WO2020203996A1 - Système d'accumulation d'électricité, nouveau système d'énergie, système de distribution d'électricité, système de transmission d'électricité, équipement de transport, système de batterie pour véhicule électrique, et système de batterie pour dispositif d'alimentation sans coupure - Google Patents

Système d'accumulation d'électricité, nouveau système d'énergie, système de distribution d'électricité, système de transmission d'électricité, équipement de transport, système de batterie pour véhicule électrique, et système de batterie pour dispositif d'alimentation sans coupure Download PDF

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Publication number
WO2020203996A1
WO2020203996A1 PCT/JP2020/014664 JP2020014664W WO2020203996A1 WO 2020203996 A1 WO2020203996 A1 WO 2020203996A1 JP 2020014664 W JP2020014664 W JP 2020014664W WO 2020203996 A1 WO2020203996 A1 WO 2020203996A1
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WIPO (PCT)
Prior art keywords
power storage
power
storage element
storage system
phase
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PCT/JP2020/014664
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English (en)
Japanese (ja)
Inventor
加藤　修治
良和 ▲高▼橋
哲郎 遠藤
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国立大学法人東北大学
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Priority to JP2021512131A priority Critical patent/JP7461660B2/ja
Publication of WO2020203996A1 publication Critical patent/WO2020203996A1/fr

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483—Converters with outputs that each can have more than two voltages levels
    • H02M7/49—Combination of the output voltage waveforms of a plurality of converters

Definitions

  • the present invention relates to a power storage system capable of transmitting and receiving power between a power system and / or a load, and a new energy system, a power distribution system, a power transmission system, and a transportation device including the power storage system, and particularly, tests of a built-in power storage element.
  • the present invention relates to a power storage system suitable for carrying out a diagnosis, and a new energy system, a power distribution system, a power transmission system, a transportation device, a battery system of an electric vehicle, and a battery system of an uninterruptible power supply equipped with the power storage system.
  • Patent Document 1 discloses an inspection device capable of inspecting a power storage system without stopping the power storage system.
  • the AC waveform is controlled and smoothed by the current flowing directly from the external power system to the thyristor when diagnosing the deterioration of the power storage element. Therefore, the current flowing into the power supply device when diagnosing the deterioration of the power storage element may fluctuate the system frequency and current pressure in the power supply network and load in the system interconnection with the power supply device, temporarily impairing the stability of the system power. There is. As a result, in the invention described in Patent Document 2, it is difficult to suppress the influence of impairing the stability of electric power on the electric power system and the load connected to the power storage system at the time of the battery test.
  • a power storage system in view of the above problems, a power storage system, a new energy system, and a power distribution that can suppress the deterioration of the stability of the power state in the external equipment when testing the battery. It is an object of the present invention to provide a battery system for a system, a power transmission system, a transportation device, a battery system for an electric vehicle, and an uninterruptible power supply.
  • an arm including a unit converter having a power storage element capable of charging and discharging is provided corresponding to each phase in a three-phase alternating current to form an annular current path, and is designated as a diagnostic target.
  • a circulating current of an arbitrary frequency is passed through the annular current path to test the deterioration state of the storage element designated as a diagnostic target. It is characterized by having.
  • an arm including a unit converter having a power storage element capable of charging and discharging is provided corresponding to each phase in a three-phase alternating current to form an annular current path, and the annular current path. It is characterized by including a detection unit that detects a voltage generated between the terminals of the power storage element designated as a diagnosis target and a current flowing through the power storage element by circulating currents of different frequencies flowing through the power storage element.
  • a transformer is provided with a primary winding and a secondary winding corresponding to each of the three-phase AC phases, and power is supplied from the three-phase AC power supply via the primary winding.
  • a unit converter having a power storage element capable of charging and discharging is provided, and a plurality of arms connected to each of the plurality of secondary windings provided corresponding to each of the three-phase alternating current phases and between the three-phase alternating current phases.
  • a plurality of annular current paths individually formed as a closed circuit formed by each of the above arms and each of the above secondary windings, and a plurality of annular current paths that control the unit converter and a plurality of the annular current paths.
  • At least one is provided with a control means for testing a deteriorated state of the power storage element designated as a diagnostic target by passing a circulating current of a different frequency.
  • the power storage system of the present invention has a power storage element and can transfer power between a plurality of unit converters connected to the external system, and power can be transmitted and received between the plurality of unit converters and the external system.
  • a control means for estimating an equivalent circuit of the power storage element by sequentially applying AC voltages having different frequencies to the power storage element of one unit converter selected from the plurality of unit converters. It is characterized by being prepared.
  • the power storage system of the present invention is a power storage system connected to an AC system and includes a main circuit unit provided with an arm including a unit converter having a charge / discharge power storage element, and power is supplied to and from the AC system. It is characterized by comprising a control means for testing the deterioration state of the power storage element designated as a diagnosis target while giving and receiving.
  • the new energy system of the present invention is characterized in that the power storage system described in any of the above is connected.
  • the power distribution system of the present invention is characterized in that the power storage system described in any of the above is interconnected.
  • the power transmission system of the present invention is characterized in that the power storage system described in any of the above is interconnected.
  • the transportation device of the present invention is characterized in that the power storage system described in any of the above is connected.
  • the battery system of the electric vehicle of the present invention is characterized in that the power storage system described in any of the above is connected.
  • the battery system of the uninterruptible power supply of the present invention is characterized in that the power storage system described in any of the above is connected.
  • the current for testing the deterioration state of the power storage element circulates inside the power storage system and does not leak to the outside. It is possible to prevent the stability of the power state in the external equipment connected to the system from being impaired.
  • the diagnosis of each power storage element in the power storage system is performed without affecting the external equipment connected to the power storage system while continuing the operation of the power storage system. Alternatively, characteristic measurement can be performed.
  • FIG. 1 It is the schematic which shows the example of the power grid system which uses the wind farm as the energy source using the power storage system of 1st Embodiment of this invention. It is a block diagram of the power storage system which transfers electric power by grid connection with an electric power system according to 1st Embodiment of this invention. It is a figure which shows the circuit structure of the unit converter which constitutes the power storage system which concerns on embodiment of this invention. It is a figure explaining the voltage conversion operation of the multi-level conversion circuit which converts the voltage of the power storage element connected in series in an arm into an AC waveform of a desired frequency. It is a figure which shows the connection state in the unit conversion circuit at the time of diagnosis of a power storage element.
  • FIG. 1 shows a power system 5 as a relatively low-pressure power distribution system that supplies power from a power generation facility to a load, and a power storage system that transfers power to and from the power system 5 by grid connection with the power system 5.
  • the power grid system 1 including 10 is illustrated. Further, in the power grid system 1 shown in FIG.
  • a wind farm 92 including a plurality of tower-type wind power generators that generate power by wind power according to a wind condition 91 is shown.
  • the wind power generation power 90A generated by the wind power is supplied from the wind farm 92 to the load 93 via the power conversion facility 94 in order to meet the power demand of the load 93 through the power grid.
  • Wind farm 92 which generates electricity with wind power, which is a natural energy source, is an unstable power generation facility in which the amount of power generation changes irregularly depending on the wind condition 91. Since the frequency of the power system 5 changes depending on the relationship between power supply and demand, it is preferable that the output from the wind farm 92 is stable.
