JP5867149B2 - Power control unit and power control system - Google Patents

Description

  The present invention relates to a power control unit and a power control system related to power control in a power network using a power generation device such as solar power generation that may be limited in power generation as a power generation source.

  In recent years, power generation using natural energy with a small environmental load is spreading. In such a power generation system, the amount of power generation varies depending on environmental conditions, so that the variation in supply amount is large, and it is difficult to stably supply power alone. It is generally used in combination with a system that can supply more stably, such as commercial power.

  In such a power generation system, supply is made to a plurality of consumers ranging from a detached house to a housing complex and a relatively large range of municipalities.

If the supply from the commercial power supply is interrupted due to a disaster or the like, the total load power may exceed the amount of power that can be supplied depending on the load conditions connected to the power generation environment. If the supply is insufficient, the power grid may suddenly lose power throughout the entire area, which may cause unforeseen circumstances due to equipment that has stopped. Therefore, in order to avoid such a failure, it is assumed that supply is not performed even when there is insufficient power. When the power supplied in this way is reduced, as a technique for avoiding a total power outage, a priority is set in advance for the connected load as in Patent Document 1, and if there is no room in the supply amount, priority is given. There has been proposed a system that avoids overload by limiting power supply in order from the lowest.

JP 2009-165249 A

  By the way, in the system of patent document 1, the apparatus for making a control part recognize the load priority and power consumption is required, and these are functions required in order to utilize the system of patent document 1, This is not related to the original function of the device, and is a heavy burden in terms of cost. In addition, when it is necessary to limit power at multiple supply destinations, such as in housing complexes, it is necessary to install the same system at all the supply destinations to be controlled, and adaptation to a wide range of power supply is appropriate. It can not be said. That is, it is necessary to separately provide a device having a dedicated control unit. Therefore, an object of the present invention is to realize a power control unit and a power control system that can simply and effectively use power that can be supplied at that time.

  The present invention calculates the power that can be distributed from the amount of power that can be supplied, and constructs a power control system that can dynamically change the current limit value of the voltage conversion unit provided to each supply destination. Make restrictions. In general, power is supplied at a constant voltage. Therefore, if the supplied voltage is known, the power can be limited by limiting the current. Since there is no need for a new device for limiting the power, the power that can be supplied at that time can be used effectively.

  As a desirable mode of the present invention, the first voltage supplied from the power generation unit that supplies the first electric power is converted into a desired second voltage, and the electric power is supplied to a load that is electrically connected to each of them. Calculates the power that can be supplied by the power generation unit using the current limit value of the voltage conversion unit that stops the power supply from the power generation unit when a current exceeding the predetermined current limit value flows from the multiple voltage conversion units to the load. The power control unit includes a current limit value changing unit to be updated based on the power supply amount calculated based on the power information to be performed and a consumption variable that is a variable that defines the power consumed by a desired load.

  According to a preferred aspect of the present invention, the current limit value of the voltage conversion unit that stops the power supply from the power generation unit is updated based on the power supply available amount and the desired consumption variable of the load. Therefore, it is possible to effectively use the power that can be supplied at that time.

  As a desirable aspect of the present invention, the consumption variable may be a distribution ratio that is a ratio of dividing the power that can be supplied by the power generation unit into the load.

  As a desirable mode of the present invention, the distribution ratio may be updated every time.

  As a desirable aspect of the present invention, the current limit value may be updated based on a consumption variable that is a desired power consumption amount consumed by a load connected to each voltage conversion unit and a power supply possible amount. .

  As a desirable mode of the present invention, the current limit value may be updated when the consumption variable is the sum of the rated output power of the voltage conversion unit and the power supply possible amount is less than the consumption variable.

  A desirable aspect of the present invention may be characterized in that the current variable is updated when the amount of power supply is less than the consumption variable, with the consumption variable being the amount of power predicted by the load demand.

  As a desirable mode of the present invention, the power supply available amount is less than the consumption variable, using the power consumption information based on the measurement unit that measures the power consumption consumed by the load electrically connected to the voltage conversion unit as the consumption variable. In this case, the current limit value may be updated.

  As a desirable mode of the present invention, power supply may be stopped based on a current limit value or a forced cutoff signal.

  According to the desirable mode of the present invention, it is not necessary to provide a breaker separately, and the number of parts can be reduced.

