A charging start system and method for a cascaded supercapacitor energy storage device

Abstract

The present invention discloses a charging start system and method for a cascaded supercapacitor energy storage device. The system includes: a first three-phase bypass switch, three-phase soft start resistors, each power module cascade-connected and electrically connected to each other on three phases, and a control module; the three-phase soft start resistors are connected in parallel with the three-phase bypass switch; a three-phase AC power supply is electrically connected to each power module cascade-connected and electrically connected to each other on three phases through the bypass switch; when the output voltage of each power module on any phase is less than a first preset voltage, the control module controls the corresponding phase contact of the first bypass switch to disconnect, and each power module enters an uncontrolled rectification mode; when the output voltage of each power module is less than a second preset voltage, the control module controls the corresponding phase contact of the first bypass switch to disconnect and controls each power module to enter an equalizing charging stage mode; when the output voltage of each power module is less than a third preset voltage, the control module controls the corresponding phase contact to close and controls each power module to enter a controllable charging mode.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of supercapacitor, and particularly to a charging start system and method for a cascaded supercapacitor energy storage device. Background Art

[0002] At present, a high-voltage cascaded energy storage device based on a supercapacitor energy storage medium has the characteristics of high single-machine power, pulsed discharge, high efficiency, etc., and has become the main technical route for current high-power pulsed power supply systems and grid-forming SVG. The voltage level of the cascaded energy storage device is relatively high. Due to the relatively high voltage level of the cascaded energy storage device, it is urgent to improve the charging efficiency of the cascaded energy storage device. In the current charging schemes for cascaded energy storage devices, the charging efficiency is relatively low. Summary of the Invention

[0003] The present invention provides a charging start system and method for a cascaded supercapacitor energy storage device to meet the high-voltage direct-hanging energy storage requirements of cascaded supercapacitors, and at the same time shorten the charging time of the cascaded energy storage device.

[0004] To achieve the above object, in a first aspect, an embodiment of the present invention provides a charging start system for a cascaded supercapacitor energy storage device, the system includes: a first three-phase bypass switch, three-phase soft start resistors, each power module cascaded and electrically connected to each other on three phases, and a control module; the three-phase soft start resistors are electrically connected in parallel with the first three-phase bypass switch; a three-phase AC power supply is electrically connected to each of the power modules cascaded and electrically connected to each other on three phases through the first three-phase bypass switch; each of the power modules is electrically connected to each supercapacitor cluster to be charged;

[0005] The control module is configured to control the corresponding phase contact of the first three-phase bypass switch to disconnect when the output voltage of each of the power modules on any phase is less than a first preset voltage, and each of the power modules enters an uncontrolled rectification mode so that each of the power modules charges each supercapacitor cluster in the uncontrolled rectification mode;

[0006] The control module is configured to control the corresponding phase contact of the first three-phase bypass switch to disconnect and control each of the power modules to enter an equalizing charging stage mode so that each of the power modules charges each supercapacitor cluster in the equalizing charging stage mode when the output voltage of each of the power modules is less than a second preset voltage;

[0007] The control module is configured to control the corresponding phase contact of the first three-phase bypass switch to close and control each of the power modules to enter a controllable charging mode so that each of the power modules charges each supercapacitor cluster in the controllable charging mode when the output voltage of each of the power modules is less than a third preset voltage.

[0008] Optionally, each of the power modules includes an H-bridge circuit, a support capacitor, and a bypass control switch;

[0009] The second end of the corresponding phase contact of the first three-phase bypass switch is electrically connected to one side of the H-bridge circuit and the first end of the bypass control switch; the second end of the bypass control switch is electrically connected to the other side of the H-bridge circuit; the H-bridge circuit is electrically connected in parallel with the supercapacitor cluster through the support capacitor;

[0010] The control module is configured to control each of the power modules to enter the equalizing charging stage mode when the output voltage of each of the power modules is less than a second preset voltage, including:

[0011] The control module is configured to sort the DC-side output voltages of the H-bridge circuits in ascending order when the DC-side output voltages of the H-bridge circuits are all less than a second preset voltage;

[0012] Control a preset bypass control switch to close according to the sorted DC-side output voltages of the H-bridge circuits and the rated voltage of the AC side of the H-bridge circuit, so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors;

[0013] Delay for a preset time to determine whether the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage;

[0014] If the DC-side output voltages of the H-bridge circuits are all less than the second preset voltage, return to sort the DC-side output voltages of the H-bridge circuits in ascending order until it is determined that the DC-side output voltages of the H-bridge circuits are greater than the second preset voltage.

[0015] Optionally, the control module is further configured to control the H-bridge circuit corresponding to the preset bypass control switch to disconnect according to the sorted DC-side output voltages of the H-bridge circuits, so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors.

[0016] Optionally, the system further includes: a three-phase open-circuit detection resistor and a second three-phase bypass switch; the three-phase open-circuit detection resistor is electrically connected in parallel with the second three-phase bypass switch; the second three-phase bypass switch is electrically connected in series with the first three-phase bypass switch;

[0017] Each of the power modules further includes a DC / DC switching power supply and a power controller; each of the power controllers is connected in parallel with the H-bridge circuit through the DC / DC switching power supply; the power controller is configured to be powered on when the DC-side output voltage of the H-bridge circuit reaches the starting voltage at a first preset time, and start sending the operation state signals of the power modules;

[0018] The control module is further configured to, after closing the corresponding phase contacts of the first three-phase bypass switch and disconnecting the corresponding phase contacts of the second three-phase bypass switch, determine whether each of the power modules and each of the supercapacitor clusters are disconnected according to whether the operation status signals sent by each of the power controllers are received within a second preset time.

