WO2024251209A1 - 储能阀子模块和高压直挂储能系统 - Google Patents
储能阀子模块和高压直挂储能系统 Download PDFInfo
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- WO2024251209A1 WO2024251209A1 PCT/CN2024/097814 CN2024097814W WO2024251209A1 WO 2024251209 A1 WO2024251209 A1 WO 2024251209A1 CN 2024097814 W CN2024097814 W CN 2024097814W WO 2024251209 A1 WO2024251209 A1 WO 2024251209A1
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- storage valve
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/28—Arrangements for balancing of the load in networks by storage of energy
- H02J3/32—Arrangements for balancing of the load in networks by storage of energy using batteries or super capacitors with converting means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/28—Arrangements for balancing of the load in networks by storage of energy
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/001—Arrangements for handling faults or abnormalities, e.g. emergencies or contingencies
- H02J3/0014—Arrangements for handling faults or abnormalities, e.g. emergencies or contingencies for preventing or reducing power oscillations in networks
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/002—Flicker reduction, e.g. compensation of flicker introduced by non-linear load
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
- H02J7/60—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including safety or protection arrangements
- H02J7/62—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including safety or protection arrangements against overcurrent
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
- H02J7/60—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including safety or protection arrangements
- H02J7/64—Circuit arrangements for charging or discharging batteries or for supplying loads from batteries including safety or protection arrangements against overvoltage
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/36—Arrangements for transfer of electric power between AC networks via high-voltage DC [HVDC] links; Arrangements for transfer of electric power between generators and networks via HVDC links
- H02J2003/365—Reducing harmonics or oscillations in HVDC
Definitions
- the present application relates to the field of energy storage technology, and in particular to an energy storage valve submodule and a high-pressure direct-mounted energy storage system.
- the high-voltage direct-mounted energy storage system includes a plurality of cascaded energy storage valve submodules, each of which includes an energy storage unit.
- the charging and discharging of the energy storage unit in each energy storage valve submodule can be achieved by controlling the switching state of each energy storage valve submodule.
- an embodiment of the present application provides an energy storage valve sub-module, which includes a power conversion unit, a first capacitor, a suppression circuit and an energy storage unit.
- the suppression circuit is connected in series with the first capacitor to form a resistor-capacitor branch, and the resistor-capacitor branch is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the energy storage valve submodule provided in the embodiment of the present application adds an under-damped oscillation suppression circuit in the energy storage valve submodule, the suppression circuit is connected in series with the first capacitor, and the resistance-capacitance branch formed by the suppression circuit and the first capacitor in series is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the suppression circuit can suppress the under-damped oscillation current generated by the energy storage valve submodule at the switching state by adjusting the resistance value of the impedance in the energy storage valve submodule, the under-damped oscillation current generated by the energy storage valve submodule at the switching state is greatly reduced, thereby achieving the effect of suppressing the under-damped oscillation current, so that the harm caused by the under-damped oscillation current to the energy storage valve submodule is greatly reduced, thereby improving the reliability of the energy storage valve submodule.
- the first capacitor includes a DC link capacitor.
- the energy storage valve submodule includes a power conversion unit, a DC support capacitor, a suppression circuit and an energy storage unit.
- the suppression circuit and the DC support capacitor are connected in series to form a resistor-capacitor branch, and the resistor-capacitor branch is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the energy storage valve submodule provided in the embodiment of the present application adds an under-damped oscillation suppression circuit in the energy storage valve submodule, the suppression circuit is connected in series with the DC support capacitor, and the resistance-capacitance branch formed by the suppression circuit and the DC support capacitor in series is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the suppression circuit can suppress the under-damped oscillation current generated by the energy storage valve submodule at the switching state switching moment by adjusting the resistance value of the impedance in the energy storage valve submodule, the under-damped oscillation current generated by the energy storage valve submodule at the switching state switching moment is greatly reduced, thereby achieving the effect of suppressing the under-damped oscillation current, so that the harm caused by the under-damped oscillation current to the energy storage valve submodule is greatly reduced, thereby improving the reliability of the energy storage valve submodule.
- the suppression circuit includes a resistive element.
- the suppression circuit is realized by a resistor element, so that the resistor element provides the resistance required to suppress the under-damped oscillating current generated by the energy storage valve submodule at the time of input, which is not only economical but also convenient and simple, and greatly reduces the additional impact on the overall function of the energy storage valve submodule, thereby further improving the reliability of the energy storage valve submodule. sex.
- the suppression circuit further includes a switch circuit, and the switch circuit is used to control the switching state of the resistance element.
- the switch circuit is used to control whether the resistance element is in the energy storage valve submodule or is cut out. Only when it is put into operation in the energy storage valve submodule can the under-damped oscillation generated at the time of the energy storage unit being put into operation in the corresponding state be suppressed, thereby improving the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the switch circuit is connected in parallel with the resistance element.
- a switch circuit is connected in parallel next to the resistance element, and the opening and closing of the switch circuit is used to realize whether the resistance element is in the energy storage valve submodule or is cut out. Only when it is put into operation in the energy storage valve submodule can the under-damped oscillation generated at the time of input under the corresponding state of the energy storage unit be suppressed, thereby improving the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the suppression circuit further includes a switch circuit connected in parallel with the resistance element.
- a switch circuit is connected in parallel next to the resistance element, and the opening and closing of the switch circuit is used to realize whether the resistance element is in the energy storage valve submodule or is cut out. Only when it is put into operation in the energy storage valve submodule can the under-damped oscillation generated at the time of input under the corresponding state of the energy storage unit be suppressed, thereby improving the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the resistance element includes a first resistor and a second resistor connected in series
- the switch circuit also includes a first switch and a second switch, the first switch is connected in parallel with the first resistor, and the second switch is connected in parallel with the second resistor.
- two resistors are added to the energy storage valve submodule, and then two different switches are added to control the switching states of the two resistors in the energy storage valve submodule respectively. Only one of the two resistors is switched on when the energy storage unit is in the charging state or when the energy storage unit is in the discharging state. On this basis, the resistance values of the two resistors are different, so that the degree of underdamped oscillation that can be suppressed when the energy storage unit is in the charging state or when the energy storage unit is in the discharging state is also different. In this way, the suppression of underdamped oscillation of the energy storage unit in different charging and discharging states is more accurate.
- the first switch and/or the second switch is a diode.
- a diode is used to implement the first switch and the second switch. Since the diode does not need to be controlled and relies on the voltage in the circuit to switch between the on and off states, it has the advantages of fast switching speed and extremely short switching time, so that the switching state of the resistance element can be quickly and accurately controlled, thereby achieving a more accurate effect of suppressing the under-damped oscillation of the energy storage unit in different charging and discharging states.
- the resistance of the first resistor is greater than the resistance of the second resistor.
- the under-damped oscillating current generated when the energy storage unit is in the charging state can be suppressed to a greater extent, and the degree of suppression of the under-damped oscillating current generated when the energy storage unit is in the discharging state can be less.
- the under-damped oscillating current generated when the energy storage unit is in the charging state and the discharging state can be suppressed differently, so as to improve the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the under-damped oscillating current generated when the energy storage unit is in the charging state can be suppressed to a greater extent, and the degree of suppression of the under-damped oscillating current generated when the energy storage unit is in the discharging state can be less.