  • the power storage system 10 is connected to the power supply line between the power system 5 and the load 93, and power is exchanged between the power system 5 and the power system 5 to supply and receive power from the power system. It is used as a system power stabilizer that balances the relationship and stabilizes the system frequency and current pressure in the power system 5. That is, when the electric power output from the power generation facility is insufficient with respect to the required electric power on the load 93 side, the power storage system 10 discharges the electric power system 5 to supply the insufficient electric power. On the contrary, when the electric power output from the power generation facility becomes surplus with respect to the required electric power on the load 93 side, the power storage system 10 charges the electric power system 5 to recover and store the surplus electric power. I do.
  • the power storage system 10 when the amount of power generated by the wind farm 92, which is a power generation facility, increases with a change in the wind condition 91 and a surplus occurs in the system power in the power system 5, the power storage system 10 is connected to the system. It works to charge and store part of the electricity. On the contrary, when the power generation amount of the wind farm 92 decreases due to the windless state or the power demand of the load 93 suddenly increases and the system power becomes insufficient, the power storage system 10 stores the power by discharging. Power is supplied to the power system 5. For example, referring to FIG.
  • the power storage system 10 discharges the stored charge / discharge power 90C to the power system 5, so that the wind power generated by the wind power 90A and the power storage system 10
  • the combined power 90B which is a combination of the discharged charge / discharge power 90C, is supplied to the load 93.
  • the power storage system 10 shown in FIG. 1 includes a circuit configuration in which a plurality of power storage elements capable of charge / discharge are connected. , The function of converting AC power from the power system 5 to DC so that the power storage element can be charged, and conversely, converting the DC power discharged by the power storage element to AC so that it can be output to the power system 5. It also has a circuit configuration as a power converter.
  • the state, for example, the storage performance and the life of the plurality of power storage elements constituting such a power storage system change depending on the operation of the power storage system.
  • the life diagnosis of each power storage element constituting the power storage system is performed while the power storage system is in operation. It is necessary to identify which power storage element should be replaced with a new one.
  • the system frequency and current pressure in the power system may fluctuate, and the stability of the system power may be temporarily impaired.
  • the power storage system of some embodiments according to the present invention is external when a large number of power storage elements constituting the power storage system are individually diagnosed, as will be described in detail with reference to FIGS. 2 to 5. It is possible to suppress the loss of power stability in the power system and load.
  • the power storage system of the first embodiment in which power is transferred and received by grid connection with the power system will be described in detail with reference to FIGS. 2 to 5.
  • the exemplary power grid system 1 has a configuration in which the power storage system 10 is connected to the power system 5.
  • the power system 5 and the power storage system 10 are connected by terminals 57u, 57v, 57w.
  • the power generation facility 50 for supplying three-phase AC power and the load 56 are connected by distribution lines 53u, 53v, 53w.
  • the wind farm 92 of FIG. 1 is schematically shown as a power generation facility 50.
  • the load 56 is the same as the load 93 in FIG. 1, and is, for example, a consumer such as a factory or a machine or a manufacturing apparatus owned by the consumer.
  • 52u, 52v, 52w and 51u, 51v, 51w in FIG. 2 schematically represent the reactance component and the resistance component of the distribution lines 53u, 53v, 53w on the power generation facility 50 side from the terminals 57u, 57v, 57w.
  • 54u, 54v, 54w and 55u, 55v, 55w schematically represent the reactance component and resistance component of the distribution lines 53u, 53v, 53w on the load 56 side of the terminals 57u, 57v, 57w.
  • the power storage system 10 of the first embodiment is used as a power system stabilizer for stabilizing the power system 5 in the power grid system 1 which is such a three-phase AC system.
  • the power storage system 10 is not limited to the one connected to the power system 5 as a system power stabilizer, and as an external system, for example, an electric vehicle, a railroad vehicle, a truck, or a bus. It can also be used for other purposes such as an AC power supply that supplies power to the load of transportation equipment such as.
  • the power storage system 10 includes a main circuit unit 10a, an impedance characteristic measurement unit 12, and a control unit (control means) 13.
  • the power storage system 10 has a main circuit unit 10a capable of converting a DC voltage that can be increased or decreased in multiple stages into three interphase voltages in three-phase AC and outputting the power to the power network system 1, an impedance characteristic measurement unit 12, and a diagnosis target.
  • the main circuit portion 10a has a so-called ⁇ connection MMC configuration. More specifically, the main circuit unit 10a includes an annular current path 71 having a delta-connected circuit topology, and is connected to the power system 5 by a three-phase AC power line. On top of that, each of the three sides of the annular current path 71 having the ⁇ connection topology corresponds to the three interphase voltages in the three-phase alternating current, and each of the above three sides uses the charging power as each waveform of the three-phase alternating current. It is configured as a multi-level power converter that converts and outputs.
  • Each side of the annular current path 71 having a delta connection topology is composed of three arms 11A, 11B, 11C and reactors 14A, 14B, 14C.
  • the reactor 14A, the arm 11A, the reactor 14B, the arm 11B, the reactor 14C, the arm 11C, and the reactor 14A are connected in this order to form an annular current path.
  • Each of the three arms 11A, 11B, 11C has a plurality (K) cascade (series) of unit converters C x (i) (1 ⁇ i ⁇ K) (K is an arbitrary positive integer). It is configured to be connected to.
  • the main circuit unit 10a can increase / decrease in multiple stages between the arms 11A and the S phase and T phase, which supply an electromotive voltage that can be increased / decreased in multiple stages between the R phase and the S phase. It is provided with an arm 11B for supplying an electromotive voltage, and an arm 11C for supplying an electromotive force that can be increased or decreased in multiple stages between the T phase and the R phase. Arms 11A, to output can be increased and decreased DC voltage in multiple stages, a plurality of unit converters includes a rechargeable electric storage element 35 C A (i) (1 ⁇ i ⁇ K) (K pieces) series It is configured by connecting to.
  • the arm 11B is configured by connecting a plurality (K pieces) of unit converters C B (i) (1 ⁇ i ⁇ K) in series
  • the arm 11C is composed of unit converters C C (i) ( 1 ⁇ i ⁇ K) are connected in series (K pieces).
  • the number of unit converters C x (i) included in each of the arms 11A, 11B, and 11C can be appropriately set and may be one.
  • the number of unit converters C x (i) provided in each of the arm 11A, arm 11B, and arm 11C is large, the number of stages of the AC voltage output by the power storage system 10 increases, and the waveform of the AC voltage becomes closer to a sine wave. Can be made into a waveform.
  • Each of the arm 11A, arm 11B and arm 11C is connected to the terminals 57u, 57v, 57w of the distribution lines 53u, 53v, 53w of the power system 5 via the reactors 14A, 14B, 14C at one end, respectively.
  • the distribution line 53u has a terminal 57u, and the terminal 57u is connected to a connection point between the arm 11A and the arm 11C of the main circuit portion 10a.
  • the distribution line 53v has a terminal 57v, and the terminal 57v is connected to a connection point between the arm 11B and the arm 11C of the main circuit portion 10a.
  • the distribution line 53w has a terminal 57w, and the terminal 57w is connected to a connection point between the arm 11C and the arm 11A of the main circuit portion 10a. In this way, the main circuit unit 10a of the power storage system 10 is connected to the power system 5.
  • the configuration of the unit converter C x (i) will be described.
  • the configuration of the unit converter C x (i) is shown in FIG.
  • the unit converter C x (i) includes a first switch arm 33 in which a first switch 33H and a second switch 33L are connected in series, a third switch 34H, and a fourth switch 34L.
  • a second switch arm 34 connected in series and a power storage element 35 capable of charging and discharging are provided.
