the system frequency. . The quality level of the system frequency during the independent operation is determined from the control of the load following operation control during the interconnection operation by replacing the fluctuation of the generator with the purchased power at the power receiving point during the interconnection operation. Thereby, the quality of the system frequency at the time of shifting to the independent operation can be evaluated while performing the interconnection operation.

  Specifically, the time until the generator output during the proportional operation changes from the minimum output to the maximum output is changed, and the relationship between the power change rate and the fluctuation of the system frequency is evaluated. Thereby, the magnitude of the output fluctuation of the generator per unit time necessary for keeping the system frequency within a certain fluctuation range becomes clear. In addition, system frequency fluctuation is evaluated for a sine wave response in which the output command to the generator during sine wave operation changes from maximum to minimum. Thereby, load frequency response performance is acquired.

FIG. 12A is a graph showing the system frequency fluctuation when the gas engine 2 performs the proportional operation, and FIG. 12B is the system frequency fluctuation when the gas engine 2 performs the sine wave operation. It is the graph which showed.
As shown in FIG. 12 (a), if the system frequency deviation at the time of independent operation is set, the range of the allowable change rate of the generator output necessary to be within the deviation is determined. For this reason, it can be used as a standard for measuring the accuracy of control that suppresses fluctuations in the generator output during the self-sustained operation from the control accuracy of the operation in which the electric power purchased during the grid operation is constant. Further, as shown in FIG. 12 (b), the frequency band necessary to be within the set system frequency deviation is found. Therefore, when the autonomous operation is actually performed, the generator output is controlled so as to follow the load in the frequency band described above.

FIG. 13 is a schematic diagram showing a system when the system frequency level is evaluated.
During the independent operation, in order to keep the power quality of the system constant, it is necessary to evaluate the system frequency fluctuation with respect to the load fluctuation for the rotating generator. However, it is difficult to actually test using an actual load because some of the actual load of a computer or the like may cause a failure or the like unless power of high quality is used. Therefore, as shown in FIG. 13, the dummy load 11 is connected to a distributed power source to construct a simulated independent system. Then, various load fluctuation cases are simulated by controlling the dummy load, and the responses of the distributed power sources 2 to 5 to the fluctuation are confirmed.

  According to the construction method of the microgrid system having the above-described configuration, since the process of measuring the load fluctuation in a specific area and performing frequency analysis of the measurement data, various processes from very slow load fluctuation to instantaneous load fluctuation are performed. A load fluctuation in a specific area configured by overlapping load fluctuations at a high speed is grasped by being decomposed into each frequency component. In addition, a shared frequency assigned to each distributed power source 2 to 5 is determined based on each frequency response characteristic of each distributed power source 2 to 5, and a load analysis frequency analysis result is distributed to each distributed frequency based on the shared frequency. In order to perform the process of determining the capacity of each of the distributed power sources 2 to 5 by assigning to the power sources 2 to 5, each of the distributed power sources 2 to 5 is responsible for the frequency band suitable for each. Furthermore, since the capacity | capacitance of each distributed power supply 2-5 is each calculated by the above-mentioned frequency analysis result and shared frequency, each distributed power supply 2-5 becomes an appropriate capacity | capacitance. As described above, since the microgrid system 1 is constructed based on the speed of the load fluctuation and the response performance of the distributed power sources 2 to 5, the load fluctuation to be compensated is appropriately captured to efficiently compensate for the load fluctuation. In addition, it is possible to prevent insufficient capacity and excess facilities of the distributed power sources 2 to 5. As described above, since the selection of the distributed power sources 2 to 5 and the determination of the configuration are considered so as to realize the operation suitable for the performance of each of the distributed power sources 2 to 5, the power generation in the microgrid system 1 The balance with the load can be matched. As a result, the microgrid system 1 can be operated independently, or the load can be tracked during operation during interconnection.

  In addition, since the load fluctuation measurement cycle is determined by creating the transition probability distribution of the load change amount and the transition probability distribution of the load change rate, the time interval of the fluctuation subject to fluctuation compensation is clarified. be able to.

  In addition, for the gas engines 2 and 3 that use fuel, the fuel efficiency characteristics are evaluated by combining the power generation efficiency during steady operation and the power generation efficiency during transient operation, and the operation of the gas engines 2 and 3 is performed based on the evaluation results. Therefore, the gas engines 2 and 3 that use fuel can be operated efficiently, the fuel consumption of the gas engines 2 and 3 can be reduced, and the operation of the microgrid system 1 taking into account the economy can be realized. be able to.

  In addition, for distributed power sources consisting of rotating generators, system frequency fluctuations are evaluated against load fluctuations, and the generator output value range is determined based on the evaluation results. Can be kept within a predetermined deviation, and desired power quality can be ensured.

  Furthermore, a simulated virtual system is constructed by connecting a test dummy load 10 to a distributed power source consisting of a generator, and the system load fluctuation is evaluated using this virtual system. The system frequency level can be evaluated without failure.

As mentioned above, although embodiment of the construction method of the microgrid system concerning this invention was described, this invention is not limited to above-described embodiment, In the range which does not deviate from the meaning, it can change suitably. For example, in the above-described embodiment, the load fluctuation measurement cycle is determined using the transition probability distribution of the load change amount and the transition probability distribution of the load change rate. However, in the present invention, the transition probability of the load change amount is determined. The load fluctuation measurement period may be determined using only the distribution, or the load fluctuation measurement period may be determined using only the transition probability distribution of the load change rate .

