JP2016039761A - Controller for power conversion device, power system, and control method for power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable quick start-up even in a state in which charging/discharging using a storage battery is stopped, and suppress a power loss in the charging/discharging stop state.SOLUTION: A CSP 30 is a controller for a PCS 28. The PCS 28 is provided between a power system 16 and a storage battery 26 connected to the power system 16 and includes a power conversion unit for performing conversion between DC power and AC power and a breaker for connecting or disconnecting the storage battery 26 and the power system 16. The CSP 30, in the case of stopping charging/discharging using the storage battery 26, selects a first stop mode in which the power conversion unit is stopped without performing disconnection using the breaker or a second stop mode in which the power conversion unit is stopped together with disconnection using the breaker.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for a power conversion device, a power system, and a control method for the power conversion device.

  Some power generation devices linked to the power system include a storage battery, and charge and discharge the storage battery to level the amount of power transmitted to the power system.

For example, when the power generation device is solar power generation, leveling operation using a storage battery is not necessary because it does not generate power at night. For this reason, in order to reduce unnecessary power loss of the power generation system by solar power generation, the operating state and the stopped state of the power generation system are managed based on the time schedule in which the start time and stop time of the power generation system are set. .
Moreover, in patent document 1, when the state where the fluctuation | variation of the generated electric power of a power generator becomes smaller than a predetermined | prescribed reference | standard continues for the predetermined period or more, charging / discharging which stops charging / discharging control of a storage battery, and extends the life of a storage battery The system is described.

  Thus, a technique for stopping charging / discharging from the storage battery has been developed.

Japanese Patent No. 5355721

  However, even if charging / discharging from the storage battery is stopped as in Patent Document 1, if the generated power of the power generation apparatus is increased or decreased more than necessary, quick charge / discharge activation is required. For this purpose, it is preferable not to stop the power conversion device that is connected to the storage battery and converts DC power and AC power, but it is useless to operate the power conversion device until charging / discharging from the storage battery is unnecessary. Cause significant power loss.

  The present invention was made in view of such circumstances, and can be quickly started even if charging / discharging from the storage battery is in a stopped state, and suppresses power loss in the charging / discharging stopped state, It aims at providing the control apparatus of a power converter device, a power system, and the control method of a power converter device.

  In order to solve the above-described problems, the power converter control device, power system, and power converter control method of the present invention employ the following means.

  A control device for a power conversion device according to the first aspect of the present invention is provided between a storage battery connected to a power system and the power system, and a power conversion unit that converts direct current power and alternating current power, and the storage battery, A control device for a power conversion device having a switch for connecting or disconnecting the power system, wherein when stopping charging / discharging by the storage battery, the power conversion unit is stopped without being cut off by the switch. A selection unit that selects a stop mode or a second stop mode that stops the power conversion unit together with a cutoff by the switch based on a schedule or prediction of a required power amount of the power system, and the selection unit selected by the selection unit Stop means for stopping charging and discharging by the storage battery in the first stop mode or the second stop mode.

  The storage battery according to this configuration is connected to the power system, and for example, leveles the power transmitted from the power generation device to the power system. For example, when the generated power of the power generator is greater than the demand from the power system, the storage battery charges the surplus of the generated power. On the other hand, when the generated power of the power generation device is less than the demand from the power system, the storage battery is discharged to transmit the shortage to the power system.

And since a storage battery performs charging / discharging by direct current | flow, while an electric power grid | system performs alternating current power transmission, direct-current power and alternating current power are converted by the power converter device provided between a storage battery and an electric power system.
The power converter includes a power converter that converts DC power and AC power, and a switch that connects or disconnects the storage battery and the power system. The power conversion unit is configured using, for example, an IGBT (Insulated Gate Bipolar Transistor). The switch physically connects or disconnects the storage battery and the power system.

