JP2017041919A - Power conversion system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which, on a power conversion system for adjusting by converting power of a power source such as a solar cell and a storage battery, when a failure occurs, a related portion connected to the failed portion is stopped or the total device is stopped even when there are sound portions, so that the sound portions cannot be effectively used.SOLUTION: By providing an input route switching part between a plurality of input parts of a power conversion system and a plurality of power conversion parts corresponding to the input parts, and separating a failed portion when a failure occurs and connecting a sound portion to other route, it becomes possible to change connections of a power circuit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power conversion system, and in particular, is connected between a plurality of power sources such as a power generation device or a power storage device, and an output unit to a load such as a household electrical appliance or an output unit to a power system. The present invention relates to a power conversion system that converts power from a power source and supplies the power to an output unit.

  Electric power is generated by a power generation device such as a solar power generation device, a part of the power is used as household electricity, and the rest is supplied to an electric power system. In the case of a solar power generation device, a plurality of solar power generation modules are connected in series to form a power generation unit, and a power conversion unit is provided for each power generation unit, and adjustment of power conversion such as voltage is performed. Patent Document 1 discloses a distributed power generation system in which the output of each power converter is connected to a DC power bus and used as a power supply source.

  When power generated by a power generation device such as a solar power generation device is used for household electrical appliances, or when surplus power is supplied to the power system, power conversion such as voltage is adjusted by the power conversion system. ing. A power conversion system is also used when power is stored in a power storage device that stores energy, such as a storage battery, and power is supplied from the power storage device to household electrical appliances as needed. It is carried out.

Each of the power conversion systems includes a plurality of input units, a power conversion unit, and an output unit. Each input unit is connected to a power source such as a power generation device and a power storage device. The power conversion unit converts the power of the power source and outputs the power. It is comprised so that it may output from a part.
In addition, in the case of a power generation device using solar power generation or the like, a power generation device that can supply power larger than the required power capacity is arranged, assuming fluctuations in generated power due to weather fluctuations. A power storage device having a power capacity larger than the required power capacity is arranged.

Special table 2007-520985

  In a conventional power conversion system, a power conversion unit is connected to each of a plurality of power supplies, and the power of each power supply is converted and output. When a failure occurs in either the power supply or the power conversion unit that is configured, the entire apparatus is stopped or one unit including the failed power conversion unit is stopped. For this reason, if there is a failure, it becomes impossible to supply the required power capacity of the system, so the only way to stop the system or to continue operation below the required power capacity is Assuming the time, it is necessary to preset the capacity of the power source and the power conversion unit to be larger than the required power capacity, which has been a factor in increasing the cost of the power generation device or the entire power storage device.

In the power conversion system having a plurality of power conversion units in parallel, assuming that a failure has occurred in the power supply or the power conversion unit, the present invention stops only the failed part and is sound before and after the failed part. The purpose of this invention is to provide a power conversion system with low system cost by effectively using a healthy part when there is such a part.

  In the power conversion system of the present invention, a plurality of input units to which power sources are respectively connected, a plurality of power conversion units provided corresponding to each of the plurality of input units, and an input unit and a power conversion unit An input path switching unit that is provided between the input unit and the power conversion unit and switches the connection relationship according to a predetermined condition.

  According to the present invention, a sound power source, power conversion unit, etc. can be used effectively in the event of a failure of a power conversion unit, output unit, etc., so that the redundancy of the device is increased, and maintenance costs and system costs are increased. Can be reduced.

It is a block diagram which shows schematic structure of the power conversion system by Embodiment 1 of this invention. It is a block diagram which shows the specific structural example of the power conversion system by Embodiment 1 of this invention. It is explanatory drawing simplified for description of operation | movement of the power conversion system by Embodiment 1 of this invention. It is explanatory drawing explaining the connection switching destination of the failure site | part of the power conversion system by Embodiment 1 of this invention, and a healthy site | part. It is a block diagram which shows the structure of the input path switching part and the output path switching part of the power conversion system by Embodiment 1 of this invention. It is a flowchart for demonstrating the connection switching control operation | movement of the DC / DC converter 2 at the time of the power supply 2 failure in Embodiment 1 of this invention. In FIG. 3 of Embodiment 1 of this invention, it is a flowchart for demonstrating the connection switching operation at the time of failure of the DC / DC converter 2 when all the power supplies are power generation devices. FIG. 3 of the first embodiment of the present invention is a flowchart for explaining a connection switching operation when the DC / DC converter 2 fails when all the power sources are power storage devices. It is a flowchart which shows the example of control of the switching operation | movement for outputting more electric power generation by Embodiment 2 of this invention. It is the block diagram which showed the example of the unit structure of the power conversion system by Embodiment 3 of this invention.