- the under-damped oscillating current generated when the energy storage unit is in the charging state and the discharging state can be suppressed differently, so as to improve the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the resistance element includes a third resistor and a fourth resistor connected in parallel with each other
- the switch circuit also includes a third switch and a fourth switch, the third switch is connected in series with the third resistor, and the fourth switch is connected in series with the fourth resistor.
- two resistors are added to the energy storage valve submodule, and then two different switches are added to control the switching states of the two resistors in the energy storage valve submodule respectively. Only one of the two resistors is switched on when the energy storage unit is in the charging state or when the energy storage unit is in the discharging state. On this basis, the resistance values of the two resistors are different, so that the degree of underdamped oscillation that can be suppressed when the energy storage unit is in the charging state or when the energy storage unit is in the discharging state is also different. In this way, the suppression of underdamped oscillation of the energy storage unit in different charging and discharging states is more accurate.
- the third switch and/or the fourth switch is a diode.
- diodes are used to implement the third switch and the fourth switch. Since the diodes do not need to be controlled and rely on the voltage in the circuit to switch between the on and off states, they have the advantages of fast switching speed and extremely short switching time, so that the switching state of the resistance element can be quickly and accurately controlled, thereby achieving a more accurate effect of suppressing the under-damped oscillation of the energy storage unit in different charging and discharging states.
- the resistance of the third resistor is greater than the resistance of the fourth resistor.
- the under-damped oscillating current generated when the energy storage unit is in the charging state can be suppressed to a greater extent, and the degree of suppression of the under-damped oscillating current generated when the energy storage unit is in the discharging state can be less.
- the under-damped oscillating current generated when the energy storage unit is in the charging state and the discharging state can be suppressed differently, so as to improve the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the resistance value of the resistor element ranges from 10 ohms (m ⁇ ) to 500 m ⁇ .
- the value range of the resistance element is set to 10m ⁇ -500m ⁇ , so that the resistance element matches the capacitance of the first capacitor in the high-voltage direct-hung energy storage system scenario, the inductance of the equivalent stray inductance in the energy storage unit, and the resistance of the equivalent internal resistance in the energy storage unit, thereby accurately suppressing the under-damped oscillation of the energy valve sub-module in the high-voltage direct-hung energy storage system scenario.
- the energy storage valve submodule further includes a second capacitor, and the second capacitor is connected in parallel with the resistor-capacitor branch.
- the overvoltage stress of the power device in the power conversion unit at the time of shutdown can be reduced.
- the risk of failure of the power device in the power conversion unit due to excessive overvoltage stress is reduced, thereby increasing the working reliability of the power device in the power conversion unit, and further increasing the working reliability of the energy storage valve submodule.
- the second capacitor includes a buffer capacitor.
- the energy storage valve submodule further includes a buffer capacitor, which is connected in parallel with the resistor-capacitor branch.
- a buffer capacitor is connected in parallel next to the RC branch as a whole, so that the overvoltage stress of the power device in the power conversion unit at the time of shutdown can be reduced. In this way, the risk of failure of the power device in the power conversion unit due to excessive overvoltage stress is reduced, thereby increasing the working reliability of the power device in the power conversion unit, and further increasing the working reliability of the energy storage valve submodule.
- the capacitance of the second capacitor is smaller than the capacitance of the first capacitor.
- the capacitance of the second capacitor by setting the capacitance of the second capacitor to be smaller than that of the first capacitor, a certain distinction is made between the high-frequency current passing through the second capacitor and the high-frequency current passing through the first capacitor when the energy storage valve submodule is put into operation. And because the capacitance of the second capacitor is much smaller than that of the first capacitor, the degree of underdamped oscillation of the energy storage valve submodule aggravated by the excessive capacitance of the second capacitor is reduced, so that the overvoltage stress at the time of shutting off the power device in the power conversion unit is reduced while reducing the risk of generating additional impacts, thereby increasing the working reliability of the energy storage valve submodule.
- the capacitance of the buffer capacitor is smaller than the capacitance of the DC link capacitor.
- the capacitance of the buffer capacitor by setting the capacitance of the buffer capacitor to be smaller than the capacitance of the DC support capacitor, a certain distinction is made between the high-frequency current passed by the buffer capacitor and the high-frequency current passed by the DC support capacitor when the energy storage valve submodule is put into operation. And because the capacitance of the buffer capacitor is much smaller than the capacitance of the DC support capacitor, the degree of under-damped oscillation of the energy storage valve submodule aggravated by the excessive capacitance of the buffer capacitor is reduced, so that the overvoltage stress at the time of shutting off the power device in the power conversion unit is reduced while reducing the risk of generating additional impacts, thereby increasing the working reliability of the energy storage valve submodule.
- the capacitance range of the second capacitor includes 10 uF to 300 uF.
- the capacitance range of the second capacitor is set to include 10uF to 300uF. This can not only reduce the overvoltage stress of the power device in the power conversion unit at the time of shutdown in the high-voltage direct-mounted energy storage scenario, but also reduce the additional impact on the overall topology of the energy storage valve sub-module, thereby increasing the working reliability of the energy storage valve sub-module.
- the capacitance range of the buffer capacitor includes 10uF to 300uF.
- the capacitance range of the buffer capacitor is 10uF to 300uF, which can not only reduce the overvoltage stress of the power device in the power conversion unit at the time of shutting down in the high-voltage direct-mounted energy storage scenario, but also reduce the The overall topology of the energy storage valve submodule produces an additional influence, which increases the working reliability of the energy storage valve submodule.
- the energy storage valve submodule further includes a bypass circuit, and the bypass circuit is connected in parallel with the energy storage valve submodule.
- a bypass circuit is provided between the ports at which the energy storage valve submodule is connected to the main circuit of the high-voltage direct-hung energy storage system, so that in the event of a failure in the energy storage valve submodule, the energy storage valve submodule can be cut out of the high-voltage direct-hung energy storage system, thereby improving the operating stability and safety of the high-voltage direct-hung energy storage system.
- the switching frequency of the energy storage valve submodule is positively correlated with the energy loss generated by the suppression circuit.
- the embodiment of the present application sets the equivalent switching frequency of the energy storage valve submodule when it is switched on and off in the high-voltage direct-hung energy storage system through the characteristic that the switching frequency of the energy storage valve submodule is positively correlated with the energy loss generated by the suppression circuit, so that the energy storage valve submodule can be switched on and off at a lower equivalent switching frequency, thereby reducing the loss of the energy storage valve submodule and improving the economy and safety of the application of the energy storage valve submodule.
- the turn-off current change rate of the power device in the power conversion unit is inversely correlated with the parameter value of the driving device in the driving circuit of the power device.
- the turn-off current change rate of the power device in the power conversion unit is inversely correlated with the parameter value of the driving device in the driving circuit of the power device, it is possible to reduce the turn-off current change rate of the power device in the power conversion unit, thereby further reducing the turn-off overvoltage of the power device in the power conversion unit, and greatly reducing the problem of failure of the power device in the power conversion unit due to excessive overvoltage stress, thereby increasing the working reliability of the power conversion unit.
- the parameter value of the driving device includes the resistance value of the gate turn-off resistor in the driving circuit and/or the capacitance value of the gate capacitor in the driving circuit.
- an embodiment of the present application provides a high-pressure direct-hung energy storage system, which includes an energy storage valve submodule provided in any embodiment of the first aspect above.