When stopping charging / discharging by the storage battery, the first stop mode or the second stop mode is selected by the selection unit based on the schedule or prediction of the required power amount of the power system. The first stop mode is a stop mode in which the power conversion unit is stopped without being interrupted by a switch. The second stop mode is a stop mode in which the power conversion unit is stopped together with the interruption by the switch. And charging / discharging by a storage battery is stopped by a stop means in the selected 1st stop mode or 2nd stop mode.
By stopping the power conversion unit, it is possible to suppress power loss when charging / discharging by the storage battery is stopped. Moreover, even if it stops, a power converter can be started rapidly.

  On the other hand, if the storage battery and the power system are cut off by the switch, it takes time to connect again. For this reason, in the 1st stop mode in which the interruption | blocking by a switch is not performed, resumption of charging / discharging of a storage battery can be performed rapidly. On the other hand, in the 2nd stop mode which also performs interruption | blocking by a switch, although time is required for restarting charging / discharging of a storage battery, a power loss becomes smaller.

  As described above, when charging / discharging by the storage battery is stopped, by using the first stop mode and the second stop mode properly, even if charging / discharging from the storage battery is stopped, quick start-up is possible and charging / discharging is possible. The power loss in the stop state can be suppressed.

  In the first aspect, the switch may be provided between the power conversion unit and the storage battery.

  According to this configuration, since the power conversion unit and the storage battery are cut off, it is possible to prevent the charging power of the storage battery from being consumed by the power conversion unit due to spontaneous discharge, and thus it is possible to suppress power loss in the charge / discharge stop state. .

  In the first aspect, when a power generation device is connected to the power system and the required power amount of the power system is larger than the power generation amount of the power generation device, the storage battery is discharged to compensate for the insufficient power amount. Also good.

  According to this configuration, the amount of power transmitted to the power system can be leveled.

  In the first aspect, in the case where the selection unit charges / discharges the storage battery from the state where charging / discharging by the storage battery is stopped in the second stop mode, the time when the time reaches a time earlier than the start time of charge / discharge The first stop mode may be selected.

  According to this configuration, while the second stop mode has a small power loss, the first stop mode starts quickly, so that the power loss when the power conversion device is stopped for a long time is suppressed and the charge / discharge from the storage battery is quickly performed. Can start.

  In the first aspect, the switch is a first switch provided between the power conversion unit and the power system, a second switch provided between the power conversion unit and the storage battery, and the power system. After charging and discharging the storage battery until the generated power of the power generation device connected to the power system becomes equal to the required power amount of the power system, the selection means is based on the schedule or prediction of the required power amount of the power system, The first stop mode or the second stop mode is selected, and as the second stop mode, the first switch is shut off and the second switch is not shut off, or the first switch and the first switch You may select the all interruption | blocking mode which interrupts | blocks 2 switches.

According to this configuration, the first switch is provided between the power conversion unit and the power system, and the second switch is provided between the power conversion unit and the storage battery. The partial cut-off mode in which the first switch is cut off and the second switch is not cut off has a large power loss although the startup time of the power conversion device is shorter than the full cut-off mode in which the first switch and the second switch are cut off.
Therefore, this structure can stop a power converter more efficiently by selecting partial cut-off mode or all cut-off mode according to time to stop a power converter.

  In the first aspect, the selection unit selects the partial cut-off mode when a voltage transmitted from the power generation device to the power system fluctuates in a state where the power conversion device is in the first stop mode. May be.

According to this configuration, the storage battery is used to level the power transmitted from the power generation device to the power system.
Here, since the power conversion device outputs reactive power using the filter circuit, there is a possibility that the voltage transmitted from the power generation device to the power system may fluctuate in the state of the first stop mode. For this reason, when the transmission voltage to the power system varies in the state of the first stop mode, the partial cut-off mode is selected. In the partial cut-off mode, the power conversion device and the power system are cut off, so that the transmission voltage to the power system is not changed by the reactive power generated by the power conversion device.
Therefore, this structure can prevent the fluctuation | variation of the transmission voltage which arises by stopping a power converter device.

  In the first aspect, when the selection unit stops charging / discharging from the storage battery for a predetermined time or more, the all cutoff mode may be selected.