  As a desirable aspect of the present invention, a power generation unit that supplies first power, a load that converts the first voltage supplied from the power generation unit into a desired second voltage, and each of which is electrically connected A plurality of voltage conversion units that supply power to the voltage conversion unit, and a current conversion unit having a voltage conversion unit that stops power supply from the power generation unit when a current greater than or equal to a predetermined current limit value flows from the voltage conversion unit to the load. The current limit value to be updated is updated based on the power supply amount calculated based on the power supply information for calculating the power that can be supplied by the power generation unit and the consumption variable that is a variable that defines the power consumed by the desired load. And a power control system including a power control unit.

  Since there is no need for a new device for limiting the power, it is possible to simply and effectively use the power that can be supplied at that time.

Overall configuration diagram of a power control system according to the present embodiment Calculation example of possible power supply Example of power control system when multiple secondary batteries are used First control flowchart of the present embodiment Current limit value calculation method example 1 Current limit value calculation method example 2 An example of power distribution Calculation flow using the sum of the rated output power as a consumption variable Calculation flow using the power demand predicted as a consumption variable Calculation flow using the total power consumption information as a consumption variable

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment)
Before describing the features of the embodiment of the present invention, the overall configuration of a power control system according to the present invention will be described with reference to FIG. A power generation unit 110 that generates first DC power, a voltage conversion unit 1a, 1b, and 1c that converts a DC voltage from the power generation unit 110 into a desired second DC voltage, and a power control unit 130 that controls the power generation unit 110. Consists of. The first DC power supplied from the power generation unit 110 is supplied to the loads 150a, 150b, and 150c via the voltage conversion units 1a, 1b, and 1c. Here, each of the loads 150a, 150b, and 150c may be a single load, or a plurality of loads (not shown) may be connected in parallel. The voltage and current supplied to the loads 150a, 150b and 150c are detected by the first detection circuits 3a, 3b and 3c, and the detected output current value and output voltage value are input to the control circuits 5a, 5b and 5c. When the control circuits 5a, 5b, and 5c determine that a current that exceeds the desired current limit value flows, the supply from the voltage converters 1a, 1b, and 1c is cut off. The power control unit 130 can communicate using the power generation unit 110, the first communication circuit 119, and the second communication circuit 131, and is necessary for controlling the power generation amount of the power generation unit 110 and calculating the power supply possible amount. Supply power information can be obtained. Further, the power control unit 130 can perform communication using the voltage conversion units 1a, 1b, and 1c, the third communication circuit 132, and the fourth communication circuits 4a, 4b, and 4c, and the voltage conversion units 1a, 1b, 1c can be monitored and the current limit value stored in the control circuits 5a, 5b, and 5c can be updated. In FIG. 1, it is assumed that one power generation unit 110 using natural energy is shared by a plurality of loads 150a, 150b, and 150c, but the power generation unit 110 is not limited to one. Further, although three sets of voltage converters 1a, 1b, and 1c and loads 150a, 150b, and 150c are described, it is not necessary to limit this number in the present embodiment. In addition, as long as the power generation unit 110 is shared, the present invention can be applied to an apartment house or a detached house, and the form thereof is not particularly limited. Here, the first communication circuit 119, the second communication circuit 131, the third communication circuit 132, and the fourth communication circuits 4a, 4b, and 4c each have a data transmission / reception unit. Examples include an antenna that performs wireless communication, an input / output end connected to an end of a cable that performs wired communication, a light emitting unit that performs optical communication, a light receiving unit, and the like.

  The power generation unit 110 will be described with reference to FIG. The solar cell 111, the fuel cell 113, the secondary battery 115, and the wind power generator 117 that generate the first DC power are connected to the circuits that control the output voltage, that is, the control circuits 112, 114, 116, and 118, respectively. The secondary battery control circuit 116 has not only discharging but also a charging function. Each control circuit includes a switch (not shown) that switches the connection between the controlled device and the DC main line 10, and can control the electrical connection to the DC main line 10. Each control circuit is connected to the first communication circuit 119. Each control circuit 112, 114, 116, 118 communicates from the first communication circuit 119 to the power control unit 130 via the second communication circuit 131 when there is an abnormality in the controlled device. Can do. Since power generation using natural energy has large fluctuations in the amount of power generation due to environmental changes, it is desirable to provide the secondary battery 115 for the purpose of suppressing fluctuations. In FIG. 1, it is not always necessary to provide all of the solar cell 111, the fuel cell 113, and the wind power generator 117 of the power generation unit 110. Natural energy other than the solar cell 111, the fuel cell 113, and the wind power generator 117 may exist in the power generation unit 110, and the form thereof is not particularly limited. The amount of power generated by natural energy depends on the environmental conditions, and is connected to the commercial AC power source to the power generation unit 110 in order to suppress fluctuations in the power generation amount. However, in this embodiment, it is not always necessary to connect the commercial AC power source. Absent. When connecting to an AC power source, an AC / DC converter 140 for converting to direct current is required.