- FIG1 is a schematic diagram of the architecture of a high-voltage direct-mounted energy storage system in one embodiment
- FIG2 is a topological schematic diagram of an energy storage valve submodule in an embodiment
- FIG3 is a schematic diagram of equivalent stray inductance and equivalent internal resistance of an energy storage unit in an energy storage valve submodule in one embodiment
- FIG4 is a topological schematic diagram of an energy storage valve submodule in another embodiment
- FIG5 is a topological schematic diagram of an energy storage valve submodule in another embodiment
- FIG6 is a schematic diagram of the implementation structure of a power conversion unit in an energy storage valve submodule in one embodiment
- FIG7 is a schematic diagram of the implementation structure of a power conversion unit in an energy storage valve submodule in another embodiment
- FIG8 is a schematic diagram of the implementation structure of the suppression circuit in the energy storage valve submodule in one embodiment
- FIG9 is a schematic diagram of an equivalent network after a suppression circuit is added to the energy storage valve submodule in one embodiment
- FIG10 is a schematic diagram of the implementation structure of the suppression circuit in the energy storage valve submodule in another embodiment
- FIG11 is a schematic diagram of the implementation structure of a switch circuit in an inhibition circuit in one embodiment
- FIG12 is a schematic diagram of the implementation structure of the suppression circuit in the energy storage valve submodule in another embodiment
- FIG13 is a schematic diagram of the implementation structure of the suppression circuit in the energy storage valve submodule in another embodiment
- FIG14 is a schematic diagram of a structure in which a second capacitor is added to an energy storage valve submodule in one embodiment
- FIG15 is a schematic diagram of a driving circuit of a power device in a power conversion unit in one embodiment
- FIG. 16 is a schematic diagram of a structure in which a bypass circuit is added to an energy storage valve submodule in one embodiment.
- connection should be understood in a broad sense, for example, it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements.
- connection should be understood in a broad sense, for example, it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements.
- the high-voltage direct-mounted energy storage system is a new type of energy storage system. It uses modular multi-level cascade technology to cascade multiple energy storage valve submodules, which can simultaneously realize AC/DC power conversion and energy storage. It has the advantages of high modularity and good harmonic characteristics. Therefore, it is increasingly widely used in power grids.
- Each energy storage valve submodule in the high-voltage direct-mounted energy storage system includes an energy storage unit, and the energy storage unit includes a battery pack. In practical applications, the energy storage units in each energy storage valve submodule can be charged and discharged by controlling the cascaded energy storage valve submodules.
- FIG. 1 is a schematic diagram of the architecture of a high-voltage AC direct-mounted energy storage system, taking a direct-mounted energy storage system of a three-phase grid A, B, and C as an example.
- the high-voltage direct-mounted energy storage system includes three-phase energy storage cascade chains A, B, and C, and each phase of the energy storage cascade chain includes a bridge arm reactor and m energy storage modules.
- the energy storage modules on the three-phase energy storage cascade chain are represented by SM1#m, SM2#m, and SM3#m, respectively, and m is 1, 2, 3, ..., n.
- the three-phase AC power can also be converted into DC power by a converter valve, the energy storage valve can be directly mounted on the DC grid, and the energy storage valve can include multiple energy storage valve sub-modules, etc.
- the topology of the energy storage valve submodule in the high-voltage direct-hung energy storage system is shown in Figure 2, including a power conversion unit 10, a first capacitor 20 and an energy storage unit 30, wherein S1 and S2 in Figure 2 represent two connection ports, and each energy storage valve submodule needs to be connected to the main circuit of the high-voltage direct-hung energy storage system through the two connection ports S1 and S2 to be connected to the high-voltage power grid through the main circuit.
- the connection relationship here can be seen in S1 and S2 in Figure 1.
- the equivalent internal resistance and equivalent stray inductance come not only from the connection row inside the energy storage unit, but also from the bus connecting the energy storage unit and the power conversion unit in the entire energy storage valve submodule topology.
- the equivalent resistance and equivalent stray inductance inside the energy storage unit and the first capacitor are equivalent to a parallel RLC network.
- the modes of the energy storage valve submodule in the entire high-voltage direct-hung energy storage system include two states: the on-state and the off-state.
- FIG. 3 is a schematic diagram of a parallel RLC network that is topologically equivalent to the energy storage valve submodule, wherein L represents equivalent stray inductance, Rdc represents equivalent internal resistance, I/P represents step current source excitation, and the power conversion unit in the energy storage valve submodule is not shown in Figure 3.
- the inductive reactance of the equivalent stray inductance L in the energy storage valve submodule does not match the capacitive reactance of the first capacitor.
- the mismatch between the inductive reactance of the equivalent stray inductance L and the capacitive reactance of the first capacitor will cause the entire RLC network to have underdamped oscillations, forming an underdamped network, thereby causing underdamped oscillations between the first capacitor and the energy storage unit.
- the underdamped oscillation may cause certain harm to the energy storage valve submodule, including but not limited to overcurrent of the energy storage unit, resulting in damage, degradation and reduced life of the energy storage unit; and the capacitor current in the energy storage valve submodule increases, for example, it can increase by about 30%, which will increase the weight, volume and cost of the capacitor; and if the energy storage valve submodule is in an overcurrent state for a long time during operation, it will also cause greater current stress on the electrical components in the energy storage valve submodule, etc., thereby affecting the working reliability of the energy storage valve submodule.
- the capacitance of the capacitor needs to be increased to several hundred mF, and the increase in the capacitance of the capacitor is accompanied by a corresponding increase in the volume, weight and cost of the capacitor, resulting in a certain impact on the applicability and convenience of the energy storage valve sub-module.
- the embodiment of the present application improves the topology of the energy storage valve submodule, adds an under-damped oscillation suppression circuit in the energy storage valve submodule, and suppresses the under-damped oscillation current generated by the entire energy storage valve submodule at the switching state, so that the under-damped oscillation current generated by the energy storage valve submodule at the switching state can be greatly reduced, achieving the effect of suppressing the under-damped oscillation current, so that the harm caused by the under-damped oscillation current to the energy storage valve submodule is greatly reduced, thereby improving the reliability of the energy storage valve submodule.
- the energy storage valve submodule includes a power conversion unit 10, a first capacitor 20, a suppression circuit 40 and an energy storage unit 30, and the suppression circuit 40 is connected in series with the first capacitor 20 to form a resistance-capacitance branch, and the resistance-capacitance branch is connected in parallel with the power conversion unit 10 and the energy storage unit 30 respectively.
- the energy storage valve submodule generally refers to any submodule in the energy storage system, wherein the energy storage system can adjust the direction or size of the current for the power grid system current, similar to the function of a valve, and is also called an energy storage valve.
- the submodule in the energy storage system is referred to as an energy storage valve submodule, which is only an example of a synonym for each submodule in the energy storage system, and does not limit the function, structure or usage scenario of each submodule. Therefore, in the application, it can also be called an energy storage submodule, a charging and discharging electronic module, a submodule, etc. according to its actual needs. This application does not limit the names of the submodules in the energy storage system.
- a suppression circuit 40 is connected in series to the branch where the first capacitor 20 is located in the energy storage valve submodule to form a resistance-capacitance branch, which is connected in parallel with the power conversion unit 10 and the energy storage unit 30.
- FIG. 4 is only an example of one connection method.
- the RC branch can also be connected in the manner shown in FIG. 5 .