  According to this configuration, since the power loss is small in the full cut-off mode, it is possible to suppress the power loss when the power converter is stopped.

  The electric power system which concerns on the 2nd aspect of this invention is the electric power which has the switch which connects or interrupts | blocks the storage battery connected to an electric power grid, the electric power conversion part which converts direct-current electric power, and alternating current electric power, and the said electric battery. A conversion device and the control device described above are provided.

  A method for controlling a power conversion device according to a third aspect of the present invention is provided between a storage battery connected to a power system and the power system, a power conversion unit that converts DC power and AC power, and the storage battery. A control method for a power conversion device having a switch for connecting or disconnecting the power system, wherein when stopping charging / discharging by the storage battery, the power conversion unit is stopped without being shut off by the switch. A first step of selecting a stop mode or a second stop mode for stopping the power conversion unit together with the interruption by the switch based on a schedule or prediction of a required power amount of the power system, and the selected first stop mode Or the 2nd process of stopping charging and discharging by the storage battery by the 2nd stop mode.

  ADVANTAGE OF THE INVENTION According to this invention, even if charging / discharging from a storage battery is made into a stop state, it has the outstanding effect that a quick start is possible and the power loss in the stop state of charging / discharging can be suppressed.

It is a lineblock diagram of an electric power system concerning an embodiment of the present invention. It is a block diagram which shows the electric constitution of PCS which concerns on embodiment of this invention. It is a block diagram which shows the electric constitution of CSP which concerns on embodiment of this invention. It is a schematic diagram which shows the selection state of the stop mode which concerns on embodiment of this invention. It is a graph which shows the example of operation of stop mode selection concerning an embodiment of the present invention. It is a graph which shows the example of operation in the case of satisfy | filling system | strain required electric energy only by a power generator. It is a graph which shows the other example of operation of stop mode selection concerning an embodiment of the present invention. It is a graph which shows the operation example of stop mode selection at the time of using a power generator concerning an embodiment of the present invention as a solar cell.

  Hereinafter, an embodiment of a control device for a power conversion device, a power system, and a control method for a power conversion device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a power system 10 according to the present embodiment.

  The power system 10 includes a power generation device 12 and a power storage system (hereinafter referred to as “ESS”) 14. The power system 10 is grid-connected to the power system 16 via the transformer 18 and transmits power to the power system 16.

The power generation device 12 is connected to the power system 16 and transmits the generated power to the power system 16.
As an example, the power generation device 12 is a gas turbine 24 in which a generator 22 is provided on a rotary shaft 20.

  The ESS 14 includes a storage battery 26, a bidirectional power conversion device (Power Conditioning System, hereinafter referred to as “PCS”) 28, and a control device (Control System Panel, hereinafter referred to as “CSP”) 30.

The storage battery 26 is connected to the power system 16 via the PCS 28 and leveles the power transmitted from the power generator 12 to the power system 16. For example, when the power generation amount of the power generation device 12 is larger than the required power amount from the power system 16 (hereinafter referred to as “system required power amount”), the storage battery 26 charges the surplus of the generated power. On the other hand, when the system required power amount is larger than the generated power amount of the power generation device 12, the power amount that is insufficient due to the discharge of the storage battery 26 is transmitted to the power system 16 to compensate.
In addition, although the storage battery 26 is not specifically limited, such as a lithium ion secondary battery, a lead storage battery, and a nickel hydride secondary battery, it is preferable that the followability of charging / discharging is good.

And the storage battery 26 performs charging / discharging by direct current, while the electric power grid | system 16 performs alternating current power transmission.
For this reason, DC power and AC power are converted by the PCS 28 provided between the storage battery 26 and the power system 16.

FIG. 2 is a block diagram showing an electrical configuration of the PCS 28.
The PCS 28 includes a power conversion unit 31 that converts DC power and AC power, and circuit breakers 32-1 and 32-2 that are switches that connect or block the storage battery 26 and the power system 16.