Embodiment 1
FIG. 1 is a configuration diagram showing a schematic configuration of a power conversion system according to Embodiment 1 of the present invention. As shown in this figure, the power conversion system 100 has an input unit 3 to which a power generation device such as a solar cell or a power source 1 such as a storage battery or an electric vehicle (EV) is connected. Connected to the input path switching unit 11, connected to the input path switching unit 11, connected to the power conversion unit 12 that performs DC / DC conversion and DC / AC conversion, and connected to the power conversion unit 12. It is comprised by the output path | route switching part 13 for switching the path | route which outputs an output to a household appliance or an electric power grid | system. That is, the input path switching unit 11 is provided between the input unit 3 and the power conversion unit 12.

FIG. 2 is a diagram illustrating a specific configuration example of the power conversion system 100 according to Embodiment 1 of the present invention.
In this configuration example, the input path switching unit 11 in the power conversion system 100 shows a first input path switching unit 11a, a second input path switching unit 11b, and a third input path switching unit 11c. As shown here, each input path switching unit 11a, 11b, 11c has a first terminal connected to the input unit 3 of the power source 1 by the power generation device or the power storage device, and a second terminal a power conversion unit. 12, the third and fourth terminals are connected to the adjacent input path switching unit 11, and the switching element for separating each of the terminals and the voltage difference when switching to another input path are excessive. A cushion circuit for suppressing the generation of current, a reverse blocking element, and a short-circuit switch for enabling bidirectional energization thereof are provided.

  The configurations and connection destinations of the input path switching unit 11 and the output path switching unit 13 are not limited to those described above. For example, one end of the input path switching unit 11 is directly connected to the power source 1 or the power conversion unit 12. They may be connected and only need to be able to switch the power paths of the adjacent power source 1 and power converter 12. Further, the cushion circuit and the reverse blocking element may not be provided depending on the case, and the location thereof is not limited to that shown in FIG. Further, the switch elements shown in the power conversion unit 12 are not necessarily installed.

The power conversion unit 12 includes a first DC / DC converter 12aa, a second DC / DC converter 12ab, a third DC / DC converter 12ac, a first DC / AC converter 12ba, A DC / AC converter 12bb and a common DC bus 12c for connecting them are provided.
Further, the power conversion unit 12 includes a switch for separating the first DC / DC converter 12aa and the first DC / AC converter 12ba from the DC bus 12c, the input path switching unit 11, or the output path switching unit 13. Device.

  The first DC / DC converter 12aa, the first DC / AC converter 12ba, the switch element, the input path switching unit 11, and the output path switching unit 13 are controllers that exchange information with the integrated controller 15 or an external controller (see FIG. (Not shown). The output path switching unit 13 has a first terminal connected to the power conversion unit 12, a second terminal connected to the output unit 2 due to a load such as a power system or home appliance, and a third terminal adjacent to the output path switching. The input path switching unit 11 and the output path switching unit 13 are controlled by the controller 14 provided in the power conversion unit 12 or the integrated controller 15. Has been.

The power conversion unit 12 may be configured by only the DC / DC converter 12a or only the DC / AC converter 12b. In this case, the DC bus 12c is included in the power conversion unit 12. , No need to provide.
Further, the controller 14 may be the integrated controller 15 alone. In this case, the integrated controller 15 controls the power conversion unit 12, the input path switching unit 11, and the output path switching unit 13, and an external controller (not shown) or Communication is performed with the power source 1 such as a power generation device or a power storage device.

