Charging starting system and method for cascaded super-capacitor energy storage device

Abstract

The invention discloses a cascade type super-capacitor energy storage device charging starting system and a cascade type super-capacitor energy storage device charging starting method. The system comprises a first three-phase bypass switch, a three-phase soft start resistor, power modules and a control module, wherein the power modules and the control module are electrically connected in a cascade mode on three phases respectively; the three-phase soft start resistor is electrically connected with the three-phase bypass switch in parallel; a three-phase alternating-current power supply is electrically connected with the power modules which are electrically connected in a cascading manner on three phases through the bypass switch; when the output voltage of each power module on any phase of the control module is smaller than a first preset voltage, a corresponding phase contact of the first bypass switch is controlled to be disconnected, and each power module enters an uncontrolled rectification mode; when the output voltage of each power module is smaller than a second preset voltage, the control module controls the corresponding phase contact of the first bypass switch to be disconnected and controls each power module to enter a voltage-sharing charging stage mode; and when the output voltage of each power module is smaller than a third preset voltage, the control module controls the corresponding phase contact to be closed and controls each power module to enter a controllable charging mode.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of supercapacitor technology, and in particular to a charging start-up system and method for a cascade supercapacitor energy storage device. Background Art

[0002] At present, high-voltage cascade energy storage devices based on supercapacitor energy storage media have the characteristics of single-machine high power, pulsed discharge, and high efficiency, and have become the main technical route for current high-power pulsed power supply systems and grid-type SVG. The voltage level of cascade energy storage devices is relatively high. Due to the high voltage level of cascade energy storage devices, it is urgent to improve the charging efficiency of cascade energy storage devices. At present, the charging efficiency of cascade energy storage devices is relatively low. Summary of the invention

[0003] The present invention provides a charging start-up system and method for a cascade type supercapacitor energy storage device, so as to meet the high voltage direct-hanging energy storage demand for the cascade type supercapacitor, and at the same time shorten the charging time of the cascade type energy storage device.

[0004] To achieve the above objectives, in a first aspect, an embodiment of the present invention provides a cascade supercapacitor energy storage device charging and starting system, the system comprising: a first three-phase bypass switch, a three-phase soft-start resistor, power modules electrically connected in cascade on the three phases, and a control module; the three-phase soft-start resistor is 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 electrically connected in cascade 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;

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

[0006] The control module is used to control the corresponding phase contacts of the first three-phase bypass switch to be disconnected when the output voltage of each power module is less than the second preset voltage, and control each power module to enter the voltage-balanced charging stage mode so that each power module charges each supercapacitor cluster in the voltage-balanced charging stage mode;

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

[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 used to control each of the power modules to enter a voltage-balanced charging stage mode when the output voltage of each of the power modules is less than a second preset voltage, and includes:

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

[0012] According to the sorted DC side output voltages of the H-bridge circuits and the rated voltages of the AC side of the H-bridge circuits, the preset bypass control switches are controlled to close, so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors;

[0013] Delaying a preset time to determine whether the DC side output voltage of each H-bridge circuit 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 sorting the DC side output voltages of the H-bridge circuits 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 also used to control the H-bridge circuit corresponding to the preset bypass control switch to disconnect according to the DC side output voltage of each H-bridge circuit after high and low sorting, so that the other H-bridge circuits corresponding to the remaining bypass control switches charge the remaining 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 comprises: a DC / DC switching power supply and a power controller; each of the power controllers is connected in parallel with the H-bridge circuit via the DC / DC switching power supply; the power controller is configured to be powered when the DC side output voltage of the H-bridge circuit reaches the starting voltage at a first preset time, and start sending the operating status signal of each of the power modules;

[0018] The control module is also used to determine whether each of the power modules and each of the supercapacitor clusters are disconnected according to whether an operating status signal sent by each of the power controllers is received within a second preset time after controlling the corresponding phase contacts of the first three-phase bypass switch to close and the corresponding phase contacts of the second three-phase bypass switch to open.

[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; the first end of the support capacitor is electrically connected to the first end of the first unidirectional diode; the second end of the first unidirectional diode is electrically connected to the first input end of the DC / DC switching power supply; the second end of the support capacitor is electrically connected to the second input end of the DC / DC switching power supply; the output end of the DC / DC switching power supply is electrically connected to the power controller;

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

[0022] Optionally, the power controller is also used to control each of the power modules to enter an uncontrolled rectification mode and each of the power modules to enter a controlled charging mode.