The power conversion unit 31 is configured using, for example, an IGBT (Insulated Gate Bipolar Transistor).
The circuit breaker 32-1 is provided between the power conversion unit 31 and the power system 16, and the circuit breaker 32-2 is provided between the power conversion unit 31 and the storage battery 26. Thereby, the circuit breakers 32-1 and 32-2 physically connect or block the storage battery 26 and the power system 16.
In addition, in the following description, when distinguishing each circuit breaker 32-1 and 32-2, either 1 or 2 is attached | subjected to the end of a code | symbol, and each circuit breaker 32-1 and 32-2 is not distinguished. In this case, 1 and 2 are omitted.

  Further, a filter circuit 34 that is an LC filter is provided between the power conversion unit 31 and the circuit breaker 32-1.

The CSP 30 controls the start and stop of the PCS 28 and charging / discharging of the storage battery 26 and monitors the charge rate (SOC) of the storage battery 26.
The CSP 30 includes, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program as an example, and the CPU reads the program into a RAM or the like to execute information processing / arithmetic processing. As a result, various functions are realized. The program is preinstalled in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Etc. may be applied. The computer-readable storage medium is a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

  The CSP 30 stops the PCS 28 when power transmission / reception of the ESS 14 (charging / discharging of the storage battery 26) is unnecessary in order to suppress power loss. The CSP 30 according to the present embodiment selectively controls the stop state of the PCS 28 from a plurality of stop modes according to the power demand request schedule from the power system 16 and the power demand situation.

FIG. 3 is a block diagram showing an electrical configuration of the CSP 30 relating to activation and deactivation of the PCS 28.
The CSP 30 includes a storage unit 40, a selection unit 42, a stop unit 44, and an activation unit 46.

The storage unit 40 stores a time schedule that is a power demand request schedule.
The time schedule is a schedule showing a time change of the system required power amount based on the schedule or prediction of the system required power amount, and the system required power amount is shown for each time. The time schedule is updated and stored in the storage unit 40 every day by, for example, an administrator of the power system 16 that instructs the power generation amount of the power generation facilities existing in each place with respect to the power demand.

The selection unit 42 is based on a time schedule read from the storage unit 40, a difference between the grid required power amount and the generated power amount, or a power generation end voltage whose details will be described later, a predetermined stop mode among a plurality of stop modes, Alternatively, the activation of the stopped PCS 28 is selected.
Since the selection unit 42 selects the stop mode and activation based on a predetermined time schedule, the PCS 28 can be efficiently stopped and activated.

  When the selection unit 42 selects the stop mode, the stop unit 44 stops the PCS 28 according to the selected stop mode. When the PCS 28 is stopped, charging / discharging of the storage battery 26 is stopped.

  When the selection unit 42 selects the activation of the PCS 28, the activation unit 46 activates the PCS 28. When the PCS 28 is activated, charging / discharging of the storage battery 26 is started.

  Next, details of the stop mode according to the present embodiment and the operation of the CSP 30 according to the present embodiment will be described.

The first stop mode and the second stop mode are set as stop modes when charging / discharging by the storage battery 26 is stopped. The first stop mode is a stop mode in which the power conversion unit 31 is stopped without being interrupted by the circuit breaker 32. The second stop mode is a stop mode in which the power conversion unit 31 is stopped while being interrupted by the circuit breaker 32.
Thus, both the first stop mode and the second stop mode stop the power conversion unit 31. By stopping the power conversion unit 31, it is possible to suppress power loss when charging / discharging by the storage battery 26 is stopped. Moreover, even if it stops, the power conversion part 31 can be started rapidly since it only switches on and off of switching elements, such as IGBT.

A semiconductor element such as an IGBT constituting the power conversion unit 31 can perform high-speed switching, but switching on and off of the circuit breaker 32 requires more time than a semiconductor element such as an IGBT. For this reason, when the storage battery 26 and the electric power system 16 are shut off by the circuit breaker 32, it takes time to connect again. Therefore, in the first stop mode in which the interruption by the breaker 32 is not performed, the recharging / discharging of the storage battery 26 can be quickly performed. On the other hand, in the second stop mode in which the interruption by the breaker 32 is also performed, it takes time to restart charging and discharging of the storage battery 26, but the power loss becomes smaller as will be described in detail later.
Thus, when charging / discharging by the storage battery 26 is stopped, by using the first stop mode and the second stop mode properly, quick start (return) is possible even if charging / discharging from the storage battery 26 is stopped. And the power loss in the stop state of charging / discharging can be suppressed.