  Further, like the input path switching unit 11, the output path switching unit 13 may be provided with a cushion circuit for suppressing the occurrence of an excessive current due to a voltage difference or the like when switching to another output path. The cushion circuit is equipped with a current limiting element such as a resistor for current limiting at the time of path switching. By providing a current limiting element, overcurrent at the time of path switching can be prevented, and the device stops. The connection path can be switched without incurring a failure. Further, by making it possible to connect to any part, redundancy at the time of failure increases.

FIG. 3 illustrates the power conversion system 100 in FIG. 2 so that it can be easily distinguished for the sake of explanation.
As shown in FIG. 3, the power source 1 includes a first power source 1a, a second power source 1b, and a third power source 1c, and each power source 1a, 1b, 1c is a power conversion system that is a subject of the present invention. It is connected to 100 input units (not shown). In the power conversion system 100, upon receiving the input of the first power supply 1a, the first input path switching unit 11a and the first DC / DC converter 12a operate and the output of the DC / DC converter 12a becomes the DC bus. It is configured to output to 12c. On the power supply side, as shown in FIG. 3, the connection relation of the power from the power supply 1 is switched to the first to third DC / DC converters 12aa, 12ab, 12ac according to predetermined conditions. ing. On the power output side, the first DC / AC converter 12ba, the second DC / AC converter 12bb, and the third DC / AC converter 12bc are connected to the DC bus 12c. The output path switching units 13a, 13b, and 13c are connected to the first load 2a, the second load 2b, and the third load 2c.

Next, switching operation when the power conversion system 100 according to Embodiment 1 of the present invention fails will be described.
FIG. 4 shows a list in which connection switching destinations of parts connected to the failed part by the input path switching unit 11 and the output path switching unit 13 when each part fails in the power conversion system 100 in FIG. Is. Note that the input path switching unit 11 and the output path switching unit 13 of the power conversion system 100 according to Embodiment 1 of the present invention include any one of the power conversion units 12 and the power supplies 1 on both sides as illustrated in FIG. It can be connected to the output unit 2 by the load or power system, or can be connected to the power conversion unit 12, the power source 1, and the output unit 2 by the load or power system as shown in FIG. 5B. It is comprised by the switch element.

  The power conversion system 100 of the present invention converts power output from a power source 1 such as a power generation device or a power storage device into power suitable for an electric power system, sells generated power, supplies power to a load, Electric power purchase adjustment operation such as peak cut operation is performed. In some cases, when the power supply is interrupted during a disaster or the like, the power is supplied to home appliances or equipment in the common part of the building. In such an application, if it is necessary to stop other parts connected to the device in the event of a partial failure of the device, such as an increase in purchased power or no supply of power at the time of a disaster, etc. There will be challenges. Therefore, when a failure occurs, the failure part is cut off as soon as possible and the operation is continued with a healthy part.

Next, the connection switching operation by the input path switching unit 11 and the output path switching unit 13 will be described by taking as an example a case where the second power source 1b in FIG. 3 fails.
When the second power source 1b fails, the second DC / DC converter 12ab connected to the second power source 1b also needs to be stopped. This second DC / DC converter 12ab is effectively utilized. Therefore, the second input path switching unit 11b disconnects the connection line between the second DC / DC converter 12ab and the second power source 1b, and the second DC / DC converter 12ab is adjacent to the first DC. Path switching is performed so as to connect the power source 1a or the third power source 1c.

  When the second DC / DC converter 12ab fails, the second power supply 1b is connected to the second DC / DC converter 12ab and is supplied by the second DC / DC converter 12ab. In this case, the input path switching unit 11b connects the second power source 1b and the second DC / DC converter 12ab to effectively use the second power source 1b. The line is disconnected, and the second power supply 1b and the first DC / DC converter 12aa or the third DC / DC converter 12ac are connected. The second DC / DC converter 12ab disconnects the connection with the DC bus 12c by a switch arranged at the output of the second DC / DC converter 12ab.

In the power conversion system 100 of the present invention, a healthy part can be effectively utilized by cutting off the failed part as described above and connecting the healthy part connected to the failed part with another healthy part. .
Next, in the power conversion system 100 of the present invention, regarding the operation of the faulty part to be disconnected and the healthy part to be used, the operations at the time of the failure of the power source 1b and the failure of the DC / DC converter 12ab are also described. And explained.