[0019] Optionally, each of the power modules further includes a circuit breaker, a first unidirectional diode, and a second unidirectional diode;

[0020] Each of the H-bridge circuits is connected in parallel with each of the supercapacitor clusters through the circuit breaker; a first end of the support capacitor is electrically connected to a first end of the first unidirectional diode; a second end of the first unidirectional diode is electrically connected to a first input terminal of the DC / DC switching power supply; a second end of the support capacitor is electrically connected to a second input terminal of the DC / DC switching power supply; an output terminal of the DC / DC switching power supply is electrically connected to the power controller;

[0021] A second end of the circuit breaker is electrically connected to a first end of the second unidirectional diode; a second end of the second unidirectional diode is electrically connected to the first input terminal of the DC / DC switching power supply.

[0022] Optionally, the power controller is further configured to control each of the power modules to enter an uncontrolled rectification mode and each of the power modules to enter a controllable charging mode.

[0023] Optionally, the system further includes: a three-phase first filter inductor; each of the power modules further includes a second filter inductor;

[0024] The corresponding phase contacts of the first three-phase bypass switch are electrically connected to each of the power modules connected in series through the corresponding phase first filter inductor of the three-phase first filter inductor; a first end of the support capacitor is electrically connected to a first end of the second filter inductor; a second end of the second filter inductor is electrically connected to the circuit breaker.

[0025] In a second aspect, an embodiment of the present invention further provides a method for starting charging of a cascaded supercapacitor energy storage device. The method is applied to the cascaded supercapacitor energy storage device charging start system described in the first aspect, and the method includes:

[0026] When the output voltages of each of the power modules in any one phase are all less than a first preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to be disconnected, and controls each of the power modules to enter an uncontrolled rectification mode so that each of the power modules charges the supercapacitor cluster in the uncontrolled rectification mode;

[0027] When the output voltage of each of the power modules is less than the second preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to disconnect, and controls each of the power modules to enter the equalizing charging stage mode so that each of the power modules charges the supercapacitor bank in the equalizing charging stage mode;

[0028] When the output voltage of each of the power modules is less than the third preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to close, and controls each of the power modules to enter the controllable charging mode so that each of the power modules charges the supercapacitor in the controllable charging mode.

[0029] Optionally, each of the power modules includes an H-bridge circuit, a support capacitor, and a bypass control switch;

[0030] The control module controls each of the power modules to enter the equalizing charging stage mode, including:

[0031] When the DC-side output voltage of each of the H-bridge circuits is less than the second preset voltage, sort the DC-side output voltages of each of the H-bridge circuits from high to low;

[0032] According to the DC-side output voltages of each of the H-bridge circuits after sorting from high to low and the rated voltage of the AC side of the H-bridge circuit, control the preset bypass control switch to close so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors;

[0033] Delay for a preset time to determine whether the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage;

[0034] If the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage, return to sort the DC-side output voltages of each of the H-bridge circuits from high to low until it is determined that the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage.

[0035] Optionally, the cascade-type supercapacitor energy storage device charging start system further includes: an open-circuit detection resistor and a second three-phase bypass switch; each of the power modules further includes a DC / DC switching power supply and a power controller;

[0036] When the output voltage of each of the power modules in any one phase is less than the first preset voltage, before the control module controls the corresponding phase contacts of the first three-phase bypass switch to disconnect and controls each of the power modules to enter the uncontrolled rectification mode, further includes:

[0037] After the control module closes the corresponding phase contacts of the first three-phase bypass switch and opens the corresponding phase contacts of the second three-phase bypass switch, it determines whether the power modules and the supercapacitor clusters in the corresponding phase are disconnected according to whether the operation status signals sent by the power controllers are received within a preset time.

[0038] In the embodiment of the present invention, the three-phase soft start resistor is electrically connected in parallel with the first three-phase bypass switch; the three-phase AC power supply is electrically connected to each of the power modules cascaded on the three phases through the first three-phase bypass switch; each of the power modules is electrically connected to each supercapacitor cluster to be charged; thus, when the output voltages of the power modules in any phase are all less than the first preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to be disconnected, so that each power module enters the current-limiting soft start mode, and further each power module charges the supercapacitor cluster in the uncontrolled rectification mode; when the output voltages of the power modules are all less than the second preset voltage, the corresponding phase contacts of the first three-phase bypass switch are controlled to be disconnected, so that each power module maintains the current-limiting soft start mode, and controls each power module to charge the supercapacitor cluster in the equalizing charging stage mode; when the output voltages of the power modules are all less than the third preset voltage, the control module controls each power module to enter the controllable charging mode. Since each power module enters the controllable charging mode, the corresponding phase contacts of the first three-phase bypass switch can be controlled to be closed at the same time, so that each power module charges the supercapacitor cluster in the controllable charging mode; in this way, each power module meets the high-voltage direct-connected energy storage requirements of the cascaded supercapacitor through different charging stages; and different charging modes are used for charging in different charging stages, which also shortens the charging time of the cascaded energy storage device.

