JP6469021B2 - Electricity supply and demand control device - Google Patents

Description

  The present invention relates to a power supply and demand control device for a plurality of power generation facilities in a distributed power system that is configured by a plurality of power generation facilities and is connected so as to be able to transfer power to an external power system.

  In recent years, for example, distributed power generation systems in which a plurality of power generation facilities using a prime mover such as a steam turbine, a gas turbine, a gas engine, and a diesel engine are connected have been studied. Such a distributed power generation system has a weak external power system such as a commercial power system, and is not used in regions where the received power from the external power system is limited or unstable, such as emerging countries and remote islands. Expected.

  When installing a decentralized power generation system in such an area, in particular, adjust the power generation amount of multiple power generation facilities quickly so as not to exceed the power supply capacity and transmission line capacity of the external power system. It is required to keep the power (received power) at a predetermined power receiving point connected to the grid constant. If the power received from the external power system to the distributed power system exceeds the power supply capacity or transmission line capacity of the external power system, the power quality of the entire system may be degraded or a power failure may occur. is there.

  As a configuration that can adjust the received power, for example, a configuration as in Patent Document 1 has been proposed.

JP 2006-333563 A

  In the configuration of Patent Document 1, it is stored in a power storage facility such as a capacitor in order to cover the follow-up ability of a prime mover generator whose response tends to be delayed with respect to a transient change in received power based on a load variation or the like. Power fluctuation is compensated by temporarily using power.

  However, although the configuration of Patent Document 1 describes the power compensation for one prime mover generator, it does not describe how the generated power is shared among the plurality of prime mover generators.

  Furthermore, with the conventional configuration as described above, a prime mover generator with better response characteristics cannot be used for power compensation. That is, since the output command in the steady state to the power generation facility that performs power compensation converges to zero, only the power storage device that does not share the load in the steady state can be used.

  In the configuration as described above, it is necessary to separately measure the demand power of the load connected to the power generation system. However, when the power generation system is applied to a wide area such as an industrial park, It is arranged for people with power generation facilities mixed together. For this reason, it is necessary to install many configurations for measuring the demand power of the load, and the configuration becomes complicated. In particular, when the load of a factory or the like increases after the installation of a power generation system, such as in an emerging country, it becomes necessary to add a configuration for measuring the demand power of the load, which is complicated.

  An object of the present invention is to solve the above-described problem, and it is possible to quickly respond to fluctuations in received power from an external power system with a relatively simple configuration and with a relatively simple configuration. An object of the present invention is to provide an electric power supply and demand control device that can be used.

  The power supply and demand control apparatus according to one aspect of the present invention is a distributed power generation system configured by a plurality of power generation facilities and connected to an external power system so as to be able to transfer power to each of the plurality of power generation facilities. A power supply / demand control apparatus that commands a power sharing amount, and measures power received from the external power system and integrates a deviation from a predetermined target value of received power to generate power by the plurality of power generation facilities A total generated power target value calculation unit that calculates a total generated power target value as a power target value, and one or a plurality individually determined based on the transient and / or steady characteristics of each of the plurality of power generation facilities Generating an output command value to each of the plurality of power generation facilities according to the characteristic coefficient of each of the plurality of power generation facilities and the total generated power target value And an output command value generating section for outputting to Bei.

  According to the above configuration, the power target value to be generated by the plurality of power generation facilities is calculated based on the received power from the external power system. That is, the load demand power is estimated by measuring the received power from the external power system. For this reason, it is not necessary to add the structure which measures the power demand of load separately, and a structure can be simplified. Furthermore, in addition to the rated capacities of the plurality of power generation facilities, the share ratio of the power to be generated is changed according to the characteristics of the plurality of power generation facilities. For this reason, efficient and effective load sharing adjustment can be performed, and it is possible to cope with larger load fluctuations without reducing the power generation efficiency. Therefore, prompt control of received power quickly by a plurality of power generation facilities is realized with a relatively simple configuration.

  The output command value generation unit is configured to determine, based on the total generated power target value, the maximum generated power that can be stably operated even when the plurality of power generation facilities has a maximum demand power increase that is assumed in the distributed power generation system. By dividing the total power generation capacity that determines the value, an output sharing rate specified value calculation unit that calculates an output sharing rate specified value that serves as a reference for the output sharing rate of the plurality of power generation facilities, the output sharing rate specified value, and the Based on one or a plurality of characteristic coefficients individually determined for a plurality of power generation facilities and a rated capacity of the plurality of power generation facilities, a generated power target value in each of the plurality of power generation facilities is calculated as the output command value And a generated power target value calculation unit. According to this, the maximum value of the generated power that can be stably operated even when the maximum demand power increase assumed in the distributed power generation system occurs is predetermined based on the characteristics of the power generation equipment. Therefore, by changing the load sharing rate for each power generation facility based on this, it is possible to set a more efficient load sharing rate as compared with a case where distribution is simply performed at the rate of the rated capacity.

  The characteristic coefficient is a parameter having a larger value as the power generation efficiency in the steady state of the power generation facility is higher and / or the power generation cost is lower, or a parameter having a smaller value as the transient response performance of the power generation facility is higher. The output sharing ratio prescribed value calculation unit includes the characteristic coefficient of 1 and the total generated power target value is multiplied by the first characteristic coefficient of the plurality of power generation facilities and the rated capacity, and is totaled for all the power generation facilities. The value divided by the total power generation capacity obtained in this way may be calculated as the output sharing rate prescribed value. As a result, the total power generation capacity is determined on the basis of the steady state or transient characteristics of the power generation equipment, so that the ability to perform load sharing separately based on the characteristics of the power generation equipment during the transient response when the received power changes greatly. Can be stored in each power generation facility.

  The characteristic coefficient is a parameter having a larger value as the power generation efficiency in the steady state of the power generation facility is higher and / or the power generation cost is lower, or a parameter having a smaller value as the transient response performance of the power generation facility is higher. The output command value may include a component obtained by multiplying the first characteristic coefficient in the corresponding power generation facility by the rated capacity. As a result, power generation equipment with high power generation efficiency and / or low power generation cost in a steady state or power generation equipment with low transient response performance of power generation equipment can be preferentially generated, and more efficient load sharing can be achieved. It can be carried out.

  The characteristic coefficient includes a second characteristic coefficient that is a parameter having a larger value as the transient response performance of the power generation equipment is higher, and the generated power target value calculation unit corresponds to a first-order differential element. The output command value including a component obtained by multiplying the second characteristic coefficient and the rated capacity in the power generation facility may be calculated. As a result, when the temporal change in the total generated power target value is steep, it is possible to preferentially load the change to a power generation facility with a high transient response performance, thereby performing more efficient load sharing. be able to.

The power supply and demand control device includes a power generation facility start / stop determination unit that performs power generation facility start / stop determination for switching whether to generate power for each of the plurality of power generation facilities, and the power generation facility start / stop determination unit Outputs a signal to increase the number of activated power generation facilities among the plurality of power generation facilities when the output share ratio specification value exceeds a predetermined first threshold, When the value is equal to or lower than a predetermined second threshold value lower than the first threshold value, the signal generator is configured to output a signal to reduce the number of activated power generation facilities among the plurality of power generation facilities. May be. Thereby, the number of the power generation facilities to be activated can be optimized according to the required power generation amount.

  Each of the plurality of power generation facilities is set such that the priority for start-up is higher as the power generation capacity is larger, and / or the number of the start-ups is proportional to the transient response performance of the entire equipment, The power supply / demand control apparatus, when a signal to reduce the number of power generation facilities activated from the power generation facility activation / deactivation determination unit is input, the priority order for activation most among the plurality of power generation facilities activated When a signal to increase the number of activated power generation facilities is input to a power generation facility with a low power, the power generation facility with the highest priority for activation among the power generation facilities that are stopped You may provide the starting electric power generation equipment selection part which sends an activation signal. As a result, it is possible to prevent frequent switching between start and stop, or to prevent the same power generation facility from repeatedly starting and stopping.