  The voltage conversion units 1a, 1b, and 1c include DC / DC converters 2a, 2b, and 2c that convert the first DC voltage generated by the power generation unit 110 into a desired second DC voltage suitable for power feeding. . In the present embodiment, the second DC voltage that is the output voltage of the DC / DC converters 2a, 2b, 2c supplied to the loads 150a, 150b, 150c is the input voltage of the DC / DC converters 2a, 2b, 2c. It is not necessarily higher or lower than a certain first DC voltage, and the operations of the voltage conversion units 1a, 1b, and 1c do not need to limit step-up or step-down. The first DC voltage and the second DC voltage may be the same value.

  A switching power supply is generally used for the DC / DC converters 2a, 2b, and 2c of the voltage converters 1a, 1b, and 1c. In this embodiment, the DC / DC converter used in the voltage converters 1a, 1b, and 1c may be either an insulating type or a non-insulating type, and the form is not particularly limited.

  The voltage conversion units 1a, 1b, and 1c include first detection circuits 3a, 3b, and 3c as measurement units that measure the power consumed by the loads 150a, 150b, and 150c. The first detection circuits 3a, 3b, and 3c can measure the output current and output voltage supplied to the loads 150a, 150b, and 150c.

  The voltage conversion units 1a, 1b, and 1c have control circuits 5a, 5b, and 5c, and the output current and the output voltage measured by the first detection circuits 3a, 3b, and 3c are fed back. Here, the output voltage of the voltage converters 1a, 1b, and 1c is controlled so that the output voltage is constant. That is, in the case of a switching power supply, generally, the output voltage can be controlled to be constant by performing on / off control of switch portions (not shown) of the DC / DC converters 2a, 2b, and 2c.

  The voltage conversion units 1a, 1b, and 1c include fourth communication circuits 4a, 4b, and 4c, and output power information output from the voltage conversion units 1a, 1b, and 1c may be transmitted to the power control unit 130. it can.

  In the state where sufficient power is supplied from the power generation unit 110, the voltage conversion units 1a, 1b, and 1c use the maximum value of the current voltage permitted to be output as the rated output voltage and the rated output current. The power is set as the rated output power.

  The voltage conversion units 1a, 1b, and 1c have a protection unit (not shown) in the control circuits 5a, 5b, and 5c that functions to stop the output when a current greater than the rated current value flows. The output current value detected by the first detection circuits 3a, 3b, and 3c is input to the control circuits 5a, 5b, and 5c, and compared with the current limit value stored in the control circuits 5a, 5b, and 5c. When a current exceeding the limit value flows, the control circuits 5a, 5b, and 5c transmit a power supply stop command to the DC / DC converters 2a, 2b, and 2c. Normally, the current limit value is determined by the rated output current. The first detection circuits 3a, 3b, and 3c are present on the secondary side of the DC / DC converters 2a, 2b, and 2c, but the primary side input current value is input to the control circuits 5a, 5b, and 5c. May be. That is, if a current flows on the primary side, a current flows on the secondary side. Therefore, the current value input to the primary side can be regarded as substantially defining the current value flowing to the load. Therefore, an input current value output from a second detection circuit (not shown) that detects an input current may be input to the control circuits 5a, 5b, and 5c. Further, normally, DC power is supplied to the secondary side by controlling on / off of a switch unit (not shown) existing on the primary side of the DC / DC converters 2a, 2b, 2c, so that the control circuits 5a, 5b, It is possible to stop the supply of power to the loads 150a, 150b, and 150c by executing a control in which a protection unit (not shown) included in 5c turns off a primary-side switch unit (not shown). It has become.

  The power control unit 130 calculates a power supply possible amount. The amount of power that can be supplied refers to the amount of power that can be supplied to the voltage conversion units 1a, 1b, and 1c generated by the power generation unit 110. Supply power information, which is information necessary for calculating the power supply possible amount, can be obtained from the power generation unit 110 using the transmission / reception units (not shown) of the first communication circuit 119 and the second communication circuit 131. .

  As an example of power supply information, the amount of power generated by solar cells 111 and wind power generators 117, which are natural energy, is estimated by factors such as weather information and environmental changes such as aging deterioration, and fuel cells have an environment such as remaining fuel and aging deterioration. The secondary battery includes the remaining amount of charge, such as a coefficient that takes into account changes.