  In the present embodiment, as the second stop mode, the circuit breaker 32-1 is blocked and the circuit breaker 32-2 is not blocked, or the circuit breaker 32-1 and the circuit breaker 32-2 are blocked. All block mode is set.

Table 1 below shows the characteristics of each stop mode.

The first stop mode does not shut off the circuit breaker 32 as described above. And as above-mentioned, even if it stops, the power conversion part 31 can start quickly, since it only switches on / off of switching elements, such as IGBT.
For this reason, the activation time which is the time required to activate the stopped PCS 28 is the shortest. On the other hand, since the circuit breaker 32 is physically switched between connection and disconnection, its operation time is longer than on / off of the switching element.

Further, the start-up time is the longest in the all-blocking mode. This is because the circuit breaker 32-2 provided between the power conversion unit 31 and the storage battery 26 is blocked. If the circuit breaker 32-2 is turned on again after the circuit breaker 32-2 is blocked (off), an inrush current may flow from the storage battery 26 to the PCS 28.
Therefore, in order to prevent the occurrence of inrush current, the storage battery 26 is connected to a capacitor of an initial charging circuit (not shown) provided between the storage battery 26 and the power conversion unit 31 before turning on the circuit breaker 32-2. Is charged, and the potential difference between the storage battery 26 and the power converter 31 is made equal. Thereafter, the circuit breaker 32-2 is turned on, and the storage battery 26 can be charged and discharged. As described above, in the start-up from the full cut-off mode, it takes time to charge the capacitor for preventing the occurrence of the inrush current, so that the start-up time becomes long.

Further, the total cutoff mode has a smaller power loss than the first stop mode and the partial cutoff mode.
The reason for this is that, in the full cutoff mode, the power conversion unit 31 and the storage battery 26 are cut off, so that the charging power of the storage battery 26 is prevented from being consumed by the power conversion unit 31 due to natural discharge. On the other hand, since the power conversion unit 31 and the storage battery 26 are connected in the first stop mode and the partial cut-off mode, the charging power of the storage battery 26 is gradually consumed by the power conversion unit 31. Power loss.
Thus, although the first stop mode and the partial cut-off mode are short in startup time, it is preferable that the time for stopping the PCS 28 in the first stop mode and the partial cut-off mode is short from the viewpoint of power loss.

In addition, the first stop mode has lower voltage stability than the second stop mode. The voltage stability is an index that is better as the fluctuation of the power generation end voltage is smaller. As shown in FIG. 1, the power generation end voltage is measured on the power system 16 side from the transformer 18.
The PCS 28 outputs reactive power by the filter circuit 34. For this reason, in the first stop mode in which the circuit breaker 32-1 is not shut off, the power generation end voltage may fluctuate due to excessive or insufficient supply of reactive power, and fluctuations in the power generation end voltage are undesirable.
For this reason, when the power generation end voltage fluctuates while the PCS 28 is in the first stop mode, the second stop mode is selected. In the second stop mode, the PCS 28 and the power system 16 are cut off, so that the power generation end voltage is not affected by the reactive power output from the filter circuit 34. Thereby, the fluctuation | variation of the electric power generation end voltage which arises by stopping PCS28 is prevented.
As described above, in the first stop mode, there is a possibility that the power generation end voltage may fluctuate. From the viewpoint of voltage stability, it is preferable that the time for stopping the PCS 28 in the first stop mode is short.