[0039] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0041] Figure 1 It is a schematic structural diagram of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention;

[0042] Figure 2It is a schematic diagram of the specific structure of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention Figure 1 ;

[0043] Figure 3 It is a schematic diagram of the specific structure of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention Figure 2 ;

[0044] Figure 4 It is a schematic diagram of the specific structure of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention Figure 3 ;

[0045] Figure 5 It is a schematic diagram of the specific structure of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention Figure 4 ;

[0046] Figure 6 It is a schematic flow chart of a method for starting the charging of a cascaded supercapacitor energy storage device provided by an embodiment of the present invention;

[0047] Figure 7 It is a schematic flow chart of another method for starting the charging of a cascaded supercapacitor energy storage device provided by an embodiment of the present invention. Detailed implementation manners

[0048] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1It is a schematic structural diagram of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention. As Figure 1 shown, the system includes: a first three-phase bypass switch 10, three-phase soft start resistors 20, each power module 30 and a control module 40 that are cascade-connected and electrically connected to each other on three phases; the three-phase soft start resistors 20 are electrically connected in parallel with the first three-phase bypass switch 10; the three-phase AC power supply is electrically connected to each power module 30 that is cascade-connected and electrically connected to each other on three phases through the first three-phase bypass switch 10; each power module 30 is electrically connected to each supercapacitor cluster to be charged; the first three-phase bypass switch 10 includes a phase A contact 11, a phase B contact 12 and a phase C contact 13, and the three-phase soft start resistors 20 include a phase A soft start resistor 21, a phase B soft start resistor 22 and a phase C soft start resistor 23;

[0051] The control module 40 is configured to control the corresponding phase contact of the first three-phase bypass switch 10 to disconnect when the output voltage of each power module 30 on any phase is less than a first preset voltage V1, and control each power module 30 to enter an uncontrolled rectification mode so that each power module 30 charges each supercapacitor cluster in the uncontrolled rectification mode;

[0052] The control module 40 is configured to control the corresponding phase contact of the first three-phase bypass switch 10 to disconnect when the output voltage of each power module 30 is less than a second preset voltage V2, and control each power module 30 to enter an equal voltage charging stage mode so that each power module 30 charges each supercapacitor cluster in the equal voltage charging stage mode;

[0053] The control module 40 is configured to control the corresponding phase contact of the first three-phase bypass switch 10 to close when the output voltage of each power module is less than a third preset voltage V3, and control each power module 30 to enter a controllable charging mode so that each power module 30 charges each supercapacitor cluster in the controllable charging mode.

[0054] Among them, the power module 30 is a power module composed of an H-bridge circuit; generally, within any phase, each power module 30 may include a soft start stage and a controllable charging stage; in the soft start stage, the power module 30 is generally considered approximately equivalent to an RC charging circuit; since the RC charging circuit takes a long time to output a DC voltage, in this embodiment, the soft start stage is divided into two stages. Specifically, taking phase A as an example for illustration, when the output voltages of each power module 30 in phase A are all less than the first preset voltage V1, control each power module 30 to enter the uncontrolled rectification mode. Since the current is uncontrollable when each power module 30 enters the uncontrolled rectification mode, the corresponding phase contact 11 of the first three-phase bypass switch 10 can be controlled to disconnect, and the corresponding phase soft start resistor 21 of the three-phase soft start resistor 20 is used for current limiting, so that each power module charges the supercapacitor bank in the uncontrolled rectification mode until each supercapacitor is charged to the first preset voltage V1; the first preset voltage V1 can be designed according to the target required charging time;

[0055] When the output voltages of each power module 30 are all less than the second preset voltage V2, then control each power module 30 to enter the equalizing charging stage mode, and control the corresponding phase contact 11 of the first three-phase bypass switch 10 to disconnect, so as to maintain current limiting through the corresponding phase soft start resistor 21 of the three-phase soft start resistor 20, and then make each power module 30 charge the supercapacitor bank in the equalizing charging stage mode until each supercapacitor bank is charged to the second preset voltage V2; in this way, each power module 30 can make each supercapacitor charge to the second preset voltage V2 more quickly through the uncontrolled rectification mode and the equalizing charging stage mode in the soft start stage; it should be noted that the equalizing charging stage mode is a mode that can quickly increase the output voltage of each power module and balance the voltage difference between each power module during the charging process of each power module;

[0056] After each power module 30 enters the equalizing charging stage mode, the maximum DC voltage output by each power module 30 is limited and cannot meet the high-voltage energy storage requirements of each supercapacitor cluster. When the output voltage of each power module is less than the third preset voltage V3 (V3 is the target charging voltage), the control module 40 controls each power module to enter the controllable charging mode. After each power module enters the controllable charging mode, the voltage and current of each power module are controllable. Then, the corresponding phase contact 11 of the first three-phase bypass switch 10 can be controlled to close simultaneously, and there is no need for the corresponding phase soft-start resistor 21 of the three-phase soft-start resistor 20 to limit the current. In this way, each power module 30 charges the supercapacitor cluster in the controllable charging mode; thus, each power module meets the high-voltage direct-hanging energy storage requirements of the cascaded supercapacitor through different charging stages; and in the soft-start stage, it charges in a mixed charging mode of uncontrolled rectification mode and equalizing charging stage mode, and combines with the uncontrolled charging mode to realize charging in different charging stages with different charging modes, which overall shortens the charging time of the cascaded high-voltage energy storage device.