  The power control unit 130 controls each of the control circuits 112, 114, 116, 118 provided using the transmission / reception units (not shown) of the first communication circuit 119 and the second communication circuit 131. It is possible to control a switch (not shown) for switching the connection of the existing device to the DC main line 10.

  Based on FIG. 1 and FIG. 2, the example of calculation of the electric power supply possible amount in a certain time range is demonstrated. As shown in FIG. 1, there is a power generation unit 110 including a solar cell 111, a fuel cell 113, a wind power generator 117, and a secondary battery 112. The predicted power generation amount up to 6t is shown in 700, 701, and 702 in FIG. FIG. 2 shows the power generation unit 110 with the vertical axis representing the amount of power generation and the horizontal axis representing time. Assume that the expected power generation amount 700 of the solar cell is 12 kW, the predicted power generation amount 701 of the wind power generator is 9 kW, the remaining amount 702 of the fuel cell is 3 kW, the secondary battery is 0 W, and the total power supply is 24 kW.

  Consider the case where power is evenly distributed at all times. Since the amount of power that can be supplied during 6 t is 24 kW, 4 kW per 1 t of time. Since the electric power of the solar battery and the wind power generator cannot be leveled by itself, it is considered that the power is used while being generated in consideration of efficiency. A combination of the solar cell and the wind power generator is shown at 710 in FIG. As shown at 710 in FIG. 2, the power shortage from 4 kW is compensated by power generation by the fuel cell. The amount of power in that case is indicated by reference numeral 711 in FIG. Since there is power exceeding 4 kW, the secondary battery 115 is temporarily charged, and the secondary battery 115 is discharged in the shortage time period, so that the power is evenly distributed as shown at 712 in FIG. Can be supplied. As described above, the power generation unit 110 is preferably composed of a plurality of power generation devices so as to complement each characteristic. In addition, it is preferable that a plurality of secondary batteries exist, and power can be supplied by discharging another secondary battery that has already been charged during charging. This will be described below.

  A calculation example of the power supply possible amount when a plurality of secondary batteries 115 are used will be described with reference to FIG. The power control system of FIG. 3 shows a case where there is a secondary battery 1 (115a) that has been fully charged and a secondary battery 2 (115b) that has not been fully charged. The solar cell 111, the wind power generator 117, and the fuel cell 113 are connected to the changeover switch 120 via the power generation unit side DC main line 11, and the changeover switch 120 is connected to the secondary battery 2 (115b) for charging. Each control circuit 112, 116, 118 communicates with the power control unit 130 from the first communication circuit 119 via a second communication circuit (not shown) when there is an abnormality in the controlled device. can do. The changeover switch 121 connected to the DC main line 10 is connected to the secondary battery 1 (115a) that has been charged, and supplies power to the voltage conversion units 1a, 1b, and 1c. That is, the secondary battery 1 (115a) is discharged. The control circuit 122 controls the secondary batteries 115a and 115b and the switches 120 and 121. The control circuit 123 also manages the charging information of the secondary battery, and uses the first communication circuit 119 and the transmission / reception unit (not shown) of the second communication circuit (not shown) as necessary. It can be transmitted to the power control unit 130. Since it is only necessary to grasp the remaining charge amount of the secondary batteries 115a and 115b that have already been charged, the amount of electric power can be grasped more reliably. In FIG. 3, there are only two sets of secondary batteries, but the number is not limited. The secondary battery need not be fully charged.

  When the power control unit 130 compares the power supply available amount with the consumption variable and determines that the power supply available amount is insufficient and the power supply amount needs to be limited, the control circuit 134 in the power control unit 130 is used. A new current limit value can be updated using a current limit value changing unit (not shown) existing in FIG.

  Here, the consumption variable is a variable that defines the power consumed by the load. In other words, it refers to the power that needs to be supplied. The consumption variable is not limited to one value, but the distribution ratio shown below, the desired power consumption of the load connected to each voltage converter, the amount of power predicted in the future demand, the rating of the voltage converter Any variable that regulates the power consumed by the load, such as power and power actually consumed, can be changed as appropriate.