  The power generation facility activation / deactivation determination unit is configured to perform the first operation in a predetermined first period in which a rate of increase in demand power assumed in the distributed power generation system per predetermined time is equal to or greater than a predetermined first ratio. A threshold value and a second threshold value are each set lower than a value set during a period in which the change in the demand power is within a predetermined range, and the rate of decrease of the demand power per predetermined time is a predetermined first value. The second threshold value is set to the demand in a predetermined second period in which the rate of increase of the demand power per predetermined time is equal to or higher than a predetermined third ratio. You may set lower than the value set in the period when the change of electric power is in a predetermined range. By setting the first threshold value and the second threshold value low during a period in which the rate of increase in demand power is large, the load burden rate of the power generation facility is reduced, so the efficiency is reduced. You can make room for your ability. Therefore, it is possible to cope with a delay in output increase due to the startup time of the power generation equipment. Further, when the load decreases and then increases again, only the second threshold value of the output sharing ratio prescribed value is set low. Thereby, it is possible to prevent the stoppage and start-up of the power generation facility in a short time with respect to a rapid decrease and increase in the output sharing ratio prescribed value due to a rapid decrease and increase in demand power.

  The distributed power generation system includes a distributed power system connected to the external power system so as to be able to exchange power, the plurality of power generation facilities are connected to the distributed power system, and the power supply and demand control device includes: And an output command value correction unit that measures a system frequency in the distributed power system and corrects the output command value to each of the plurality of power generation facilities based on a deviation from a predetermined system frequency target value. . Thereby, when the frequency fluctuation occurs in the external power system, the output fluctuation of the power generation facility can be suppressed.

  The distributed power generation system includes a distributed power system connected to the external power system so as to be able to exchange power, and the plurality of power generation facilities are connected to the distributed power system, and the total generated power target value The calculation unit includes: an interconnected operation state indicating that the external power system and the plurality of power generation facilities are interconnected; and an independent operation state indicating that the plurality of power generation facilities are operating independently. When the state signal indicating any of them is received and in the interconnected operation state, the total generated power target value is calculated by integrating the deviation between the received power and the received power target value, and the independent In the operating state, the system frequency in the distributed power system may be measured, and the total generated power target value may be calculated based on a deviation from a predetermined system frequency target value. Thereby, when switching from the grid operation to the independent operation, it is possible to eliminate the steady frequency deviation due to the load fluctuation during the independent operation. Therefore, it is possible to maintain the power supply quality satisfactorily.

  The above object, other objects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments with reference to the accompanying drawings.

  According to the present invention, by having the above-described configuration, the generated power of the plurality of power generation facilities can be made to quickly respond to fluctuations in the received power from the external power system with a relatively simple configuration.

FIG. 1 is a block diagram showing a schematic configuration of a distributed power generation system to which a power supply and demand control apparatus according to a first embodiment of the present invention is applied. FIG. 2 is a block diagram showing a more specific configuration example of the power supply / demand control apparatus shown in FIG. FIG. 3 is a block diagram showing an outline of calculation in the total generated power target value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 4 is a block diagram showing an outline of the calculation in the output sharing ratio prescribed value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 5 is a schematic block diagram showing a generated power target value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 6 is a block diagram showing an outline of calculation in the power generation facility i output command value calculation unit of the generated power target value calculation unit shown in FIG. FIG. 7 is a block diagram showing a configuration example of the power supply and demand control apparatus according to the second embodiment of the present invention. FIG. 8 is a graph showing a power generation facility start sequence when the power generation facility start / stop determination unit of the power supply / demand control apparatus shown in FIG. 2 transmits a power generation facility start command signal to a predetermined power generation facility. FIG. 9 is a graph showing a power generation facility stop sequence when the power generation facility start / stop determination unit of the power supply / demand control apparatus shown in FIG. 2 transmits a power generation facility stop command signal to a predetermined power generation facility. FIG. 10 is a graph showing the relationship between the predicted demand power according to the time and the upper limit value and the lower limit value of the output sharing rate prescribed value. FIG. 11 is a block diagram showing a configuration example of a power supply and demand control apparatus according to the third embodiment of the present invention. FIG. 12 is a block diagram showing an outline of calculation in the frequency target correction value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 13 is a block diagram showing an outline of calculation in the output command value correction unit of the power supply and demand control apparatus shown in FIG. FIG. 14 is a block diagram showing an outline of calculation in the power generation facility i correction value calculation unit of the output command value correction unit shown in FIG. FIG. 15 is a block diagram showing a configuration example of a power supply and demand control apparatus according to the fourth embodiment of the present invention. FIG. 16 is a block diagram showing an outline of calculation in the total generated power target value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 17 is a block diagram showing an outline of the calculation of the received power control unit shown in FIG. FIG. 18 is a block diagram showing an outline of the calculation of the system frequency control unit shown in FIG. FIG. 19 is a graph showing a temporal change after the start of the shift to the independent operation in the corrected frequency target value output from the first interconnection independent switching processing unit shown in FIG. FIG. 20 is a block diagram showing an outline of calculation in the frequency target correction value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 21 is a graph showing a temporal change after the start of the transition to the independent operation in the frequency correction value output from the second interconnection independent switching processing unit shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout all the drawings, and redundant description thereof is omitted.

<First Embodiment>
First, the overall configuration of the power supply and demand control apparatus according to the first embodiment of the present invention will be described. FIG. 1 is a block diagram showing a schematic configuration of a distributed power generation system to which a power supply and demand control apparatus according to a first embodiment of the present invention is applied.

As shown in FIG. 1, the distributed power generation system 1 according to the first embodiment of the present invention includes a plurality of power generation facilities 3 _i (connected to a distributed power system 27 connected to an external power system 2 so as to be able to exchange power. i = 1, 2,..., n). In other words, the plurality of power generation facilities 3 i are connected to the external power system 2 through the distributed power system 27 so as to be able to exchange power. Furthermore, the distributed power generation system 1 includes a power supply and demand control device 4 that instructs each of the plurality of power generation facilities 3 _i to share the amount of power generation. One or more loads L are connected to the distributed power system 27. Further, the plurality of power generation facilities 3 i are configured such that the generated power can be adjusted by the power supply and demand control device 4.

  The external power system 2 is a commercial power system, for example. For example, in commercial power systems in emerging countries, power generation facilities and transmission / distribution facilities have not been able to keep up with the increase in power demand, power shortages continue, and power supply quality is often poor (unstable). When an industrial park is constructed in such an area, a stable supply of electric power, which is an important infrastructure, is desired. For this reason, the needs for the distributed power generation system 1 are increasing.

The plurality of power generation facilities 3 _i include at least one of power generation facilities using a prime mover such as a steam turbine, a gas turbine, a gas engine, a diesel engine, or the like. These power generation facilities are common in that a prime mover is used, but their characteristics are greatly different. For this reason, in particular, when the power generation equipment 3 _i using a plurality of types of prime movers is connected to the distributed power system 27, if the output is adjusted evenly to the plurality of power generation equipment 3 _i , the power generation efficiency is steady in a steady state. It becomes worse and the power generation cost becomes higher. In addition, when a transient and steep load change occurs, the load change concentrates on the specific power generation equipment 3 _i , and an overload state may occur. For this reason, the inventors of the present invention, it becomes necessary to adjust the output separately for a plurality of power generation equipment 3 _i on the basis of the transient characteristics and constant characteristics of each power generation equipment 3 _i Thus, the present invention has been conceived.

  Note that one or more power generation facilities 28 independent of the power supply and demand control device 4 may be connected to the distributed power system 27. The power generation facility 28 is a power generation facility using renewable energy such as a solar power generation facility. Since such a power generation facility cannot adjust the generated power, it is not connected to the power supply and demand control device 4 and is not controlled. Renewable energy means natural energy such as sunlight, hydropower, wind power, and geothermal heat. Moreover, even if it is a power generation facility in which generated power can be adjusted by the power supply and demand control device 4 such as a prime mover generator, a power generation facility that is not connected to the power supply and demand control device 4 may exist.

The plurality of power generation facilities 3 _i connected to the power supply and demand control device 4 preferably include a plurality of types of power generation facilities having different power generation efficiency, power generation cost, response performance, and the like. Further, the plurality of power generation facilities 3 _i may include power storage facilities such as capacitors.

Such a distributed power generation system 1 is configured such that a plurality of power generation facilities 3 _i are interconnected with the distributed power system 27. The distributed power system 27 may be configured to perform independent operation without being connected to the external power system 2 (independent of the external power system 2). That is, the distributed electric power system 27 may be configured to be able to switch between the grid operation and the independent operation. For this reason, in this embodiment, the circuit breaker 26 is connected between the external power system 2 and the distributed power system 27. Thereby, the distributed power generation system 1 is configured to be able to cut off power transfer from the external power system 2.