[0057] Optionally, based on the above embodiments, each power module on any one phase in the system is further refined and optimized. Figure 2 It is a schematic structural diagram of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention. Figure 1 ; As Figure 2 shown, taking any one phase as an example for illustration, each power module 30 includes an H-bridge circuit, a support capacitor C, and a bypass control switch K; the second end of the corresponding phase contact 11 of the first three-phase bypass switch 10 is electrically connected to one side of the H-bridge circuit and the first end of the bypass control switch K; the second end of the bypass control switch K is electrically connected to the other side of the H-bridge circuit; the H-bridge circuit is connected in parallel with the supercapacitor cluster C0 through the support capacitor C.

[0058] The control module 40 is used to control each power module 30 to enter the equalizing charging stage mode when the output voltage of each power module 30 is less than the second preset voltage V2, and includes:

[0059] The control module 40 is used to sort the DC-side output voltages of each H-bridge circuit in terms of high and low when the DC-side output voltage of each H-bridge circuit is less than the second preset voltage V2.

[0060] According to the DC-side output voltages of each H-bridge circuit sorted in terms of high and low and the rated voltage of the AC side of the H-bridge circuit, control the preset bypass control switch K to close so that the other H-bridge circuits corresponding to the other bypass control switches K charge the other supercapacitor clusters C0.

[0061] After a preset delay time, determine whether the DC-side output voltage of each H-bridge circuit is greater than the second preset voltage V2. If the DC-side output voltage of each H-bridge circuit is less than the second preset voltage V2, return to perform a high-low sorting on the DC-side output voltage of each H-bridge circuit until it is determined that the DC-side output voltage of each H-bridge circuit is greater than the second preset voltage V2.

[0062] Specifically, taking the A-phase as an example for illustration, each power module in the A-phase charges the supercapacitor in an uncontrolled rectification mode until each supercapacitor is charged to the first preset voltage V1. Due to actual measurement errors, after the charging of the supercapacitor in the uncontrolled rectification mode ends, there is a certain deviation between the charging voltage of each supercapacitor (the same as the DC-side output voltage of the H-bridge circuit) and the first preset voltage V1. During the process of entering the voltage equalization charging stage mode, first perform a high-low sorting on the DC-side output voltage of each H-bridge circuit, and determine the number of H-bridge circuits that need to be started in the voltage equalization charging stage mode according to the rated voltage of the AC side of the H-bridge circuit; then retain the corresponding number of lower output voltages from the high-low sorting of the DC-side output voltage of each H-bridge circuit, and ensure that the corresponding H-bridge circuits with lower output voltages work, and then control the preset bypass control switch K corresponding to the remaining H-bridge circuits to close, so that the remaining power modules do not work, so that the corresponding H-bridge circuits with lower output voltages charge the corresponding supercapacitor cluster C0;

[0063] After a preset delay time (generally in ms), as the corresponding H-bridge circuits with lower output voltages charge the corresponding supercapacitor clusters C0, the DC-side output voltage of the corresponding H-bridge circuits increases, and since the preset bypass control switch K is closed, the voltage of the remaining H-bridge circuits remains at the voltage output in the previous non-rectifiable mode; then cycle again to perform a high-low sorting on the DC-side output voltage of each H-bridge circuit, and control the preset bypass control switch K to close according to the DC-side output voltage of each H-bridge circuit after the high-low sorting and the rated voltage of the AC side of each H-bridge circuit until it is determined that the DC-side output voltage of each H-bridge circuit is greater than the second preset voltage V2; thus, since the preset bypass control switch K is closed during the process of entering the voltage equalization charging stage mode, the DC-side output voltage of the corresponding H-bridge circuits with lower output voltages increases, improving the charging efficiency; in addition, in the voltage equalization charging stage mode, the preset bypass control switch K closes cyclically, so that the difference between the voltage output by the H-bridge circuit corresponding to the closed preset bypass control switch K and the voltage output by the H-bridge circuit corresponding to the open preset bypass control switch K is guaranteed within the balance value, ensuring the charging safety and avoiding the problem of unsafe charging caused by a large difference between the voltage output by the H-bridge circuit corresponding to the continuously closed preset bypass control switch K and the voltage output by the H-bridge circuit corresponding to the open preset bypass control switch K.

[0064] It should be noted that in some other embodiments, during the process of entering the equalizing charging stage mode, first, the DC-side output voltages of each H-bridge circuit are sorted in ascending order, and then, based on the DC-side output voltages of each H-bridge circuit after sorting and the rated voltage of the AC side of the H-bridge circuit, the H-bridge circuit corresponding to the bypass control switch can also be controlled to disconnect. In this way, the other H-bridge circuits corresponding to the remaining bypass control switches can also charge the remaining supercapacitors. After a preset time delay, it is determined whether the DC-side output voltage of each H-bridge circuit is greater than the second preset voltage V2. If the DC-side output voltages of all H-bridge circuits are less than the second preset voltage V2, the process returns to sorting the DC-side output voltages of each H-bridge circuit until it is determined that the DC-side output voltage of each H-bridge circuit is greater than the second preset voltage V2.