  The example of the update of the current limiting value by a current limiting value change part (not shown) is shown. First, a method for determining a current limit value based on a desired distribution ratio, that is, a case where a consumption variable is a distribution ratio will be described. The distribution ratio is a ratio for dividing the power that can be supplied by the power generation unit into each supply destination, that is, a load. As an example, when the power Po that can be supplied is 4 kW, the supply destination, that is, there are three loads, and there are at least three power conversion units 1, the supply ratio R1 of each of the supply destinations, that is, the loads A1, A2, and A3 , R2 and R3 are described as R1: R2: R3 = 1: 2: 1. The ratio sum Rs is 1 + 2 + 1 = 4. When the power P that can be supplied is divided by 4 kW and the sum Rs of the ratios, the power amount Pu per unit ratio (a value obtained by dividing the power P that can be supplied by the sum Rs of the ratios) is 1 kW. Since each supply destination, ie, load, is determined by each distribution ratio (unit ratio × supply ratio), 1 kW × 1 = 1 kW for the supply destinations A and C, and 1 kW × 2 = 2 kW for the B consumption. It is a variable that defines power. That is, since the DC voltage supplied to the voltage converter is uniquely determined, the current limit value is updated based on the supplied DC voltage value and the distribution ratio that is a variable that defines the power consumed by the load. It will be possible. These processes will be described with reference to the flowchart of FIG. When the power supply possible amount is below the consumption variable, the calculation of the current limit value is started (S501). The sum Rs of the determined distribution ratio is obtained (S510), and the calculation of the amount of power Pu per unit ratio is started from the sum Rs of the distribution ratio and the power supply possible amount (S511). Each distribution ratio Rn is added to the obtained power amount Pu per unit ratio, and the current limit value of each supply destination is calculated (S513). This calculation is performed for all supply destinations (S512). The calculation ends for all the supply destinations (S502). By varying the distribution ratio, it is possible to make a difference in the suppliable amount for each supply destination.

  A method of receiving the demand of the supplier, that is, the power consumption information of the load and reflecting it in the current limit value will be described with reference to FIG. When the power supply possible amount is less than the consumption variable, update of the current limit value is started (S501). A notification is made about the time during which power supply is restricted to the supply destination, that is, the load connected to each voltage conversion unit, and the power that can be used by each supply destination within the time limit (S520). Based on the notification, the supply destination returns the desired time and the power value to be used, that is, the consumption variable to the power control unit 130 (S521). A comparison is made as to whether each supply destination is within the range of the power supply possible amount (S522). When the power supply possible amount exceeds the consumption variable that is the desired power usage amount of each supply destination, the desired power usage amount is approved, and the desire of each supply destination is determined as the current limit value within the time limit (S502). . If the power supply available amount falls below the consumption variable that is the desired power usage amount of each supply destination, the request from the supply destination, that is, the load power consumption information is received again, and the desired power usage amount is the power supply available amount. Continue until it is within range. As one method, an alternative of the distribution ratio is presented to the supplier that did not satisfy the request (S523), and the request of the supplier that did not satisfy the request, that is, the power consumption information of the load is received (S524), It is compared whether it is within the range of the power supply possible amount (S522), and is repeated until it falls within the range of the power supply possible amount.

  The power control unit 130 uses the third communication circuit 132 and the fourth communication circuits 4a, 4b, and the new current limit value calculated using a current limit value changing unit (not shown) existing in the control circuit 134. The current limit values of the control circuits 5a, 5b, and 5c can be updated using the 4c transmission / reception unit (not shown).

  The control circuit 134 forcibly stops the operation of the voltage converters 1a, 1b, and 1c, and sends a forcible cutoff signal that stops the supply of power to the loads 150a, 150b, and 150c to the third communication circuit 132 and the fourth communication. The signals are transmitted to the voltage conversion units 1a, 1b, and 1c using the transmission / reception units (not shown) of the circuits 4a, 4b, and 4c, and the control circuits 5a, 5b, and 5c stop the DC / DC converters 2a, 2b, and 2c. The supply of electric power can be stopped by a protection unit (not shown). That is, it is possible to limit the power supply based on the control signal or the forced cut-off signal, and it is possible to omit a power supply disconnecting unit such as a breaker when there is an abnormality. Further, since no mechanical switch is required, the power supply can be stopped by a forced cutoff signal from the outside.