  First, when the second power source 1b fails, as described above, the second DC / DC converter 12ab is connected to the first power source 1a or the third power source 1c. In this case, connection switching is determined by the power supply and load conditions. This determination method needs to be performed in consideration of constraints such as the amount of power that can be energized.

  In the operation at the time of failure of the second power source 1b of the power conversion system 100 according to the present invention, as described above, the second DC / s that are sound according to the states of the first power source 1a and the third power source 1c. By switching and operating the connection of the DC converter 12b, even when the second power source 1b breaks down, it is possible to supply the necessary power capacity of the system or supply the maximum power corresponding to the power source capacity. It is.

  FIG. 6 is a flowchart for explaining the connection switching control operation of the second DC / DC converter 12ab when the second power source 1b in FIG. 3 of Embodiment 1 of the present invention fails. When a controller in a control system (not shown) that controls the power conversion system 100 detects a failure of the second power source 1b, the controller supplies the power supply capability of the first power source 1a and the power supply capability of the third power source 1c. In comparison, for example, when the power supply capability of the first power supply 1a is large, the suppliable power of the first DC / DC conversion unit 12aa connected to the power supply and the second DC / DC conversion unit The required output power from 12ab to the DC bus 12c is compared. As a result, when the suppliable power of the second DC / DC converter 12ab is smaller than the required supply power to the DC bus 12c, the input path switching unit 11 causes the second DC / DC converter 12ab to When the first power source 1a is limited in its output by the power that can be supplied from the first DC / DC converter 12aa, the first power source 1a is originally connected to the power source 1a. The power value obtained by adding the suppliable power value of the second DC / DC converter 12ab to the suppliable power value of the first DC / DC converter 12aa that has been made can be supplied, and the required power capacity of the system even in the event of a failure Or, the maximum power supply capacity can be obtained.

  On the other hand, when the suppliable power value of the second DC / DC converter 12ab is larger than the necessary suppliable power value to the DC bus 12c, the above-described compared first DC / DC converter 12aa can be supplied. The power value is compared with the necessary supply power value to the DC bus 12c, and it is determined whether or not the first DC / DC converter 12aa is connected in parallel. If the suppliable power value of the first DC / DC converter 12aa and the third DC / DC converter 12ac is also larger than the required supply power value to the DC bus 12c, the second DC / DC converter 12ab Is disconnected from both sides and stops operating. By stopping the operation, it is possible to reduce the loss generated by the second DC / DC converter 12ab.

  Here, the power supply capability of the first power source 1a or the power supply capability of the third power source 1c varies depending on the solar radiation intensity, the temperature of each part, and the remaining capacity. The controller 14 provided in the power converter 12 infers from the communication from each power supply 1 or the information such as temperature and voltage obtained from the detection circuit and transmits the estimated information to the integrated controller 15. The signal indicating the connection destination of the second DC / DC converter 12ab is transmitted to the controller 14 of the power converter 12. The controller 14 possessed by the power conversion unit 12 receives this signal and controls the switching destination. Further, for example, when the first power source 1a is a power generation device and the third power source 1c is a power storage device, it may be preferentially determined so that supply from the first power source 1a is not restricted. Good. Furthermore, the power generation device priority or the power storage device priority may be set in advance by the user so that the user-specified power source is not restricted.

Next, the operation when the second DC / DC converter 12ab fails will be described.
As described above, when the second DC / DC converter 12ab fails, the second power source 1b is switched to the first DC / DC converter 12aa or the third DC / DC converter 12ac and connected. The

Since the power conversion system 100 of the present invention is also used for the purpose of supplying surplus power to the power system, as described above, the power generation device and the power storage device cannot be used due to the failure of the peripheral device. Then, since surplus power cannot be supplied, the amount of reduction in power charges due to power generation and power purchase suppression is reduced, resulting in an increase in running cost.
Even if the second DC / DC converter 12ab of the power conversion system 100 according to Embodiment 1 of the present invention fails, the second power supply connected to the failed second DC / DC converter 12ab By disconnecting 1b and connecting it to the first DC / DC converter 12aa or the third DC / DC converter 12ac, the power of the second power source 1b can be used effectively.