[0023] Optionally, the system further comprises: a three-phase first filter inductor; each of the power modules further comprises 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 inductors of the three-phase first filter inductors; the first end of the support capacitor is electrically connected to the first end of the second filter inductor; and the 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 charging start method for a cascade type supercapacitor energy storage device, which is applied to the charging start system for the cascade type supercapacitor energy storage device described in the first aspect, and the method comprises:

[0026] When the output voltage of each of the power modules in any phase is less than the first preset voltage, the control module controls the corresponding phase contact 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 be disconnected, and controls each of the power modules to enter the voltage-balanced charging stage mode so that each of the power modules charges the supercapacitor cluster in the voltage-balanced 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 a 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 a voltage-balanced charging stage mode, including:

[0031] When the DC side output voltages of the H-bridge circuits are all less than the second preset voltage, the DC side output voltages of the H-bridge circuits are sorted in order of high and low;

[0032] According to the sorted DC side output voltages of the H-bridge circuits and the rated voltages of the AC side of the H-bridge circuits, a preset bypass control switch is controlled to close so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors;

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

[0034] If the DC side output voltage of each H-bridge circuit is greater than the second preset voltage, return 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.

[0035] Optionally, the cascade type supercapacitor energy storage device charging start-up 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 power module in any phase is less than the first preset voltage, the control module controls the corresponding phase contact of the first three-phase bypass switch to be disconnected, and controls each power module to enter the uncontrolled rectification mode, and further includes:

[0037] After controlling the corresponding phase contacts of the first three-phase bypass switch to close and the corresponding phase contacts of the second three-phase bypass switch to open, the control module determines whether the power modules and supercapacitor clusters of the corresponding phases are disconnected according to whether an operating status signal sent by each power controller is 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 that are electrically connected in cascade 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; in this way, when the output voltage of each power module of any phase is 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 then each power module charges the supercapacitor cluster in the uncontrolled rectification mode; when the output voltage of each power module is less than the second preset voltage, the corresponding phase contacts of the first three-phase bypass switch are controlled to be disconnected, Thereby, each power module is maintained in the current limiting soft start mode, and each power module is controlled to charge the supercapacitor cluster in the voltage equalization charging stage mode; when the output voltage of each power module is 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 close 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-power direct-hanging energy storage demand for the cascade supercapacitor through different charging stages; and charging is performed in different charging modes at different charging stages, which also shortens the charging time of the cascade energy storage device.

[0039] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended 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 briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0042] Figure 2The specific structure of a cascade type supercapacitor energy storage device charging start system provided by an embodiment of the present invention is shown in FIG. Figure 1 ;

[0043] Figure 3 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by an embodiment of the present invention is shown in FIG. Figure 2 ;

[0044] Figure 4 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by an embodiment of the present invention is shown in FIG. Figure 3 ;

[0045] Figure 5 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by an embodiment of the present invention is shown in FIG. Figure 4 ;

[0046] Figure 6 It is a schematic flow chart of a charging start-up method of a cascade type supercapacitor energy storage device provided by an embodiment of the present invention;

[0047] Figure 7 It is a flow chart of another charging start-up method of a cascade supercapacitor energy storage device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, 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 "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Figure 1is a structural diagram of a cascade type supercapacitor energy storage device charging start-up system provided by an embodiment of the present invention, such as Figure 1 As shown, the system includes: a first three-phase bypass switch 10, a three-phase soft-start resistor 20, power modules 30 electrically connected in cascade on the three phases, and a control module 40; the three-phase soft-start resistor 20 is electrically connected in parallel with the first three-phase bypass switch 10; the three-phase AC power supply is electrically connected to the power modules 30 electrically connected in cascade on the 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 an A-phase contact 11, a B-phase contact 12 and a C-phase contact 13, and the three-phase soft-start resistor 20 includes an A-phase soft-start resistor 21, a B-phase soft-start resistor 22 and a C-phase soft-start resistor 23;

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

[0052] The control module 40 is used to control the corresponding phase contacts of the first three-phase bypass switch 10 to be disconnected when the output voltage of each power module 30 is less than the second preset voltage V2, and control each power module 30 to enter the voltage-balanced charging stage mode so that each power module 30 charges each supercapacitor cluster in the voltage-balanced charging stage mode;

[0053] The control module 40 is used to control the corresponding phase contacts of the first three-phase bypass switch 10 to close when the output voltage of each power module is less than the 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 a controllable charging mode.