The power supply and demand control device 4 measures the received power P at a predetermined power receiving point R of the external power system 2 and generates an output command value U _i for each power generation facility 3 _i . The power supply / demand control apparatus 4 includes a computer such as a microcontroller or a personal computer installed at a predetermined position of the distributed power system 27. The power supply and demand control device 4 may be provided in any one of the plurality of power generation facilities 3 _i , may be provided in a predetermined load L, or may be a power management of the external power system 2. It may be provided in a facility. The power supply and demand control device 4 includes a total generated power target value calculation unit 5 and an output command value generation unit 6.

Total generated power target value calculating section 5, a reception power P which is measured by integrating the deviation with a predetermined received power target value P _o, the power target value to be generated by the plurality of power generation equipment 3 _i Total A generated power target value _Pe is calculated. Output command value generation unit 6, each of the respective transient and / or one defined individually on the basis of the steady-state characteristics or characteristic coefficient and a plurality of power generation equipment 3 _i of the plurality of power generation equipment 3 _i The output command value U _i for each of the plurality of power generation facilities 3 _i is generated according to the rated capacity S _i and the total generated power target value P _e and output to each power generation facility 3 _i . Each of the plurality of power generation facilities 3 _i performs output adjustment so that the generated power becomes the input output command value U _i . Thereby, the outputs of the plurality of power generation facilities 3 _i are dynamically controlled by the power supply and demand control device 4.

According to the above configuration, the power target value (total generated power target value P _e ) to be generated by the plurality of power generation facilities 3 _i is calculated based on the received power P from the external power system 2. That is, the power demand of the load L is estimated by measuring the received power P from the external power system 2. For this reason, it is not necessary to add the structure which measures the power demand of the load L separately, and a structure can be simplified. Furthermore, in addition to the rated capacity S _i of a plurality of power generation equipment 3 _i, to change the power share of the to be power in accordance with the characteristics of a plurality of power generation equipment 3 _i. For this reason, load sharing can be performed efficiently, and fluctuations in received power can be dealt with more quickly. Therefore, with a relatively simple configuration, the generated power of the plurality of power generation facilities 3 _i can be quickly responded to fluctuations in the received power P from the external power system 2. Also, when calculating the total generated power target value P _e, using only the reception power P, it is not required the means for measuring the power demand of the load L. For this reason, cost can be reduced when the distributed power generation system 1 is applied in a large-scale area where the load L is large. In addition, even in a region where the distributed power generation system 1 in the present embodiment has already been applied, even when a new load L is additionally connected to the distributed power system 27 due to an area expansion of the industrial park or the like. It is possible to suppress the occurrence of additional costs such as attaching a device for measuring the demand power of the load to the new load L.

Hereinafter, a more specific configuration example will be described in detail. FIG. 2 is a block diagram showing a more specific configuration example of the power supply / demand control apparatus shown in FIG. As shown in FIG. 2, the power supply and demand control device 4 in the present embodiment includes an output sharing ratio prescribed value calculation unit 7 and a generated power target value calculation unit 8 as the output command value generation unit 6. Power sharing ratio specified value calculation unit 7, the total generated power target value P _e, can be operated stably even when the maximum power demand increases plurality of power generation equipment 3 _i is assumed in a distributed power generation system 1 has occurred by dividing the total generating capacity S _K to determine the maximum value of the generated power, calculates an output sharing ratio specified value Q as a reference of the output sharing ratio of a plurality of power generation equipment 3 _i. Generator power target value calculating section 8, based on the rated capacity of the power sharing ratio specified value Q and one defined individually to a plurality of power generation equipment 3 _i or more characteristic coefficient and a plurality of power generation equipment 3 _i, It calculates the generated power target value in each of the plurality of power generation equipment 3 _i as an output command value U _i.

FIG. 3 is a block diagram showing an outline of calculation in the total generated power target value calculation unit of the power supply and demand control apparatus shown in FIG. As described above, the total generated power target value calculation unit 5 receives the received power P measured at the power receiving point R. The received power P is calculated from the voltage and current at the power receiving point R, and the direction flowing from the external power system 2 to the distributed power system 27 is positive. Reception power P is subtracted from the received power target value P _o predetermined, the deviation P _o -P is calculated. This deviation P _o −P is input to the integrator 9. The integrator 9 integrates the deviation P _o −P, inverts positive and negative, and outputs the result. Output from the integrator 9 value becomes the total generated power target value P _e. The total generated power target value P _e means the sum of the power target value to be generated by the plurality of power generation equipment 3 _i.

FIG. 4 is a block diagram showing an outline of the calculation in the output sharing ratio prescribed value calculation unit of the power supply and demand control apparatus shown in FIG. Power sharing ratio specified value calculation unit 7, the output sharing ratio by dividing the total generated power target value P _e output from the total generated power target value calculating section 5 a total generation capacity S _K at a plurality of power generation equipment 3 _i The specified value Q is calculated (that is, Q = P _e / S _K is output). According to this, the maximum value of the generated power that can be stably operated even when the maximum demand power increase assumed in the distributed power generation system 1 occurs is predetermined based on the characteristics of the power generation equipment 3 _i . Therefore, by changing the load sharing rate for each power generation facility 3 _i based on this, a more efficient load sharing rate can be set as compared with the case where distribution is simply performed at the ratio of the rated capacity S _i . In addition, by standardizing the output sharing ratio specified value Q, even if the configuration of the power generation facility 3 _i changes, it is not necessary to readjust the control parameters of the power generation facility 3 _i and the control can be easily performed. It can be carried out.

The total generating capacity S _K is multiplied by the rated capacity S _i of the first characteristic coefficient K _{i (described} below) and power generation equipment 3 _i defined based on each of the plurality of power generation equipment 3 _i of power generation equipment 3 _i Is defined as a value (S _K = Σ (K _i S _i )) obtained by adding all the power generation facilities 3 _i together.

Here, the first characteristic coefficient K _i has a larger value as the power generation efficiency in the steady state is higher and / or the power generation cost is lower, or has a smaller value as the transient response performance of the power generation facility 3 _i is higher. It is defined as a parameter, and is set according to the performance of each of the plurality of power generation facilities 3 _i . The first characteristic coefficient K _i is set in a range of 0 <K _i ≦ 1. Thus, since the total generating capacity S _K is determined based on the characteristics of the steady state or transient state of the power plant 3 _i, if the change in the reception power P is large, the characteristics at the time of additional transient response of the power plant 3 _i The ability to share the load based on the power generation facilities 3 _i can be preserved. Details will be described later.

FIG. 5 is a schematic block diagram showing a generated power target value calculation unit of the power supply and demand control apparatus shown in FIG. FIG. 6 is a block diagram showing an outline of calculation in the power generation facility i output command value calculation unit of the generated power target value calculation unit shown in FIG. The generated power target value calculation unit 8 includes a power generation facility i output command value calculation unit 10 _i corresponding to the plurality of power generation facilities 3 _i . As shown in FIG. 5, the power generation facility i output command value calculation unit 10 _i is configured as a plurality of calculation units (a plurality of functional modules that perform calculations in parallel). However, the present invention is not limited to this, and one power generation facility output command value calculation unit may sequentially perform calculations for each power generation facility 3 _i .

Power generation facilities i output command value calculating section 10 _i, the output sharing ratio specified value Q is input, the output command value based on the characteristic coefficient and rated capacity S _i of the corresponding power generation equipment 3 _i to each of the power generation facility 3 _i U _i is calculated. In the present embodiment, the characteristic coefficient includes the first characteristic coefficient K _i and the second characteristic coefficient K _Di. The second characteristic coefficient K _Di is defined as a parameter having a larger value as the transient response performance of the power generation facility 3 _i is higher.

The output command value U _i output from the power generation facility i output command value calculation unit 10 _i includes a component obtained by multiplying the first characteristic coefficient K _i and the rated capacity S _i in the corresponding power generation facility 3 _i . . Further, the output command value U _i includes a component obtained by multiplying the differential element of the first-order lag by the second characteristic coefficient K _Di and the rated capacity S _i in the corresponding power generation facility 3 _i . Therefore, the power generation facility i output command value calculation unit 10 _i includes a proportional calculation unit 11, a first-order lag differential calculation unit 12, and a rated capacity multiplication unit 13.