  • the power storage element 35 is composed of, for example, a secondary battery such as a lithium ion battery, a nickel hydrogen battery, and a nickel cadmium battery.
  • the unit converter C x (i) is connected to the power grid system 1 as an external system, and can transfer power to and from the power grid system 1.
  • the unit converter C x (i) is a terminal of the first switch 33H side end of the first switch arm 33, the third switch 34H side end of the second switch arm 34, and the power storage element 35 (the present embodiment).
  • the positive side is connected, and the second switch 33L side end of the first switch arm 33, the fourth switch 34L side end of the second switch arm 34, and other terminals of the power storage element 35 (in this embodiment, (Minus side) is connected.
  • the unit converter C x (i) has a full bridge circuit configuration in which the first switch arm 33, the second switch arm 34, and the power storage element 35 are connected in parallel. In this embodiment, the full bridge configuration is used, but a half bridge configuration may be used.
  • the first switch 33H is between the first terminal FT and the second terminal ST.
  • the third switch 34H are connected in series (reverse series), and the second switch 33L and the fourth switch 34L are connected in series.
  • one of the switches (first switch 33H and third switch 34H) connected in series between the first terminal FT and the second terminal ST is referred to as a first switch group 36, and the other of the switches connected in series.
  • (2nd switch 33L and 4th switch 34L) will be referred to as a 2nd switch group 37.
  • a control unit 13 (FIG. 2), which will be described later, is connected to the unit converter C x (i) , and each switch is connected to the first switch 33H, the second switch 33L, the third switch 34H, and the fourth switch 34L.
  • a drive voltage for controlling on / off (for example, a gate voltage in the case of a switching element composed of a FET (field effect transistor)) is supplied from the control unit 13.
  • the first terminal FT is pulled out from the connection point 30 between the first switch 33H of the first switch arm 33 and the second switch 33L, and becomes the third switch 34H of the second switch arm 34.
  • the second terminal ST is pulled out from the connection point 32 with the fourth switch 34L.
  • Two adjacent unit converter C x (i) is being a second terminal ST of the first terminal FT and the other unit converter C x of one of the unit converters C x (i) (i) is connected , Connected in series.
  • the voltage between the output terminals is set in three stages as follows.
  • each of the unit converters C x (i) is configured to output the same voltage, but each of the unit converters C x (i) has a configuration of a power storage element 35. It is also possible to output different voltages by appropriately changing (capacity of the power storage element, etc.).
  • the power storage system 10 includes an arm 11A that applies a voltage between the R phase and the S phase, an arm 11B that applies a voltage between the S phase and the T phase, and an arm 11C that applies a voltage between the T phase and the R phase. in, by switching the number of unit converters C x for outputting a voltage (i), respectively, the multi-step voltage corresponding to the number of unit converters C x (i) can be output by each arm.
  • the power storage system 10 includes a power storage element 35 in which each unit converter C x (i) can charge and discharge electric power, it is also possible to store electric energy by charging the power storage element 35 from the power system 5.
  • the impedance characteristic measuring unit 12 includes a voltage measuring unit 120 and a current measuring unit 121.
  • the voltage measuring unit 120 is connected between the terminals of each power storage element 35 and measures the voltage between the terminals.
  • the current measuring unit 121 is inserted between the connection point 30 between the first switch 33H and the second switch 33L and the first terminal FT, and measures the current flowing through the annular current path 71.
  • the current measuring unit 121 can be inserted at any position on the annular current path 71.
  • the control unit 13 is configured to execute a control sequence for controlling so that circulating currents of different frequencies flow through the annular current path 71, and to test the deterioration state of the power storage element designated as a diagnosis target.
  • the control unit 13 is realized by software on, for example, a processor, dedicated hardware designed for executing a control operation described later, or a general-purpose arithmetic unit such as a PC. Further, in one example, the control unit 13 may be configured as an information processing device including an arithmetic circuit and an input / output interface for an electric signal, and the arithmetic circuit implements arithmetic logic for executing the following control or command. You may be.
  • the arithmetic circuit in the control unit 13 controls (1) the operation of controlling the connection state of the plurality of power storage elements 35 connected along the annular current path 71, and (2) the same principle as the conventional ⁇ connection MMC. Output control for controlling the output of active power and reactive power to the power system 5 by circuit operation, (3) Operation of designating the power storage element 35 to be diagnosed from among a plurality of power storage elements 35, (4) ) And the arithmetic logic for executing the operation command to the impedance characteristic measuring unit 12, respectively. Further, the control unit 13 can also control the active power and reactive power input / output by the power storage system 10.
  • the control unit 13 sends a command to the control circuit of each unit converter for the control unit 13 to control the on / off of the switch of each unit converter C x (i) , and the arm 11A, the arm 11B, and the control unit 13 send a command.
  • a multi-stage three-phase AC voltage is generated from the arm 11C and output between the R phase and the S phase, between the S phase and the T phase, and between the T phase and the R phase, respectively.
  • the arms 11A, 11B, and 11C output different voltages from the voltages between the terminals 57u, 57v, and 57w of the distribution lines 53u, 53v, and 53w, so that active power and reactive power can be exchanged with the distribution system. It can be performed.
  • each arm 11A, 11B, 11C also outputs a voltage close to a sine wave.
  • the mechanism is the same for each arm 11A, 11B, 11C, the case where the voltage output from the arm 11A between the R phase and the S phase is output so as to have a waveform close to a sine wave will be taken as an example. explain.
  • the vertical axis represents the voltage generated between the R phase and the S phase (positive or negative, but the value normalized with the maximum output voltage of each unit converter as 1) is plotted on the horizontal axis. takes a time, and a target voltage output from the arm 11A of the main circuit unit 10a, the unit converter C a (1) constituting the arm 11A between the respective output terminals of ⁇ C a (6) (between FT-ST) The relationship with the voltage generated in is shown over one cycle of the AC waveform.
  • the target voltage in the arm 11A is a target value of the AC voltage output as the interphase voltage between the R phase and the S phase, and is along the AC voltage waveform to be generated as a sine wave between the R phase and the S phase. Is set to change.
  • FIG. 4 from the top, can be increased and decreased voltage V out applied to the multi-stage arm 11A between the phase of R-phase and S-phase of the power storage system 10, unit converter C A (1) constituting the arm 11A ⁇ V A (1) , V A (2) , V A (3) , V A (4) , V A (5) applied between the output terminals of C A (6) ( between FT and ST ). And VA (6) are shown. Further, in FIG. 4, the intersection of the vertical axis and the horizontal axis is set as the reference potential 0, the upper side of the reference potential 0 is the positive potential, and the lower side of the reference potential 0 is the negative potential.
  • the main circuit unit 10a between the respective output terminals of the unit converters C A constituting the arm 11A (1) ⁇ C A ( 6) ( between FT-ST), the amplitude of the reference potential And rectangular wavy voltage pulses with different widths are generated.
  • the unit converter C A (1) ⁇ C A respective first switches 36 and second switches 37 (6) Open / close control is performed.
  • the pulse is obtained by shifting the phase of a triangular wave controlled by a triangular wave PWM (Pulse-Width Modulation) and performing pulse width modulation.
  • PWM Pulse-Width Modulation
  • the control unit 13 to the power storage system 10 is provided on the basis of the target voltage waveform represented by a sine wave, between the respective output terminals of the unit converters C A (1) ⁇ C A (6) (FT-ST In between), a drive signal for opening / closing control of the corresponding first switch group 36 and second switch group 37 is generated so that the rectangular wavy voltage that approximates the target voltage waveform is generated.
