WO2013128731A1

WO2013128731A1 - Independent power supply system

Info

Publication number: WO2013128731A1
Application number: PCT/JP2012/080661
Authority: WO
Inventors: 内山　倫行; 近藤　真一; 永山　祐一
Original assignee: 株式会社日立製作所
Priority date: 2012-02-27
Filing date: 2012-11-28
Publication date: 2013-09-06
Also published as: JP5625005B2; IN2014DN06999A; JP2013176234A

Abstract

The purpose of the present invention is the provision of an independent power supply system that is capable of reducing the costs associated with installation. This independent power supply system is characterized by using weather forecast data to calculate demand prediction data for a load device and power output prediction data for a natural energy generator, limiting power output from the natural energy generator when it is predicted on the basis of the demand prediction data and the power output prediction data that charging of a battery will take place at a level surpassing the maximum charging power of the battery, and limiting power consumption by a load for adjustment when it is predicted on the basis of the demand prediction data and the power output prediction data that power discharge from the battery will surpass the maximum discharge power of the battery.

Description

Stand-alone power supply system

The present invention relates to a stand-alone power supply system, and more particularly to a reduction in capacity of a power storage device.

The introduction of power generation facilities that use natural energy such as wind and solar as a countermeasure against the emergence of global environmental problems such as global warming and acid rain, the depletion of fossil resources, and ensuring energy security Yes.

Especially in isolated areas and depopulated areas in tropical areas, where power is often supplied mainly by diesel engine generators, etc., the sunshine conditions are good and suitable for solar power generation. In addition, there is a great need for an electric power supply system that can contribute to the realization of a low-carbon society, while at the same time improving the economic efficiency by effectively using renewable energy. Even in areas where power system infrastructure has already been established, when the power system stops due to a natural disaster, etc., the solar power generation system installed in the customer's facility is separated from the system and is operated autonomously. There is an increasing expectation for a system that supplies power stably and continuously to a load even when it is stopped.

Among the power generation facilities using natural energy, for example, an independent power supply system centering on a solar power generation device is disclosed in Patent Document 1, for example. In this patent document, when the automatic frequency control is performed by the power storage device, the output suppression state of the photovoltaic power generation device is controlled indirectly by changing the target frequency according to the state of charge (SOC) and charge / discharge power. A technique for preventing system stoppage due to overcharging of a power storage device is described.

JP 2008-17762 A

With regard to a power supply system that has a natural energy power generation device and a power storage device such as a solar power generation device and a wind power generation device and is operated independently from the power system, while maintaining the frequency and voltage in the independent system at appropriate values In order to supply power to the load stably and continuously, it is necessary to prevent not only overcharging of the power storage device but also overdischarge at night or rainy weather when the solar power generation device does not generate power.

With the technology disclosed in Patent Document 1, it is possible to prevent operation stop due to overcharging of the power storage device, but avoid operation stop due to overdischarge of the storage battery, including at night when the output of solar power generation becomes zero. Therefore, it is necessary to separately provide a power source for adjustment such as a diesel engine, or it is necessary to increase the capacity of the power storage device, which may increase the installation cost.

Therefore, an object of the present invention is to provide an independent power supply system that can reduce installation costs.

In order to solve the above-described problems, an independent power supply system according to the present invention includes a natural energy power generation device, a load device that has a load for adjustment and that operates by generated power from the natural energy power generation device, and the natural energy An independent power supply system including a power generation device and a power storage device having a storage battery connected to the load device for charging and discharging, the independent power supply system using the weather prediction data of the load device Demand prediction data and power generation output prediction data of the natural energy power generation apparatus are calculated, and the storage battery is predicted to be charged by exceeding the maximum charge power of the storage battery by the demand prediction data and the power generation output prediction data. In the case, the power generation output from the natural energy power generation device is suppressed, the demand forecast data and the power generation output The chromatography data, which comprises suppressing the power consumption of the adjustment load when being discharged from the storage battery exceeds the maximum discharge power of the battery is predicted.

According to the present invention, it is possible to provide a stand-alone power supply system that can reduce installation costs.

1 is a configuration example of a stand-alone power supply system in Embodiment 1. It is the figure which represented typically the example of the output shift operation | movement of the solar power generation device which comprises the stand-alone power supply system in Example 1, and an electrical storage apparatus. It is a functional block diagram of the control apparatus of the stand-alone power supply system in Example 1. It is a control flow figure of the independent type electric power supply system in Example 1. It is a figure showing the control operation of the stand-alone power supply system in Example 1. It is an example of a structure of the stand-alone power supply system in Example 2. FIG. 6 is a functional configuration diagram of a storage device internal control device according to a second embodiment. It is a functional block diagram of the solar power generation device control apparatus in Example 2. FIG. It is a functional block diagram of the control apparatus in a load apparatus in Example 2. FIG. FIG. 10 is a control flow diagram of the storage device internal control device according to the second embodiment. It is a control flowchart of the solar power generation device control apparatus in Example 2. FIG. 6 is a control flow diagram of a control device in a load device in Embodiment 2. It is a figure showing the control operation of the stand-alone power supply system in Example 2. It is a control flow figure in the case of performing power factor adjustment driving | operation with the solar power generation device in Example 3. FIG. It is a figure explaining the control operation in the case of performing power factor adjustment driving | operation with the solar power generation device in Example 3. FIG. It is a control flow figure in the case of performing a power factor adjustment driving | operation with the solar power generation device in Example 4. FIG. FIG. 10 is a control flow diagram utilizing a start / stop notice signal of a load device according to a fifth embodiment. It is a figure explaining the operation | movement of the control using the start stop notification signal of the load apparatus in Example 5. FIG.

Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. The following content is only an example of implementation, and the content of the invention is not limited to the following specific mode, and can be modified into various modes to satisfy the content described in the claims. Needless to say. In particular, in the following examples, the case of solar power generation will be described as an example of the form of natural energy power generation. However, the content of the present invention is not intended to be limited to solar power generation. It can be applied to other renewable energy generation.

A first embodiment will be described with reference to FIGS.
FIG. 1 is a diagram illustrating an outline of an independent power supply system to which centralized control is applied. As shown in the figure, the stand-alone power supply system 10 includes a solar power generation device 2 whose power generation output varies according to solar radiation conditions, a power storage device 3 including a secondary battery such as a lead storage battery or a lithium ion battery, The load device 4 is schematically configured by being connected to the power line 1 via the interconnection

power receiving devices

25, 35, and 45, respectively. The solar power generation device 2, the power storage device 3, and the load device 4 are respectively control devices. 5 is operated based on a control command transmitted from 5 through a line. The control device 5 transmits weather forecast information transmitted through the public line 6, electric quantities such as electric power, voltage, and power factor transmitted from the solar power generation device 2, the power storage device 3, and the load device 4, and a charging state ( Based on an operation state signal such as SOC (State of Charge), it has a function of transmitting a control command such as a power generation output suppression amount, charge / discharge power, and load adjustment amount to each device. The independent power supply system 10 according to the present embodiment does not include a power generator for adjusting the output of a rotating machine system having inertia such as a diesel generator. Therefore, the power storage device 3 is responsible for the operation for maintaining the voltage and frequency as a reference power source for the independent power supply system 10. For this purpose, the power storage device 3 performs an automatic voltage adjustment operation (AVR). On the other hand, in the solar power generation device 2 and the load device 4, in order to assist the automatic voltage adjustment operation of the power storage device 3, temporary power generation output suppression or load adjustment is performed.