  FIG. 4 shows a first control flow for updating the current limit value based on a desired consumption variable. The power generation unit 110 starts power generation, and at the same time as preparation for power supply is completed, control for supply is started (S100). The power control unit 130 obtains supply power information necessary for calculating the power supply possible amount from the power generation unit 110 using the transmission / reception units (not shown) of the first communication circuit 119 and the second communication circuit 131. Then, the amount of electric power that can be supplied is calculated (S200). Next, consumption variables are calculated (S300). The consumption variable is a variable that defines the power consumed by the load. In other words, it refers to the power that needs to be supplied. For calculation of the consumption variable, information is obtained using the third communication circuit 132 and the transmission / reception units (not shown) of the fourth communication circuits 4a, 4b, and 4c as necessary. The calculated amount of power supply and the consumption variable are compared (S400). If the amount of power that can be supplied exceeds the consumption variable, it is not necessary to limit the current value, and the process ends (S110). When the power supply available amount is below the consumption variable, the power control unit calculates a power value that can be supplied from the power supply available amount, and updates the current limit value according to each supply destination (S500). The power control unit 130 uses the third communication circuit 132 and the transmission / reception units (not shown) of the fourth communication circuits 4a, 4b, and 4c to control the voltage conversion units 1a, 1b, and 1c. The value of the current limit value 5c is updated (S600), and the control is terminated (S110).

  A second control method for updating the current limit value when the power supply possible amount is below the consumption variable will be described. The calculation of the consumption variable of the control flow shown in FIG. 4 (S300) is merely changed to the sum of the rated output powers of the voltage converters 1a, 1b, 1c, and the subsequent processing is the same. FIG. 8 shows a calculation flow in which the sum of the rated output powers of the voltage converters 1a, 1b, and 1c is a consumption variable. In response to the command for calculating the sum of the rated output powers, the calculation of the consumption variable is started (S310). The power control unit 130 uses the transmission unit (not shown) of the third communication circuit 132 and the reception units (not shown) of the fourth communication circuits 4a, 4b, and 4c, and uses the voltage conversion units 1a, 1b, A request is transmitted to each rated output power to 1c (S311). Each of the voltage converters 1a, 1b, and 1c outputs its rated output power by a transmitting unit (not shown) of the fourth communication circuits 4a, 4b, and 4c and a receiving unit (not shown) of the third communication circuit 132. To the power control unit 130. (S312). The sum of the received rated output powers, that is, the consumption variable is calculated (S313). The calculation ends and the process ends (S314). For example, when the sum of the rated output power does not change, such as when the number of voltage conversion units 1a, 1b, and 1c and the rated output power are unchanged, the power control unit 130 stores them in advance as fixed values. Therefore, it is possible not to perform these processes.

  The sum of the rated output power is equal to the maximum power that must be supplied.By using this sum as a consumption variable, even if sudden load fluctuation occurs, the value is less than the maximum power. Can be surely prevented. Further, the sum of the rated output powers is rarely changed since the introduction of the power control system, and is often known before the start of power supply. For this reason, the sum of the rated output power can be stored in advance as a consumption variable in the power control unit 130, and information collection for calculating the consumption variable using communication can be omitted. It is possible to enter a restricted state.

  A third control method for updating the current limit value when the amount of power that can be supplied is less than this consumption variable will be described using the consumption variable as the amount of power predicted for the load demand. Similar to the second control method, the calculation of the consumption variable of the control flow (S300) shown in FIG. 4 is changed to the power demand predicted for the load, and the subsequent processing is the same. Based on FIG. 9, a calculation flow using the demand-predicted power amount as a consumption variable will be described. In response to the demand prediction calculation command, calculation of demand prediction, which is the sum of power expected to be consumed by the load, that is, calculation of consumption variables is started (S320). Past power consumption data (S325) representing the trend of power consumption that has been consumed so far, environmental condition data (S326) including weather conditions at the time of prediction and aging of the power control system, the number of suppliers, Obtain information data (S327) such as fluctuations in the rated value. Based on these pieces of information, a load demand prediction that is an expected value of power consumption, that is, a consumption variable is calculated (S321). The calculation ends and the process ends (S322).

  Since a value close to the actual usage status is a criterion for determining whether or not to limit, it is not necessary to wait for an excessive supply amount, and surplus power can be reduced. Since demand forecast is a forecast amount, it is possible to provide information to the supply destination before the time when the limit is actually applied, and it is determined by time and used for calling for power saving and power distribution within the limit time. For example, the current limit value can be set flexibly.

  Next, an example in which the current limit value is flexibly updated will be described with reference to FIG. The power that can be supplied 800 is 3Po at the time of 3t. When distributing evenly to three supply destinations, there are a method of dividing the power supply and a method of dividing the power. In the above, 3 Po of power 810 is supplied to the supply destination A until time t, and supply to the supply destinations B and C is not performed during that time. From the next t to 2t, 3Po electric power 811 is supplied to the supply destination B, and from 2t to 3t, 3Po electric power 811 is supplied to the supply destination C. Alternatively, 3 Po of power 800 is distributed evenly (820, 821, 822) to three supply destinations, and the same power is supplied until time 3t. Since the current limit value is updated every time in consideration of the usage state of the load as the supply destination in this way, it is possible to supply power efficiently. That is, it can be considered that each distribution ratio of the supply destination is updated every time. Here, the case of even distribution is described, but it is not necessary to be equal.