In the proportional calculation unit 11, the output sharing ratio specified value Q is multiplied by the first characteristic coefficient K _i . In the first-order lag derivative calculation unit 12, the output sharing ratio prescribed value Q is multiplied by the second characteristic coefficient K _Di and the transfer function G (s) in the first-order lag differential element. The transfer function G (s) is expressed as T _Dis / (1 + T _Dis s). T _Di is a time constant of the first-order lag differential element. In this example, T _Di is the same value in the numerator and denominator of the transfer function G (s), and the transfer function G (s) functions as a high-pass filter. In this case, _TDi is set to the same value in all the power generation facilities _3i , and the response time of the distributed power generation system 1 is set as a guide. Further, T _Di may be set individually in each power generation facility 3 _i . The output of the proportional calculation unit 11 and the first-order lag differentiating unit 12 is summed, further rated capacity S _i of the corresponding power generation equipment 3 _i is multiplied by the rated capacity multiplication unit 13. The output of the rated capacity multiplication unit 13 becomes the output command value U _i . That is, the output command value U _i is expressed as follows.
U _i = Q · {K _i + K _Di · T _Diss / (1 + T _Dis s)} · S _i
The first characteristic coefficient K _i and the second characteristic coefficient K _Di are preferably set based on the dynamic characteristics of the corresponding power generation equipment 3 _i . By adjusting the first characteristic coefficient K _i , it is possible to adjust the load sharing ratio with respect to the steady fluctuation of the received power P. By adjusting the second characteristic coefficient K _Di , it is possible to adjust the load sharing ratio with respect to the transient fluctuation of the received power P.

For example, the power generation efficiency in a steady state at high power generation equipment 3 _i and power generation equipment 3 _i is lower power cost in the steady state, is set high first characteristic coefficient K _i. For example, in a power generation facility using a prime mover such as a gas engine or a steam turbine, the first characteristic coefficient K _i is set high (for example, K _i = 1). Thereby, the adjustment of the electric power due to the fluctuation of the received power P in the steady state is performed by a large amount of power generation equipment 3 _i having a high power generation efficiency in the steady state and / or a power generation equipment 3 _i having a low power generation cost. Therefore, load sharing can be performed more efficiently and at a lower cost.

Further, in the power generation equipment 3 _i having high response performance, the second characteristic coefficient K _Di is set high. For example, the power generation facility using a prime mover such as a gas turbine sets the second characteristic coefficient K _Di high. Thus, the power adjustment by the variation (generally steep change) transient reception power P is performed by the transient response performance to bear high power generation equipment 3 _i number. Therefore, it is possible to respond quickly even when the received power P changes sharply.

In the second characteristic coefficient K _Di power generation equipment 3 _i being a predetermined value than the set high for the second characteristic coefficient K _Di, the first characteristic coefficient K _i is first characteristic coefficient K _i Is preferably set lower than a predetermined value. As a result, in the power generation equipment 3 _i that shares a larger load when the received power P changes transiently, the load sharing rate in the steady state becomes lower, so that the load can be shared when the received power P changes transiently. In addition, the power generation capacity of the corresponding power generation facility 3 _i can be preserved. Therefore, the power generating plant 3 _i to more share the load at the time variations of the transitional reception power P, to the power generation equipment 3 _i are generated power to be too large burden overload the steep fluctuation of reception power P Can be effectively prevented.

Thus, in this embodiment, the load in the steady state and the transient state is adjusted according to the characteristics of the power generation equipment 3 _i by independently adjusting the first characteristic coefficient K _i and the second characteristic coefficient K _Di. The sharing rate can be adjusted independently. Further, the output command value U _i obtained in this way is generated as a command value according to the characteristics of the corresponding power generation facility 3 _i . Therefore, each power generation facility 3 _i does not require special control, and efficient load sharing can be easily realized with the configuration of the known power generation facility 3 _i .

It is also possible to change the load sharing rate of the respective power generation equipment 3 _i in the steady state. When changing the load sharing ratio, the load sharing ratio can be easily changed by changing the value of the first characteristic coefficient K _i set for each power generation facility 3 _i . When the first characteristic coefficient K _i is changed during power generation, the first characteristic coefficient K K before the change is changed in the same manner as in a startup sequence (FIG. 8) or a stop sequence (FIG. 9) described later. It is preferable to gradually change the value of _i from the value of _{i to} the value of the first characteristic coefficient K _i after the change. Thereby, the change of the load sharing rate of power generation equipment can be performed smoothly.

Second Embodiment
Next, a second embodiment of the present invention will be described. FIG. 7 is a block diagram showing a configuration example of the power supply and demand control apparatus according to the second embodiment of the present invention. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 7, the power supply / demand control apparatus 4 </ b> A of the present embodiment is different from the power supply / demand control apparatus 4 of the first embodiment in that it includes a power generation facility start / stop determination unit 14 and a start power generation facility selection unit 29. It is that you are.

The power generation facility start / stop determination unit 14 is configured to perform power generation facility start / stop determination for switching whether or not to generate power for each of the plurality of power generation facilities 3 _i . More specifically, the power generation facility activation / deactivation determination unit 14 is activated among the plurality of power generation facilities 3 _i when the output sharing ratio prescribed value Q exceeds a predetermined first threshold value (upper limit value) Q1. When a signal to increase the number of power generation facilities is output as an output signal w, and the output sharing ratio specified value Q is equal to or lower than a predetermined second threshold value (lower limit value) Q2 lower than the first threshold value Q1, A signal to reduce the number of activated power generation facilities among the plurality of power generation facilities 3 _i is configured to be output as an output signal w.

The startup power generation facility selection unit 29 is configured to be able to transmit a stop signal X _i and a startup signal Y _i to the power generation facility 3 _i . More specifically, the activated power generation facility selection unit 29 is activated when a signal (output signal w) to reduce the number of activated power generation facilities 3 _i is input from the power generation facility activation / deactivation determination unit 14. A stop signal X _i is sent to the power generation facility 3 _i having the lowest priority for activation among the plurality of power generation facilities 3 _{i, and} a signal (output signal w) to increase the number of the power generation facilities 3 _i activated is generated. When input, the activation signal Y _i is sent to the power generation facility 3 _i having the highest priority for activation among the stopped power generation facilities 3 _i . The power generation facility 3 _{i that} has received the stop signal X _i switches the power generation facility 3 _i from the activated state to the stopped state. In addition, the power generation facility 3 _{i that} has received the activation signal Y _i switches the power generation facility 3 _i from the stopped state to the activated state.

Thereby, the number of the power generation facilities to be activated can be optimized according to the required power generation amount. For example, large power generated plurality of power generation equipment 3 _i should power generation, when only currently activated (doing generator) power plant 3 _i to insufficient power supply, the number of power generation equipment 3 _i Increase. On the other hand, when the generated power to be generated by the plurality of power generation facilities 3 _i is small and is shared by all the power generation facilities 3 _i that are currently activated, the sharing ratio of one power generation facility 3 _i is small or the efficiency is low In addition, the number of power generation facilities 3 _i is reduced. Thus, the power sharing ratio specified value Q obtained in the process of controlling the plurality of power generation equipment 3 _i, by using as an index for evaluating the operating conditions of the power plant 3 _i, power generation equipment 3 _i to the power demand The number of can be optimized.

The first threshold value Q1 and the second threshold value Q2 may be set based on the total generated power target value P _e.

FIG. 8 is a graph showing a start-up sequence of the power generation facility when the power supply / demand control apparatus shown in FIG. 7 transmits a start signal Y _i to a predetermined power generation facility. Further, FIG. 9 is a graph showing the stop sequence of the power plant when the power supply and demand control apparatus shown in FIG. 2 transmits a stop signal X _i to a predetermined power generation equipment. In this example, it is assumed that there is no load fluctuation at the time of transition to the start state or at the time of transition to the stop state. However, the start or stop sequence can be executed even if the load fluctuates. It is.

As shown in FIG. 8, the power generation facility 3 _{i that} has received the activation signal Y _i starts activation after setting the value of the first characteristic coefficient K _i of the power generation facility 3 _i to 0, and the first The characteristic coefficient K _i is gradually increased from 0 to the original set value (a value corresponding to the characteristic of the power generation equipment 3 _i ). In the example of FIG. 8, a mode in which the value of the first characteristic coefficient K _i is increased proportionally is illustrated, but the present invention is not limited to this.

When the first characteristic coefficient K _i gradually increases, the output (output command value U _i ) of the power generation facility 3 _i also gradually increases, and the total power generation capacity _SK also gradually increases. As a result, the output sharing rate regulation value Q gradually decreases, and the output (output command value) of other power generation facilities also gradually decreases because the load sharing rate decreases. Here, the increase in the output of the newly activated power generation facility 3 _i is equal to the decrease in the output of the other power generation facilities, and the output of the plurality of power generation facilities 3 _i does not change. generated power target value P _e will not change.