The solar power generation device 2 includes a solar power generation panel 21 and a grid protection function for converting the DC power generated by the solar power generation panel 21 into AC power, controlling the output, and connecting to the power line 1. The interconnection power converter 22, the interconnection power receiving device 25 including a transformer, a switch, and the like, and a self-end voltage / current detection device used for control and protection performed by the interconnection power converter 22 (see FIG. Not shown). Although not shown, the interconnection power converter 22 incorporates a control device 220 having a function of communicating with the outside.

The power storage device 3 is a device that adjusts the power supply / demand balance of the independent power supply system 10 by charging or discharging, and converts DC power generated by the

storage batteries

31A and 31B and the

storage batteries

31A and 31B into AC power and controls it. In addition, the

interconnection power converters

32A and 32B having a protection function for connecting to the power line 1, the interconnection power receiving device 35 including a transformer, a switch, and the like, and the interconnection power converter 32A, Control commands such as charge / discharge power and operation / stop information to be transmitted to the power converter for interconnection connected to control the storage battery and its own voltage / current detection device (not shown) used for control / protection in 32B And the auxiliary device 34 of the

storage batteries

31A and 31B. The

interconnection power converters

32A and 32B are effective for maintaining the frequency and voltage in the independent power supply system 10 within an appropriate range based on the control command from the control device 33 and the voltage / current information at its own end, respectively.・ Has a function to control reactive power. As the

storage batteries

31A and 31B, secondary batteries such as lead storage batteries, lithium ion batteries, sodium / sulfur batteries, and redox flow batteries can be applied. In addition, since these batteries need to be refreshed regularly, in order to allow the power supply system to stably supply power during that period, at least two sets can be independently operated. It is desirable.

The load device 4 includes an adjustment load 41 capable of adjusting power consumption, a load 42 having a function of notifying activation or stop at a predetermined timing, and a load adjustment command transmitted from the control device 5 to the adjustment load 41. And a control device 43 that transmits the start / stop notice signal transmitted from the load 42 and transmits it to the control device 5. Although not shown, a self-end voltage / current detection device and other loads having no special function are also installed.

FIG. 2 schematically shows an operation pattern in the case where the output of the photovoltaic power generation apparatus 2 which is a basic operation method of the independent power supply system is shifted at night. The solar power generation device 2 basically supplies generated power determined by the amount of solar radiation, and normally does not particularly limit output. The figure is clear and shows an example in the case where the power generation output reaches the rated capacity. The power storage device 3 charges the power generated by the solar power generation device 2 during the daytime and discharges it at night. A so-called peak shift operation is performed to supply power to the load, and the combined output shown in the figure is supplied to the load device 4 by both the solar power generation device 2 and the power storage device 3.

FIG. 3 is a diagram showing a functional configuration of the control device 5 of the independent power supply system in the present embodiment. A control arithmetic unit 51 that calculates a control command such as a power generation output suppression / cancellation command, a charge / discharge power command or a load adjustment command transmitted to the solar power generation device 2, the power storage device 3 or the load device 4, and the amount of solar radiation, temperature, etc. A weather data storage device 52 for storing weather forecast data, a measurement data storage device 53 for storing measurement data such as the amount of electricity and operating state information transmitted from the solar power generation device 2, the power storage device 3, and the load device 4, Signal input / output interface device 54 for controlling transmission / reception of measurement commands and control commands transmitted to the photovoltaic power generation device 2, the power storage device 3, and the load device 4, and operations for the operator to correct the control commands and perform maintenance An input device 55 for inputting a command and a display device 56 for an operator to check an operation status and the like are provided.

The control calculation device 51 further includes a prediction calculation function 511, an output shift operation pattern generation function 512, and an output shift operation pattern correction function 513.

The prediction calculation function 511 is a solar power generation output prediction for predicting the power generation output of the solar power generation device 2 by using weather prediction data such as weather, solar radiation amount, and temperature stored in the weather data storage device 52 in advance. A calculation unit 5111 and a demand power prediction calculation unit 5112 for predicting the demand power of the load device 4 are provided.

The output shift operation pattern generation function 512 includes a storage battery charge / discharge pattern calculation unit 5121 for calculating an initial set value of the charge / discharge pattern of the power storage device 3 using the prediction result of the photovoltaic power generation output and the demand power. On the basis of the determination results in the charge / discharge level determination unit 5122 and the charge / discharge level determination unit 5122 for determining whether or not the charge and discharge levels are in appropriate ranges, respectively, A photovoltaic power generation output suppression amount / load adjustment amount calculation unit 5123 for calculating a power generation output suppression amount of the photovoltaic power generation device 2 or an adjustment amount of the load device 4, an initial setting value of the charge / discharge pattern, and a solar power generation output suppression amount, Output shift operation pattern for generating output shift operation patterns of the photovoltaic power generator 2, the power storage device 3, and the load device 4 based on the adjustment amount of the load And a generation unit 5124.

Furthermore, the output shift operation pattern correction function 513 determines an SOC evaluation calculation unit 5131 that calculates the time transition of the charge / discharge state (SOC) of the power storage device 3 and whether or not the SOC level is within an appropriate range. An SOC level determination unit 5132 to perform, and a photovoltaic power generation output suppression amount / load adjustment amount correction calculation for correcting and calculating a power generation output suppression amount of the solar power generation device 2 or an adjustment amount of the load device 4 based on the determination result Output shift operation pattern for correcting the output shift operation pattern of the solar power generation device 2, the power storage device 3, and the load device 4 based on the correction calculation result of the amount of suppression of the solar power generation output and the adjustment amount of the load. And a correction unit 5134. Here, SOC (State of Charge) is an index representing the remaining amount (charged electric energy) of the storage battery and is expressed as a percentage of the rated charge capacity.

Next, the flow of control processing of the control device 5 of the independent power supply system 10 will be described with reference to FIG. The process described below represents the process of the control arithmetic unit 51, and the case where the control cycle is set in the range of several minutes to 30 minutes will be described here in relation to the time resolution of the output shift operation pattern data. Furthermore, here, a case where the control cycle is 10 minutes will be described as an example.

First, in S41, weather forecast data such as the solar radiation amount Sr (W / m ² ) and the outside air temperature To (° C.) collected and stored via the public line 6 and stored in the weather data storage device 52 are read. Here, as an example of the weather forecast data, it is assumed that data (48 points) up to 24 hours ahead with 30-minute values in this embodiment is stored. In processing S42, either periodically measured and processed by that power generation output Ppv_m photovoltaic device 2 as an average of 10 minutes (W) and power factor Pf_m, charge-discharge electric power P _BATT _m (W of power storage device 3 ), The state of charge SOC (%), and the latest measurement data of the demand power Pd (W) of the load device 4 are read. Here, the charge / discharge power is expressed as positive discharge power and negative charge power.

In S43, using the solar radiation amount and temperature prediction data read in S42, the power generation output Ppv (t) (t = 1 to 48) as power generation output data up to 24 hours ahead of the solar power generation device 2 is predicted. Perform the calculation. Specifically, the solar radiation amount predicted value Sr (t) (W / m ² ) and the outside air temperature predicted value To (t) (° C.) in each time interval, and the ratio Kα ( Using t), the power generation output in each time interval is predicted from the product of the coefficient values according to the following formula (1).