As described above, each stop mode has a difference in start-up time, power loss, and voltage stability, and has contradictory characteristics.
Therefore, for example, as shown in FIG. 4, the selection unit 42 selects the all-blocking mode when the stop time of the PCS 28 is long and selects the first stop mode when the stop time of the PCS 28 is short according to the time schedule. To do. Then, when the system required power amount and the generated power amount do not match, the selection unit 42 selects activation of the PCS 28. Thereby, the starting part 46 starts PCS28, ESS14 makes the storage battery 26 charge or discharge, and makes the electric power transmitted to the electric power grid | system 16 correspond with the system | strain required electric energy.

  Further, even when the first stop mode is selected, the selector 42 selects the partial cut-off mode and changes the first stop mode to the partial cut-off mode when the generation end voltage varies. As an example, it is assumed that the power generation end voltage fluctuates when the time change exceeds a predetermined value. In addition, since the fluctuation | variation of an electric power generation end voltage may be temporary, the selection part 42 may select a 1st stop mode again after progress for a predetermined time, and may make it change from a partial interruption | blocking mode to a 1st stop mode. .

  Here, as described above, in this embodiment, the stop mode is selected based on the time schedule as an example. Thus, the CSP 30 controls the PCS 28 based on the schedule or prediction of the system required power amount. For example, when the time required for the system required power amount is close due to the time schedule (for example, 5 minutes before) or an increase in the system required power amount can be expected, the PCS 28 can be started in the shortest time as the stop mode. One stop mode is selected. Note that the increase in system power requirement that is not in the time schedule is, for example, when the actual temperature is higher or lower than expected, causing a significant deviation from the predicted value, or in an emergency (disaster or unexpected power plant shutdown) This is a prediction that requires a power value not in the time schedule.

FIG. 5 is a graph showing an operation example of stop mode selection according to the present embodiment.
FIG. 5 shows a selection state of the stop mode in the time schedule in which the system power requirement increases from 75% to 100% (rated value) of the generated power.

When the generated power is 75%, the PCS 28 is in a stopped state because the system required power amount can be covered only by the power generator 12. In the example of FIG. 5, since the generated power has a long state of 75%, the PCS 28 is stopped in the full interruption mode with the least power loss.
The time schedule is set so that the system power requirement increases to 100% from time t.

  However, the power generation device 12 cannot increase the generated power sharply. In order to set the generated power to 100% at time t, the power generation device 12 needs to gradually increase the generated power from the time before that as shown in FIG. However, the generated power in the increasing stage (region A in FIG. 6) exceeds the grid power requirement and is a wasteful power generation.

Therefore, the ESS 14 capable of sharp power transmission discharges at time t, thereby performing power transmission that supplements the system power requirement. On the other hand, the power generator 12 increases the generated power from time t. The power generated from the power generator 12 becomes the time t ₂ has been reached the system power requirements, ESS14 stops power transmission.

Here, the PCS 28 is stopped in the full cutoff mode in a state where the generated power satisfies the system power requirement. And, as shown in Table 1, it takes time to start the PCS 28 from the full shutdown mode.
For this reason, the selection part 42 which concerns on this embodiment is charging / discharging, when charging / discharging the storage battery 26 based on a time schedule in the state in which PCS28 was set to the 2nd stop mode (all interruption | blocking mode in the example of FIG. 5). to select the first stop mode reaches the fast time t ₁ a predetermined period of time than the start time t.
As a result, the second stop mode has less power loss, while the first stop mode starts quickly, so the CSP 30 suppresses power loss when the PCS 28 is stopped for a long time and starts charging / discharging the storage battery 26 quickly. it can.

Then, after the CSP 30 charges and discharges the storage battery 26 until the generated power of the power generation device 12 becomes equal to the system required power amount, the selection unit 42 selects the first stop mode or the second stop mode (one Part cut-off mode or full cut-off mode).
In the example of FIG. 5, the selection unit 42 at time t ₂ is to select a total shut-down mode, stopping the PCS28.
In the case stopping PCS28 is short, the selection unit 42 at time t ₂ may be selected cutoff mode first stop mode or in part.