Further, as shown in FIG. 9, the power generation facility 3 _{i that} has received the stop signal X _i gradually decreases the value of the first characteristic coefficient K _i of the power generation facility 3 _i from the set value, and the first characteristic After the coefficient K _i becomes 0, the power generation equipment 3 _i is disconnected and stopped. In the example of FIG. 9, a mode in which the value of the first characteristic coefficient K _i is decreased proportionally is illustrated, but the present invention is not limited to this.

When the first characteristic coefficient K _i is gradually decreased, the output (output command value U _i ) of the power generation facility 3 _i is also gradually decreased, and the total power generation capacity _SK is also gradually decreased. As a result, the output sharing rate regulation value Q gradually increases, and the outputs (output command values) of other power generation facilities also gradually increase because the load sharing rate increases. Here, since the decrease in the output of the power generation facility 3 _{i to be} stopped is equal to the increase in the output of the other power generation facilities, and the output of the plurality of power generation facilities 3 _i does not change, the received power P and the total generated power target value _{P e} does not change.

When the power generation facility 3 _i is started or stopped, the first characteristic coefficient K _i is gradually increased or decreased as described above, so that the power generation facility 3 _i can be started or stopped smoothly. it can. Further, in the control loop of the power generation equipment 3 _i , complicated operation such as signal switching or change of control parameters other than the first characteristic coefficient K _i is unnecessary, and the state of the power generation equipment is smooth with simple operation. Switching can be done.

When a new power generation facility 3 _i is activated, and there are a plurality of power generation facilities 3 _i in a stopped state, the decision as to which of the power generation facilities 3 _i to activate is based on a predetermined priority order. It may be performed. Similarly, when there are a plurality of activated power generation facilities 3 _i and one of them is stopped, the power generation facility 3 _i to be stopped may be determined based on a predetermined priority order.

The switching states at power plant 3 _i is to the operator in the corresponding power generation equipment 3 _i may be performed manually, the power generation equipment 3 _i may be performed automatically. In this case, the startup power generation facility selection unit 29 may be configured to transmit a switching command signal for switching the start or stop state of the predetermined power generation facility toward all the power generation facilities 3 _i . The switching command signal may include information for specifying the power generation facility 3 _i whose state is to be switched. Thereby, it is possible to grasp which power generation facility 3 _i is activated even in a power generation facility other than the power generation facility that is switched between start and stop.

Here, in a case where the start or stop of power generation equipment 3 _i automatically, has the following problems.

First, it is necessary to set an upper limit value and a lower limit value for the output sharing ratio prescribed value Q. If the upper limit value and lower limit value of the output sharing rate regulation value Q are not set appropriately, the output of the power generation equipment 3 _i cannot follow the load fluctuation, the power generation efficiency decreases, the power generation equipment 3 _i is frequently started or There is a risk of problems such as stopping. Moreover, there is a possibility that the appropriate values of the upper limit value and the lower limit value may change depending on the load condition and time zone. Further, the power generation equipment 3 _i has different response characteristics and efficiency depending on its type (type of prime mover). For this reason, when starting or stopping the power generation equipment 3 _i , it is necessary to select a generator that can ensure a desired adjustment capability (capability to cope with sudden load fluctuations) and improve the overall operation efficiency. is there. Furthermore, it is necessary to consider the start-up time of the power generation equipment 3 _i . When starting up the power generation equipment 3 _i , since the output is gradually increased after the start-up, it takes time to reach a predetermined output. Therefore, when starting the power generation equipment 3 _i , it is necessary to consider these time delays. Furthermore, it is necessary to appropriately prevent unnecessary start or stop operations. If transient load variation in the power generation equipment 3 _i is frequently generated, the upper limit value and the lower limit value of the set output sharing ratio specified value Q, which may start or stop of the power generation facility 3 _i occurs frequently. Other start or extra fuel to stop the power generation equipment 3 _i is consumed, since it is a possibility to reduce the power generation equipment 3 _i life, extra start or stop is required to avoid generation.

The following automatic start / stop algorithms can be applied to the above problems. First, an upper limit value (first threshold value) Q1 and a lower limit value (second threshold value) Q2 of the output sharing rate prescribed value Q at each time are determined in advance from the past load results, etc. The start / stop determination unit 14 determines whether to start or stop the power generation equipment 3 _i based on the upper limit value Q1 and the lower limit value Q2 of the output sharing rate prescribed value Q at the time of the determination at every predetermined timing. . In other words, when the power generation facility activation / deactivation determination unit 14 determines that the output sharing ratio specified value Q is larger than the upper limit value Q1 at that time, the predetermined activation of the power generation facilities 3 _i that are stopped is determined. The switching command signal for starting the power generation equipment with the highest priority is output. In addition, when the power generation facility activation / deactivation determination unit 14 determines that the output sharing ratio prescribed value Q is smaller than the lower limit value Q2 at that time, a predetermined stop among the activated power generation facilities 3 _i is performed. The switching command signal for stopping the power generation equipment having the highest priority is output.

  FIG. 10 is a graph showing the relationship between the predicted demand power according to the time and the upper limit value and the lower limit value of the output sharing rate prescribed value. The lower graph of FIG. 10 is a graph showing a predicted change in demand power according to time in a certain area where the distributed power generation system 1 is applied. The upper graph in FIG. 10 is a graph showing temporal changes in the upper limit value Q1 and the lower limit value Q2 of the output sharing rate prescribed value according to the predicted demand power. Time period A in which the fluctuation of predicted power demand is small (within a predetermined range) is predicted in period A, and a time slot in which the increase rate of demand power predicted is large (greater than or equal to the first ratio) is predicted in period B. A period C in which the fluctuation cycle of demand power is short (increases after decreasing in a short period) is defined as period C. The period C is set as a case where the predicted decrease rate of demand power is equal to or higher than the second rate and the predicted increase rate of demand power thereafter is equal to or higher than the third rate. Note that the first ratio, the second ratio, and the third ratio are each suitably set, and each value may be the same or different.

  In the present embodiment, the power generation facility start / stop determination unit 14 determines the demand power predicted in the distributed power generation system 1 (the power required by all the loads L connected to the distributed power system 27) per predetermined time. In a predetermined first period B in which the increase rate is equal to or higher than a predetermined first ratio, an upper limit value (first threshold value) Q1 and a lower limit value (second threshold value) Q2 are respectively set to demand power. Is set to be lower than a value set in the period A in which the change in the range is within a predetermined range. Further, the power generation facility activation / deactivation determination unit 14 has a decrease rate of the demand power per predetermined time that is equal to or greater than a predetermined second rate, and thereafter, the increase rate of the demand power per predetermined time is a predetermined third rate. In a predetermined second period C that is equal to or greater than the ratio, the lower limit value (second threshold value) Q2 is set lower than the value set in period A in which the change in demand power is within a predetermined range.

As described above, in the period B, the upper limit value Q1 and the lower limit value Q2 of the output sharing ratio prescribed value are both set lower than the period A. By setting the upper limit value Q1 and the lower limit value Q2 low in the period B in which the rate of increase in demand power is large, the load burden rate of the power generation equipment 3 _i is reduced, so the efficiency is reduced, but the power generation capacity of the power generation equipment 3 _i Can be afforded. Therefore, it is possible to cope with a delay in output increase due to the startup time of the power generation equipment 3 _i . Also, as shown as period C, for example, when the load decreases during the daytime break time in factory equipment and then increases again, only the lower limit value Q2 of the output sharing rate prescribed value is lower than the period A. Is set. As a result, it is possible to prevent the power generation equipment 3 _i from stopping and starting in a short time with respect to the rapid decrease and increase in the output sharing ratio prescribed value Q due to the sudden decrease and increase in demand power. In addition, since it takes less time to stop the power generation equipment 3 _i than in the case of the start-up, the upper limit value Q1 similar to the time zone in which the fluctuation of the demand power is small as the period A in the time zone where the reduction rate of the demand power is large, A lower limit value Q2 is set.

In addition, although a priority is not specifically limited, it determines so that power generation efficiency and adjustment capability may be balanced moderately. For example, as the power generation capacity of the power plant 3 _i is larger set a higher priority for the start, to set lower the priority of the stop. This prevents frequent switching between start and stop. In addition, since the required transient response performance tends to increase in proportion to demand, the order is set so that the transient response performance increases at a constant rate as the number of power generation equipment 3 _i that is activated increases. Is done. In other words, the priority order for activation is set so that the number of activations is proportional to the transient response performance of the entire facility. In addition, when there are a plurality of power generation facilities 3 _i of the same type, those having a long start time may be preferentially stopped, and those having a long stop time may be preferentially started. Thereby, it is possible to prevent the same power generation facility 3 _i from repeatedly starting and stopping. Moreover, the priority order for stopping the power generation equipment 3 _i may be set to be the reverse order of the priority order for starting, or a completely different priority order may be adopted.