Ppv (t) = Sr (t) · Ks · Kpv · Kt (To) · Kb · Kc
・ Kpcs ・ Kα (t) × 10 ⁻³ (kW) (1)
However,
Ks: Solar radiation correction coefficient Kpv: Panel capacity conversion coefficient Kt (To): Temperature correction coefficient Kb: Dirt coefficient Kc: Cable efficiency coefficient Kpcs: Power converter efficiency coefficient Kα (t): Latest measurement value / previous prediction value .

In S44, the power demand of the load device 4 is predicted. In the present invention, a statistical method, a metaheuristic method, or the like can be applied as a prediction method. For example, in the statistical method, a prediction calculation is performed using weather prediction data as a parameter based on statistical processing of past demand power patterns stored in the measurement data storage device 53. For each parameter, it is possible to predict the power demand with relatively high accuracy by an algorithm that repeatedly corrects the degree of influence of the parameters so as to reduce the difference between the predicted value and the actually measured value. Specifically, this is performed as follows. First, a plurality of demand power patterns, such as seasons, days of the week, and weather, which are close in condition to the prediction target date, are extracted from the stored data in the measurement data storage device. Next, an average of the plurality of extracted demand power patterns is taken as a basic predicted demand power pattern Pd0 (t). Finally, the correction factors G1 (t) and G2 (t) are added to the basic forecast demand power pattern Pd0 (t) based on the weather and temperature of the day, and the demand becomes forecast power demand data according to equation (2). A predicted power value Pd (t) is calculated.

Pd (t) = Pd0 (t) + G1 (t) + G2 (t) (2)
However,
G1 (t): Correction factor for demand power due to weather G2 (t): Correction factor for demand power due to temperature

The correction coefficients G1 (t) and G2 (t) are sequentially corrected so that the difference between the predicted value and the actually measured value becomes small.

S45 represents processing of the output shift operation pattern generation function 512 shown in FIG. In S451, using the predicted value Ppv (t) of the power generation output of the solar power generation device 2 predicted by the formulas (1) and (2) and the predicted value Pd (t) of the demand power of the load device 4, the formula (3 ), The charge / discharge power P _BATT (t) of the power storage device 3 is calculated from the difference between Pd (t) and Ppv (t) and set as an initial value.

P _BATT (t) = Pd (t) −Ppv (t) (3)
Next, in S452, whether or not the charge and discharge levels are within the appropriate ranges as shown in equations (4) to (6) for the initial set value P _BATT (t) of the charge / discharge pattern of the power storage device 3. Make a decision.

If P _BATT (t) <Pcmax, go to S453 (4)
If P _BATT (t)> Pdmax, go to S454 (5)
If Pcmax ≦ P _BATT (t) ≦ Pdmax, go to S455 (6)
However,
Pcmax: Maximum charge power (W)
Pdmax: Maximum discharge power (W)
And

In the case where P _BATT (t) exceeds the maximum charging power Pcmax (as an absolute value. The sign is negative because it is charging power and reverses in terms of the magnitude relationship) as shown in Equation (4), the independent power Since the generated power is larger than the demand power in the supply system 10, the output suppression amount ΔPpv (t) of the solar power generation device 2 is calculated by Equation (7) and set (suppressed) in S453.

ΔPpv (t) = P _BATT (t) −Pcmax (7)
Further, as shown in Equation (5), when P _BATT (t) exceeds the maximum discharge power Pdmax, the demand power is larger than the generated power in the independent power supply system 10, so in S454 The adjustment amount ΔPd (t) of the adjustment load 41 capable of adjusting the power consumption of the load device 4 is calculated by Expression (8) and set (suppressed).

ΔPd (t) = P _BATT (t) −Pdmax (8)
When the charge / discharge power P _BATT (t) is within an appropriate range as expressed by Equation (6), ΔPpv (t) and ΔPd (t) are set to zero.

In S455, using the output suppression amount ΔPpv (t) and load adjustment amount ΔPd (t) obtained in S452 to 454, the photovoltaic power generation output Ppv (t) ^* and the load power consumption Pd ( t) ^* and storage battery charge / discharge pattern P _BATT (t) ^* are generated.

Ppv (t) ^* = Ppv (t) + ΔPpv (t) (9)
Pd (t) ^* = Pd (t) + ΔPd (t) (10)
P _BATT (t) ^* = P _BATT (t) −ΔPpv (t) + ΔPd (t) (11)
Even with the output shift operation pattern created based on the above method, the capacity of the power storage device can be reduced to some extent. Hereinafter, correction of the output shift operation pattern will be described in order to further increase the accuracy.

S46 represents the process of the output shift operation pattern correction function 513 shown in FIG. In S461, the charge / discharge power P _BATT (t) ^* of the power storage device 3 calculated by the equation (11) is used to charge / charge 24 hours ahead (30 points, 48 points), which is the future time. The discharge state SOC (t) is calculated by Equation (12). How many hours ahead is calculated, and how much time is divided between them varies depending on the installation environment and the like. Here, a case where 24 hours ahead is divided every 30 minutes is described as an example.

SOC (t) = SOC (t−1) + ((P _BATT (t) ^* × 0.5) / Ph_rated)
× 100 (%) (12)
Here, Ph_rated is the rated capacity (Wh) of the power storage device 3.

Next, at 462, the charge / discharge state SOC (t) of the power storage device 3 is determined as to whether or not the charge / discharge state is in an appropriate range as shown in equations (13) to (15).

If Smin ≦ SOC (t) ≦ Smax, go to S465 (13)
If SOC (t)> Smax, go to S463 (14)
If SOC (t) <Smin, go to S464 (15)
However,
Smax: Maximum charge energy (%)
Smin: Minimum charge energy (%)
And

In the case of Expression (13), since the charge / discharge state SOC (t) is within the appropriate range as shown in FIG. 5A, the output shift operation patterns Ppv (t) ^* , Pd (t ) ^* , P _BATT (t) ^* need not be further corrected.

When SOC (t) exceeds the maximum charge power amount Smax as shown in Equation (14), that is, as shown in FIG. 5B, for example, the predicted value of demand power decreases from the previous predicted value, and the photovoltaic power generation When the output becomes excessive and the SOC exceeds the maximum charge power amount Smax in the time interval Tb, the output Ppv of the solar power generation device 2 is suppressed and the charge amount of the power storage device 3 is limited as shown by the dotted line in FIG. This prevents the state of charge SOC (t) from exceeding. Therefore, in S463, the output suppression amount ΔPpv (t) ^* of the solar power generation device 2 is calculated and set by Expression (16).

ΔPpv (t) ^* = ((Smax−SOC (Tmax)) / 100
× Ph_rated) / ΔT (16)
Here, Tmax is a time interval in which SOC (t) is maximum, and ΔT is a time interval width (= Te−Ts) for suppressing the output of the photovoltaic power generator 2. The time interval Ts for starting the correction according to Equation (16) is from the current time interval to the time interval Tb at which SOC (t) starts to exceed Smax.

When SOC (t) falls below the minimum charge power amount Smin as shown in Equation (15), that is, as shown in FIG. 5C, for example, the predicted value of the photovoltaic power generation output decreases from the previous predicted value in the time interval Tc. However, when the power generation amount is insufficient, the state of charge SOC (t) is insufficient by limiting the demand power Pd of the load device 4 and increasing the charge amount of the power storage device 3 as indicated by the dotted line in FIG. To prevent. Therefore, in S464, the adjustment amount ΔPd (t) ^* of the load device 4 is calculated and set by Expression (17).