  • the drive signal is generated by standardizing the voltage command value for the arm 11A to output the voltage and comparing the standardized voltage command value with the triangular wave.
  • the control unit 13 outputs the generated drive signal to the gates of the semiconductor switching elements constituting the corresponding first switch group 36 and the second switch group 37, and switches (on, off) the corresponding switching elements.
  • each of the arms 11A, 11B, and 11C executes a voltage conversion operation of a multi-level conversion circuit that converts the combined voltage of the power storage elements connected in series inside the arm 11A, 11B, and 11C into an AC waveform of a desired frequency. It becomes.
  • This is an example of a control sequence that allows circulating currents of different frequencies to flow through the annular current path 71.
  • the opening / closing timing of the switching element in the unit converter C x (i) can be controlled from the control unit 13. Then, by this control operation by the control unit 13, the current pressures in the three arms 11A, 11B, and 11C each of which are formed by connecting two or more charge / discharge charge storage elements 35 in series are the desired AC waveform and frequency. It is possible to control so that it changes with. As an example, at both ends of each of the three arms 11A, 11B and 11C, it is possible to generate three interphase voltages in the three-phase AC power to be supplied to the power system 5.
  • the magnitude (instantaneous value) of the current flowing through each of the three arms 11A, 11B and 11C can be changed so as to have an AC waveform corresponding to each phase in the three-phase AC power.
  • the control unit 13 controls the phase difference (power factor) between the current waveform flowing through each of the three arms 11A, 11B, and 11C and the interphase voltage waveform appearing at both ends of the arm so as to have a desired power factor. can do. Therefore, by controlling the power factor of the AC power in each of the three arms 11A, 11B, and 11C, the control unit 13 controls the output for controlling the output of the active power and the reactive power to the power system 5. It is configured to do.
  • the control unit 13 executes a control sequence so that circulating currents of different frequencies flow through the annular current path 71.
  • the control unit 13 outputs a signal for designating the power storage element 35 to be diagnosed and a signal for instructing that the designated power storage element 35 should be diagnosed to the impedance characteristic measurement unit 12.
  • the control unit 13 diagnoses all the power storage elements 35 arranged along the annular current path 71 by sequentially switching the designation of the power storage element 35 to be diagnosed along the annular current path 71. be able to.
  • the impedance characteristic measurement unit 12 that receives the command from the control unit 13 first receives the diagnosis target from among the plurality of power storage elements 35 arranged along the annular current path 71 according to the designation of the diagnosis target by the control unit 13. The power storage element 35 is identified. Subsequently, the impedance characteristic measuring unit 12 measures the current value of the test current passed through the power storage element 35 to be diagnosed by the current measuring unit 121. Subsequently, the impedance characteristic measuring unit 12 estimates the impedance characteristic of the power storage element 35 from the voltage value measured between the terminals of the power storage element 35 by the voltage measuring unit 120 and the current value. Finally, the impedance characteristic measurement unit 12 outputs the impedance characteristic estimated for the power storage element 35 to the control unit 13.
  • the impedance characteristic measuring unit 12 detects the voltage generated between the terminals of the power storage element 35 designated as the diagnosis target and the current flowing through the power storage element by the circulating currents of different frequencies flowing through the annular current path 71, respectively. It serves as a detection unit.
  • the power storage system 10 In order to diagnose the power storage element 35 without affecting the system, the power storage system 10 according to the embodiment of the present invention has a positive phase voltage or a positive phase voltage for exchanging active power or reactive power with the power system 5.
  • the control unit 13 controls the unit converter so as to output the reverse phase voltage.
  • the zero-phase component does not affect the active power or reactive power. Therefore, in order to diagnose the deterioration of the power storage element 35, it is preferable to use a zero-phase current or a zero-phase voltage.
  • the power storage system 10 since the power storage system 10 has an annular current path 71 configured as a circulation path that goes around between each phase, a zero-phase voltage is applied to the annular current path 71, and a zero-phase current is passed through the annular current path 71.
  • Deterioration diagnosis of an arbitrary power storage element 35 may be performed by flowing the current. The operation of generating the circulating current will be described below.
  • the control unit 13 determines the operating state of the unit converter C x (i) including the power storage element 35 designated as the diagnosis target, and the impedance characteristics of the power storage element 35 from the normal operating state of transmitting and receiving power to and from the power system 5. Switch to the test operating state to be measured. At this time, the control unit 13 controls the switching element as follows in the unit converter C x (i) having a full bridge circuit configuration including the power storage element 35 in order to switch to the test operation state.
  • the switching element is controlled so that the positive electrode and the negative electrode of the power storage element 35 are connected to one and the other of the output terminal pair (pair of FT terminal and ST terminal) of the full bridge circuit, respectively. Then, in the full bridge circuit in which the positive electrode and the negative electrode of the power storage element 35 are connected to one and the other of the output terminal pair, the pair of switching elements that are simultaneously in a conductive state are pointed to "diagonal positions". It is defined as "switching element in”. In this way, the deterioration state of the power storage element 35 designated as the diagnosis target is tested by bringing the pair of switching elements diagonally located in the full bridge circuit into a conductive state.
  • the other switching elements other than the switching elements at the pair of short-circuited diagonal positions are not short-circuited so that the terminals of the power storage element 35 are not short-circuited. Please note that it must be in a conductive state.
  • the control unit 13 is configured to execute the control sequence for performing the control so that the circulating currents I cil of different frequencies flow through the annular current path 71.
  • the annular current passage 71 corresponding to each of the phases, it is possible to flow a circulating current I cil for testing the deterioration state of the power storage element 35 while varying the frequency.
  • the current and voltage of the power storage element 35 are measured while changing the frequency of the circulating current I cil .
  • the frequency dependence of the complex impedance of the power storage element 35 is calculated from the voltage value and current value of the same frequency component as the frequency of the circulating current I cil extracted from the above-mentioned voltage and current measurement results by Fourier transform or the like. ..
  • the impedance of each part of the power storage element 35 is estimated from this complex impedance component, and the deterioration state is diagnosed. The diagnostic method will be described later.
  • a method of preventing a direct current from flowing out to the power system 5 in the measurement of the complex impedance will be described.
  • the corresponding unit converter C x (i) When the power storage element 35 of the specific cell of the specific arm is measured with a continuous sinusoidal current, the corresponding unit converter C x (i) outputs a DC voltage.
  • the other unit converter C x (i) of the corresponding arm outputs a voltage that compensates for the DC voltage generated by the measurement, so that the arm to which the power storage element 35 measuring the complex impedance belongs is the DC voltage. Can be output to prevent the direct current from flowing out to the power system 5.
  • the voltage at which the other two arms other than the arm to which the power storage element 35 measuring the complex impedance belongs compensates for the DC voltage generated by the measurement. Should be output. In this case, since the DC voltage becomes zero phase, the DC current does not flow out to the outside of the power storage system 10. Further, it is also possible to measure the voltage and current of a predetermined power storage element 35 of each phase (arm) at the same time by utilizing the fact that all the phases (arms) output DC voltage.
  • an intermittent sinusoidal zero-phase current is passed through a specific power storage element 35 by applying a voltage pulse such as a PWM pulse, and the voltage and current are passed only when the intermittent current is flowing. It is also possible to obtain the complex impedance of the frequency by measuring discrete Fourier expansion or the like. Also in this case, it is possible to measure the voltage and current of the predetermined power storage element 35 at the same time for each phase (arm). In this way, the current for testing the deterioration state of the power storage element 35 circulates inside the power storage system 10 and does not leak to the external power system 5, so that the external power connected to the power storage system 10 is connected to the system. It is possible to prevent the stability of the power state in the system 5 and the load 56 from being impaired.