[0065] Optionally, Figure 3 is a schematic diagram of the specific structure of a charging start system for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention Figure 2 ; as Figure 3 shown, the system further includes: a three-phase open-circuit detection resistor 50 and a second three-phase bypass switch 60 (only the A-phase contact 61 of any one-phase open-circuit detection resistor 51 and the second three-phase bypass switch 60 is schematically shown in the figure); the open-circuit detection resistor 50 is electrically connected in parallel with the second three-phase bypass switch 60; the second three-phase bypass switch 60 is electrically connected in series with the first three-phase bypass switch 10;

[0066] Each power module 30 further includes; a DC / DC switching power supply 31 and a power controller 32; each power controller is electrically connected in parallel with the H-bridge circuit through the DC / DC switching power supply 31; the power controller 32 is configured to be powered on when the DC-side output voltage of the H-bridge circuit reaches the starting voltage (the starting voltage is less than the first preset voltage V1) within the first preset time, and starts to receive the operation status signals output by each power module 30;

[0067] The control module 40 is further configured to, after controlling the corresponding phase contact 11 of the first three-phase bypass switch to close and the corresponding phase contact 61 of the second three-phase bypass switch to open, determine whether each power module 30 and each supercapacitor cluster C0 on the corresponding phase are disconnected according to whether the operation status signals sent by each power controller 32 are received within the second preset time.

[0068] Among them, when the supercapacitor of a certain power module is disconnected from the DC side of the H-bridge circuit, since the capacitance value of the support capacitor C is at the mF (millifarad) level, at the initial stage of the soft start phase, the voltage of the support capacitor C rapidly rises to reach the startup voltage of the DC / DC switching power supply 31 (usually at the second preset time), and the power controller 32 is powered on and sends an operating status signal; while when the supercapacitor of a normal power module is normally connected to the DC side of the H-bridge circuit, since the capacitance value of the supercapacitor cluster C0 is at the farad level, the output voltage of the DC side of the H-bridge circuit will not reach the startup voltage V1 of the DC / DC switching power supply 31 at the second preset time, and the power controller 32 will not be powered on, but will reach the startup voltage V1 of the DC / DC switching power supply 31 at the first preset time (the second preset time is less than the first preset time), and the power controller 32 is powered on.

[0069] Taking the A phase as an example for illustration, after the control module 40 of this embodiment controls the corresponding phase contact of the first three-phase bypass switch 10 to close and the corresponding phase contact 61 of the second three-phase bypass switch 60 to open, it enters the initial stage of the soft start phase, and the open-circuit detection resistor 50 also enters the current-limiting function. When the voltage status signals sent by each power controller 32 are received within the second preset time, it can be determined that each power module 30 on the A phase is disconnected from each supercapacitor cluster C0; when the operating status signal sent by the power controller 32 is not received within the second preset time, it can be determined that each power module 30 on the A phase is not disconnected from each supercapacitor cluster C0.

[0070] Optionally, continue to refer to Figure 3 , the power controller 32 is further configured to control each power module 30 to enter the uncontrolled rectification mode and each power module 30 to enter the controllable charging mode. Among them, in some embodiments, the power controller 32 can jointly execute the logic program for entering the uncontrolled rectification mode and each power module 30 to enter the controllable charging mode with the control module 40; this embodiment does not limit the execution entity of the logic program for entering the uncontrolled rectification mode and each power module 30 to enter the controllable charging mode.

[0071] Optionally, Figure 4 is a specific structural schematic of a cascaded supercapacitor energy storage device charging and starting system provided by an embodiment of the present invention Figure 3 ; as Figure 4As shown, any phase is taken as an example for illustration here. Each power module 30 further includes a circuit breaker 70, a first unidirectional diode D1, and a second unidirectional diode D2. Each H-bridge circuit is connected in parallel with each supercapacitor bank C0 through the circuit breaker 70. The first end of the support capacitor C is electrically connected to the first end of the first unidirectional diode D1. The second end of the first unidirectional diode D1 is electrically connected to the first input terminal of the DC / DC switching power supply 31. The second end of the support capacitor C is electrically connected to the second input terminal of the DC / DC switching power supply 31. The output terminal of the DC / DC switching power supply 31 is electrically connected to the power controller 32.

[0072] The second end of the circuit breaker 70 is electrically connected to the first end of the second unidirectional diode D2. The second end of the second unidirectional diode D2 is electrically connected to the first input terminal of the DC / DC switching power supply 31.

[0073] Among them, the starting voltage of the power controller 32 can be taken from the DC-side output voltage of the H-bridge circuit or the voltage across the supercapacitor bank C0. Through the first unidirectional diode D1 and the second unidirectional diode D2, the higher voltage end of the DC-side output voltage of the H-bridge circuit and the voltage across the supercapacitor bank C0 can be automatically selected. Then, it is converted into control electricity such as DC24V / DC220V / DC400V through the DC / DC switching power supply 31.