- the first capacitor 20 includes a DC support capacitor, wherein the DC support capacitor refers to a capacitor located at the DC end of the module, having a relatively large capacitance, and used to support the module voltage or suppress voltage fluctuations.
- the energy storage valve submodule includes a power conversion unit, a DC support capacitor, a suppression circuit and an energy storage unit.
- the suppression circuit and the DC support capacitor are connected in series to form a resistance-capacitance branch, and the resistance-capacitance branch is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the power conversion unit 10 mainly realizes the two working modes of the energy storage unit 30 in the charging and discharging state through different paths.
- the power conversion unit 10 can be realized by a half-bridge circuit composed of power semiconductor devices, a full-bridge circuit composed of power semiconductor devices, a quasi-full-bridge circuit composed of power semiconductor devices, and so on.
- FIG6 illustrates a half-bridge circuit composed of a power semiconductor device, wherein T1 and T2 are both power devices, for example, they can be implemented by an insulated gate bipolar transistor (IGBT).
- IGBT insulated gate bipolar transistor
- FIG. 7 illustrates a full-bridge circuit, in which T1, T2, T3 and T4 are all power devices, and can also be implemented by IGBTs.
- the power device in the power conversion unit 10 is an IGBT as an example
- the IGBT is a switch tube
- the gate of the IGBT in FIG6 and FIG7 is connected to a driving circuit, which is mainly used to drive the IGBT to turn on and off.
- the embodiment of the present application does not illustrate the driving circuit connected to the gate of the IGBT.
- the energy storage unit 30 in the energy storage valve submodule is divided into an input mode and a cut-off mode in a charging state, and an input mode and a cut-off mode in a discharging state.
- FIG. 6 the working principle in the above input mode and cut-off mode is explained in combination with the circuit schematic diagram, as follows:
- the energy storage unit 30 is in the charging state in the input mode: In this mode, the T2 tube is turned off, and the D2 and T1 tubes are also not turned on due to the reverse voltage. Then, the current on the main circuit of the high-voltage direct-hung energy storage system enters the energy storage unit 30 from the S1 port through D1 and then flows out through the S2 port to form a loop, so that the energy storage unit 30 can be charged.
- the energy storage unit 30 is in the discharging state in the input mode: In this mode, the T2 tube, D2 and D1 are not conducting, while the T1 tube is conducting. Then, the current on the main circuit of the high-voltage direct-hung energy storage system directly enters the energy storage unit 30 from the S2 port, passes through the T1 tube, and then flows out from the S1 port to form a loop, so that the energy storage unit 30 is in the discharging state.
- the mismatch between the capacitive reactance of the first capacitor 20 and the inductive reactance of the equivalent stray inductance in the energy storage valve submodule causes the energy storage valve submodule to oscillate underdamped when the switching state is switched. Then to suppress this underdamped oscillation, it is necessary to minimize the mismatch between the capacitive reactance of the first capacitor 20 and the inductive reactance of the equivalent stray inductance, that is, in essence, to suppress the underdamped oscillation current generated by the energy storage valve submodule.
- the functions of the first capacitor 20 in the energy storage valve submodule include but are not limited to filtering high-frequency harmonics during IGBT switching, constructing a power device commutation circuit, etc., it is an indispensable key part of the energy storage valve submodule, and the equivalent stray inductance is also caused by the indispensable energy storage unit 30 in the energy storage valve submodule, so the capacitive reactance and inductive reactance cannot be adjusted as mentioned in the above embodiment of the present application.
- the impedance of the RLC network equivalent to the first capacitor 20 and the energy storage unit 30 has resistance in addition to the reactance composed of capacitive reactance and inductive reactance.
- the embodiment of the present application adjusts the resistance in the impedance value of the RLC network by adding a suppression circuit 40, so that the RLC network is in an over-damped state, suppressing the under-damped oscillation phenomenon of the RLC network, thereby suppressing the under-damped oscillation current.
- the suppression circuit 40 may include a resistor element. That is, the suppression circuit 40 in the embodiment of the present application may be implemented by a resistor element.
- the resistor element provides the resistance required to suppress the under-damped oscillating current generated by the energy storage valve submodule at the time of input, which is not only highly economical and easy to use, but also greatly reduces the additional impact on the overall function of the energy storage valve submodule.
- the resistance element in the embodiment of the present application can be realized by any device with resistance through any connection method, for example, it can be realized by a resistor, or it can be realized by some passive devices with resistance, etc.
- the energy storage valve submodule provided in the embodiment of the present application adds an under-damped oscillation suppression circuit in the energy storage valve submodule, the suppression circuit is connected in series with the first capacitor, and the resistance-capacitance branch formed by the suppression circuit and the first capacitor in series is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the suppression circuit can suppress the under-damped oscillation current generated by the energy storage valve submodule at the switching state by adjusting the resistance value of the impedance in the energy storage valve submodule, the under-damped oscillation current generated by the energy storage valve submodule at the switching state is greatly reduced, thereby achieving the effect of suppressing the under-damped oscillation current, so that the harm caused by the under-damped oscillation current to the energy storage valve submodule is greatly reduced, thereby improving the reliability of the energy storage valve submodule.
- the suppression circuit in the energy storage valve submodule is connected in series with the DC support capacitor, and the resistance-capacitance branch formed by the suppression circuit and the DC support capacitor in series is respectively connected in parallel with the power conversion unit and the energy storage unit.
- the suppression circuit can suppress the under-damped oscillating current generated by the energy storage valve submodule at the switching state by adjusting the resistance value of the impedance in the energy storage valve submodule, greatly reducing the under-damped oscillating current generated by the energy storage valve submodule at the switching state, achieving the effect of suppressing the under-damped oscillating current, greatly reducing the harm caused by the under-damped oscillating current to the energy storage valve submodule, thereby improving the reliability of the energy storage valve submodule.
- the embodiment of the present application takes the above-mentioned resistor element as an example to explain in detail the implementation of the above-mentioned suppression circuit 40.
- FIG8 takes the resistor element 401 as an example, and by adding the resistor element 401 to the branch of the first capacitor 20, the under-damped state of the entire energy storage valve submodule is changed to suppress the under-damped oscillating current.
- the resistor element 401 can be set according to requirements, and can include a single resistor, or a series-parallel combination of multiple resistors.
- the suppression circuit 40 if the under-damped oscillating current generated by the energy storage valve submodule at the switching state is to be suppressed by adjusting the resistance value of the impedance in the energy storage valve submodule, it is necessary to accurately design the resistance value of the resistor element 401.
- the resistance value of the resistor element 401 needs to be able to make the current generated in the entire network at the switching state of the energy storage valve submodule not exceed the tolerance current of the energy storage unit 30, so that the entire network can be in a critical damping or over-damping state.
- FIG. 9 is a schematic diagram of an equivalent network formed by combining FIG. 3 and FIG. 8 above with a damping resistor connected in series in the energy storage valve submodule.
- L represents the equivalent stray inductance value in the energy storage unit 30
- C represents the capacitance value of the first capacitor
- Rc represents the resistance value of the resistor element 401 in the suppression circuit 40
- R1 represents the equivalent
- the resistance value of the internal resistor Rdc, u c represents the voltage on the first capacitor 20, naturally, represents the current on the first capacitor 20, is represents the current entering the energy storage unit 30 when the energy storage valve submodule is put into operation
- OCV represents the starting voltage on the first capacitor 20 of the energy storage valve submodule under steady-state conditions, and because the energy storage valve submodule is in a steady state before the step current on the main circuit enters the energy storage valve submodule, the capacitor does not pass direct current in this steady state, which is equivalent to an open circuit, so OCV can be understood as the voltage on the energy storage unit 30.