ΔPd (t) ^* = ((Smin−SOC (Tmin)) / 100
× Ph_rated) / ΔT '(17)
Here, Tmin is a time interval in which SOC (t) is minimum, and ΔT ′ is a time interval width (= Te−Ts) for limiting the power demand of the load device 4. The time interval Ts for starting the correction according to Expression (17) is from the current time interval to the time interval Tc at which SOC (t) starts to exceed Smin.

In S465, using the output suppression correction amount ΔPpv ^* and load adjustment correction amount ΔPd ^* obtained in S452 to 454, output shift operation patterns Ppv (t) ^* , Pd (t) ^* , P _BATT (t ) Correct ^* .

Ppv (t) ^** = Ppv (t) ^* + ΔPpv (t) ^* (18)
Pd (t) ^** = Pd (t) ^* + ΔPd (t) ^* (19)
P _BATT (t) ^** = P _BATT (t) ^{* −} ΔPpv (t) ^* + ΔPd (t) ^* (20)
In S47, a control command is generated from the operation pattern obtained by the formulas (18) to (20), and commanded to the solar power generation device 2, the power storage device 3, and the load device 4.

According to the independent power supply system in the present embodiment, when the demand prediction data and the power generation output prediction data are predicted to charge the

storage batteries

31A and 31B exceeding the maximum charging power of the

storage batteries

31A and 31B. In the case where the power generation output from the solar power generation device 2 is suppressed and the demand prediction data and the power generation output data predict that discharge from the

storage batteries

31A and 31B exceeds the maximum discharge power of the

storage batteries

31A and 31B. Since the power consumption of the adjustment load 41 is suppressed, it can be controlled so as not to exceed the maximum charge and discharge power of the

storage batteries

31A and 31B. Therefore, it is necessary to separately provide an adjustment power source such as a diesel engine. Since there is no need to increase the capacity of the installation, the installation cost, which is the cost at the time of introduction, can be reduced.

Furthermore, when the charge / discharge state of the storage battery in a predetermined future period is calculated in a predictive manner and the charge / discharge state in the future predetermined period is predicted to exceed the maximum charge power amount of the storage battery, the photovoltaic power generator 2 The power generation output from the control load 41 is suppressed, and the power consumption of the adjustment load 41 is suppressed when the charge / discharge state in the future predetermined period is predicted to be lower than the minimum charge power amount of the

storage batteries

31A and 31B. Therefore, in addition to the above effects, the maximum charge and discharge power of the

storage batteries

31A and 31B can be controlled with higher accuracy, and the capacity of the power storage device does not need to be further increased.

In addition, according to the present embodiment, since a power source for adjustment using fossil fuel such as a diesel generator is not required, it is possible to supply power without discharging CO _2, and to reduce costs related to fuel supply. Can do.

Next, an independent power supply system to which autonomous control according to another embodiment of the present invention is applied will be described with reference to FIGS. In the first embodiment, the case where the centralized control is applied has been described. In this embodiment, the case where the autonomous control is applied will be described.

FIG. 6 is a schematic configuration example of an independent power supply system to which autonomous control is applied. The major difference from FIG. 1 is that there is no control device for controlling the entire system of the independent power supply system 110, and means for measuring the combined output of the solar power generation device 102 and the power storage device 103, respectively. It is a point provided.

The photovoltaic power generation device 102 whose power generation output varies according to the solar radiation conditions, the power storage device 103 composed of a secondary battery such as a lead storage battery or a lithium ion battery, and the load device 104 are connected to the

power receiving devices

25, 35, 45 for interconnection. Are connected to the power line 1 via the power line 1. The solar power generation device 102, the power storage device 103, and the load device 104 are each operated based on a control command from the control device 105. The control device 105 transmits the weather forecast information transmitted through the public line 6, the amount of electricity such as power, voltage, and power factor transmitted from the solar power generation device 102, the power storage device 103, and the load device 104, and the charging state ( Based on an operation state signal such as SOC (State of Charge), etc., each device has a function of transmitting control commands such as a power generation output suppression amount, charge / discharge power, and load adjustment amount. In addition, the independent power supply system 110 according to the present embodiment does not include a power generator for adjusting the output of a rotating machine system having inertia such as a diesel generator. Therefore, the power storage device 103 is responsible for the operation for maintaining the voltage and frequency as a reference power source for the independent power supply system 110. For this purpose, the power storage device 103 performs an automatic voltage adjustment operation (AVR). On the other hand, in the solar power generation device 102 and the load device 104, in order to assist the automatic voltage adjustment operation of the power storage device 103, temporary power generation output suppression or load adjustment is performed. In the present embodiment, the solar power generation device 102, the power storage device 103, and the load device 104 are each autonomously operated by a control device that is included therein.

The photovoltaic power generation apparatus 102 includes a photovoltaic power generation panel 21 and an interconnection protection function for converting DC power generated by the photovoltaic power generation panel 21 into AC power, controlling the output, and connecting to the power line 1. The interconnection power converter 122, the interconnection power receiving device 25 including a transformer, a switch, and the like, and the self-end voltage / current detection device used for control and protection performed by the interconnection power converter 122 (see FIG. Not shown). Although not shown, the interconnection power converter 122 incorporates a control device 320 having a communication function with the outside. The measurement value of the combined output of the solar power generation device 102 and the power storage device 103 is transmitted to the control device 320 of the interconnection power converter 122, and the power generation output is suppressed based on the voltage information at its own end.

The power storage device 103 is a device that adjusts the supply and demand balance of the power of the independent power supply system 110 by charging and discharging. In addition, the

interconnection power converters

32A and 32B having a protection function for connection to the power line 1, and the self-end voltage / current detection device used for control and protection performed by the

interconnection power converters

32A and 32B (Not shown), a control device 105 for determining a control command such as charge / discharge power and operation / stop information for transmission to a grid-connected power converter that controls the storage battery, and an auxiliary machine 34 for the

storage batteries

31A and 31B It consists of. Each of the

interconnection power converters

32A and 32B has a function of controlling the active / reactive power in order to maintain the frequency and voltage within an appropriate range based on the control command from the control device 105 and the voltage / current information at its own end. Have. In addition to the measurement value of the combined output of the solar power generation device 102 and the power storage device 103, weather control information is also transmitted to the control device 105 via the public line 6. As the

storage batteries

31A and 31B, secondary batteries such as lead storage batteries, lithium ion batteries, sodium / sulfur batteries, and redox flow batteries can be applied. In addition, since these batteries need to be refreshed regularly, in order to allow the power supply system to stably supply power during that period, at least two sets can be independently operated. There is a need. And it connects to the power line 1 through the power receiving apparatus 35 for interconnections, such as a transformer or a switch.

The load device 104 includes an adjustment load 41 that can adjust power consumption, a load 42 that does not have any other special functions, and a control device 143 that has a function of calculating a load adjustment amount from voltage information at its own end. Is done. Although not shown, a self-end voltage / current detection device is also installed.

7 to 9 are diagrams showing functional configurations of the control devices of the power storage device 103, the solar power generation device 102, and the load device 104 that constitute an independent power supply system to which autonomous control is applied. 7 corresponds to the control device 105 of the power storage device 103, FIG. 8 corresponds to the control device 320 of the solar power generation device 2, and FIG. 9 corresponds to the control device 143 of the load device 104.