[0074] Optionally, Figure 5 is a schematic diagram of the specific structure of a cascaded supercapacitor energy storage device charging and starting system provided by an embodiment of the present invention. Figure 4 As Figure 5 shown, the system further includes a three-phase first filter inductor L1. Each power module 30 further includes a second filter inductor L2. The corresponding phase contact 11 of the first three-phase bypass switch is electrically connected to each series-connected power module 30 through the corresponding phase first filter inductor L1 in the three-phase first filter inductor. The first end of the support capacitor C is electrically connected to the first end of the second filter inductor L2. The second end of the second filter inductor L2 is electrically connected to the circuit breaker 70. Among them, there is a second harmonic frequency on the DC side of the H-bridge circuit. The second filter inductor L2 can mainly filter the second harmonic frequency signal. The three-phase first filter inductor can filter out the harmonics output by the AC power supply.

[0075] Based on the same inventive concept, an embodiment of the present invention further provides a method for charging and starting a cascaded supercapacitor energy storage device. This method is applied to the cascaded supercapacitor energy storage device charging and starting system described in the above embodiment. Figure 6 is a schematic flowchart of a method for charging and starting a cascaded supercapacitor energy storage device provided by an embodiment of the present invention. As Figure 6 shown, this method includes the following steps:

[0076] When the output voltages of the power modules on any phase are all less than the first preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to disconnect, and controls each power module to enter the uncontrolled rectification mode so that each power module charges each supercapacitor cluster in the uncontrolled rectification mode.

[0077] S120: When the output voltages of the power modules are all less than the second preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to disconnect, and controls each power module to enter the equalizing charging stage mode so that each power module charges each supercapacitor cluster in the equalizing charging stage mode.

[0078] S130: When the output voltages of the power modules are all less than the third preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to close, and controls each power module to enter the controllable charging mode so that each power module charges each supercapacitor cluster in the controllable charging mode.

[0079] In the embodiment of this method, the power modules meet the high-voltage direct-connected energy storage requirements of the cascaded supercapacitors on each phase through different charging stages; and in the soft start stage, charging is carried out in a mixed charging mode of the uncontrolled rectification mode and the equalizing charging stage mode, and combined with the uncontrollable charging mode, different charging stages are charged in different charging modes, thus overall shortening the charging time of the cascaded high-voltage energy storage device.

[0080] Optionally, on the basis of the above method embodiment, it is further refined and optimized. Figure 7 It is a schematic flowchart of a charging start method for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention. As Figure 7 shown, the method specifically includes the following steps:

[0081] S210: After the control module closes any phase contact of the first three-phase bypass switch and disconnects the corresponding phase contact of the second three-phase bypass switch, it determines whether the power modules and the supercapacitors on the corresponding phase are disconnected according to whether the operation status signals sent by each power controller are received within a preset time.

[0082] Among them, referring to Figures 3 - 5 , the system further includes: a second three-phase bypass switch 60 and a three-phase open-circuit detection resistor 50; each power module further includes; a DC / DC switching power supply 31 and a power controller 32; the power controller is used to obtain power when the output voltage of the DC side of the H-bridge circuit reaches the starting voltage at the first preset time when any phase contact of the first three-phase bypass switch is in the normally closed state and the corresponding phase contact of the second three-phase bypass switch is in the normally closed state, and starts to receive the operation status signals output by each power module 30.

[0083] After the control module in this embodiment controls any phase contact of the first three-phase bypass switch to remain closed and the corresponding phase contact of the second three-phase bypass switch to open, it enters the initial stage of the soft start phase, and the three-phase open-circuit detection resistor also enters the current-limiting function. When the operation status signal sent by the power controller is received within the second preset time, it can be determined that the power modules and the super capacitor clusters of the corresponding phase are disconnected; when the operation status signal sent by the power controller is not received within the second preset time (the second preset time is less than the first preset time), it can be determined that the power modules 30 and the super capacitor clusters C0 of the corresponding phase are not disconnected; thus, before the high-voltage direct connection energy storage of the cascaded super capacitor, the connection detection of the power modules and the super capacitor clusters is realized, ensuring the normal energy storage of the subsequent cascaded super capacitor.

[0084] S220. When the output voltages of all power blocks are less than the first preset voltage, the control module controls the corresponding phase contact of the first three-phase bypass switch to open, and controls all power modules to enter the uncontrolled rectification mode so that all power modules charge the super capacitor clusters in the uncontrolled rectification mode.

[0085] S230. When the output voltages of all power modules are less than the second preset voltage, the control module controls the corresponding phase contact of the first three-phase bypass switch to open, and controls all power modules to enter the equalizing charging stage mode so that all power modules charge the super capacitor clusters in the equalizing charging stage mode.