  • unit conversion includes an electric storage device 35 designated as a diagnostic target device C x (i), while in the test operating state for measuring the impedance characteristic of the power storage element 35, the other unit converter C x (I) is in a normal operating state in which power is exchanged with the power system 5.
  • the control unit 13 while transferring power between a plurality of unit converters C x (i) and power network system 1 (external system), a plurality of unit converters C x (i) AC voltages with different frequencies can be sequentially applied to the power storage element 35 of one selected unit converter, the equivalent circuit of the power storage element 35 can be estimated, and the deterioration state of the power storage element 35 designated as the diagnosis target can be tested. it can.
  • the circulating current I cil for testing the deteriorated state of the power storage element 35 has various frequencies.
  • the impedance characteristic measuring unit 12 measures the impedance characteristic of the power storage element 35 while the current is flowing through the annular current path 71 while changing. Specifically, the impedance characteristic measuring unit 12 measures the voltage between terminals of the power storage element 35 by the voltage measuring unit 120 in a state where currents of various different frequencies are flowing through the power storage element 35 designated as a diagnosis target. At the same time, the current flowing through the power storage element 35 is measured by the current measuring unit 121. Impedance can be calculated from the AC voltage and AC current of the frequency component. As a result, the impedance characteristic measuring unit 12 investigates how the impedance of the power storage element 35 changes according to the change in the frequency of the circulating current I cil .
  • the impedance characteristic measuring unit 12 determines the impedance of the power storage element 35 to be diagnosed from this impedance.
  • a specific example of a method for estimating the deterioration state of 35 will be described with reference to FIG.
  • the deterioration state of the power storage element 35 is estimated based on the complex impedance characteristic described by the internal resistance and the equivalent capacitance indicated by the power storage element 35 in which the circulating current I cil is flowing.
  • the above complex impedance characteristic is drawn on the complex plane PL having the real axis R and the imaginary axis Im as the coordinate axes according to the frequency change of the circulating current I cil , by the locus of the complex impedance.
  • the equivalent circuit can be estimated, and the deterioration state of each part of the power storage element can be estimated from the value.
  • the semicircular locus 300a corresponds to the equivalent circuit 320a and is represented by the equivalent capacitance 321a and the internal resistance 322a according to each frequency of the test current flowing in the power storage element 35.
  • the complex impedance corresponds to the locus drawn on the complex plane PL.
  • the semicircular locus 300b corresponds to the equivalent circuit 320b
  • the semicircular locus 300c corresponds to the equivalent circuit 320c.
  • the semicircular locus 300b corresponds to a locus drawn on the complex plane PL by the complex impedance represented by the equivalent capacitance 321b and the internal resistance 322b according to the frequency change of the test current flowing in the power storage element 35.
  • the semi-circular locus 300c corresponds to a locus drawn on the complex plane PL by the complex impedance represented by the equivalent capacitance 321c and the internal resistance 322c according to each frequency of the test current flowing through the power storage element 35.
  • the equivalent circuit of the power storage element 35 to be diagnosed usually has an equivalent capacitance 321 and an internal resistance 322 as shown in FIG. It can be represented as a parallel connector connected in series. Since the impedance of the power storage element 35 is represented by a circuit in which one or more parallel connectors formed by connecting the equivalent capacitance and the internal resistance in parallel are connected in series, it can be quantified as a complex impedance including a real number component and an imaginary number component. Can be understood.
  • control unit 13 In order to perform an analysis using such a complex impedance, the control unit 13 describes the deterioration state of the power storage element by the complex impedance equivalent to the internal resistance indicated by the power storage element 35 in which the circulating current I cil is flowing.
  • a discriminating means for discriminating based on the characteristics may be provided.
  • the magnitude of the internal resistance 322a of the equivalent circuit 320a corresponds to the width of the base portion of the semicircular locus 300a (arrow 380a shown in FIG. 6) in the width direction along the real number axis R. ..
  • the magnitude Rd2 of the internal resistance 322b of the equivalent circuit 320b can be obtained from the width of the bottom portion of the semicircular locus 300b (arrow 380b shown in FIG. 6).
  • the size of the equivalent capacitance 321b of the equivalent circuit 320b is determined by the frequency ⁇ 2max when the imaginary component of the locus 300b peaks (vertex 310b shown in FIG. 6) and the size Rd2 of the internal resistance 322b. It can be obtained by 1 / ( ⁇ 2max ⁇ Rd2).
  • the magnitude Rd3 of the internal resistance 322c can be obtained from the width of the bottom portion of the semicircular locus 300c (arrow 380c shown in FIG. 6).
  • the magnitude of the equivalent capacitance 321c of the equivalent circuit 320c is determined by the frequency ⁇ 3max when the imaginary component of the locus 300c peaks (vertex 310c shown in FIG. 6) and the magnitude Rd3 of the internal resistance 322c. It can be obtained by 1 / ( ⁇ 3max ⁇ Rd3).
  • the discriminating means applies the equivalent circuit to each part in the power storage element 35 such as the positive electrode part, the negative electrode part, and the electrolyte part, calculates the resistance value and the capacitance value of each equivalent circuit, and calculates the resistance value and the capacitance value thereof.
  • the deterioration state of the power storage element 35 is determined from the time change of the value and the like.
  • a storage battery having any battery characteristics is used to configure the power storage element 35, and (b) what kind of inside the power storage system 10 is used.
  • the power storage elements are arranged by the arrangement method, and (c) an analysis result that serves as a clue for knowing what kind of configuration is optimal for the system configuration of the entire power grid including the power storage system 10 can be obtained.
  • time-series data such as effective current value and invalid current value (input / output information) output by each phase of the power storage system 10 to the external system, and equivalent circuit information of each power storage element 35.
  • data mining is performed by providing a data mining means in the learning unit, it is possible to obtain a useful clue as to how the output of the power storage system 10 is related to the deterioration of the battery. Further, if data mining is performed using the time-series data of the input / output current, input / output voltage, SOC (State of charge), etc.
  • the output voltage value and output current value (output voltage value and output current value of the unit converter) of each power storage element 35 and the resistance value and capacitance value (hereinafter referred to as impedance value) of each equivalent circuit are used. combine. From this, it is possible to know how the power storage element 35 is used and how much deterioration of which part of the power storage element 35 progresses. Further, as another example of data mining, how to operate the power storage system 10 by combining the output voltage value / output current value and the circulating current I cil value of the power storage system 10 with the impedance value of each equivalent circuit. It is possible to know which part of the power storage element 35 is likely to deteriorate.
  • the change in the deterioration state of the power storage element 35 that is, the association between the change in the impedance value of each equivalent circuit (time-series data of impedance value) and the time-series data of element information and input / output information (derivation of correspondence, impedance) Derivation of parameters such as the degree of contribution to value change) can be efficiently associated by performing the AI technology represented by data mining and reinforcement learning as described above. As a result, it is possible to operate the power storage system 10 that minimizes the deterioration of the power storage element 35 and to estimate the accurate replacement time of the power storage element 35. Further, by causing the control unit 13 to perform this operation and having the control unit 13 automatically correct the control operation of the power storage system 10 based on the estimation result, more efficient operation can be performed.