In FIG. 7, the control device 105 includes a control arithmetic device 51 that calculates a charge / discharge power command transmitted to the interconnection power converters 32 </ b> A and 32 </ b> B of the power storage device 103 and a voltage target command in the independent power supply system 110, and an amount of solar radiation. A meteorological data storage device 52 that stores weather forecast data such as temperature and temperature, a measurement data storage device 53 that stores measurement data such as the amount of electricity at its own end and the combined output of the solar power generation device 102 and the power storage device 103, The control command transmitted to the

system power converters

32A and 32B and the signal input / output interface device 54 for controlling transmission / reception of the measurement information, and the operator corrects the control command or inputs an operation command for maintenance. Input device 55 and a display device 56 for the operator to check the operation status and the like.

The control calculation device 51 includes a prediction calculation function 511, an output shift operation pattern generation function 512, and an output shift operation pattern correction function 513.

The prediction calculation function 511 is a solar power generation output prediction for predicting the power generation output of the solar power generation device 102 using weather prediction data such as weather, solar radiation amount, and temperature stored in the weather data storage device 52 in advance. A calculation unit 5111 and a demand power prediction calculation unit 5112 for predicting the demand power of the load device 104 are included.

The output shift operation pattern generation function 512 includes a storage battery charge / discharge pattern calculation unit 5121 for calculating an initial set value of the charge / discharge pattern of the power storage device 103 using the prediction result of the photovoltaic power generation output and the demand power. The charge / discharge level determination unit 5122 for determining whether or not the charge and discharge levels are in appropriate ranges with respect to the initial setting of the charge / discharge pattern, and the power generation output of the photovoltaic power generation apparatus 102 based on the determination result Of the solar power generation output suppression amount / load adjustment amount calculation unit 5123 for calculating the amount of suppression of the load or the load device 104, the initial setting value of the charge / discharge pattern, the amount of solar power generation output suppression, and the load adjustment amount. Based on the output shift operation pattern generation for generating the output shift operation patterns of the solar power generation device 102, the power storage device 103, and the load device 104 based on Composed of the part 5124. Furthermore, the output shift operation pattern correction function 513 determines the SOC evaluation calculation unit 5131 for calculating the time transition of the charge / discharge state (SOC) of the power storage device 103 and whether the SOC level is within an appropriate range. An SOC level determination unit 5132 to be performed, and a target voltage setting unit 5133 that estimates a correction amount of the output suppression amount and the load adjustment amount of the photovoltaic power generation apparatus 2 based on the determination result and sets a voltage target value in the independent system. And an output shift operation pattern correction unit 5134 that corrects the charge / discharge pattern of the power storage device 103 and the target voltage based on the correction calculation result of the suppression amount of the photovoltaic power generation output and the adjustment amount of the load.

In FIG. 8, the control device 320 of the interconnection power converter 122 of the solar power generation device 102 includes an output suppression amount calculation function 321 and a power control function 322. The output suppression amount calculation function 321 reads the measured value of the self-end voltage and determines the level of the self-end voltage determination unit 3211 and the charge / discharge power of the storage battery using the self-generated power output and the measured value of the combined power. Using the storage battery charge / discharge power calculation unit 3212 to calculate, the charge / discharge state determination unit 3213 for determining the charge / discharge state from the charge / discharge power of the storage battery, the determination result of the self-end voltage and the charge / discharge state determination result of the storage battery It has a photovoltaic power generation output suppression control calculation unit 3214 that calculates a power generation output suppression amount, and a delay timer 3215 that holds an output suppression command for a predetermined time. The power control function 322 generates and transmits a gate pulse signal that controls the output power of the interconnection power converter 122 using measured values of the voltage and current at its own end.

In FIG. 9, the control device 143 of the load device 104 reads the measured value of the self-end voltage and determines its level, and the load limit that calculates the load limit amount from the self-end voltage determination result. A control calculation unit 432 and a delay timer 433 for holding a load limit command for a predetermined time are provided.

Next, the flow of control processing of each device of the independent power supply system during autonomous control will be described with reference to FIG. 10 corresponds to the control device 105 of the power storage device 103, FIG. 11 corresponds to the control device 320 of the solar power generation device 102, and FIG. 12 corresponds to the control device 143 of the load device 104. In the following, as in FIG. 4, an example in which a range of several minutes to 30 minutes is set will be described. Here, a case where the control cycle is 10 minutes will be described.

First, in FIG. 10, in S81, weather forecast data such as solar radiation amount Sr (W / m ² ) and outside temperature To (° C.) collected and stored via the public line 6 and stored in the weather data storage device 52 are displayed. Read. Here, for example, it is assumed that a 30-minute value is stored. In S82, the combined output Psum (W) and the power factor Pf of the photovoltaic power generation apparatus 2 and the power storage apparatus 103, which are regularly measured and processed as an average value for 10 minutes, the charge / discharge power P _BATT ( W) and charge state SOC (%) are read. As in the first embodiment, the charge / discharge power P _BATT is represented here as positive discharge power and negative charge power.

In S83, S84, and S85, the predicted value of the power generation output of the photovoltaic power generation apparatus 102, the predicted value of the demand power of the load apparatus 104, and the output shift operation pattern are calculated, respectively, which are the same as the method described in FIG. Therefore, the description is omitted here.

S86 represents the process of the output shift operation pattern correction function 513 shown in FIG. In S861, using the charge / discharge power P _BATT (t) ^* of the power storage device 103 calculated by Expression (11), the charge / discharge state SOC (t ) Is calculated by Equation (12).

Next, in S862, with respect to the charge / discharge state SOC (t) of the power storage device 103, it is determined whether or not the charge / discharge state is within an appropriate range as represented by equations (13) to (15).

In the case of Expression (13), as shown in FIG. 5A, the charge / discharge state SOC (t) is within the appropriate range, so that the output shift operation pattern Ppv (t) ^* , Pd (t) obtained in S45. ^* , P _BATT (t) ^* need not be further corrected.

When SOC (t) exceeds the maximum charge power amount Smax as shown in Equation (14), that is, for example, as shown in FIG. 5B, the predicted value of demand power decreases from the previous predicted value in the time interval Tb. When the output of solar power generation becomes excessive, the state of charge SOC (t) is controlled by limiting the charge amount of the power storage device 103 by suppressing the output Ppv of the solar power generation device 102 as shown by the dotted line in FIG. To prevent excess. Therefore, in process S863, the output suppression amount ΔPpv (t) ^* of the photovoltaic power generation apparatus 102 is calculated and set by Expression (16). By the way, in the case of the centralized control in the first embodiment, a command is directly sent from the control device 105 to each device through a line. However, in the case of the autonomous control, the control device 105 located inside the power storage device 103 receives a sun. Since the output suppression command cannot be directly transmitted to the photovoltaic power generation apparatus 102, the operation of suppressing the power generation output is indirectly performed by controlling the target voltage Vref of the independent power supply system 110. . That is, the target voltage Vref is temporarily set to a value Va larger than the rated voltage Vo in S864, and the photovoltaic power generation apparatus 102 suppresses the power generation output when the target voltage exceeds Va for a predetermined time or more. To be controlled.