[0086] Among them, continue to refer to Figures 3 - 5 , each power module includes an H-bridge circuit, a support capacitor and a bypass control switch; the control module controls each power module to enter the equalizing charging stage mode, including: when the DC-side output voltages of all H-bridge circuits are less than the second preset voltage, sorting the DC-side output voltages of all H-bridge circuits from high to low; controlling the preset bypass control switch to close according to the DC-side output voltages of all H-bridge circuits after sorting from high to low and the rated voltages of the AC sides of all H-bridge circuits so that the other H-bridge circuits corresponding to the remaining bypass control switches charge the remaining super capacitors;

[0087] Delay the preset time to determine whether the DC-side output voltages of all H-bridge circuits are greater than the second preset voltage. If the DC-side output voltages of all H-bridge circuits are greater than the second preset voltage, return to sort the DC-side output voltages of all H-bridge circuits in ascending or descending order until it is determined that the DC-side output voltages of all H-bridge circuits are greater than the second preset voltage. Since the preset bypass control switch K is closed during the process of entering the equalizing charging stage mode, the DC-side output voltages of other H-bridge circuits are increased, shortening the charging time. Additionally, in the equalizing charging stage mode, the preset bypass control switch K is cyclically closed, ensuring that the difference between the voltage output by the H-bridge circuit corresponding to the closed preset bypass control switch K and the voltage output by other H-bridge circuits corresponding to the open preset bypass control switch K is within the balance value, guaranteeing the charging safety and avoiding the charging safety problem caused by a large difference between the voltage output by the H-bridge circuit corresponding to the continuously closed preset bypass control switch K and the voltage output by other H-bridge circuits corresponding to the open preset bypass control switch K.

[0088] Certainly, in some other embodiments, during the process of entering the equalizing charging stage mode, first sort the DC-side output voltages of all H-bridge circuits in ascending or descending order, and then, according to the DC-side output voltages of all H-bridge circuits after sorting and the rated voltage of the AC side of the H-bridge circuit, the H-bridge circuit corresponding to the preset bypass control switch can also be controlled to disconnect, which can also enable other H-bridge circuits corresponding to the remaining bypass control switches to charge the remaining supercapacitors. After delaying the preset time, determine whether the DC-side output voltages of all H-bridge circuits are greater than the second preset voltage V2. If the DC-side output voltages of all H-bridge circuits are less than the second preset voltage V2, return to sort the DC-side output voltages of all H-bridge circuits in ascending or descending order until it is determined that the DC-side output voltages of all H-bridge circuits are greater than the second preset voltage V2.

[0089] S240. When the output voltages of all power modules are less than the third preset voltage, the control module controls the first circuit breaker to close and controls all power modules to enter the controllable charging mode so that all power modules charge the supercapacitor clusters in the controllable charging mode.

[0090] Based on the above method embodiments, in this embodiment, before the normal high-voltage energy storage of the cascaded supercapacitor energy storage device charging start system, the connection between each power module and each supercapacitor cluster of any phase is detected; and the charging of the supercapacitor clusters in the equalizing charging stage mode is refined, thus improving the reliability of the high-voltage energy storage of the cascaded supercapacitor and also improving the charging safety of the cascaded high-voltage energy storage device.

[0091] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A charging start system for a cascaded supercapacitor energy storage device, characterized in that, Comprising: A first three-phase bypass switch, three-phase soft start resistors, each power module and a control module cascade-connected and electrically connected respectively on three phases; the three-phase soft start resistors are electrically connected in parallel with the first three-phase bypass switch; a three-phase AC power supply is electrically connected to each of the power modules cascade-connected on three phases through the first three-phase bypass switch; each of the power modules is electrically connected to each supercapacitor cluster to be charged; The control module is configured to, when the output voltages of each of the power modules on any one phase are all less than a first preset voltage, control the corresponding phase contact of the first three-phase bypass switch to disconnect, and each of the power modules enters an uncontrolled rectification mode so that each of the power modules charges each of the supercapacitor clusters in the uncontrolled rectification mode; The control module is configured to, when the output voltages of each of the power modules are all less than a second preset voltage, control the corresponding phase contact of the first three-phase bypass switch to disconnect, and control each of the power modules to enter an equalizing charging stage mode so that each of the power modules charges each of the supercapacitor clusters in the equalizing charging stage mode; The control module is configured to, when the output voltages of each of the power modules are all less than a third preset voltage, control the corresponding phase contact of the first three-phase bypass switch to close, and control each of the power modules to enter a controllable charging mode so that each of the power modules charges each of the supercapacitor clusters in the controllable charging mode; The charging start system of the cascaded supercapacitor energy storage device further includes: three-phase open circuit detection resistors and a second three-phase bypass switch; the three-phase open circuit detection resistors are electrically connected in parallel with the second three-phase bypass switch; the second three-phase bypass switch is electrically connected in series with the first three-phase bypass switch; Each of the power modules includes an H-bridge circuit, a support capacitor, a DC / DC switching power supply and a power controller; each of the power controllers is connected in parallel with the H-bridge circuit through the DC / DC switching power supply; the H-bridge circuit is electrically connected in parallel with the supercapacitor cluster through the support capacitor; the power controller is configured to be powered on when the DC-side output voltage of the H-bridge circuit reaches a start voltage at a first preset time, and start sending operation status signals of each of the power modules; The control module is further configured to, after controlling the corresponding phase contact of the first three-phase bypass switch to close and the corresponding phase contact of the second three-phase bypass switch to disconnect, determine whether each of the power modules on the corresponding phase is disconnected from each of the supercapacitor clusters according to whether operation status signals sent by each of the power controllers are received within a second preset time.