Further, in the example of FIG. 5, the PCS 28 in the all cut-off mode is set to the first stop mode at the time t _1. However, the present invention is not limited to this, and it is necessary to cope with a sudden system power demand that is not in the time schedule before the time t _1. if there is a request or the like to speed up the response speed at that time, a part cut off mode instead of the total shut-down mode, PCS28 may first stop mode at time t ₁ a.

FIG. 7 is a graph showing another operation example of the stop mode selection according to the present embodiment.
Example of FIG. 7, between time t time t _2, the shows the selection state of the stop mode when the system power requirements exceed the generated power of 100% from the power generator 12.

  If an output of 100% (rated value) or more from the power generation device 12 is overloaded (overloaded), not only the power generation efficiency is lowered, but also the life of the power generation device 12 may be shortened. For this reason, it is not preferable to continue the power generator 12 at an output of 100% or more. Therefore, the amount of electric power that is deficient by power transmission from the ESS 14 is covered.

Therefore, similarly to the example of FIG. 5, the selection unit 42 starts discharge (system required power amount increases in a state where the PCS 28 is stopped in the second stop mode (the full shut-off mode in the example of FIG. 7). ) to select the first stop mode reaches the fast time t ₁ a predetermined period of time than the time t. Thereby, CSP30 can start the power transmission from the storage battery 26 rapidly while suppressing the power loss at the time of stopping PCS28 for a long time.
In the example of FIG. 7, the PCS 28 is stopped by the selection unit 42 selecting the full cutoff mode at time t ₂ when the system required power amount and the generated power 100% match.

  As described above, the CSP 30 according to the present embodiment is a control device for the PCS 28, and the PCS 28 is provided between the storage battery 26 connected to the power system 16 and the power system 16, and includes DC power and AC power. And a breaker 32 that connects or blocks the storage battery 26 and the power system 16. And when stopping charging / discharging by the storage battery 26, the CSP 30 stops the power conversion unit 31 together with the first stop mode in which the power conversion unit 31 is stopped without performing the interruption by the circuit breaker 32 or the interruption by the circuit breaker 32. The second stop mode to be selected is selected.

  Therefore, the CSP 30 according to the present embodiment, when stopping the charging / discharging by the storage battery 26, quickly uses the first stop mode and the second stop mode, even if charging / discharging from the storage battery 26 is stopped. Startup is possible, and power loss in the charge / discharge stop state can be suppressed.

  As mentioned above, although this invention was demonstrated using the said embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which the changes or improvements are added are also included in the technical scope of the present invention. Moreover, you may combine the said embodiment suitably.

  For example, in the above-described embodiment, the form in which the power generation device 12 is the gas turbine 24 and the generator 22 has been described. However, the present invention is not limited to this, and the power generation device 12 uses a steam turbine or natural energy. It is good also as a form made into the power generator 12 which was made.

The power generation device 12 using natural energy is, for example, a solar battery. Even when the power generation device 12 is a solar cell, the operation in the stop mode for the PCS 28 is the same.
FIG. 8 is a graph showing an operation example of the stop mode selection when the power generation device 12 is a solar battery.

The solar cell can generate power from sunrise to sunset, and the generated power increases as the amount of solar radiation per hour increases. Therefore, the generated power for each time is set as a set value in the time schedule accordingly.
Then, the PCS 28 is activated from the sunrise to the sunset set in the time schedule (from 6 o'clock to 18 o'clock in the example of FIG. 8). When the power generation amount of the solar battery is larger than the set value, the PCS 28 charges the surplus battery 26, and when the power generation amount of the solar battery is less than the set value, the shortage is discharged from the storage battery 26. , Level the generated power.
On the other hand, since the PCS 28 is stopped from sunset to sunrise, the PCS 28 is set to the all shut-off mode. When the time reaches a predetermined time earlier than the power generation start time in the time schedule, the first stop mode is used to shorten the startup time of the PCS 28. It is said.