Since the operation method of the second power source 1b differs depending on whether the second power source 1b is a power generation device or a power storage device, each case will be described below. First, the case where all the power supplies 1 are power generation devices will be described.
When the power source 1 is a power generation device, outputting the generated power of the power generation device as much as possible leads to an increase in the amount of reduction in power charges. In addition, when power is supplied during a disaster, the external power supply is cut off, and the total amount of power that can be operated depends on the power generated by the power generator. From this, it is possible to maintain power supply for a longer period by outputting the generated power as much as possible.

  FIG. 7 is a flowchart for explaining the connection switching operation when the second DC / DC converter 12ab fails in the case where the power source 1 is entirely a power generation device in FIG. 3 of the first embodiment of the present invention. is there. When a controller in a control system (not shown) that controls the power conversion system 100 detects a failure of the second DC / DC converter 12ab, the other first DC / DC converter 12aa and the third DC are detected. The power supply margin of the DC / DC converter 12ac is compared.

  As a result, the power value obtained as a result of subtracting the power value that can be supplied from the first power source 1a from the power value that can be supplied from the first DC / DC converter 12aa can be supplied to the third DC / DC converter 12ac. When the power value is greater than the power value obtained by subtracting the power value that can be supplied from the third power source 1c from the power value, the first power source 1a and the first power source 1a are connected to the input of the first DC / DC converter 12aa. The path is switched so as to connect the second power source 1b in parallel.

  Further, the power value obtained by subtracting the power value that can be supplied from the first power source 1a from the power value that can be supplied from the first DC / DC converter 12aa is the power that can be supplied from the third DC / DC converter 12ac. In the case where the value becomes smaller than the power value obtained by subtracting the suppliable power value from the third power source 1c from the value, the input to the third DC / DC converter 12ac is connected in parallel with the third power source 1c. The path is switched so as to connect the second power source 1b.

  Here, the power supply capability of the first power source 1a and the third power source 1c and the power that can be supplied by the DC / DC converter 12a vary depending on the solar radiation intensity, the temperature of each part, etc. 12 is inferred from communication from each power supply 1 or information such as temperature and voltage obtained from the detection circuit and transmitted to the integrated controller 15, and the integrated controller 15 determines and compares the state of the power supply 1. Then, a signal indicating the connection destination of the DC / DC converter 12a is transmitted to each power conversion unit 12. The controller 14 possessed by the power conversion unit 12 receives this signal and controls the switching destination of the power conversion unit 12.

  Moreover, the maximum electric power which can be taken from each power supply 1 may not be taken out at the time of parallel connection by the impedance difference and characteristic difference (for example, the maximum power point characteristic in solar power generation) of a power generator. In such a case, a means for detecting the output power characteristic of the power generation device is provided, and by comparing and determining, for example, the first power source 1a is disconnected and the second power source 1b is connected. It is also possible to adopt a connection method that can obtain power.

  Next, the case where all the power sources 1 are power storage devices will be described. When the power source 1 is a power storage device, it is often a voltage source as its characteristics. In parallel connection of voltage sources, if the potential difference between the power storage devices connected in parallel is not sufficiently reduced, there is a risk that an excessive current flows from the high voltage side to the constant voltage side. In a storage battery or the like, since a large current is required to fill the voltage difference, an excessive current may continue for a long time.

  Further, in power storage devices, it is important to use power capacity more effectively than electric power during normal times other than disasters. In other words, in the case of an application that charges (charges) as much as possible during nighttime, when the power consumption is relatively low, such as peak cut operation, and discharges as much as possible during the time when power consumption is high, such as during the daytime. Since it is desirable to cover the daytime power consumption with the stored power, the total amount of daytime power consumption needs to be stored at night. However, when the power capacity of the power storage device decreases due to a failure or the like, there arises a disadvantage that the daytime power consumption cannot be covered. Therefore, when the power storage device is switched, the power source 1 is connected to the DC / DC converter 12a instead of being connected in parallel, and the power capacity of the power storage device is operated as much as possible. Moreover, since the deterioration of the storage battery is accelerated depending on the frequency of use, it is desirable that each storage battery is used on average. In view of such a case, the storage capacity is set to a larger power capacity than the daytime power consumption so that the daytime power consumption can be covered by the stored power even in the event of a failure, which is a factor in increasing the system cost. It was.