Power consumption information based on the output of the first detection circuits 3a, 3b, 3c that measure the power consumption consumed by the load electrically connected to the voltage conversion units 1a, 1b, 1c is transmitted to the power control unit 130. The fourth communication circuits 4a, 4b, 4c and the third communication circuit 132 are used, and the received power consumption information is used as a consumption variable, and the current limit value is updated when the power supply available amount is lower than the consumption variable. The fourth control method will be described. Similar to the second and third control methods, the calculation of the consumption variable of the control flow (S300) shown in FIG. 4 shows the power consumption consumed by each connected load 150a, 150b, 150c as the first detection circuit. The rest of the processing is the same except that the sum of the power consumption information based on 3a, 3b, and 3c is changed. Based on FIG. 10, a calculation flow using the sum of power consumption information as a consumption variable will be described. In response to the power consumption information calculation command, the power control unit 130 starts calculating the power consumption information (S330). The power control unit 130 uses a transmission unit (not shown) of the third communication circuit 132 to request transmission of power consumption information that is the power output to each of the voltage conversion units 1a, 1b, and 1c. Is transmitted (S331). Each voltage conversion unit 1a, 1b, 1c measures the power that it is currently outputting with the first detection circuits 3a, 3b, 3c, and power consumption information exists in the fourth communication circuits 4a, 4b, 4c. The data is transmitted to the power control unit 130 using the transmission unit. (S332). The sum of the transmitted power consumption information, that is, the consumption variable is calculated from each voltage conversion unit 1a, 1b, 1c (S333). The calculation ends and the process ends (S334).

  Since the power is actually consumed, not predicted, there is no error due to prediction, and it is not necessary to have excessive power. In the power control system with little load fluctuation, the power supply can be controlled most efficiently. In addition, when there are a plurality of loads for one power conversion unit, the sum of the power consumption information is obtained for the plurality of loads as a whole. That is, although control with respect to a single load is not executed, it is possible to always operate a plurality of loads by setting a priority order such as setting a priority order in the voltage conversion unit.

  A description will be given in which the second transmission / reception unit (not shown) also serves as the third transmission / reception unit (not shown). A third transmission / reception unit that receives power consumption information based on the first detection circuits 3a, 3b, and 3c consumed by the loads 150a, 150b, and 150c from the voltage conversion units 1a, 1b, and 1c to the power control unit 130 ( Transmission / reception between the current transmitting / receiving unit (not shown) and the second transmitting / receiving unit (not shown) that transmits the current limit value calculated by the power control unit 130 to the voltage converting units 1a, 1b, 1c is performed using the same transmitting / receiving unit. Also good. Therefore, it is possible not to increase new facilities.

  Further, the second communication circuit 131 and the third communication circuit 132 can be shared, and it is possible not to increase new facilities.

  The voltage conversion units 1a, 1b, and 1c are power control units 130 that stop power supply based on the current limit value or the forced cutoff signal.

  An example of forced cutoff will be described. A switch (not shown) is provided in the voltage conversion units 1a, 1b, and 1c, and a forced cutoff is generated by a person operating the switch. Alternatively, the supply can be cut off by the power control unit 130 outputting a forced cut-off signal.

  In the event of a fire in the vicinity of the supply destination, it is possible to cut off the power supply before an abnormality occurs on the power control system, preventing secondary disasters such as the occurrence of fire due to electric shock or surge. . Therefore, it is not necessary to provide a separate breaker, and the number of parts can be reduced.

  In addition, while using the electric power control part of this embodiment, while converting the 1st voltage supplied from the electric power generation part which supplies 1st electric power to the electric power generation part into a desired 2nd voltage, each is electric A plurality of voltage conversion units that supply power to the connected load, and a voltage conversion unit that stops the power supply from the power generation unit when a current greater than a predetermined current limit value flows from the voltage conversion unit to the load. The current limit value having is updated based on the power supply available amount calculated based on the power supply information for calculating the power that can be supplied by the power generation unit and the consumption variable that is a variable that defines the power consumed by the desired load. A stable power supply can be realized by using a power control system including a power control unit including a current limit value changing unit.