- Formula 2 is a homogeneous equation, and p represents the Therefore, according to Formula 2, the resistance value of the resistor element 401 is related to the capacitance value of the first capacitor 20 in the energy storage valve submodule, the inductance value of the equivalent stray inductance L in the energy storage valve submodule, and the resistance value of the equivalent internal resistance Rdc in the energy storage valve submodule.
- the resistance range of the resistor element 401 can be between 10m ⁇ -500m ⁇ .
- the resistance of the resistor element 401 can be 50m ⁇ , 100m ⁇ , 150m ⁇ , etc., which are not listed here one by one, as long as they are within the value range.
- the value range of the resistance element is set to 10m ⁇ -500m ⁇ , so that the resistance element matches the capacitance of the first capacitor, the inductance of the equivalent stray inductance in the energy storage unit, and the resistance of the equivalent internal resistance in the energy storage unit in the high-voltage direct-hung energy storage system scenario, thereby being able to accurately suppress the under-damped oscillation of the energy valve sub-module in the high-voltage direct-hung energy storage system scenario.
- a second-order differential equation of the topological network model of the energy storage valve submodule is constructed, and the second-order differential equation is solved to obtain the functional relationship between the equivalent stray inductance of the energy storage unit, the equivalent internal resistance of the energy storage unit, the first capacitor and the resistance element, and then the capacitance of the first capacitor, the equivalent stray inductance value of the energy storage unit, and the equivalent internal resistance value of the energy storage unit in actual application are substituted into the functional relationship for solution to obtain the resistance value of the resistance element.
- the second-order differential equation is constructed based on the energy storage valve submodule with the resistance element added, the second-order differential equation can accurately reflect the characteristics of the entire topology of the energy storage valve submodule, so that the resistance value of the resistance element can be accurately calculated, thereby effectively suppressing the under-damped oscillating current generated in the energy storage valve submodule.
- the under-damped oscillation current in the energy storage valve submodule may be generated not only when the energy storage unit 30 is put into the charging state, but also when the energy storage unit 30 is put into the discharging state
- a method is provided in the embodiment of the present application to achieve accurate suppression of the under-damped oscillation of the energy storage unit 30 in different charging and discharging states.
- the suppression circuit 40 further includes a switch circuit 402, and the switch circuit 402 is used to control the switching state of the resistance element.
- the embodiment of the present application provides three methods, and the three methods are described in detail below.
- the switch circuit 402 is connected in parallel with the resistor element 401 .
- the function of the switch circuit 402 is to control the switching state of the resistor element 401 in the energy storage valve submodule. That is, by connecting the switch circuit 402 in parallel with the resistor element 401, when the energy storage unit 30 is in the charging state, the switch circuit 402 is disconnected to put the resistor element 401 in the switching state; when the energy storage unit 30 is in the discharging state, the switch circuit 402 is turned on to put the resistor element 401 in the switching-out state.
- the switch circuit 402 When the resistor element 401 is in the on state, the switch circuit 402 is disconnected, and in this case the current on the main circuit will pass through the resistor element 401 to suppress the under-damped oscillating current generated when the energy storage unit 30 is in the charging state. Similarly, when the resistor element 401 is in the off state, the switch circuit 402 is turned on, and in this case the current on the main circuit will pass through the switch circuit 402, which is equivalent to almost no current passing through the resistor element 401, which is short-circuited by the switch circuit 402, so that in this case the under-damped oscillating current generated when the energy storage unit 30 is in the discharging state is not suppressed.
- the suppression circuit 40 is illustrated by taking the switching circuit 402 as a diode as an example.
- the switching characteristics of the diode make the diode in the off state when the energy storage unit 30 is in the charging state, so the current of the main circuit can only pass through the resistor element 401 at the time of input.
- the diode is in the on state, the resistor element 401 is short-circuited, and the current in the main circuit directly flows through the diode at the time of input.
- the diode is used to implement the switching circuit. The diode does not need to be controlled. It relies on the voltage in the circuit to switch between the on and off states.
- the switch circuit when the switch circuit is a diode, the positive and negative directions of the diode when connected are not unique, and the diode position and the positive and negative connection directions of the diode can be set according to the circuit where the resistor to be turned on is located.
- the above diode is only an example. If the switch circuit uses a non-directional switch, it is only necessary to consider the circuit where the resistor to be turned on is located to control the on and off of the switch circuit.
- a switch circuit is connected in parallel next to the resistance element, and the opening and closing of the switch circuit is used to realize whether the resistance element is in the energy storage valve submodule or is cut out. Only when it is put into operation in the energy storage valve submodule can the under-damped oscillation generated at the time of input under the corresponding state of the energy storage unit be suppressed, thereby improving the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- the above is an embodiment of realizing precise suppression of under-damped oscillations in different charging and discharging processes of the energy storage unit 30 by using a resistor in the resistor element 401 and a switch in the switch circuit 402.
- Precise suppression of under-damped oscillations in different charging and discharging processes of the energy storage unit 30 can also be realized by using multiple resistors in the resistor element 401 and multiple switches in the switch circuit 402.
- the resistor element 401 includes a first resistor R1 and a second resistor R2 connected in series
- the switch circuit 402 also includes a first switch D5 and a second switch D6, wherein the first switch D5 is connected in parallel with the first resistor R1, and the second switch D6 is connected in parallel with the second resistor R2.
- the first switch D5 and/or the second switch D6 are diodes.
- Fig. 12 is a schematic diagram using a diode D5 as the first switch, a diode D6 as the second switch, R1 as the first resistor, and R2 as the second resistor as an example. It should be noted that in actual applications, the first switch D5 and the second switch D6 are both diodes, or one of the first switch D5 and the second switch D6 can be a diode.
- the first switch D5 When the energy storage unit 30 is in a discharging state, once the energy storage valve submodule is put into operation, the first switch D5 is forward-conducted and the second switch D6 is reversely turned off, and the current in the main circuit passes through the second resistor R2 and then through the first switch D5.
- the second resistor R2 it is equivalent to that only the second resistor R2 is in the engaged state, and the first resistor R1 is cut out, so the second resistor R2 can suppress the under-damped oscillating current generated when the energy storage unit 30 is in a discharging state.
- the positive and negative directions of the connections are not unique, and can be set according to the position of the diode in the loop where the resistor to be turned on is located and the positive and negative connection directions of the diode.
- the degree of under-damped oscillating current generated when the energy storage unit 30 is in the charging state is greater than the under-damped oscillating current generated when the energy storage unit 30 is in the discharging state, and the degree of suppression of the under-damped oscillating current generated when the energy storage unit 30 is in the charging state can be set to be greater, while the degree of suppression of the under-damped oscillating current generated when the energy storage unit 30 is in the discharging state can be smaller.
- the resistance value of the first resistor R1 is greater than the resistance value of the second resistor R2, that is, the greater the resistance value, the stronger the degree of suppression of the under-damped oscillating current, so that by setting the first resistor R1 and the second resistor R2 to different resistance values, the under-damped oscillating current generated when the energy storage unit 30 is in the charging state and the discharging state can be suppressed differently, so as to improve the accuracy of suppressing the under-damped oscillation of the energy storage valve submodule.