  FIG. 8 is a flowchart for explaining the connection switching operation when the second DC / DC converter 12ab fails in the case where the power source 1 is entirely a power storage device in FIG. 3 of the first embodiment of the present invention. is there. When a controller in a control system (not shown) that controls the power conversion system 100 detects a failure of the second DC / DC converter 12ab, it determines whether the system is discharging or storing electricity. Then, the remaining capacity of the power source 1 is compared. As a result, switching control is performed as follows.

  When the system discharge amount is compared with the system charge amount, and the system discharge amount is larger than the system charge amount, the power capacity of the first power source 1a, the power capacity of the second power source 1b, The power capacities of the power supplies 1c are compared, and the upper two power supplies 1 are connected to different first DC / DC converters 12aa or third DC / DC converters 12ac as power capacities. For example, when the power capacity value of the first power source 1a is larger than the power capacity value of the second power source 1b, and the power capacity value of the second power source 1b is larger than the power capacity value of the third power source 1c. The first power source 1a is connected to the first DC / DC converter 12aa, the second power source 1b is connected to the third DC / DC converter 12ac, and the third power source 1c is DC / DC converted. The device 12a is disconnected from the DC bus 12c. When the power capacity is the same, switching is not performed in order to reduce power fluctuation at the time of switching as much as possible.

  As described above, since it is possible to discharge from a storage battery having a larger remaining power, the power conversion system can discharge and output larger power. Moreover, since it becomes possible to discharge electric power from each storage battery on average, it is possible to suppress unevenness in the degree of deterioration of the storage battery without uneven power capacity. Furthermore, since the storage batteries are not connected in parallel, an excessive current does not flow.

Next, a case where the system discharge amount is smaller than the system charge amount will be described.
The power capacity of the first power supply 1a, the power capacity of the second power supply 1b, and the power capacity of the third power supply 1c are compared, and the lower two power supplies are connected to different DC / DC converters 12a as power capacity values. For example, when the power capacity value of the first power source 1a is smaller than the power capacity value of the second power source 1b, and the power capacity value of the second power source 1b is smaller than the power capacity value of the third power source 1c. The second power supply 1b is connected to the first DC / DC converter 12aa, the third power supply 1c is connected to the third DC / DC converter 12ac, and the first power supply 1a is connected to the first DC / DC converter 12aa. Disconnect from the DC / DC converter 12aa. When the power capacity is the same, switching is not performed in order to reduce power fluctuation at the time of switching as much as possible.

  As described above, it is possible to preferentially charge a storage battery having a smaller remaining power capacity, so that it is possible to charge each storage battery on average, and to suppress a bias in the degree of deterioration of the storage battery. Furthermore, since the storage batteries are not connected in parallel, an excessive current does not flow.

Next, a case where a power generation device and a power storage device coexist as the power source 1 will be described.
When the power generation device and the power storage device coexist as the power source 1, the power conversion system 100 according to the present invention performs the path switching by performing the above-described determination basically giving priority to the output of the power generation device. However, when the power supply from the power system is interrupted at the time of a disaster, or when there is a priority power supply command by a user setting at night, the above-mentioned determination is performed while giving priority to the output of the power storage device, and the path is switched.

  In the power conversion system 100 according to Embodiment 1 of the present invention, as described above, when a failure occurs in each part, the failure part is separated and the connection of the healthy part is switched, so that the healthy part can be effectively used. In addition, it is not necessary to have an extra power source or power conversion unit for redundancy, and the system cost can be reduced.

In this power conversion system 100, as shown in FIG. 3 in which each unit is divided, an input path switching unit that interconnects adjacent power conversion units independently of the conventional power conversion system. 11, the input path switching unit 11 is detachable. Normally, the input path switching unit 11 is operated only when a failure occurs by operating the power conversion units independently. Can be attached to deal with the failure.
That is, FIG. 3 shows a state in which the input path switching unit is attached, and a general usage state is obtained by deleting the input path switching units 11a, 11b, and 11c and the lines connecting them to each other from FIG. This is the configuration of the power conversion system.
The above-described controller is configured to be included in the block of the input path switching unit to be added.