Further, when SOC (t) is lower than the minimum charge power amount Smin as shown in Equation (15), that is, for example, as shown in FIG. 5C, the predicted value of the photovoltaic power generation output is more than the previous predicted value in the time interval Tc. If the power generation amount is insufficient and the power generation amount is insufficient, the demand state Pd of the load device 4 is limited and the charge amount of the power storage device 103 is increased as shown by the dotted line in FIG. To prevent. Therefore, in S866, the adjustment amount ΔPd (t) ^* of the load device 104 is calculated and set by Expression (17). Similarly to the above, in the case of autonomous control, since it is not possible to directly transmit a demand power adjustment command from the control device 105 to the load device 104, it is indirectly controlled by controlling the target voltage in the independent system. To adjust the power demand. That is, in S867, the target voltage Vref is temporarily set to a value Vb smaller than the rated voltage Vo, and the load device 104 suppresses the demand power when the target voltage continues below Vb for a predetermined time or more. I tried to control it.

In S868, the charge / discharge power amount P _BATT (t) ^* is corrected by Equation (20) using the charge / discharge pattern output suppression correction amount ΔPpv ^* and the load adjustment correction amount ΔPd ^* obtained in S862 to S867. Further, the target voltage Vref is set to Va (> Vo) or Vb (<Vo) according to the state of SOC (t). In S47, the charge / discharge amount and the target voltage Vref are commanded to the

interconnection power converters

32A and 32B as control commands.

Next, the processing of the control device 320 of the interconnection power converter 122 of the solar power generation device 2 will be described with reference to FIG. In S81b, the self-end voltage / current and the combined output Psum (W) of the photovoltaic power generation apparatus 102 and the power storage apparatus 103 that are periodically measured and processed as an average value for 10 minutes are read. In S82b, the charge / discharge power P _BATT of the power storage device 103 is calculated as the difference between the combined output Psum and the self-generated power output Ppv. In S83b, the self-end voltage Vpv is compared with the reference voltage Va, and if the state where Vpv is smaller than Va continues, the output suppression amount ΔPpv is set to zero. When the state where Vpv is larger than Va continues, if the storage battery is in a charged state (P _BATT <0) in S84b, a predetermined value is set for ΔPpv, and the storage battery is in a discharged state (P _BATT ≧ 0). In this case, ΔPpv is set to zero. After maintaining this state for a predetermined time, an output suppression command is transmitted by the power control function 322 of FIG.

Similarly, the processing of the control device 43 of the load device 4 will be described with reference to FIG. In S81c, the voltage / current at the terminal is read. In S82c, the self-end voltage Vd is compared with the reference voltage Vb, and when the state where Vd is larger than Vb continues, the load adjustment amount ΔPd is set to zero. When the state where Vd is smaller than Vb continues, a predetermined value is set to ΔPd in step S83c. After maintaining this state for a predetermined time, an output suppression command is transmitted.

FIG. 13 is a diagram illustrating a control operation when the state of charge SOC of the power storage device 103 exceeds the maximum charge amount or falls below the minimum charge amount during the autonomous control described with reference to FIGS. 7 to 12.

(A) in the figure is a case where the SOC exceeds the maximum charge amount. In this case, since the SOC may exceed the maximum charge amount Smax, the control device 105 of the power storage device 103 raises the target voltage Vref from the rated voltage Vo to Va at time T1. As a result, at T1, the charging power of the power storage device 103 follows the decreasing direction (positive direction), and the terminal voltage instantaneously becomes Va. In this state, the output Ppv of the photovoltaic power generation apparatus 102 is suppressed by a predetermined value ΔPpv after being held until time T2. As a result, the output is increased in the discharge direction so that the power storage device 103 follows up and compensates for the insufficient power generation amount, and the voltage is maintained at the reference value Va. Thereafter, the target voltage is returned to the original Vo at time T3.

On the other hand, FIG. 5B shows a case where the SOC is below the minimum charge amount. In this case, since the SOC may be lower than the maximum charge amount Smin, the control device 105 of the power storage device 103 has lowered the target voltage Vref from the rated voltage Vo to Vb. As a result, at T5, the charging power of power storage device 103 follows the increasing direction (negative direction), and the terminal voltage instantaneously becomes Vb. In this state, after holding until time T6, the demand power Pd of the load 2 is limited by a predetermined value ΔPd. As a result, the output is increased in the discharging direction so that the power storage device 103 follows up and compensates for the insufficient power generation amount, and the voltage is maintained at the reference value Vb. Thereafter, the target voltage is returned to the original Vo at time T7.

As explained in the present embodiment, not only the central control shown in the first embodiment but also autonomous control is possible. In the present embodiment, the case where the control device 105 having the control role as described in the first embodiment is arranged inside the power storage device 103 is described in the case where the autonomous control is used. Since the control device is arranged inside one device (regardless of whether it is inside the power storage device 103 or not), the output is directly suppressed with respect to the other device (the control device). -Commands such as power consumption suppression cannot be transmitted, and control is performed indirectly by controlling the target voltage in the independent power supply system 110. Specific control contents are as described above. By performing the target voltage control in this way, it is possible to perform the same control as the centralized control by the control device that is indirectly arranged in one device.

Even if autonomous control is used, the control contents can be made the same although there is a difference between direct and indirect, so that the effects described in the first embodiment can be obtained in the same way. become.

Next, an independent power supply system to which a photovoltaic power generation device that performs reactive power control by centralized control is applied as Example 3 will be described with reference to FIGS. 14 and 15.

FIG. 14 is a diagram illustrating a processing flow of the control device 5 when the solar power generation device 2 that performs reactive power control is applied to the independent power supply system 10 operated by centralized control. The processing additionally performed in the first embodiment with respect to the present embodiment is performed by the control arithmetic device 51 in FIG. 3 used in the description of the first embodiment. Since the configuration of the independent power supply system 10 and the functional configuration of the control device 5 are the same as those described in FIGS. 3 and 4, detailed description thereof is omitted here.

The control cycle of the control arithmetic unit 51 is set in the range of several minutes to 30 minutes here because of the relationship with the time resolution of the output shift operation pattern data. For example, here, the control cycle is assumed to be 10 minutes. In the figure, the processing from S101 to S106 is the same as the processing from S41 to S46 shown in FIG. 4, and the description is omitted here. In S107, the power factor commanded to the interconnection power converter 22 of the photovoltaic power generator 2 is calculated. First, the measured value of the charge and discharge power of the storage battery is averaged by the moving average or the like in S1071, calculates the charge and discharge levels P _BATT _ave power storage device 3. Then compared with a threshold charge and discharge levels P _BATT _ave at S1072, a predetermined range, for example, when there within 50% of the rated output sets the command value of the power factor 1 (S1073), a predetermined When deviating from the range, the command value of the power factor Pf is set to the optimum power factor Pf _OPT determined from the impedance of the local system (S1074). Here, the optimum power factor Pf _OPT is approximately calculated in advance by Equation (21) as the ratio of the resistance R of the system impedance from the output end of the photovoltaic power generation device 2 to the connection point of the load device 4 and the reactance X. Is possible.

Pf _OPT ≒ R / X (21)
Next, the contents of control when performing power factor adjustment operation with a solar power generation device of an independent power supply system to which centralized control is applied will be described using FIG. FIG. 6A shows a case where the photovoltaic power generation apparatus 2 does not perform reactive power control and always operates with a power factor of 1. FIG. It is an example of the driving | running result in performing an optimal power factor driving | operation. In the independent power supply system 10, in addition to the voltage fluctuation caused by the supply / demand imbalance described in each of the above embodiments, as shown in FIG. As a result, a combined voltage fluctuation is generated in which the voltage fluctuation generated by the output fluctuation on the impedance is superimposed. Even in the contents described in the above embodiments, the charge / discharge power is adjusted by the automatic voltage control of the power storage device 3 so as to control the target voltage including the voltage fluctuation. However, the load device 4 and the solar power generation device 2 When the power fluctuation is large, the compensation amount of the power storage device 3 is increased. On the other hand, as shown in FIG. 5B, by operating the solar power generation device 2 at the optimum power factor determined by the formula (21), voltage fluctuation caused by output fluctuation of the solar power generation device 2 is suppressed. Therefore, the combined voltage fluctuation compensated by the power storage device 3 is only the voltage fluctuation due to the load device 4, and the compensation amount can be reduced. Of course, other methods may be used as the power factor calculation method.