  • the control unit 13 When the control unit 13 is to be associated using AI, for example, the control unit 13 is provided with a learning means for associating the output voltage and output current of the power storage element 35 with the deteriorated state of the power storage element 35, and the learning means are associated with each other. To do. An example of association by learning means will be described.
  • the learning means stores the element information of the power storage element 35 detected by the impedance characteristic measuring unit 12 and creates time-series data of the element information. Further, the learning means stores the impedance value of the equivalent circuit estimated from the complex impedance of the power storage element 35 and the deteriorated state of the power storage element 35, and creates time-series data of the impedance value of the equivalent circuit.
  • the learning means associates the element information of the power storage element 35 with the deteriorated state of the power storage element 35 based on the time series data of the created element information and the time series data of the impedance value of the created equivalent circuit.
  • the learning means may be provided with teacher data relating the element information of the power storage element 35 and the deterioration state (impedance value of the equivalent circuit) of the power storage element 35 to be trained.
  • the learning means uses the learning result of the association between the element information of the power storage element 35 and the deterioration state of the power storage element 35 as new teacher data, and again obtains the element information of the power storage element 35 and the deterioration state of the power storage element 35. May be associated. By repeating this work, the accuracy of the association is improved.
  • the learning means may associate the input / output information of the power storage system 10 with the deterioration state of the power storage element 35 instead of the element information of the power storage element 35. In this case, a detector for measuring the active current and the reactive current is provided, and the learning means stores the detection results of the voltage and the current from the detector.
  • the learning means is realized by software on a general-purpose arithmetic unit such as a processor, dedicated hardware, or a PC, for example.
  • a part or all of the learning means may be provided separately from the control unit 13, or may be provided as an external device of the power storage system 10.
  • the learning means separates at least a part of the associating work from the external device configured separately from the control unit 13 and the external device configured separately from the power storage system 10, that is, the learning means. It may be configured and allowed to be performed by an external device connected to the learning means. For example, the calculation time can be shortened by letting dedicated hardware equipped with a high-performance GPU (Graphics Processing Unit) and a large amount of memory perform heavy calculation work such as data mining. The association work can be performed more efficiently.
  • a high-performance GPU Graphics Processing Unit
  • association can be performed more efficiently.
  • the arms 11A and 11B do not stop the operation of the power system 5 and the main circuit unit 10a for transmitting and receiving electric power. And, deterioration diagnosis of each power storage element 35 connected in series inside each of 11C can be performed. As a result, it is possible to grasp the remaining life of the power storage element 35 constituting each arm 11x in real time without stopping the operation of the power storage system 10 while the power storage system 10 is connected to the power system 5. Therefore, even if the characteristics of the power storage element 35 vary, it is possible to grasp in real time which power storage element 35 should be replaced with a new one at a given timing during the continuous operation of the power storage system 10.
  • the impedance of each power storage element 35 connected in series inside each of the arms 11A, 11B and 11C of the main circuit unit 10a in order to transfer power to and from the power system 5 is the power storage element 35. How it changes depending on the frequency of the current flowing through the power storage element 35 is investigated, and deterioration diagnosis of the power storage element 35 is performed from this impedance change. Therefore, by recording the fluctuation history of the output frequency from the power storage system 10 as the operation history data of the power storage system 10 in chronological order with the deterioration diagnosis data of each power storage element 35, it is possible to operate the power grid. Useful information can be obtained.
  • the life of the power storage system 10 including the power storage element 35 can be extended by operating the power storage system 10 in a state of being connected to the power system 5 according to what pattern. You can get information that can be a clue to know.
  • the exemplary power storage system 100 shown in FIG. 7 is a circuit system disclosed in Japanese Patent No. 6212361, in which a zero-phase voltage is applied to each phase to generate a zero-phase current. It is possible to pass through. Therefore, as in the first embodiment, by having a circulation path that goes around between each phase, each arm 15rs, arm 15st, and arm that have individual circulation paths and are composed of a series of unit converters 151. A zero-phase voltage is applied to 15 tr to allow a zero-phase current to pass through, and deterioration diagnosis of an arbitrary power storage element 35 can be performed.
  • the power storage system 100 according to this embodiment will be specifically described.
  • the power storage system 100 is connected to a power system 5 that supplies three-phase AC power composed of R phase, S phase, and T phase, and is connected to the power system 5.
  • the power storage system 100 includes a transformer 110, an arm 15rs that supplies power between the RS phases, an arm 15st that supplies power between the ST phases, an arm 15tr that supplies power between the TR phases, and a control unit (control). Means) 13 and voltmeters 19rs, 19st, 19tr are provided.
  • the power storage system 100 is an MMC for three-phase alternating current, but the arm 15rs, the arm 15st and the arm 15tr are not delta-connected, and three single-phase circuits are magnetic circuits. The difference is that they are interconnected by electromagnetic induction coupling via.
  • the arms 15rs, the arms 15st and the arms 15tr are magnetically formed by the iron core 113 of the transformer 110. It is electromagnetically induced and coupled to the power system 5 via a circuit.
  • the side to which the power system 5 or the like is connected is referred to as the “primary side”, and the side to which the arms 15rs, 15st, and 15tr are connected is referred to as the “secondary side”. ..
  • the primary side of the transformer 110 is delta-connected to form a circulation path that goes around between the phases.
  • the power storage system 100 shown in FIG. 7 is provided with a primary winding 111 (111rs, 111st, 111tr) and a secondary winding 112 (112rs, 112st, 112tr) corresponding to each of the three-phase AC phases, and the primary winding is provided.
  • a transformer 110 that receives power from a three-phase AC power supply via 111 and a unit converter 151 having a chargeable and dischargeable power storage element are provided, and a plurality of two are provided corresponding to each of the three-phase AC phases.
  • a plurality of arms 15 (15rs, 15st, 15tr) connected to the next winding 112 (112rs, 112st, 112tr), and a control unit 13 for controlling the connection state of the power storage element inside the arm 15 are provided. It is configured. Further, in the power storage system 100 shown in FIG. 7, a plurality of annular current paths corresponding to each of the three-phase AC phases are provided for each arm 15 (15rs, 15st, 15tr) and each secondary winding 112 (112rs, 112st).
  • the control unit 13 is a diagnostic frequency, that is, a power system frequency in each of the plurality of annular current paths. Is configured to execute the control sequence for performing the above control so that zero-phase circulating currents of different frequencies flow, and to test the deterioration state of the power storage element designated as the diagnosis target. That is, this individual circulation path becomes a zero-phase circulation path. Further, the zero-phase circulating current is a current that circulates in the ⁇ connection on the primary side.
  • the transformer 110 is a three-phase transformer, and a tripod iron core is used.
  • the transformer 110 includes legs 113rs, 113st, and 113tr.
  • the primary winding 111rs and the secondary winding 112rs of the RS phase are wound around the leg 113rs and magnetically coupled to each other.
  • a primary winding 111st and a secondary winding 112st of the ST phase are wound around the leg 113st and magnetically coupled to each other.
  • a primary winding 111tr and a secondary winding 112tr of the TR phase are wound around the leg 113tr and magnetically coupled to each other.
  • Six unit converters 151 are connected in series to the arm 15rs that supplies power between the RS phases, the arm 15st that supplies power between the ST phases, and the arm 15tr that supplies power between the TR phases. There is. Both ends of the secondary winding 112rs of the RS phase of the transformer 110 are connected to both ends of the arm 15rs between the uS phases. Both ends of the secondary winding 112st between the S and T phases of the transformer 110 are connected to both ends of the arm 15st between the S and T phases. Both ends of the secondary winding 112tr between the TR phases of the transformer 110 are connected to both ends of the arm 15tr between the TR phases.