Embodiment 2
The configuration of the power conversion system according to the second embodiment of the present invention is the same as that shown in FIGS. 1 and 2 described in the first embodiment.
In the power conversion system 100 according to the second embodiment of the present invention, the connection switching operation is applied to other than the time of failure so that the power generation device and the power storage device can be effectively used. The operation will be described below.

First, the switching operation for outputting a larger amount of power generation will be described.
In general, the power converter 12 is limited in the power that can be energized due to restrictions due to size and introduction cost. In addition, the power that can be supplied to the power conversion unit 12 may be further limited due to the influence of temperature and power system fluctuations. Due to this limitation, the power generated by the power generator may not be sufficiently discharged.
In the power conversion system 100 according to the second embodiment of the present invention, in order to be able to output a larger amount of power generation, the path is switched as follows.

  FIG. 9 is a flowchart illustrating a control example of the switching operation for outputting a larger amount of power generation. In the power control system including the power conversion system, when the control controller detects the output restriction state of the power conversion unit, this flow starts, and the output restriction state and the power source type of the adjacent power conversion unit are determined. When the output is not limited and the adjacent power source is a power generation device, the power source that is output limited and the adjacent power source are connected in parallel, and the power conversion unit that is output limited Adjacent power converters are connected in parallel. When the adjacent power source is a power storage device, the power conversion unit connected to the general power storage device is disconnected from the power storage device, and the output from the power generation device whose output is restricted is input to the general power conversion unit. The power converters are driven in parallel.

  In Embodiment 2 of the present invention, by performing input switching as described above, when the power generation device is output limited due to the convenience of the power conversion unit, by using a power conversion unit that is not output limited, It is possible to suppress the power generation device from being limited in output, and it is possible to output a larger amount of power generation.

Next, a switching operation for effectively using the storage battery will be described.
It is necessary to prevent life deterioration and destruction due to heat generation and the like, and there is a difference between power that can be supplied instantaneously and power that can be supplied constantly. In general, in order to prevent the apparatus cost from increasing, the power conversion unit determines the power to be handled on the basis of the power that can be constantly supplied, not the power that can be supplied instantaneously. However, when the power supply is cut off at the time of a disaster and the load is driven only by the power supply from the power generation device or power storage device, the power that can be constantly supplied during an instantaneous overload such as startup may become insufficient. is there. For this reason, in the power conversion unit according to Embodiment 2 of the present invention, the power conversion unit is disconnected from the power generation device when the power generation device at the start of operation at the time of disaster or when the power generation device is stopped at night or the like. Is connected in parallel to the power conversion unit that is originally connected to the power storage device, thereby increasing the power that can be instantaneously output from the power storage device.

  In addition, it detects the deterioration state of the storage battery, disconnects the storage battery with the most severe deterioration of the storage battery, connects the storage battery with relatively little deterioration of the storage battery to the power conversion unit connected to the storage battery with the strong deterioration, and is originally connected By driving in parallel with the power conversion unit, the deterioration variation of the storage battery is suppressed. Thereby, the life extension of the apparatus due to variation in deterioration of the storage battery can be realized.

  In the power conversion system according to the second embodiment of the present invention, as described above, the power generation device and the power storage device are effectively used by performing path switching according to the state of the power generation device, the power storage device, and the load. Therefore, the system cost of the power conversion system can be reduced.

Embodiment 3
The configuration of the power conversion system according to the third embodiment of the present invention is the same as that shown in FIGS. 1 and 2 shown in the first embodiment.
In the power conversion system 100 according to the third embodiment of the present invention, the input path switching unit 11, the power conversion unit 12, and the output path switching unit 13 are individually unitized, and each unit has an interface with a different power source 1. is there. In this way, by configuring each unit as a unit that can be separated and connected, it becomes easy to select a wide range of system configurations, and the system can be constructed without a dedicated design, thereby reducing system construction costs. Is possible.