In the present embodiment, whether or not the average value of the measured values of the charge / discharge power of the storage battery is within a predetermined range is compared, and if the threshold value is exceeded and falls outside the predetermined range, the power of the photovoltaic power generation device 2 The rate command value is set to a value determined using the impedance of the power system in the stand-alone power supply system. This suppresses combined voltage fluctuations in which fluctuations in power consumption of the load device 4 and output fluctuations of the photovoltaic power generation device 2 act on the impedance are superimposed, thereby suppressing automatic voltage control (AVR) of the power storage device. It becomes possible to reduce the burden. Furthermore, if it is within the predetermined range, by setting the command value of the power factor of the solar power generation device 2 to 1, it is possible to perform the power generation operation without wasting power that can be generated.

In the present embodiment, the case where the first embodiment is applied together with the first embodiment is described. When the second embodiment is applied together, the compensation which can be realized in the first embodiment is complementarily compensated. Better) and a more effective combination. However, it is of course possible to perform the control as described in the present embodiment without using it in combination with the first embodiment, and in this case, voltage fluctuation can be suppressed, so that the capacity of the power storage device can be reduced. Contribute.

Further, in this embodiment, attention is paid to the average value of the measured value of the charge / discharge power of the storage battery, and the control content is changed by comparing whether or not this average value is within a predetermined range. If the value does not have to be a value and varies in a correlated manner with the measurement value including the measurement value itself, the same control can be performed by determining the predetermined value together. When the average value of the measurement values is used, the comparison can be performed with high accuracy without being influenced by instantaneous fluctuations, which is beneficial because it increases reliability. This also applies to Example 4 below.

In the third embodiment, the independent power supply system to which the photovoltaic power generation apparatus that performs reactive power control by centralized control is described. However, in this embodiment, reactive power control is performed on the independent power supply system operated by autonomous control. The case where the photovoltaic power generation apparatus to perform is applied is demonstrated using FIG. The overall configuration of the stand-alone power supply system 110 in this embodiment is the same as that shown in FIG. 6, and thus detailed description thereof is omitted here.

FIG. 16 shows a flow of processing of the control device of the solar power generation apparatus 102 in the present embodiment. Note that the control flows of the power storage device 103 and the load device 104 are the same as those described in FIGS. 10 and 12, respectively. In FIG. 12, the processing from S121 to S127 is the same as the processing from S81b to S87b shown in FIG. Therefore, description of these processes is omitted in this embodiment.

In S128, the driving power factor of the interconnection power converter 122 of the photovoltaic power generation apparatus 102 is calculated in the same manner as the process described in S107 of FIG. First, the measured value of the charge and discharge power of the storage battery is averaged by the moving average or the like in S1281, calculates the charge and discharge levels P _BATT _ave of the power storage device 103. Then compared with a threshold charge and discharge levels P _BATT _ave at S1282, a predetermined range, for example, when there within 50% of the rated output sets the command value of the power factor 1 (S1283), a predetermined When deviating from the above range, the command value of the power factor Pf is set to the optimum power factor Pf _OPT determined from the impedance of the local system (S1284). Here, the optimal power factor Pf _OPT is calculated in advance by the formula (21) as a ratio of the low resistance component R and the reactance component X of the system impedance from the output terminal of the photovoltaic power generation device 102 to the connection point of the load device 104. Is possible.

In the present embodiment, the photovoltaic power generation apparatus 102 compares whether or not the average value of the measured values of the charge / discharge power of the

storage batteries

31A and 31B is within a predetermined range. By setting the command value of the power factor of the device 102 to a value determined using the impedance of the power system in the independent power supply system, independent power supply is possible even when autonomous control is performed regardless of centralized control. The entire system can be operated in the same manner as in the third embodiment, and therefore the same effect can be obtained. Furthermore, if it is within the predetermined range, by setting the command value of the power factor of the solar power generation device 2 to 1, it is possible to perform the power generation operation without wasting power that can be generated.

In addition, in this embodiment, the case where it is applied in combination with the embodiment 2 is described, and if it is applied together, the compensation that can be realized in the embodiment 2 is complementarily compensated. Better) and a more effective combination. However, it is of course possible to perform the control as described in the present embodiment without using it together with the second embodiment, and in this case as well, voltage fluctuation can be suppressed, so that the capacity of the power storage device can be reduced. Will contribute.

Example 5 A stand-alone power supply system using load start / stop information will be described with reference to FIGS. 17 and 18. Note that the configuration of the stand-alone power supply system 10 and the functional configuration of the control device 5 in this embodiment are the same as those described in FIGS. 3 and 4, and a description thereof is omitted here.

FIG. 17 shows a processing flow of the control device 5 when the load start / stop notice information is utilized in an independent power supply system operated by centralized control. The process described below represents the process of the control arithmetic unit 51 of FIG. 3, and the control cycle is set in the range of several minutes to 30 minutes here in relation to the time resolution of the output shift operation pattern data. desirable. For example, here, the control cycle is assumed to be 10 minutes.

In FIG. 17, the processing from S131 to S136 is the same as the processing from S41 to S46 shown in FIG. In S137, the control command based on the load start / stop notice information is calculated. First, in S 1371, it is determined whether or not there is a start / stop notice signal transmitted from the power storage device 3. When the load stop notice signal is received, the output suppression amount of the solar power generation device 2 and the charge / discharge power adjustment amount of the power storage device 3 are calculated in S1372 by the method described below.

That is, as shown in FIG. 18 (a), when the stop notice signal is received at time T1, the load is stopped at time T2 after a predetermined time has elapsed. The amount of suppression is calculated, and after the power factor control calculation in S138, the output suppression is instructed to the photovoltaic power generation apparatus 2 in S139. As a result, the amount of power generation is reduced, and the charge / discharge power of the power storage device 3 is shifted in the discharge direction (positive direction) so that supply and demand imbalance does not occur. When the load stops at time T2 in this state, the power storage device 3 shifts in the discharging direction and secures a sufficient compensation amount in the charging direction, so that it is possible to absorb a sudden decrease in power consumption by charging.

When the load start warning signal is received, the adjustment amount of the load device 4 and the charge / discharge power adjustment amount of the power storage device 3 are calculated by the method described below in S1373. That is, as shown in FIG. 18B, when the activation notice signal is received at time T5, the load is activated at time T6 after a predetermined time, so that the adjustment load 41 of the load device 4 is adjusted in preparation for this. The amount is calculated, and the power consumption adjustment amount is commanded to the load device 4 in S139 through the power factor control calculation in S138. As a result, the power consumption is reduced, so that the charge / discharge power of the power storage device 3 is shifted in the charging direction (negative direction) so that supply and demand imbalance does not occur. When the load is activated at time T2 in this state, the power storage device 3 shifts in the charging direction and secures a sufficient compensation amount in the discharging direction, so that the rapid increase in power consumption can be absorbed by discharging. Thereafter, when the power consumption adjustment command of the load device 4 is canceled at a time T7 after a predetermined time, the charge / discharge power of the power storage device 3 shifts in the discharge direction so as to maintain the supply-demand balance.