Moreover, it is not subject to the process of switching the start and stop of all of the power generation facility 3 _i. For example, the power generation equipment 3 _i whose adjustment capability (response performance) is not high may be always activated as a base power supply and may not be stopped.

Instead of the above configuration, the output signal w from the power generation facility activation / deactivation determination unit 14 may be configured as a signal for operating a notification unit (not shown) provided in the power supply and demand control device 4. For example, when the output sharing rate regulation value Q exceeds a predetermined first threshold value Q1, the power generation facility activation / deactivation determination unit 14 sends a signal to increase the number of activated power generation facilities 3 _i to the notification unit. by sending performs notification to the effect that increasing the number of power generation equipment 3 _i the notification unit is started. Further, for example, when the output sharing ratio prescribed value Q is equal to or less than the predetermined second threshold value Q2, the power generation equipment start / stop determination unit 14 notifies the signal to reduce the number of the power generation equipment 3 _i that has been started. To notify that the number of power generation facilities 3 _i activated by the notification unit should be reduced. The notification mode in the notification unit can be applied in various ways, for example, by turning on a predetermined lamp, displaying a warning on the management screen, or reporting by voice. Thus, upon receiving the notification from the notification unit, the operator may instruct the power generation equipment 3 _i to be manually switched to start or stop, or the operator may manually start the power generation equipment 3 _i or The stop state may be switched.

The determination process in the power generation equipment start / stop determination unit 14 and the generation of the output command value U _{i in} the generated power target value calculation unit 8 are performed independently. Accordingly, the output command value U _i of the other power generation equipment 3 _i needs to be readjusted by starting or stopping one power generation equipment 3 _i . In this case, the power generation facility activation / deactivation determination unit 14 may automatically send a difference calculation command to the generated power target value calculation unit 8, or the generated power target value calculation unit 8 may be based on an operator instruction. You may be comprised so that recalculation is possible. Further, instead of the example of the present embodiment, after the determination processing in the power generation facility start / stop determination unit 14 is performed (after the number of power generation facilities 3 _i is adjusted), the generated power target value calculation unit 8 is adjusted. The output command value U _i may be calculated based on the power generation equipment 3 _i .

<Third Embodiment>
Next, a third embodiment of the present invention will be described. FIG. 11 is a block diagram showing a configuration example of a power supply and demand control apparatus according to the third embodiment of the present invention. In addition, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 11, the power supply / demand control apparatus 4B of the present embodiment is different from the power supply / demand control apparatus 4 of the first embodiment in that the system frequency f in the distributed power system 27 is measured and a predetermined system frequency is obtained. based on the difference between the target value f _ref is that it comprises an output command value correcting portion 15 for correcting the output command value U _i for each of the plurality of power generation equipment 3 _i. Further, in the present embodiment, the power supply and demand control device 4B includes a frequency target correction value calculation unit 16 that calculates a frequency target correction value f _com based on the deviation between the measured system frequency f and the system frequency target value f _ref. ing. The system frequency f of the distributed power system 27 substantially matches the frequency of the external power system 2 during the linked operation.

For example, in the weak external power system 2 such as an emerging country, there is a problem that frequency fluctuations frequently occur as well as a shortage of transmission line capacity. When the power generation facility 3 _i is connected to the external power system 2 and the frequency variation occurs in the external power system 2, the output of the power generation facility 3 _i varies. When the output of the power generation facility 3 _i is reduced, the received power P from the external power system 2 is increased to compensate for the shortage, and there is a possibility that the transmission line capacity may be exceeded. On the other hand, when the output of the power generation facility 3 _i is increased, the power generation facility 3 _i is overloaded and may be tripped.

Therefore, in the configuration of the present embodiment, a correction value corresponding to the frequency variation of the distributed power system 27 is added to the output command value U _i for sharing the load with each power generation facility 3 _i . Thus, it is possible if the frequency variation occurs in the external electric power system 2, fluctuation of the output power generation equipment 3 _i. Therefore, it is possible to stably supply power to consumers (load L) in the power system.

FIG. 12 is a block diagram showing an outline of calculation in the frequency target correction value calculation unit 16 of the power supply and demand control apparatus shown in FIG. As described above, the frequency target correction value calculation unit 16 receives the system frequency f in the distributed power system 27. This system frequency f is equal to the system frequency in the external power system 2. The system frequency f is subtracted from a predetermined system frequency target value f _ref to calculate a deviation f _ref −f. This deviation f _ref −f is input to the divider 17. The divider 17 divides the deviation f _ref −f by the rated frequency f _base , inverts the sign and outputs the result. The value output from the divider 17 becomes the frequency target correction value _fcom . The frequency target correction value f _com is a value for correcting the frequency target value of the power generation facility 3 _i so that the output variation of the power generation facility due to the frequency variation does not occur.

FIG. 13 is a block diagram showing an outline of calculation in the output command value correction unit of the power supply and demand control apparatus shown in FIG. The output command value correction unit 15 calculates the frequency target correction value f _com calculated by the frequency target correction value calculation unit 16 and outputs a plurality of power generations for calculating the output command correction value P _fi corresponding to each of the plurality of power generation facilities 3 _i. The equipment i correction value calculation unit 18 _i (i = 1 to n) is provided. The output command value correction is performed by adding the output command correction value P _fi calculated by the power generation facility i correction value calculation unit 18 _i to the output command value U _i output from the power generation facility i output command value calculation unit 10 _i. The unit 15 generates a corrected output command value U _fi to be output to each power generation facility 3 _i .

FIG. 14 is a block diagram showing an outline of calculation in the power generation facility i correction value calculation unit of the output command value correction unit shown in FIG. Power generation equipment i correction value calculation unit 18 _i is the frequency target correction value _{f com,} multiplied by the rated capacity _{S i} at the corresponding power generation equipment _{3 i,} droop in the corresponding power plant _{3 i} (speed droop) in _{D i} The divided value is output as an output command correction value P _fi in each power generation facility 3 _i . As a result, the output command correction value P _fi is converted into a power correction value, so that it can be added to the output command value U _i (power value) output from the output command value generation unit 6 as it is.

Instead of this, the power generation equipment _i correction value calculation 18 _i is not provided, and the frequency correction value f _com is separately sent directly to each power generation equipment 3 _i , and based on the output command value U _i received by each power generation equipment 3 _i. Thus, power output control may be performed while performing output correction with the frequency correction value _fcom .

Also in this embodiment, the calculation mode (load sharing mode) of each output command value U _i of the plurality of power generation facilities 3 _i is a relatively simple configuration by adopting the same configuration as in the first embodiment. The generated power of the plurality of power generation facilities 3 _i can be quickly adapted to fluctuations in the received power P from the external power system 2. However, the correction mode of the output command value U _i based on the system frequency f in this embodiment is not limited to the mode in which the output command value U _i is generated in the first embodiment, and the load is shared among the plurality of power generation facilities 3 _i. It can be applied to other configurations.

<Fourth embodiment>
Next, a fourth embodiment of the present invention will be described. FIG. 15 is a block diagram showing a configuration example of a power supply and demand control apparatus according to the fourth embodiment of the present invention. In addition, about the structure similar to 3rd Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 15, one of the differences between the power supply and demand control device 4C in the distributed power generation system 1C of the present embodiment and the power supply and demand control device 4B of the third embodiment is that the total generated power target value calculation unit 5C. However, there are an interconnection operation state that indicates that the external power system 2 and the plurality of power generation facilities 3 _i are operating in an interconnected state, and a self-sustained operation state that indicates that the plurality of power generation facilities 3 _i are operating independently. receiving a status signal SS indicating either, in the case of interconnected operation state, it calculates the total generated power target value P _e by integrating the deviation between the reception power P and the power receiving power target value P _o, When in a self-sustaining operation state, the system frequency f in the distributed power system 27 is measured, and the total generated power target value _Pe is calculated based on a deviation from a predetermined system frequency target value f _ref. Is Rukoto. Furthermore, in the power supply and demand control apparatus 4C of the present embodiment, the frequency target value calculation unit 16C receives the state signal SS and measures the system frequency f in the distributed power system 27 when it is in the interconnected operation state. The frequency target correction value f _com is calculated based on the deviation from the predetermined system frequency target value f _ref, and the output f _{com is set} to 0 in the case of the autonomous operation state.