  Further, in the above-described embodiment, for the gas engines 2 and 3 that use fuel, the fuel efficiency characteristics are evaluated by combining the power generation efficiency during steady operation and the power generation efficiency during transient operation, and based on the evaluation results, Although the operation of the gas engines 2 and 3 is determined, the present invention is a distributed power source that uses fuel without evaluating fuel efficiency characteristics that combine power generation efficiency during steady operation and power generation efficiency during transient operation. Can also be operated. For example, the fuel efficiency characteristics may be evaluated considering only the power generation efficiency during steady operation, or the fuel efficiency characteristics may be evaluated considering only the power generation efficiency during transient operation. A distributed power source may be operated without consideration.

  In the above-described embodiment, for a distributed power source composed of a rotating machine type generator, the system frequency fluctuation is evaluated with respect to the load fluctuation, and the output value range of the generator is determined based on the evaluation result. However, according to the present invention, it is also possible to determine the range of the output value of the generator without evaluating the system frequency fluctuation against the load fluctuation for the generator. For example, the range of the output value set in advance may be determined, or the range of the output value of the generator may not be determined.

  In the above-described embodiment, a dummy virtual system 10 for inspection is connected to the generator to construct a simulated virtual system, and the system frequency fluctuation is evaluated with respect to the load fluctuation using this virtual system. In the present invention, it is also possible to evaluate the system frequency fluctuation against the load fluctuation without constructing the dummy load 10. For example, if the actual load is one that does not fail even with low-quality power, the system frequency variation against the load variation can be evaluated using the actual load and the actual system without constructing a dummy load. Good.

  In the above-described embodiment, the case where a microgrid system is constructed in a facility with a certain facility as a specific area has been described. However, the present invention can be applied to a case where a microgrid system is constructed in one facility. For example, a microgrid system may be constructed in a specific area that is a collection area of a plurality of houses.

  In the above-described embodiment, the gas engines 2 and 3, the nickel metal hydride battery 4, and the electric double layer capacitor 5 are selected as the distributed power sources 2 to 5, but the distributed power source according to the present invention is described above. It is not limited to the power source, and the type of the power source is appropriately changed. For example, in principle, it is possible to select a fuel cell or gas turbine with a constant output, or it is possible to select a secondary battery (power storage device) such as a NAS battery or a lead storage battery other than a nickel metal hydride battery, It is also possible to select a power storage facility such as a superconducting power storage system capable of following very fast fluctuations. Further, the distributed power source according to the present invention is not limited to the number in the above-described embodiment, and the number of power sources can be changed as appropriate as long as it is plural.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

It is a figure showing the schematic structure of the microgrid system for demonstrating embodiment which concerns on this invention. It is the graph which showed the measurement result of the daily load fluctuation | variation for describing embodiment which concerns on this invention. It is a figure showing the production method of the transition probability distribution of the load change amount for demonstrating embodiment which concerns on this invention. It is a figure showing the preparation method of the transition probability distribution of the load change rate for demonstrating embodiment which concerns on this invention. It is a graph showing the transition probability distribution of the load change amount and the transition probability distribution of the load change rate for explaining the embodiment according to the present invention. It is a graph showing the transition probability distribution of the load change amount and the transition probability distribution of the load change rate for explaining the embodiment according to the present invention. It is a graph showing the frequency analysis result of the load fluctuation | variation for demonstrating embodiment which concerns on this invention. It is a graph showing the response characteristic at the time of changing the command value for describing embodiment concerning this invention to a sine wave form. It is a graph showing the amplitude ratio of the sine wave output value with respect to the sine wave command value and the phase difference of the sine wave output value with respect to the sine wave command value for explaining the embodiment according to the present invention. It is the graph showing the frequency analysis of the load variation which the nickel metal hydride battery for describing embodiment which concerns on this invention takes charge. It is a graph showing the power generation efficiency at the time of steady operation and transient operation for describing an embodiment according to the present invention. It is the graph which showed the system frequency fluctuation | variation at the time of performing the proportional operation and sine wave operation for demonstrating embodiment which concerns on this invention. It is a schematic diagram showing the system | strain at the time of performing the evaluation of the system | strain frequency level for describing embodiment which concerns on this invention.

Explanation of symbols

1 Microgrid system 2 Gas engine (distributed power supply)
3 Gas engine (distributed power supply)
4 Nickel metal hydride battery (distributed power supply)
5 Electric double layer capacitor (distributed power supply)
9 Load 10 Dummy load

Claims (4)

In a construction method of a microgrid system that constructs a network that controls and operates multiple types of distributed power sources in an integrated manner and supplies power to a specific area,
Measuring the load fluctuation of the specific area, and analyzing the frequency of the measurement data;
Based on the frequency response characteristics of each distributed power source, the shared frequency that each distributed power source is responsible for is determined, and the frequency analysis result of load fluctuation is assigned to each distributed power source based on the shared frequency. Determining the capacity of the power source;
Equipped with a,
A method for constructing a microgrid system , wherein the load fluctuation measurement cycle is determined by creating a transition probability distribution of a load change amount and / or a transition probability distribution of a load change rate . In the construction method of the microgrid system according to claim 1 ,
For a distributed power source that uses fuel, evaluate the fuel efficiency characteristics of the distributed power source together with the power generation efficiency during steady operation and the power generation efficiency during transient operation, and operate the distributed power source based on the evaluation results. A method of constructing a microgrid system characterized by determining. In the construction method of the microgrid system according to claim 1 or 2 ,
An evaluation of system frequency fluctuations with respect to load fluctuations is performed on a distributed power source composed of a rotating machine type generator, and a range of power output values of the distributed power source composed of the generator is determined based on the evaluation result. A construction method of a featured microgrid system. In the construction method of the microgrid system according to claim 3 ,
A micro virtual system is constructed by connecting a dummy load for inspection to a distributed power source composed of the generator, and system frequency fluctuation is evaluated with respect to the load fluctuation using the virtual system. How to build a grid system.

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