The PCS 28 may not be used together with the power generation device 12 but may be connected to the power system 16 independently and transmit power to a load to which the storage battery 26 is connected.
In the case of this form, for example, the PCS 28 charges the storage battery 26 by power transmission from the power system 16 in a predetermined time zone (night as an example). The PCS 28 is stopped in the second stop mode when the storage battery 26 is fully charged and does not require discharging. When the storage battery 26 reaches a time earlier than the start time of power transmission to the load by a predetermined time, the PCS 28 is set to the first stop mode in order to shorten the startup time.

  Moreover, although the said embodiment demonstrated the form which PCS28 has two circuit breakers 32, this invention is not limited to this, PCS28 is either one of circuit breakers 32-1 and 32-2. It is good also as a form which has.

  In the above embodiment, the mode in which the stop mode is selected based on the time schedule based on the schedule or prediction of the system required power amount has been described. However, the present invention is not limited to this, and for example, the system request A signal indicating the schedule or prediction of the electric energy may be input to the CSP 30 from another device, and the stop mode may be selected by the signal.

DESCRIPTION OF SYMBOLS 10 Electric power system 16 Electric power system 26 Storage battery 28 PCS (bidirectional power converter)
30 CSP (control device)
31 Power Conversion Unit 32 Circuit Breaker 42 Selection Unit 44 Stopping Unit

Claims (9)

A power conversion device provided between a storage battery connected to a power system and the power system, and having a power conversion unit that converts direct-current power and alternating-current power, and a switch that connects or disconnects the storage battery and the power system. A control device,
When stopping charging / discharging by the storage battery, a first stop mode for stopping the power converter without shutting off by the switch, or a second stop mode for stopping the power converter together with shutting off by the switch, Selection means for selecting based on a schedule or prediction of the required power amount of the power system;
Stop means for stopping charging / discharging by the storage battery according to the first stop mode or the second stop mode selected by the selection means;
The control apparatus of a power converter device provided with.   The said switch is a control apparatus of the power converter device of Claim 1 provided between the said power converter and the said storage battery. A power generator is connected to the power system,
The control device for a power conversion device according to claim 1 or 2, wherein when the required power amount of the power system becomes larger than the generated power amount of the power generation device, the storage battery is discharged to compensate for the insufficient power amount.   In the case where the storage battery is charged / discharged from the state where charging / discharging by the storage battery is stopped in the second stop mode, the selection unit selects the first stop mode when a time earlier than the start time of charge / discharge is reached. The control device for a power converter according to any one of claims 1 to 3. The switch is a first switch provided between the power conversion unit and the power system, a second switch provided between the power conversion unit and the storage battery,
After charging and discharging the storage battery until the generated power of the power generation device connected to the power system is equal to the required power amount of the power system,
The selection means selects the first stop mode or the second stop mode based on a schedule or prediction of the required power amount of the power system, and shuts off the first switch as the second stop mode. The control of the power converter according to any one of claims 1 to 4, wherein a partial cut-off mode in which the second switch is not cut off or a full cut-off mode in which the first switch and the second switch are cut off is selected. apparatus.   The said selection means selects the said partial interruption | blocking mode, when the voltage transmitted to the said electric power grid | system from the said electric power generating apparatus changes in the state by which the said power converter device was set to the said 1st stop mode. Control device for power converter.   The said selection means is a control apparatus of the power converter device of Claim 5 or Claim 6 which selects the said all interruption | blocking mode, when charging / discharging from the said storage battery is stopped more than predetermined time. A storage battery connected to the power system;
A power converter having a power converter that converts DC power and AC power, and a switch that connects or disconnects the storage battery and the power system; and
A control device according to any one of claims 1 to 7,
A power system comprising: A power conversion device provided between a storage battery connected to a power system and the power system, and having a power conversion unit that converts direct-current power and alternating-current power, and a switch that connects or disconnects the storage battery and the power system. A control method,
When stopping charging / discharging by the storage battery, a first stop mode for stopping the power converter without shutting off by the switch, or a second stop mode for stopping the power converter together with shutting off by the switch, A first step of selecting based on a schedule or prediction of the required power amount of the power system;
A second step of stopping charging and discharging by the storage battery according to the selected first stop mode or the second stop mode;
A method for controlling a power conversion device including:

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