For example, in areas where the external power system 2 is vulnerable, such as emerging countries, there is a risk of frequent power outages. When a distributed power generation system is installed in such an area, each power generation facility 3 _i is disconnected from the external power system 2 in order to continue power supply to consumers without being affected by a power failure in the external power system 2. A function to operate independently is desired. That is, a function of making each power generation facility 3 _i an electric power system independent of the external electric power system 2 is desired. Furthermore, since load sharing based on the received power P at the power receiving point R cannot be performed after shifting to the self-sustained operation, a steady deviation from a predetermined value occurs in the system frequency due to the characteristics of each power generation facility 3 _i. There is a risk of quality degradation.

Therefore, in the present embodiment, the power generation equipment 3 _i is configured to switch between the self-sustained operation state and the interconnected operation state (configuration including the circuit breaker 26), and then in the interconnected operation state. In some cases, the total generated power target value _Pe is calculated by integrating the deviation between the received power P and the received power target value P _o , while in the self-sustaining operation state, the system frequency f and a predetermined value are calculated. The total generated power target value _Pe is calculated based on the deviation from the system frequency target value f _ref . Thereby, when switching from the grid operation to the independent operation, it is possible to eliminate the steady frequency deviation due to the load fluctuation during the independent operation. Therefore, it is possible to maintain the power supply quality satisfactorily.

FIG. 16 is a block diagram showing an outline of calculation in the total generated power target value calculation unit of the power supply and demand control apparatus shown in FIG. Total generated power target value calculating section 5C includes a reception power P which is measured at the receiving point R and the predetermined received power target value P _o is input, received power control unit for outputting a power deviation ΔP based on these 19, a system frequency control unit 20 that receives a system frequency f in the distributed power system 27 and a predetermined system frequency target value f _ref and outputs a power deviation ΔP _f based thereon, and a received power control unit 19 or by integrating the output of the system frequency control unit 20, the power deviation output an integrator 9 for outputting generated power target value P _e by inverting the polarity, from the received power control unit 19 in accordance with the state signal SS A switching unit 21 for inputting any one of ΔP and the power deviation ΔP _f output from the system frequency control unit 20 to the integrator 9 is provided. When the state signal SS indicates the connected operation state, the switching unit 21 inputs the power deviation ΔP output from the received power control unit 19 to the integrator 9, and when the state signal SS indicates the autonomous operation state, The power deviation ΔP _f output from the system frequency control unit 20 is configured to be input to the integrator 9.

With such a configuration, the total generated power target value calculation unit 5C changes the received power P to the received power P in response to the state signal SS indicating that the plurality of power generation facilities 3 _i are in either the connected operation state or the independent operation state. Based on this, the generation power target value _Pe is generated or the generation power target value _Pe is generated based on the system frequency f.

FIG. 17 is a block diagram showing an outline of the calculation of the received power control unit shown in FIG. It received power control unit 19, the reception power P, subtracted from the received power target value P _o predetermined, and calculates the deviation P _o -P a power deviation [Delta] P.

FIG. 18 is a block diagram showing an outline of the calculation of the system frequency control unit shown in FIG. The system frequency control unit 20 receives the system frequency f and the system frequency target value f _ref when the state signal SS is switched from the interconnected operation state to the autonomous operation state, and performs the first interconnected autonomous switching process. by a first interconnection autonomous switching processing unit 22 for outputting the corrected frequency target value _{f cr,} dividing the deviation _f cr -f the corrected frequency target value _{f cr} and system frequency f at the rated frequency _{f base} a divider 23 which, multiplied by the frequency control gain K _fc to the output of the divider 23, and a multiplier 24 for outputting a value obtained by inverting the sign as a power deviation [Delta] P _f.

When switching from interconnected operation state to the autonomous operation state, when the deviation between the system frequency f and the power system frequency target value f _ref is large, there is a risk of fluctuations total generated power target value P _e is large based on it. If the total generated power target value _Pe greatly varies, the control of the plurality of power generation facilities 3 _i may become unstable. For this reason, the first interconnection independent switching processing unit 22 gradually decreases the deviation between the system frequency f and the system frequency target value f _ref when the state signal SS is switched from the interconnection operation state to the autonomous operation state. Such a system frequency target value is output as a corrected frequency target value f _cr .

FIG. 19 is a graph showing a temporal change after the start of the shift to the independent operation in the corrected frequency target value output from the first interconnection independent switching processing unit shown in FIG. When the state signal SS is in the grid operation state, the first grid self-sustained switching processing unit 22 outputs the system frequency f. At time t _1, when the state signal SS is switched to autonomous operation state from interconnected operation state, the first interconnection autonomous switching unit 22, a predetermined network frequency target value from the power system frequency f at time t ₁ A value that gradually approaches f _ref is output as the corrected frequency target value f _cr .

In FIG. 19, an example is illustrated in which the corrected frequency target value f _cr is proportionally increased with respect to time change, but is not limited thereto. For example, it is good also as an aspect which increases in a quadratic curve so that the variation | change_quantity per unit time may reduce gradually. Alternatively, the transition period may be determined in advance, and the amount of change per unit time may be determined so as to approximate the system frequency target value f _ref within the transition period. Further, in FIG. 19, although the system frequency f at time _{t 1} is explained smaller relative power system frequency target value _{f ref,} the system frequency f at time _{t 1} is relative to the power system frequency target value _{f ref} The same applies to a large case.

After the corrected frequency target value f _cr reaches the system frequency target value f _ref , the first interconnection independent switching processing unit 22 outputs the system frequency target value f _ref .

According to such a configuration, when the plurality of power generation facilities 3 _i are switched from the grid operation to the independent operation, even if the deviation between the system frequency f and the system frequency target value f _ref is large, the deviation is filled. The total generated power target value _Pe is calculated using the corrected frequency target value f _cr that gradually changes to. For this reason, it is possible to prevent the total generated power target value _Pe from fluctuating greatly when switching from the grid operation to the independent operation, and to control the plurality of power generation facilities 3 _i stably.

  When the state signal SS is switched from the autonomous operation state to the interconnection operation state, the first interconnection independent switching processing unit 22 outputs the system frequency f.

In this embodiment, the power supply and demand control device 4C is distributed to the power system frequency f is measured at the power system 27, to each of the plurality of power generation equipment 3 _i on the basis of a deviation of the predetermined power system frequency target value f _ref An output command value correction unit 15 that corrects the output command value U _i and a frequency target correction value calculation unit 16C that calculates a frequency target correction value f _com based on the deviation between the measured system frequency f and the system frequency target value f _ref. And.

FIG. 20 is a block diagram showing an outline of calculation in the frequency target correction value calculation unit of the power supply and demand control apparatus shown in FIG. As shown in FIG. 20, the frequency target correction value calculation unit 16C in the present embodiment divides the deviation f _ref −f by the rated frequency f _base and outputs the difference f f _com of the divider 17 that inverts the sign. The second interconnection independent switching processing unit 25 that performs two interconnection independent switching processing is provided.

Since the total generated power target value _Pe is originally calculated based on the deviation f _ref -f between the system frequency f and the system frequency target value f _ref during the independent operation, the output command value U _i generated based on this is calculated. Furthermore, correction based on the same deviation f _ref −f should not be performed. Accordingly, during the independent operation, the frequency target correction value calculation unit 16C needs to set the output frequency target correction value _fcom to zero. Here, as described above, at the time of switching to self-sustaining operation from interconnected operation, the total generated power target value P _e, such as gradually decreases deviation f _{ref -f} by a first interconnection autonomous switching process It is calculated based on the system frequency target value (corrected frequency target value) f _cr . That is, it is preferable to perform correction based on the deviation f _ref −f for a while after the shift to the independent operation.

For this reason, when the state signal SS is switched from the interconnection operation state to the autonomous operation state, the second interconnection independent switching processing unit 25 gradually starts from the output value f ′ _com of the divider 17 at the time of the change. A frequency target correction value _fcom that is a small value is output. The second interconnection independent switching processing unit 25 performs a process such that the frequency target correction value _fcom is finally zero.

FIG. 21 is a graph showing a temporal change after the start of the transition to the independent operation in the frequency correction value output from the second interconnection independent switching processing unit shown in FIG. When the state signal SS is interconnected operation state, the second interconnection autonomous switching unit 22 outputs an output value f _'com divider 17 as a frequency target correction value f _com. That is, the output of the frequency target correction value calculation unit 16C in the interconnected operation state is simultaneously with the output of the frequency target correction value calculation unit 16 in the second embodiment. At time _{t 1,} when the state signal SS is switched to autonomous operation state from interconnected operation state, the second interconnection autonomous switching processor 25, the frequency target correction value _{f com} at time _{t 1} (= f _'com) A value that gradually approaches 0 is output as the frequency target correction value _fcom .