  • the primary winding 111rs between the R and S phases of the transformer 110 is connected between the R and S phases of the power system 5.
  • the primary winding 111st between the S and T phases of the transformer 110 is connected between the S and T phases of the power system 5.
  • the primary winding 111tr between the TR phases of the transformer 110 is connected between the T phase and the R phase of the power system 5. That is, the primary windings 111rs, 111st, 111tr of the transformer 110 are delta-connected and connected to the power system 5.
  • the voltmeter 19rs is connected between the R phase and the S phase of the power system 5 and measures the line voltage Vsrs.
  • the voltmeter 19st is connected between the S phase and the T phase of the power system 5 and measures the line voltage Vsst.
  • the voltmeter 14tr is connected between the T phase and the R phase of the power system 5 and measures the line voltage Vstr.
  • the voltmeters 19rs, 19st, and 19tr are further connected to the control unit 13 by an optical fiber (not shown) and transmit the measured voltage information.
  • the control unit 13 is connected to the voltmeters 19rs, 19st, 19tr and the unit converter 151 constituting each arm 15rs, 15st, 15tr by an optical fiber (not shown).
  • the control unit 13 controls each arm voltage Vrs, Vst, Vtr based on each line voltage Vsrs, Vsst, Vstr measured by each voltmeter 19rs, 19st, 19tr.
  • each voltage and each current are defined as follows.
  • the voltage across the arm 15rs supplied between the RS phases is the arm voltage Vrs.
  • the voltage across the arm 15st supplied between the ST phases is the arm voltage Vst.
  • the voltage across the arm 15tr supplied between the TR phases is the arm voltage Vtr.
  • a secondary side current Irs2 flows between the arm 15rs between the uS phases and the secondary winding 112rs between the RS phases of the transformer 110.
  • a secondary side current Ist2 flows between the arm 15st between the ST phase and the secondary winding 112st of the vT phase of the transformer 110.
  • a secondary side current Itr2 flows between the arm 15tr between the wR phases and the secondary winding 112tr of the TR phase of the transformer 110.
  • a secondary side voltage Vrs2 is applied to both ends of the secondary winding 112rs of the RS phase of the transformer 110, and the secondary side voltage Vrs2 and the arm voltage Vrs are the same.
  • a secondary side voltage Vst2 is applied to both ends of the secondary winding 112st of the ST phase of the transformer 110, and the secondary side voltage Vst2 and the arm voltage Vst are the same.
  • a secondary side voltage Vtr2 is applied to both ends of the secondary winding 112tr of the TR phase of the transformer 110, and the secondary side voltage Vtr2 and the arm voltage Vtr are the same.
  • the voltage across the primary winding 111rs of the RS phase of the transformer 110 is the primary side voltage Vrs1
  • the voltage across the primary winding 111st of the ST phase of the transformer 110 is the primary side voltage. It is Vst1
  • the voltage across the primary winding 111tr of the TR phase of the transformer 110 is the primary side voltage Vtr1.
  • a system current Isr flows in the R phase of the power system 5 in the direction from the power storage system 100 to the power system 5.
  • a system current Iss flows in the S phase of the power system 5 in the direction from the power storage system 100 to the power system 5.
  • a system current Ist flows in the T phase of the power system 5 in the direction from the power storage system 100 to the power system 5.
  • the voltage between the R phase and the S phase of the power system 5 is the line voltage Vsrs.
  • the line voltage Vsrs is measured by a voltmeter 14rs.
  • the voltage between the S phase and the T phase of the power system 5 is the line voltage Vsst.
  • the line voltage Vsst is measured by a voltmeter 14st.
  • the voltage between the T phase and the R phase of the power system 5 is the line voltage Vstr.
  • the line voltage Vstr is measured by a voltmeter 14tr.
  • each of the unit converters 151 rs (j) (1 ⁇ j ⁇ J) constituting the arm 15 rs has the same circuit configuration as the full bridge circuit described in the first embodiment with reference to FIG. .. Further, each of the unit converters 151 rs (j) and (1 ⁇ j ⁇ J) controls the above-mentioned control in the first embodiment from the control unit 13 to the switching element in the full bridge circuit with reference to FIG. It is possible to do it. As a result, each of the unit converters 151 rs (j) and (1 ⁇ j ⁇ J) can realize the same circuit operation as the unit converter C x (i) described above in the first embodiment. Become.
  • the control unit 13 of the power storage system 100 of the second embodiment controls on / off of each switching element included in each of the unit converters 151 rs (1) (1 ⁇ j ⁇ J) by the carrier phase shift PWM. Do.
  • the opening and closing of the switching element for each of the J unit converters 151 rs (j) (1 ⁇ j ⁇ J) constituting the arm 15 rs the R phase and the S phase can be changed from the arm 15 rs. It is possible to output the voltage output between the phases so that the waveform is close to a sine wave.
  • the S phase and the T phase can be changed from the arm 15 st. It is possible to output the voltage output between the phases so that the waveform is close to a sine wave. Further, by controlling the opening and closing of the switching element for each of the J unit converters 151 tr (j) (1 ⁇ j ⁇ J) constituting the arm 15 tr , the T phase and the R phase are separated from the arm 15 tr. It is possible to output the voltage output to the above so as to have a waveform close to a sine wave.
  • each of the arms 15st, 15st and 15tr is a multi-level converter. Perform the voltage conversion operation as.
  • the closed circuits 155rs, 155st and 155tr through which the current for this test flows correspond to the annular current path 71 formed in the main circuit portion 10a shown in FIG. 5 with respect to the first embodiment.
  • the difference is that three closed circuits 155rs, 155st and 155tr are individually formed corresponding to each of the three arms 15rs, 15st and 15tr.
  • the circuit on the primary side of the transformer 110 is configured by ⁇ connection.
  • the control unit 13 determines the unit converter 151 rs (j) (1 ⁇ ) so that the circulating current 159 rs of different frequencies flows through the closed circuit 155 rs at the time of diagnosing the deterioration of the power storage element constituting the RS phase arm 15 rs. j ⁇ J) is controlled. Similarly, when the deterioration diagnosis of the storage element constituting the arm 15st of S-T phase, to flow circulating current 159st of different frequencies closed circuit 155St, unit converter 151 st (j) (1 ⁇ j ⁇ J) To control.
  • a control sequence that controls each is executed.
  • the test currents flowing through the closed circuits 155rs, 155st and 155tr correspond to the circulating current I cil shown in FIG. 5 with respect to the first embodiment.
  • the control unit 13 controls the unit converter, passes circulating currents of different frequencies through at least one of the plurality of annular current paths, and tests the deterioration state of the power storage element designated as the diagnostic target.
  • the circulating current 159 rs generated by the arm 15 rs provided with the unit converter 151 rs (j) (1 ⁇ j ⁇ J) having a chargeable and dischargeable power storage element is generated. It is possible to electrically test the deterioration state of the power storage element constituting the arm 15rs by flowing the electric current in the closed circuit 155rs while varying the frequencies.
  • a circulating current 159 st generated by an arm 15 st provided with a unit converter 151 st (j) (1 ⁇ j ⁇ J) having a power storage element is passed through the closed circuit 155 st while varying the frequencies.
  • the circulating current 159 tr generated by the arm 15 tr provided with the unit converter 151 tr (j) (1 ⁇ j ⁇ J) having a power storage element is passed through the closed circuit 155 tr while having various frequencies, thereby causing the arm. It is possible to electrically test the deterioration state of the power storage element constituting 15 tr.