[0054] Among them, the power module 30 is a power module composed of an H-bridge circuit; generally, in 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 to be approximately equivalent to an RC charging circuit; since the RC charging circuit outputs a DC voltage for a long time, the soft start stage is divided into two stages in this embodiment. Specifically, phase A is taken as an example for explanation. When the output voltage of each power module 30 in phase A is less than the first preset voltage V1, each power module 30 is controlled to enter an 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 be disconnected, and the corresponding phase soft start resistor 21 of the three-phase soft start resistor 20 is used to limit the current, so that each power module charges the supercapacitor cluster 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 voltage of each power module 30 is less than the second preset voltage V2, each power module 30 is controlled to enter the voltage-equalizing charging stage mode, and the corresponding phase contact 11 of the first three-phase bypass switch 10 is controlled to be disconnected, so that the corresponding phase soft-start resistor 21 of the three-phase soft-start resistor 20 is maintained to limit the current, so that each power module 30 charges the supercapacitor cluster in the voltage-equalizing charging stage mode until each supercapacitor cluster is charged to the second preset voltage V2; in this way, each power module 30 uses the uncontrolled rectification mode and the voltage-equalizing charging stage mode in the soft-start stage, so that each supercapacitor is charged to the second preset voltage V2 faster; it should be noted that the voltage-equalizing charging stage mode is a mode in which the output voltage of each power module is quickly increased, and the voltage difference between each power module is balanced during the charging process of each power module;

[0056] After each power module 30 enters the voltage-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, and the corresponding phase contact 11 of the first three-phase bypass switch 10 can be controlled to close at the same time, without the need for the corresponding phase soft-start resistor 21 of the three-phase soft-start resistor 20 to limit the current, so that each power module 30 charges the supercapacitor cluster in a controllable charging mode; in this way, 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, the mixed charging mode of the uncontrolled rectification mode and the voltage-equalizing charging stage mode is used for charging, and combined with the uncontrollable charging mode, different charging stages are charged in different charging modes, so that the charging time of the cascaded high-voltage energy storage device is shortened as a whole.

[0057] Optionally, based on the above embodiment, each power module on any phase of the system is further refined and optimized. Figure 2 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by an embodiment of the present invention is shown in FIG. Figure 1 ;like Figure 2 As shown, here any phase is taken as an example for schematic 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 electrically 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 voltage-balanced charging stage mode when the output voltage of each power module 30 is less than the second preset voltage V2, including:

[0059] The control module 40 is used to sort the DC side output voltages of each H-bridge circuit 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 voltage of each H-bridge circuit after sorting and the rated voltage of the AC side of the H-bridge circuit, the preset bypass control switch K is controlled to be closed 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 sort 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.

[0062] Specifically, phase A is taken as an example for explanation. Each power module in phase A charges the supercapacitor in an uncontrolled rectification mode until each supercapacitor is charged to a first preset voltage V1. Due to actual measurement errors, after the supercapacitor is charged in an uncontrolled rectification mode, the charging voltage of each supercapacitor (the same as the DC side output voltage of the H-bridge circuit) has a certain deviation from the first preset voltage V1. In the process of entering the voltage-equalizing charging stage mode, the DC side output voltages of each H-bridge circuit are first sorted, and the number of H-bridge circuits to be started in the voltage-equalizing charging stage mode is determined according to the rated voltage of the AC side of the H-bridge circuit. Then, the corresponding number of lower output voltages is retained from the high and low sorting of the DC side output voltages of each H-bridge circuit, and the corresponding H-bridge circuits corresponding to the lower output voltage are ensured to work, and the preset bypass control switches K corresponding to the remaining H-bridge circuits are controlled to be closed, 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 (usually ms), as each H-bridge circuit corresponding to the lower output voltage charges the corresponding supercapacitor cluster C0, the DC side output voltage of each corresponding H-bridge circuit increases, and because 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-rectifier mode; then the DC side output voltages of each H-bridge circuit are re-sorted in a cycle, and the preset bypass control switch K is controlled to be closed according to the DC side output voltages of each H-bridge circuit after the 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; in this way, since the equalizing charging stage mode is entered During the process, the preset bypass control switch K is closed, which increases the DC side output voltage of each H-bridge circuit corresponding to the lower output voltage, thereby improving the charging efficiency; in addition, in the voltage equalization charging stage mode, the preset bypass control switch K is closed cyclically, so that the difference between the voltage output of the H-bridge circuit corresponding to the closing of the preset bypass control switch K and the output voltage of the H-bridge circuit corresponding to the disconnection of the preset bypass control switch K is ensured to be within the balance value, thereby ensuring the charging safety and avoiding the problem of unsafe charging caused by the preset bypass control switch K being continuously closed, resulting in a large difference between the voltage output of the H-bridge circuit corresponding to the closing of the preset bypass control switch K and the output voltage of the H-bridge circuit corresponding to the disconnection of the preset bypass control switch K.