  FIG. 10 shows an example of the unit configuration of the power conversion system 100 according to Embodiment 3 of the present invention. In the figure, a double-headed arrow indicates that connection is possible. The input path switching unit 11 includes a power storage device interface, one or both of the power generation device interfaces, and a path switching circuit unit that switches an input path. The power conversion unit 12 includes a power conversion unit and / or a power generation device interface, an output load interface and / or a power system interface, and a power conversion unit. The output path switching unit 13 includes an output load interface and / or an electric power system interface, and an output path switching circuit. For each unit of the power conversion system 100, the power storage device, the power generation device, the load, and the power system can be interconnected as shown in FIG.

  As shown in FIG. 10, the power generation device interface, the power storage device interface, the load interface, and the power system interface are configured to be separable and connectable. By appropriately connecting the respective input / output systems, the overall function can be achieved. An unnecessary interface can be removed, and can be connected to other units and operated even when the interface is removed.

In addition, each unit may be provided with a unit having a plurality of power capacities for each configuration. In this case, various input / output power requirements can be realized.
Furthermore, the configuration of each unit is not limited to that shown in FIG. 10. For example, the power conversion unit 12 may exclude the power storage device interface, and the power storage device interface and the power conversion unit can be removed. Accordingly, the unit may be removed to reduce the cost of the unit.
The power conversion system 100 according to the third embodiment of the present invention is configured as described above, thereby requesting various input / output requests such as a power generation device, a power storage device, a load, and a power system by combining units. Can be realized.

In the drawings for explaining the above embodiments, the same reference numerals denote the same or corresponding parts, respectively, and related parts are given related numbers.
Further, within the scope of the present invention, the present invention can be freely combined with the embodiments, and arbitrary components of the embodiments can be appropriately changed or omitted.

DESCRIPTION OF SYMBOLS 1 Power supply, 1a 1st power supply, 1b 2nd power supply, 1c 3rd power supply 2 Output part, 3 input part, 11 Input path switching part, 11a 1st input path switching part, 11b 2nd input path switching 11c third input path switching unit,
12 power converter, 12a DC / DC converter, 12aa first DC / DC converter,
12ab second DC / DC converter, 12c third DC / DC converter,
12c DC bus, 13 output path switching unit, 14 controller,
15 integrated controller, 100 power conversion system

Claims (9)

  A plurality of input units to which power sources are respectively connected, a plurality of power conversion units provided corresponding to each of the input units, and provided between the input unit and the power conversion unit, An power conversion system comprising: an input path switching unit that switches a connection relationship with the power conversion unit according to a predetermined condition.   The power conversion system according to claim 1, wherein the input path switching unit is configured to be detachable.   The power source is a first power source and a second power source, the input unit includes a first input unit and a second input unit, and the power converter unit includes a first power converter unit and a second power unit. A power converter, and disconnecting the connection between the first input unit connected to the first power source and the first power converter when the first power source is faulty; 2. The power according to claim 1, wherein the connection relationship is switched by the input path switching unit so that the second input unit connected to the power source is connected to the first power conversion unit. Conversion system.   The power conversion system according to claim 1, further comprising a circuit including a current limiting element that performs current limiting when the input path switching unit is opened and closed.   2. The power conversion system according to claim 1, wherein the energizable power of the plurality of power conversion units is compared, and the input path is switched in the input path switching unit so that the energizable power becomes a maximum.   The power supply connected to a plurality of the input units is a plurality of power storage devices, acquires deterioration information of the power storage device, and switches the input path so as to preferentially charge / discharge from the power storage device with less deterioration The power conversion system according to claim 1, wherein the input path is switched by the unit.   When the power source is a first power source that is a power generation device and a second power source that is a power storage device, input is performed by the input path switching unit in order to prioritize the output of either the power generation device or the power storage device The power conversion system according to claim 1, wherein a path switching operation is performed.   The power conversion system according to claim 1, wherein the input path switching unit and the plurality of power conversion units are configured by separable units.   9. The input path switching unit and the power conversion unit configured by the separable unit include a detachable power generation device interface, a power storage device interface, a load interface, and a power system interface. The power conversion system described in 1.