  • a transformer is transformed between the arms 15rs, 15st and 15tr, which pass a current for testing the deterioration state of the power storage element at the time of diagnosing the power storage element, and the external power system 5. Electromagnetic induction coupling is performed via the magnetic circuit of the vessel 110.
  • the arms 15rs, 15st, and 15tr formed by connecting the power storage elements in series can transfer and receive electric power to each other in a state where the electric power system 5 side is not connected by wiring.
  • it is possible to prevent the current for testing the deterioration state of the power storage element from flowing to the power system 5 and suppress the deterioration of the stability of the power state in the power system 5. it can.
  • a voltage including a plurality of different frequency components may be applied to the power storage element 35 to be diagnosed at one time.
  • the complex impedance can be collectively measured over a large number of frequency components as compared with the first embodiment and the second embodiment.
  • this embodiment has the technical advantage that the time required to obtain the trajectory of the fluctuation of the complex impedance characteristic over a certain frequency range as a curve as illustrated in FIG. 7 can be shortened.
  • the power storage system 10 is connected to a power distribution system (power system 5) connected to a wind farm (wind power generation device) as a new energy system
  • a power distribution system power system 5
  • wind farm wind power generation device
  • the present invention has been described. Not limited to this.
  • it is used in connection with a power distribution system connected to a biomass (organic matter derived from animals and plants) power generation device, geothermal power generation device (binary power generation), small hydroelectric power generation device, solar power generation device, etc. as a new energy system. You can also do it.
  • the system is not limited to a relatively low-voltage power distribution system, and can be used, for example, in connection with a high-voltage power transmission system from a conventional high-power power plant to a substation.
  • a high withstand voltage switching element should be used for the switch.
  • the power storage system 10 can be used as a battery system for an uninterruptible power supply used in a data center or the like by connecting to an important load such as a data center.
  • the power storage system 10 can be used by connecting to a motor as a battery system for an electric vehicle. Further, when the power storage system 10 is used as a battery system for an electric vehicle, it is connected to the power system to charge the battery from the power system, and the power of the battery of the electric vehicle is adjusted according to the excess or deficiency of the power of the power system. Can be charged and discharged. Further, the voltage of the power system may be controlled by outputting invalid power from the battery system for the electric vehicle according to the voltage of the power system. Further, the electric vehicle having the battery system for the electric vehicle may be parked in the vicinity of a critical load having a high risk of power failure such as a data center to function as an uninterruptible power supply for the critical load. In this case, it is preferable to control the voltage of the power system in cooperation with a plurality of electric vehicles and other uninterruptible power supplies.
  • a circuit simulation is carried out for the power storage system 10 of the first embodiment, and power storage is performed without affecting the power system 5 connected to the power storage system 10 while continuing the operation of the power storage system 10. It was confirmed that the current required for the deterioration diagnosis of the element 35 could be passed.
  • the reactance components 54u, 54v, 54w and the resistance components 55u of the distribution lines 53u, 53v, 53w are connected to the power storage system 10 from the power system 5. It was carried out with a circuit of 55v and 55w, excluding the load 56.
  • Each of the three arms 11A, 11B, and 11C of the power storage system 10 has a configuration in which two unit converters C x (i) including a power storage element 35 are connected in series.
  • Each of the arms 11A, 11B, and 11C is made to output the sum voltage of the zero-phase voltage required for the circulation of the circulating current I cil and the positive-phase voltage for power control of the power system 5, and is inside the power storage system 10.
  • the flowing current and the current supplied from the power storage system 10 to the power system 5 were simulated.
  • the unit of the horizontal axis of all the current waveforms shown in FIG. 8 is seconds [sec], and the unit of the vertical axis is ampere [A].
  • 8A in FIG. 8 is a current waveform of the circulating current component I ir
  • 8B is a waveform of the current component for power control of the power system 5.
  • 8C of FIG. 8 is a waveform of the sum current of the circulating current component I cil shown by 8A and the power control current component shown by 8B, and this sum current is when the power storage element 35 is diagnosed. This is the current flowing inside the power storage system 10.
  • 8D of FIG. 8 shows the waveform of the current discharged from the power storage element 35 and supplied from the power storage system 10 to the power system 5.
  • the control unit 13 of the power storage system 10 is a power storage element designated as a diagnostic target while transmitting and receiving power to and from the external power system 5, that is, at the same time as power transfer. 35 deterioration states can be tested. Further, the test of the deteriorated state of the power storage element 35 is not limited to the time when the power storage system 10 is charging / discharging the power system 5, but also monitors other electrical signals, for example, the voltage state of the power system 5. The same can be performed while transmitting and receiving a signal for management. Further, the power storage system 10 can test the deteriorated state of the power storage element 35 designated as a diagnosis target even in a state where power is not exchanged with the external power system 5 and other signals are not exchanged. it can.
  • the power storage system 10 starts the test of the power storage element 35 in a state where power and signals are not exchanged with the power system 5, and at any subsequent timing, for example, depending on the excess or deficiency of the power of the power system 5. Then, the exchange of electric power or a signal with the electric power system 5 may be started.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

L'invention concerne un système d'accumulation d'électricité (10) pourvu d'une partie de circuit principal (10a) dans laquelle des bras (11A, 11B, 11C) pourvus de convertisseurs unitaires comprenant des éléments d'accumulation d'électricité pouvant être chargés et déchargés sont individuellement disposés de manière correspondante entre les phases d'un courant alternatif triphasé, pour former un trajet de courant électrique en forme d'anneau (71), et d'une unité de commande (13) servant à commander l'état de connexion des éléments d'accumulation d'électricité au trajet de courant électrique en forme d'anneau (71), l'unité de commande (13) étant conçue pour exécuter une séquence de commande permettant d'effectuer la commande susmentionnée de sorte qu'un courant circulant ayant une fréquence définie arbitrairement s'écoule à travers le trajet de courant électrique en forme d'anneau (71), pour tester l'état de dégradation d'un élément d'accumulation d'électricité spécifié en tant que cible de diagnostic.
PCT/JP2020/014664 2019-03-29 2020-03-30 Système d'accumulation d'électricité, nouveau système d'énergie, système de distribution d'électricité, système de transmission d'électricité, équipement de transport, système de batterie pour véhicule électrique, et système de batterie pour dispositif d'alimentation sans coupure WO2020203996A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022078171A (ja) * 2021-03-05 2022-05-24 バイドゥ ユーエスエイ エルエルシー 液冷装置、データセンターおよび電子機器を調整する方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018179145A1 (fr) * 2017-03-29 2018-10-04 東芝三菱電機産業システム株式会社 Dispositif de conversion de puissance et son procédé d'essai
WO2018216208A1 (fr) * 2017-05-26 2018-11-29 三菱電機株式会社 Dispositif de conversion de puissance

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018179145A1 (fr) * 2017-03-29 2018-10-04 東芝三菱電機産業システム株式会社 Dispositif de conversion de puissance et son procédé d'essai
WO2018216208A1 (fr) * 2017-05-26 2018-11-29 三菱電機株式会社 Dispositif de conversion de puissance

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2022078171A (ja) * 2021-03-05 2022-05-24 バイドゥ ユーエスエイ エルエルシー 液冷装置、データセンターおよび電子機器を調整する方法
JP7397111B2 (ja) 2021-03-05 2023-12-12 バイドゥ ユーエスエイ エルエルシー 液冷装置、データセンターおよび電子機器を調整する方法

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