- the resistor element 401 includes a third resistor R3 and a fourth resistor R4 connected in parallel
- the switch circuit 402 also includes a third switch D7 and a fourth switch D8, the third switch D7 is connected in series with the third resistor R3, and the fourth switch D8 is connected in series with the fourth resistor R4.
- the third switch D7 and/or the fourth switch D8 is a diode.
- FIG. 13 is a diagram showing an example in which the third switch is a diode D7 , the fourth switch is a diode D8 , the third resistor is R3 , and the fourth resistor is R4 .
- the second resistor R4 in FIG. 13 can also be interchanged with the fourth switch D8, and the two methods are substantially equivalent.
- the third switch D7 and the fourth switch D8 are both diodes, or one of the third switch D7 and the fourth switch D8 is a diode.
- the positive and negative poles of the diode as a switch can also change the connection direction accordingly, that is, in the embodiment of the present application, when the third switch D7 and the fourth switch D8 are diodes, the positive and negative poles of the diode when connected are not unique, and can be set according to the position of the diode in the circuit where the resistor to be turned on is located and the positive and negative pole connection direction of the diode.
- the third switch D7 is reversely cut off and forwardly conducted, and the current in the main circuit passes through the fourth switch D8 and then flows out through the fourth resistor R4.
- the fourth resistor R4 it is equivalent to that only the fourth resistor R4 is in the put-in state, and the third resistor R3 is cut out, so the fourth resistor R4 can suppress the under-damped oscillation current generated at the time when the energy storage unit 30 is in the discharging state.
- the degree of under-damped oscillating current generated when the energy storage unit 30 is in the charging state is greater than the under-damped oscillating current generated when the energy storage unit 30 is in the discharging state, and the under-damped oscillating current generated when the energy storage unit 30 is in the charging state is set to be suppressed to a greater extent, while the degree of suppression of the under-damped oscillating current generated when the energy storage unit 30 is in the discharging state can be smaller.
- the resistance value of the third resistor R3 is greater than the resistance value of the fourth resistor R4, that is, the greater the resistance value, the stronger the degree of suppression of the under-damped oscillating current, so that by setting the third resistor R3 and the fourth resistor R4 to different resistance values, the under-damped oscillating current generated when the energy storage unit 30 is in the charging state and the discharging state is suppressed differently, so as to improve the suppression accuracy of the under-damped oscillation of the energy storage valve submodule.
- two resistors are added to the energy storage valve submodule, and then two different switches are added to respectively control the switching states of the two resistors in the energy storage valve submodule. Only one of the two resistors is switched on when the energy storage unit is in a charging state or when the energy storage unit is in a discharging state. On this basis, the resistance values of the two resistors are different, so that the degree of under-damped oscillation that can be suppressed when the energy storage unit is in a charging state or when the energy storage unit is in a discharging state is also different. In this way, the suppression of under-damped oscillation of the energy storage unit in different charging and discharging states is more accurate.
- the overvoltage stress when the IGBT in the power conversion unit 10 is turned off will increase accordingly due to the resistance in the suppression circuit 40.
- the embodiment of the present application reduces the overvoltage stress at the IGBT turn-off time by connecting a second capacitor in parallel with the RC branch.
- the energy storage valve submodule further includes a second capacitor 50, which is connected in parallel with the RC branch.
- connection method of the second capacitor 50 shown in FIG14 is only an example.
- the second capacitor 50 can be connected in parallel between the power conversion unit 10 and the RC branch as shown in FIG14; or it can be connected in parallel between the RC branch and the energy storage unit 30.
- the RC branch is connected in parallel behind the energy storage unit 30 in the manner shown in FIG5, the second capacitor 50 can also be connected in parallel behind the RC branch as a whole based on the schematic diagram of FIG5, or between the energy storage unit 30 and the RC branch.
- the second capacitor 50 includes a buffer capacitor, that is, the function of the second capacitor 50 in the energy storage valve submodule is mainly to buffer the high-frequency current in the current of the energy storage valve submodule at the time of input, so that the turn-off current change rate at the time of IGBT shutdown is reduced, thereby reducing the overvoltage stress at the time of IGBT shutdown.
- the capacitance of the second capacitor 50 is smaller than the capacitance of the first capacitor 20 .
- the capacitance of the second capacitor 50 By setting the capacitance of the second capacitor 50 to be much smaller than that of the first capacitor 20, when the energy storage valve submodule is put into operation, a certain distinction is made between the high-frequency current passing through the second capacitor 50 and the high-frequency current passing through the first capacitor 20.
- the second capacitor 50 mainly passes the high-frequency component of the current
- the first capacitor 20 mainly passes the low-frequency component of the current.
- the determination process can be achieved through circuit simulation. During the simulation, it is necessary to consider not only the overvoltage capability of the IGBT at the time of shutdown, but also whether the excessive capacitance of the second capacitor 50 will aggravate the degree of under-damped oscillation of the energy storage valve sub-module. Therefore, it is necessary to set the capacitance of the second capacitor 50 to a range that does not generate under-damped oscillation with other devices in the energy storage valve sub-module.
- the capacitance value of the second capacitor 50 can be sub-mF.
- the capacitance range of the second capacitor 50 includes 10uF to 300uF.
- the capacitance range of the buffer capacitor includes 10uF to 300uF.
- the capacitance range can be a value range in a high-voltage direct hanging scenario. When the second capacitor 50 takes a value in this range, it can reduce the overvoltage stress at the time of IGBT shutdown while reducing the additional impact on the overall topology of the energy storage valve submodule.
- the number of the second capacitor 50 can be one buffer capacitor or a parallel combination of N buffer capacitors, where N can be a positive integer greater than or equal to 1, for example, 2, 3, 5, 8, 10, 20, 50, 100, etc.
- the embodiment of the present application does not limit the specific number of buffer capacitors.
- the overvoltage stress at the IGBT shutdown moment can be reduced, and the risk of IGBT failure due to excessive overvoltage stress is reduced, thereby increasing the working reliability of the IGBT and further increasing the working reliability of the energy storage valve submodule.
- the first capacitor 20 is a DC support capacitor
- the second capacitor 50 is a buffer capacitor
- the capacitance of the buffer capacitor is smaller than the capacitance of the DC support capacitor.
- the capacitance of the buffer capacitor is much smaller than the capacitance of the DC support capacitor, the degree of under-damped oscillation of the energy storage valve submodule aggravated by the excessive capacitance of the buffer capacitor is reduced, so that while reducing the overvoltage stress of the power device in the power conversion unit at the time of shutting down, the risk of generating additional effects is reduced, thereby increasing the working reliability of the energy storage valve submodule.
- the buffer capacitor included in the energy storage valve submodule is connected in parallel with the RC branch.
- the overvoltage stress of the power device in the power conversion unit at the time of shutting off can be reduced, thus reducing the risk of failure of the power device in the power conversion unit due to excessive overvoltage stress, thereby increasing the working reliability of the power device in the power conversion unit, and further increasing the working reliability of the energy storage valve submodule. sex.
- the overvoltage stress at the IGBT turn-off moment is reduced by connecting the second capacitor 50 in parallel.