  In the present embodiment, power supply using DC power is mentioned, but power supply using AC power is also applicable. That is, the present invention can also be applied when either power supply or power consumption is AC power. In this case, the power that can be supplied may be adopted as a value obtained by converting the effective value of the AC voltage into a DC voltage. Further, instead of the DC / DC converter, a DC / AC converter, an AC / AC converter, or an AC / DC converter may be used as appropriate.

DESCRIPTION OF SYMBOLS 1a Voltage converter 1b Voltage converter 1c Voltage converter 2a DC / DC converter 2b DC / DC converter 2c DC / DC converter 3a 1st detection circuit 3b 1st detection circuit 3c 1st detection circuit 4a 4th communication Circuit 4b Fourth communication circuit 4c Fourth communication circuit 5a Control circuit 5b Control circuit 5c Control circuit 10 DC main line 11 Power generation unit side DC main line 110 Power generation unit 111 Solar cell 112 Solar cell control circuit 113 Fuel cell 114 Fuel cell Control circuit 115 Secondary battery 115a First secondary battery 115b Second secondary battery 116 Secondary battery control circuit 117 Wind generator 118 Wind generator control circuit 119 First communication circuit 120 Power generation unit and secondary Switching switch 121 between batteries Switching switch 122 between the voltage converter and the secondary battery 120 120, 121 switching switch The control circuit 130 power control unit 131 the second communication circuit 132 third control circuit of the communication circuit 134 power control unit of the 140 AC / DC converter 150a loads (DC device)
150b load (DC equipment)
150c load (DC equipment)
700 Electric power generated by solar cell 701 Electric power generated by wind power generator 702 Electric power generated by fuel cell 710 Sum of electric power generated by solar battery and wind power generator 711 710 Power less than 4 kW Electric power 712 indicating the amount of electric power that can be supplied when the power of the fuel cell is allocated to the belt. Using the secondary battery, the electric power supply amount 800 that equalizes the electric power of 711. The electric power supply amount 810. Electric power 811 Electric power to the supplier B 812 Electric power to the supplier C 820 Electric power to the supplier A 821 Electric power to the supplier B 822 Electric power to the supplier C

Claims (9)

The first voltage supplied from the power generation unit that supplies the first electric power is converted into the second voltage, and the plurality of voltage conversion units that supply electric power to the electrically connected loads to the load. The current limit value of the voltage conversion unit that stops the power supply from the power generation unit when a current of a predetermined current limit value or more flows is used as supply power information for calculating the power that can be supplied by the power generation unit. A power control unit comprising: a current limit value changing unit that is updated based on a power supply available amount calculated based on a consumption variable that is a variable that defines a power that should be supplied to the load . The power control unit according to claim 1, wherein the consumption variable is a distribution ratio that is a ratio of dividing the power that can be supplied by the power generation unit into the load. The power control unit according to claim 2, wherein the distribution ratio is updated every time.   The current limit value changing unit updates the current limit value based on a consumption variable that is a desired power usage amount of a load connected to each of the voltage conversion units and the power supply possible amount. The power control unit according to claim 1. The current limit value changing unit updates the current limit value as the maximum power that must be supplied to the load of the voltage converter when the consumption variable is less than the consumption variable as the maximum power that must be supplied to the load of the voltage conversion unit. The power control unit according to claim 1, wherein:   The current limit value changing unit updates the current limit value when the power supply available amount is less than the consumption variable, with the consumption variable as an amount of power predicted for the load demand. Item 2. The power control unit according to Item 1.   The current limit value changing unit uses the power consumption information based on a measurement unit that measures power consumption consumed by the load electrically connected to the voltage conversion unit as the consumption variable, and the power supply possible amount is The power control unit according to claim 1, wherein the current limit value is updated when the consumption variable falls below the consumption variable. Before SL voltage converter power control unit according to any one of claims 1 to 7 for stopping the power supply on the basis of the current limit value or forced cutoff signal. A power generation unit that supplies first power, and a plurality of voltage conversions that convert the first voltage supplied from the power generation unit into a second voltage and supply power to a load that is electrically connected to the second voltage. And the current limit value of the voltage conversion unit that stops the power supply from the power generation unit when a current equal to or greater than a predetermined current limit value flows from the voltage conversion unit to the load. Current limit value update to be updated based on the power supply amount calculated based on the supply power information for calculating the power that can be supplied and the consumption variable that is a variable that defines the power that needs to be supplied to the load And a power control system comprising a power control unit.

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