In this embodiment, when the start stop notice information that is the notice information that the load stops starting is received, the output of the photovoltaic power generation apparatus 2 is suppressed, and the start notice information that is the notice information that the load starts is received. In this case, by suppressing the power consumption of the adjustment load 41, the independent power supply system 10 can be used without increasing the capacity of the power storage device 3 even for large power fluctuations caused by steep load start and stop. It becomes possible to maintain a balance between supply and demand.

In the present embodiment, it is necessary to adjust the charge / discharge level of the power storage device 3 in advance by suppressing the power generation output of the solar power generation device 2 or adjusting the power consumption of the load device 4 based on the load start / stop notification information. Secure compensation amount.

In the present embodiment, the case where it is applied in combination with the first embodiment has been described, and if it is applied together, the compensation that can be realized in the first embodiment is complementarily compensated. ) A more effective combination. However, it is of course possible to perform the control as described in the present embodiment without using it in combination with the first embodiment, and in this case, voltage fluctuation can be suppressed, so that the capacity of the power storage device can be reduced. Contribute. In addition, the contents described in the third embodiment can be applied together. In this case, it contributes most to the reduction in the capacity of the power storage device, and the introduction cost can be greatly reduced.

For the contents described in each of the above embodiments, without being linked to the power system of the power company, only a plurality of photovoltaic power generation devices and power storage devices prevent overcharge and overdischarge of the storage battery, including at night, In addition, stable power supply can be realized while maintaining the frequency and voltage against photovoltaic power generation and steep power fluctuations of the load.

It should be noted that the mathematical formulas and parameters described in the embodiments are described as examples, and it goes without saying that it is not excluded to apply methods not described here.

DESCRIPTION OF SYMBOLS 1 Power line 2,102 Solar power generation device 3,103 Power storage device 4,104 Load device 5,33,43,143,320 Control device 6 Public line 10,110 Stand-alone power supply system 21 Solar power generation panel 22,32A, 32B, 122 Interconnection power converters 25, 35, 45 Interconnection power receiving devices 31A, 31B Storage battery 34 Auxiliary machine 41 Adjustment load 42 Load 44 System interconnection device 51 Control arithmetic device 52 Weather data storage device 53 Measurement data storage Device 54 Signal input / output interface device 55 Input device 56 Display device 321 Output suppression amount calculation function 322 Power control function 431, 3211 Self-end voltage determination unit 432 Load limit control calculation unit 433, 3215 Delay timer 511 Prediction calculation function 512 Output shift operation Pattern generation function 513 Output shift operation pattern correction function 3212 Battery charge / discharge power calculation unit 3213 Charge / discharge state determination unit 3214 Solar power generation output suppression control calculation unit 5111 Solar power generation output prediction calculation unit 5112 Demand power prediction calculation unit 5121 Storage battery charge / discharge pattern calculation unit 5122 Charge / discharge level determination unit 5123 Sun Photovoltaic output suppression amount / load adjustment amount calculation unit 5124 Output shift operation pattern generation unit 5131 SOC evaluation calculation unit 5132 SOC level determination unit 5133 Solar power generation output suppression amount / load adjustment amount correction calculation unit 5134 Output shift operation pattern correction unit

Claims

An energy storage device having a natural energy power generation device, a load device having an adjustment load and operating with power generated from the natural energy power generation device, and a storage battery connected to the natural energy power generation device and the load device for charging and discharging An independent power supply system comprising:
The independent power supply system calculates demand prediction data of the load device and power generation output prediction data of the natural energy power generation device using weather prediction data,
When the demand prediction data and the power generation output prediction data are predicted to charge the storage battery beyond the maximum charging power of the storage battery, the power generation output from the natural energy power generation device is suppressed,
When the demand prediction data and the power generation output data predict that the storage battery is discharged beyond the maximum discharge power of the storage battery, the power consumption of the adjustment load is suppressed. Type power supply system.
The stand-alone power supply system according to claim 1,
The independent power supply system predictively calculates the charge / discharge state of the storage battery in a predetermined future period using the demand prediction data, the power generation output prediction data, and the rated capacity of the storage battery,
In the case where it is predicted that the charge / discharge state in the future predetermined period will exceed the maximum charge power amount of the storage battery, the power generation output from the natural energy power generation device is suppressed,
An independent power supply system that suppresses power consumption of the adjustment load when the charge / discharge state in the future predetermined period is predicted to be lower than the minimum charge power amount of the storage battery.
A stand-alone power supply system according to claim 2,
It also has a control device,
The control device suppresses power demand of the load device and calculation of power generation output prediction data of the natural energy power generation device, a command for suppressing power generation output from the natural energy power generation device, and power consumption of the adjustment load. A stand-alone power supply system that outputs a command to perform the operation.
A stand-alone power supply system according to claim 3,
The control device is disposed outside the natural energy power generation device, the load device, or the power storage device, and outputs a control command to the natural energy power generation device, the load device, and the power storage device through a line. Independent power supply system.
The stand-alone power supply system according to claim 2, wherein the control device is disposed inside the power storage device,
It also has a control device,
The control device performs calculation of demand prediction data of the load device and power generation output prediction data of the natural energy power generation device, and control of a target voltage of the independent power supply system,
The target voltage is controlled by temporarily setting the target voltage to a value larger than the rated voltage when the charge / discharge state in the future predetermined period is predicted to exceed the maximum charge power amount of the storage battery. And when it is predicted that the charge / discharge state in the future predetermined period will be less than the minimum charge power amount of the storage battery, the target voltage is temporarily set to a value smaller than the rated voltage,
In the natural energy power generation device, when the target voltage exceeds a rated voltage over a predetermined time, the power generation output from the natural energy power generation device is suppressed,
In the load device, when the target voltage falls below a rated voltage for a predetermined time or more, the power consumption of the adjustment load is suppressed.
A stand-alone power supply system according to any one of claims 2 to 4,
Compare the measured value of charge / discharge power of the storage battery or whether the average value of the measured value is within a predetermined range,
If it is out of a predetermined range, the command value of the power factor of the natural energy power generation apparatus is set to a value determined using the impedance of the power system in the independent power supply system. .
The stand-alone power supply system according to claim 6,
If the measured value of the charge / discharge power of the storage battery or the average value of the measured values is within a predetermined range, the command value of the power factor of the natural energy power generation apparatus is set to 1, independent power supply system.
The stand-alone power supply system according to claim 5,
Compare the measured value of charge / discharge power of the storage battery or whether the average value of the measured value is within a predetermined range,
If it is within a predetermined range, the command value of the power factor of the natural energy power generation device is set to 1,
If it is out of a predetermined range, the command value of the power factor of the natural energy power generation apparatus is set to a value determined using the impedance of the power system in the independent power supply system. .
A stand-alone power supply system according to any one of claims 2 to 4, 6 or 7,
The independent power supply system is
When the start / stop notice information that is the notice information that the load stops starting is received, the output of the natural energy power generation device is suppressed,
A stand-alone power supply system that suppresses power consumption of the adjustment load when start notice information, which is notice information for starting the load, is received.
A stand-alone power supply system according to any one of claims 1 to 9,
The natural energy power generation apparatus is a solar power generation apparatus having a solar power generation panel.