- the resistance value of the suppression circuit 40 will cause the IGBT to have a large turn-off overvoltage, and the second capacitor 50 alone may not be able to completely offset the IGBT turn-off overvoltage stress. Therefore, the embodiment of the present application also provides a method to reduce the IGBT turn-off di/dt, thereby further reducing the IGBT turn-off overvoltage, so that the risk of IGBT failure due to excessive overvoltage stress can be reduced.
- the power conversion unit 10 of the energy storage valve submodule is implemented with IGBT.
- the gate of the IGBT in each power conversion unit 10 is connected to a drive circuit, and the IGBT is driven on and off by the drive circuit.
- the parameter value of the driver in the drive circuit is inversely correlated with the turn-off current change rate of the IGBT. That is, the embodiment of the present application can reduce the IGBT turn-off di/dt (i.e., the turn-off current change rate) by increasing the parameter value of the driver.
- FIG15 is a schematic diagram of an IGBT driving circuit.
- FIG15 only shows a schematic diagram of one IGBT connected to a driving circuit.
- Rgon represents a gate turn-on resistor
- Rgoff represents a gate turn-off resistor
- Cg represents a gate capacitor.
- the IGBT is turned on and off by Rgon, Rgoff, diodes D1 and D2, and gate capacitor Cg.
- the above-mentioned increase in the parameter value of the driving device can be to increase the resistance of the gate turn-off resistor Rgoff, and/or to increase the capacitance of the gate capacitor Cg, that is, to increase either the parameter value of the gate turn-off resistor Rgoff or the gate capacitor Cg, or to increase both of them, etc., both of which can achieve the purpose of reducing the di/dt when the IGBT is turned off.
- the specific values that need to be increased for the gate turn-off resistance Rgoff and the gate capacitance Cg can be calculated based on the IGBT specifications.
- the voltage and current levels of the IGBT are different under different IGBT specifications, and the parameter values of the driving devices in the driving circuit need to be adjusted to different degrees. Therefore, adjustments need to be made based on actual conditions.
- the parameter value of the driver device can be adjusted so that the di/dt of the IGBT when it is turned off reaches 5000A/ ⁇ s
- the parameter value of the driver device can be adjusted so that the di/dt of the IGBT of the energy storage valve submodule when it is turned off is reduced to 3000A/ ⁇ s.
- the turn-off current change rate of the power device in the power conversion unit is inversely correlated with the parameter value of the driving device in the driving circuit of the power device, it is possible to reduce the turn-off current change rate of the power device in the power conversion unit, thereby further reducing the turn-off overvoltage of the power device in the power conversion unit. In this way, the problem of failure of the power device in the power conversion unit due to excessive overvoltage stress is greatly reduced, thereby increasing the working reliability of the power conversion unit.
- the resistance characteristics of the suppression circuit 40 will bring additional ohmic heat loss to the entire energy storage valve sub-module. Based on this, the heat loss caused by the suppression circuit 40 to the energy storage valve sub-module can be reduced by adjusting the switching frequency of the energy storage valve sub-module.
- the switching frequency of the energy storage valve submodule is positively correlated with the energy loss generated by the suppression circuit.
- the energy loss generated by the resistance of the suppression circuit 40 is E
- the equivalent switching frequency of the energy storage valve submodule is f
- the heating power P of the resistance of the suppression circuit 40 is ⁇ f*E. That is, the higher the switching frequency f, the greater the energy loss E generated by the resistance of the suppression circuit 40, so that the switching frequency should be positively correlated with the energy loss generated by the suppression circuit.
- the value of the equivalent switching frequency can be set according to the energy loss value generated by the resistance of the specific suppression circuit 40 of the energy storage valve submodule.
- the value of the converter valve f can be set to about 100Hz-200Hz; and in the application of DC direct-hung energy storage valve, the value of the switching frequency f can be set between 50Hz-150Hz.
- the value of the equivalent switching frequency of the above energy storage valve submodule is only an example.
- the equivalent switching frequency is set to a smaller value of the switching frequency acceptable to the system as much as possible, that is, the loss of the high-voltage direct-mounted energy storage system can be optimized by minimizing the system switching frequency.
- the embodiment of the present application sets the equivalent switching frequency of the energy storage valve submodule when it is switched on and off in the high-voltage direct-hung energy storage system through the characteristic that the switching frequency of the energy storage valve submodule is positively correlated with the energy loss generated by the suppression circuit, so that the energy storage valve submodule can be switched on and off at a lower equivalent switching frequency, thereby reducing the loss of the energy storage valve submodule and improving the economy and safety of the application of the energy storage valve submodule.
- the energy storage valve submodule further includes a bypass circuit 60 , and the bypass circuit 60 is connected in parallel with the energy storage valve submodule.
- a bypass circuit 60 is provided between the two ports S1 and S2 of the energy storage valve submodule and the power conversion unit 10, so that when the energy storage valve submodule fails, or when the energy storage valve submodule may fail, the energy storage valve submodule can be cut out of the high-voltage direct-mounted energy storage system through the bypass circuit 60.
- the bypass circuit 60 can conveniently and timely temporarily cut off the energy storage valve submodule from the high-voltage direct-hung energy storage system, thereby greatly reducing the probability of failure of the energy storage valve submodule due to the overvoltage generated by the high-voltage direct-hung energy storage system, thereby improving the operating stability and safety of the high-voltage direct-hung energy storage system.
- the bypass circuit 60 may be a bypass switch.
- the bypass switch may be, but is not limited to, a mechanical bypass switch or a semiconductor device bypass switch.
- the current on the main circuit enters from the S1 port.
- the bypass switch is closed, and the current flows out from the S2 port through the bypass switch, completely short-circuiting the entire energy storage valve submodule and completely cutting the energy storage valve submodule out of the high-voltage direct-hung energy storage system.
- a bypass circuit is provided between the ports at which the energy storage valve submodule is connected to the main circuit of the high-voltage direct-hung energy storage system, so that in the event of a failure in the energy storage valve submodule, the energy storage valve submodule can be cut out of the high-voltage direct-hung energy storage system, thereby improving the operating stability and safety of the high-voltage direct-hung energy storage system.
- an embodiment of the present application also provides a high-pressure direct-mounted energy storage system, which includes an energy storage valve submodule provided in any of the above embodiments.
- the high-voltage direct-mounted energy storage system in the embodiment of the present application may include a DC high-voltage direct-mounted energy storage system, or may include an AC high-voltage direct-mounted energy storage system.
- the above FIG1 shows an example of an AC high-voltage direct-mounted energy storage system.
- the energy storage valve submodule provided in the embodiment of the present application can suppress the under-damped oscillating power generated at the time of switching the switching mode, it has high reliability, so the high-voltage direct-mounted energy storage system constructed using the energy storage valve submodule in the embodiment of the present application also has high reliability.