For example, when the frequency target correction value f _com output from the second interconnection independent switching processing unit 25 reaches 0, the corrected frequency target value f _cr output from the first interconnection independent switching processing unit 22 is The amount of change in the frequency target correction value f _com per unit time in the second interconnection independent switching processing unit 25 is determined so as to approximate the system frequency target value f _ref .

According to this structure, a plurality of power generation equipment 3 _i when switching to autonomous operation from interconnected operation, the total generated power target value P _e from the value calculated based on the reception power P to the grid frequency f Even in the case of performing the first interconnection independent switching process for gradually shifting to the value calculated based on the value, the correction amount based on the deviation between the system frequency f and the system frequency target value f _ref is gradually reduced. , an output command value U _i for power generation equipment 3 _i can be appropriately corrected.

In the present embodiment, configured to switch between an input value for calculating the total generated power target value P _e based on the state signal SS (total generation power target value calculating section 5C), the configuration of the second embodiment Although the added aspect was demonstrated, it is good also considering this structure as the aspect added to the structure of 1st Embodiment. That is, for example, in FIG. 15, the output command value correction unit 15 and the frequency target value calculation unit 16C may be omitted.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the manner of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention. For example, the components in the plurality of embodiments may be arbitrarily combined.

Further, in the second embodiment and the third embodiment, the power target value to be generated by the plurality of power generation equipment 3 _i on the basis of the reception power P in the first embodiment (total generated power target value P _e) The power target value may be calculated from the total value of the load power and the renewable energy without being limited to the calculated configuration.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.

  The power supply and demand control apparatus according to the present invention is useful for quickly responding to fluctuations in received power from an external power system with a relatively simple configuration.

1, 1A, 1B, 1C Distributed power generation system 2 External power system 3 _i (i = 1, 2,..., N) Power generation equipment 4, 4A, 4B, 4C Power supply / demand control devices 5, 5C Calculation of total generated power target value Unit 6 output command value generation unit 7 output share ratio prescribed value calculation unit 8 generated power target value calculation unit 9 integrator 10 _i (i = 1, 2,..., N) power generation facility i output command value calculation unit 11 proportional calculation unit 12 First-order lag differential calculation unit 13 Rated capacity multiplication unit 14 Power generation equipment start / stop determination unit 15 Output command value correction unit 16, 16C Frequency target correction value calculation unit 17 Divider 18 _i (i = 1, 2,..., N) Power generation Facility i correction value calculation unit 19 Received power control unit 20 System frequency control unit 21 Switching unit 22 First interconnection independent switching processing unit 23 Divider 24 Multiplier 25 Second interconnection independent switching processing unit 26 Breaker 27 Dispersion Type power system 28 Electric power supply and demand control Power generation equipment not connected to the device 29 Start-up power generation equipment selection section L Load

Claims (9)

In a distributed power generation system composed of a plurality of power generation facilities and connected so as to be able to transfer power to an external power system, an electric power supply and demand control device that instructs each of the plurality of power generation facilities to allocate a power generation amount. And
Total power generation that calculates the total generated power target value as the power target value to be generated by the plurality of power generation facilities by measuring the received power from the external power system and integrating the deviation from the predetermined received power target value A power target value calculation unit;
One or more characteristic coefficients individually determined based on the transient and / or steady characteristics of each of the plurality of power generation facilities, the rated capacity in each of the plurality of power generation facilities, and the total generated power target value And generating an output command value to each of the plurality of power generation facilities, and including an output command value generation unit for outputting to each power generation facility ,
The output command value generation unit
The total power generation capacity that determines the maximum value of the generated power that can be stably operated even when the maximum power demand increase assumed in the distributed power generation system occurs is divided from the total power generation target value. An output sharing rate prescribed value calculation unit for calculating an output sharing rate prescribed value that serves as a reference of the output sharing rate of the plurality of power generation facilities,
Based on the output share ratio prescribed value, one or more characteristic coefficients individually determined for the plurality of power generation facilities, and a rated capacity of the plurality of power generation facilities, a generated power target in each of the plurality of power generation facilities A power supply / demand control apparatus , including a generated power target value calculation unit that calculates a value as the output command value . The characteristic coefficient is a parameter having a larger value as the power generation efficiency in the steady state of the power generation facility is higher and / or the power generation cost is lower, or a parameter having a smaller value as the transient response performance of the power generation facility is higher. Including one characteristic factor,
The output sharing ratio prescribed value calculation unit multiplies the total generated power target value by the first characteristic coefficient of the plurality of power generation facilities and the rated capacity, and totals the total power generation capacity obtained by all the power generation facilities. The electric power supply and demand control device according to claim 1 , wherein the value divided by is calculated as an output sharing ratio prescribed value. The characteristic coefficient is a parameter having a larger value as the power generation efficiency in the steady state of the power generation facility is higher and / or the power generation cost is lower, or a parameter having a smaller value as the transient response performance of the power generation facility is higher. Including one characteristic factor,
The generator power target value calculation unit calculates the output command value containing the first characteristic coefficient and the component by multiplying the rated capacity of power generation equipment corresponding to claim 1 or 2 The power supply and demand control device described. The characteristic coefficient includes a second characteristic coefficient that is a parameter having a larger value as the transient response performance of the power generation facility is higher,
The generated power target value calculation unit calculates the output command value including a component obtained by multiplying a differential element of a first-order lag by the second characteristic coefficient in the corresponding power generation facility and the rated capacity. To 4. The power supply and demand control device according to any one of 3 to 4 . A power generation facility start / stop determination unit for performing power generation facility start / stop determination for switching whether to generate power for each of the plurality of power generation facilities,
The power generation facility activation / deactivation determination unit outputs a signal to increase the number of activated power generation facilities among the plurality of power generation facilities when the output sharing ratio prescribed value exceeds a predetermined first threshold value. A signal to reduce the number of active power generation facilities among the plurality of power generation facilities when the output sharing ratio prescribed value is equal to or lower than a predetermined second threshold value lower than the first threshold value. configured to output, power supply and demand control apparatus according to any one of claims 1 to 4. Each of the plurality of power generation facilities is set such that the priority for activation is higher as the power generation capacity is larger, and / or the number of activated facilities is proportional to the transient response performance of the entire facility,
The power supply and demand control device, when a signal to reduce the number of power generation facilities activated from the power generation facility activation stop determination unit is input, the most priority for activation among the plurality of activated power generation facilities When a stop signal is sent to a power generation facility with a lower rank and a signal to increase the number of activated power generation facilities is input, the power generation facility with the highest priority for start-up among the stopped power generation facilities The power supply and demand control device according to claim 5 , further comprising a startup power generation equipment selection unit that sends a startup signal. The power generation facility activation / deactivation determination unit is configured to perform the first operation in a predetermined first period in which a rate of increase in demand power assumed in the distributed power generation system per predetermined time is equal to or greater than a predetermined first ratio. A threshold value and a second threshold value are each set lower than a value set in a period in which the change in the demand power is within a predetermined range;
A decrease rate of the demand power per predetermined time is equal to or greater than a predetermined second rate, and then a rate of increase in the demand power per predetermined time is equal to or greater than a predetermined third rate. The power supply / demand control apparatus according to claim 5 or 6 , wherein in the period, the second threshold value is set lower than a value set in a period in which the change in the demand power is within a predetermined range. The distributed power generation system includes a distributed power system connected to the external power system so as to be able to exchange power, and the plurality of power generation facilities are connected to the distributed power system,
The power supply and demand control device measures a system frequency in the distributed power system, and corrects the output command value to each of the plurality of power generation facilities based on a deviation from a predetermined system frequency target value with a correction unit, power supply and demand control apparatus according to any one of claims 1 to 7. The distributed power generation system includes a distributed power system connected to the external power system so as to be able to exchange power, and the plurality of power generation facilities are connected to the distributed power system,
The total generated power target value calculation unit includes a connected operation state indicating that the external power system and the plurality of power generation facilities are connected to each other, and the plurality of power generation facilities are operating independently. When the state signal indicating any one of the self-sustained operation states is received and in the interconnected operation state, the total generated power target value is obtained by integrating the deviation between the received power and the received power target value. When the system is in the autonomous operation state, the system frequency in the distributed power system is measured, and the total generated power target value is calculated based on a deviation from a predetermined system frequency target value. The power supply / demand control apparatus according to any one of claims 1 to 8 .

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