2. The charging start-up system of the cascaded supercapacitor energy storage device according to claim 1, wherein Each of the power modules further includes a bypass control switch; The second end of the corresponding phase contact of the first three-phase bypass switch is electrically connected to one side of the H-bridge circuit and the first end of the bypass control switch; the second end of the bypass control switch is electrically connected to the other side of the H-bridge circuit; The control module is configured to control each of the power modules to enter an equalizing charging stage mode when the output voltages of each of the power modules are all less than a second preset voltage, including: The control module is configured to sort the DC-side output voltages of the H-bridge circuits in ascending order when the DC-side output voltages of all the H-bridge circuits are less than a second preset voltage. According to the DC-side output voltages of the H-bridge circuits sorted in ascending order and the rated voltage of the AC side of the H-bridge circuits, control a preset bypass control switch to close, so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors. Delay for a preset time to determine whether the DC-side output voltages of all the H-bridge circuits are greater than the second preset voltage. If the DC-side output voltages of all the H-bridge circuits are less than the second preset voltage, return to sort the DC-side output voltages of the H-bridge circuits in ascending order until it is determined that the DC-side output voltages of all the H-bridge circuits are greater than the second preset voltage.

3. The charging start system of the cascaded supercapacitor energy storage device according to claim 2, wherein, The control module is further configured to control the H-bridge circuit corresponding to the preset bypass control switch to disconnect according to the DC-side output voltages of the H-bridge circuits sorted in ascending order, so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors.

4. The charging start system of the cascade-type supercapacitor energy storage device according to claim 1, characterized in that, Each power module further includes a circuit breaker, a first one-way diode, and a second one-way diode. Each H-bridge circuit is connected in parallel with each supercapacitor cluster through the circuit breaker; a first end of the support capacitor is electrically connected to a first end of the first one-way diode; a second end of the first one-way diode is electrically connected to a first input terminal of the DC / DC switching power supply; a second end of the support capacitor is electrically connected to a second input terminal of the DC / DC switching power supply; an output terminal of the DC / DC switching power supply is electrically connected to the power controller. A second end of the circuit breaker is electrically connected to a first end of the second one-way diode; a second end of the second one-way diode is electrically connected to the first input terminal of the DC / DC switching power supply.

5. The charging start system of the cascaded supercapacitor energy storage device according to claim 1, characterized in that, The power controller is further configured to control each power module to enter an uncontrolled rectification mode and each power module to enter a controllable charging mode.

6. The charging start system of the cascaded supercapacitor energy storage device according to claim 4, wherein Further included: Three-phase first filter inductors; each power module further includes a second filter inductor. Corresponding phase contacts of the first three-phase bypass switch are electrically connected to the series-connected power modules through corresponding phase first filter inductors of the three-phase first filter inductors; a first end of the support capacitor is electrically connected to a first end of the second filter inductor; a second end of the second filter inductor is electrically connected to the circuit breaker.

7. A charging start method for a cascaded supercapacitor energy storage device, characterized in that, Applied to the charging start system of the cascaded supercapacitor energy storage device according to any one of claims 1-6, including: When the output voltages of the power modules in any one phase are all less than a first preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to disconnect, and controls each power module to enter the uncontrolled rectification mode so that each power module charges the supercapacitor cluster in the uncontrolled rectification mode. When the output voltage of each of the power modules is less than the second preset voltage, the control module controls the corresponding phase contact of the first three-phase bypass switch to open, and controls each of the power modules to enter the equalizing charging stage mode so that each of the power modules charges the supercapacitor bank in the equalizing charging stage mode; When the output voltage of each of the power modules is less than the third preset voltage, the control module controls the corresponding phase contact of the first three-phase bypass switch to close, and controls each of the power modules to enter the controllable charging mode so that each of the power modules charges the supercapacitor in the controllable charging mode; The charging start system of the cascaded supercapacitor energy storage device further includes: an open-circuit detection resistor and a second three-phase bypass switch; each of the power modules includes: an H-bridge circuit, a support capacitor, a DC / DC switching power supply, and a power controller; Before the control module controls the corresponding phase contact of the first three-phase bypass switch to open and controls each of the power modules to enter the uncontrolled rectification mode when the output voltage of each of the power modules in any one phase is less than the first preset voltage, it further includes: After the control module controls the corresponding phase contact of the first three-phase bypass switch to close and the corresponding phase contact of the second three-phase bypass switch to open, it determines whether each of the power modules in the corresponding phase is disconnected from each of the supercapacitor banks according to whether the operation status signals sent by each of the power controllers are received within a preset time.

8. The charging start method of the cascaded supercapacitor energy storage device according to claim 7, wherein Each of the power modules further includes a bypass control switch; The control module controls each of the power modules to enter the equalizing charging stage mode, including: When the DC-side output voltage of each of the H-bridge circuits is less than the second preset voltage, sorting the DC-side output voltages of each of the H-bridge circuits from high to low; According to the DC-side output voltages of each of the H-bridge circuits after sorting from high to low and the rated voltage of the AC side of the H-bridge circuit, controlling a preset bypass control switch to close so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors; Delaying for a preset time to determine whether the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage; If the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage, return to sort the DC-side output voltages of each of the H-bridge circuits from high to low until it is determined that the DC-side output voltage of each of the H-bridge circuits is greater than the second preset voltage.

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