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Abstract
Description
10: 功率变换单元;
20: 第一电容;
30: 储能单元;
40: 抑制电路;
401: 电阻元件;
402: 开关电路;
50: 第二电容;
60: 旁路电路。
LCp2+(RC+R1)Cp+1=0 公式2
Claims (21)
- 一种储能阀子模块,其中,所述储能阀子模块包括功率变换单元、第一电容、抑制电路和储能单元,所述抑制电路与所述第一电容串联构成阻容支路,所述阻容支路分别与所述功率变换单元和所述储能单元并联。
- 根据权利要求1所述的储能阀子模块,其中,所述抑制电路包括电阻元件。
- 根据权利要求2所述的储能阀子模块,其中,所述抑制电路还包括开关电路,所述开关电路用于控制所述电阻元件的投切状态。
- 根据权利要求3所述的储能阀子模块,其中,所述开关电路与所述电阻元件并联。
- 根据权利要求3所述的储能阀子模块,其中,所述电阻元件包括相互串联的第一电阻和第二电阻,所述开关电路还包括第一开关和第二开关,所述第一开关与所述第一电阻并联,所述第二开关与所述第二电阻并联。
- 根据权利要求5所述的储能阀子模块,其中,所述第一开关和/或所述第二开关为二极管。
- 根据权利要求5所述的储能阀子模块,其中,所述第一电阻的阻值大于所述第二电阻的阻值。
- 根据权利要求3所述的储能阀子模块,其中,所述电阻元件包括相互并联的第三电阻和第四电阻,所述开关电路还包括第三开关和第四开关,所述第三开关与所述第三电阻串联,所述第四开关与所述第四电阻串联。
- 根据权利要求8所述的储能阀子模块,其中,所述第三开关和/或所述第四开关为二极管。
- 根据权利要求8所述的储能阀子模块,其中,所述第三电阻的阻值大于所述第四电阻的阻值。
- 根据权利要求2-10任一项所述的储能阀子模块,其中,所述电阻元件的阻值范围包括10mΩ-500mΩ。
- 根据权利要求1-11任一项所述的储能阀子模块,其中,所述储能阀子模块还包括第二电容,所述第二电容与所述阻容支路并联。
- 根据权利要求12所述的储能阀子模块,其中,所述第二电容包括缓冲电容。
- 根据权利要求12所述的储能阀子模块,其中,所述第二电容的容值小于所述第一电容的容值。
- 根据权利要求12所述的储能阀子模块,其中,所述第二电容的容值范围包括10uF~300uF。
- 根据权利要求1-15任一项所述的储能阀子模块,其中,所述第一电容包括直流支撑电容。
- 根据权利要求1-16任一项所述的储能阀子模块,其中,所述储能阀子模块还包括旁路电路,所述旁路电路与所述储能阀子模块并联。
- 根据权利要求1-17任一项所述的储能阀子模块,其中,所述储能阀子模块的投切开关频率与所述抑制电路产生的能量损耗成正相关。
- 根据权利要求1-18任一项所述的储能阀子模块,其中,所述功率变换单元中功率器件的关断电流变化率和所述功率器件的驱动电路中驱动器件的参数值成反相关。
- 根据权利要求19所述的储能阀子模块,其中,所述驱动器件的参数值包括所述驱动电路中门极关断电阻的电阻值,和/或,所述驱动电路中门极电容的容值。
- 一种高压直挂储能系统,其中,所述高压直挂储能系统包括权利要求1-20任一项所述的储能阀子模块。
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| JP2025559741A JP2026512137A (ja) | 2023-06-09 | 2024-06-06 | エネルギー貯蔵弁サブモジュール及び高電圧昇圧トランスレスエネルギー貯蔵システム |
| EP24818740.3A EP4716052A4 (en) | 2023-06-09 | 2024-06-06 | Energy storage valve sub-module and energy storage system directly connected to high voltage |
| KR1020257032002A KR20250166924A (ko) | 2023-06-09 | 2024-06-06 | 에너지 저장 밸브 서브모듈 및 고전압 직연결 에너지 저장 시스템 |
| US19/341,911 US20260024999A1 (en) | 2023-06-09 | 2025-09-26 | Energy storage valve submodule and high-voltage direct-connected energy storage system |
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| CN202310687041.1A CN119109090A (zh) | 2023-06-09 | 2023-06-09 | 储能阀子模块和高压直挂储能系统 |
| CN202310687041.1 | 2023-06-09 |
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| US19/341,911 Continuation US20260024999A1 (en) | 2023-06-09 | 2025-09-26 | Energy storage valve submodule and high-voltage direct-connected energy storage system |
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| EP (1) | EP4716052A4 (zh) |
| JP (1) | JP2026512137A (zh) |
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| JP7901405B1 (ja) * | 2025-07-22 | 2026-08-06 | 山東大学 | 2次高調波電流を抑制するためのカスケード式エネルギー貯蔵用電力変換システム及び制御方法 |
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| CN122268117A (zh) * | 2024-12-20 | 2026-06-23 | 宁德时代未来能源(上海)研究院有限公司 | 储能阀子模块、高压直挂储能系统 |
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| CN202524283U (zh) * | 2012-04-11 | 2012-11-07 | 中国矿业大学 | 一种模块化多电平变流器子模块的缓冲电路结构 |
| CN109039046A (zh) * | 2018-07-20 | 2018-12-18 | 华中科技大学 | 一种模块化多电平换流器半全桥子模块的缓冲电路 |
| WO2020094030A1 (zh) * | 2018-11-07 | 2020-05-14 | 南京南瑞继保电气有限公司 | 一种能量消耗装置及其控制方法 |
| CN114113798A (zh) * | 2021-11-08 | 2022-03-01 | 国网浙江省电力有限公司舟山供电公司 | 一种柔直换流阀子模块直流电容故障在线检测方法 |
| CN114189135A (zh) * | 2021-11-10 | 2022-03-15 | 许继电气股份有限公司 | 具备过压抑制功能的换流阀桥臂子模块及其控制方法、换流阀 |
-
2023
- 2023-06-09 CN CN202310687041.1A patent/CN119109090A/zh active Pending
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2024
- 2024-06-06 KR KR1020257032002A patent/KR20250166924A/ko active Pending
- 2024-06-06 EP EP24818740.3A patent/EP4716052A4/en active Pending
- 2024-06-06 JP JP2025559741A patent/JP2026512137A/ja active Pending
- 2024-06-06 WO PCT/CN2024/097814 patent/WO2024251209A1/zh not_active Ceased
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- 2025-09-26 US US19/341,911 patent/US20260024999A1/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202524283U (zh) * | 2012-04-11 | 2012-11-07 | 中国矿业大学 | 一种模块化多电平变流器子模块的缓冲电路结构 |
| CN109039046A (zh) * | 2018-07-20 | 2018-12-18 | 华中科技大学 | 一种模块化多电平换流器半全桥子模块的缓冲电路 |
| WO2020094030A1 (zh) * | 2018-11-07 | 2020-05-14 | 南京南瑞继保电气有限公司 | 一种能量消耗装置及其控制方法 |
| CN114113798A (zh) * | 2021-11-08 | 2022-03-01 | 国网浙江省电力有限公司舟山供电公司 | 一种柔直换流阀子模块直流电容故障在线检测方法 |
| CN114189135A (zh) * | 2021-11-10 | 2022-03-15 | 许继电气股份有限公司 | 具备过压抑制功能的换流阀桥臂子模块及其控制方法、换流阀 |
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| JP7901405B1 (ja) * | 2025-07-22 | 2026-08-06 | 山東大学 | 2次高調波電流を抑制するためのカスケード式エネルギー貯蔵用電力変換システム及び制御方法 |
Also Published As
| Publication number | Publication date |
|---|---|
| US20260024999A1 (en) | 2026-01-22 |
| EP4716052A4 (en) | 2026-08-19 |
| KR20250166924A (ko) | 2025-11-28 |
| EP4716052A1 (en) | 2026-03-25 |
| CN119109090A (zh) | 2024-12-10 |
| JP2026512137A (ja) | 2026-04-14 |
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