[0064] It should be noted that in other embodiments, when entering the equalizing charging stage mode, the DC side output voltages of each H-bridge circuit are first sorted, and then the H-bridge circuit corresponding to the bypass control switch can be controlled to be disconnected according to 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, so that the other H-bridge circuits corresponding to the remaining bypass control switches can charge the remaining supercapacitors. After a preset delay time, 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 each H-bridge circuit are less than the second preset voltage V2, the DC side output voltages of each H-bridge circuit are returned to be sorted until it is determined that the DC side output voltage of each H-bridge circuit is greater than the second preset voltage V2.

[0065] Optional, Figure 3 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by an embodiment of the present invention is shown in FIG. Figure 2 ;like Figure 3 As shown, the system further includes: a three-phase open circuit detection resistor 50 and a second three-phase bypass switch 60 (only any one-phase open circuit detection resistor 51 and the A-phase contact 2 61 of the second three-phase bypass switch 60 are 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 connected in parallel with the H-bridge circuit via the DC / DC switching power supply 31; the power controller 32 is used to be powered 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) at a first preset time, and starts to receive the operating status signal output by each power module 30;

[0067] The control module 40 is also used to determine whether each power module 30 and each supercapacitor cluster C0 on the corresponding phase are disconnected according to whether an operating status signal sent by each power controller 32 is received within a second preset time after controlling the corresponding phase contact 11 of the first three-phase bypass switch to close and the corresponding phase contact 2 61 of the second three-phase bypass switch to open.

[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 of the supporting capacitor C is in the mF (millifarad) level, at the beginning of the soft start stage, the voltage of the supporting capacitor C quickly rises to reach the starting voltage of the DC / DC switching power supply 31 (usually at the second preset time), the power controller 32 is powered on, and sends an operating status signal; while the supercapacitor of a normal power module is normally connected to the DC side of the H-bridge circuit, since the capacitance of the supercapacitor cluster C0 is in the farad level, the DC side output voltage of the H-bridge circuit will not reach the starting voltage V1 of the DC / DC switching power supply 31 at the second preset time, the power controller 32 will not be powered, but will reach the starting 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 phase A as an example, 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 early stage of the soft start stage, and the open circuit detection resistor 50 also enters the current limiting function. When the voltage status signal sent by each power controller 32 is received within the second preset time, it can be determined that each power module 30 on phase A 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 phase A is not disconnected from each supercapacitor cluster C0.

[0070] Optional, continue to refer to Figure 3 The power controller 32 is also used to control each power module 30 to enter an uncontrolled rectification mode and each power module 30 to enter a controlled charging mode. In some embodiments, the power controller 32 can jointly execute the logic program of entering the uncontrolled rectification mode and each power module 30 entering the controlled charging mode with the control module 40; this embodiment does not limit the execution subject of the logic program of entering the uncontrolled rectification mode and each power module 30 entering the controlled charging mode.

[0071] Optional, Figure 4 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by the embodiment of the present invention is shown in FIG. Figure 3 ;like Figure 4As shown, any phase is taken as an example for schematic illustration, each power module 30 also 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 cluster 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 end of the DC / DC switching power supply 31; the second end of the support capacitor C is electrically connected to the second input end of the DC / DC switching power supply 31; the output end 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 end 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, and can also be taken from the voltage across the supercapacitor cluster C0; the DC side output voltage of the H-bridge circuit and the higher voltage across the supercapacitor cluster C0 can be automatically selected through the first unidirectional diode D1 and the second unidirectional diode D2; and then converted into control voltage such as DC24V / DC220V / DC400V through the DC / DC switching power supply 31.

[0074] Optional, Figure 5 The specific structure of a cascade type supercapacitor energy storage device charging start system provided by the embodiment of the present invention is shown in FIG. Figure 4 ;like Figure 5 As shown, the system also includes a three-phase first filter inductor L1; each power module 30 also includes a second filter inductor L2; the corresponding phase contact 11 of the first three-phase bypass switch is electrically connected to each power module 30 connected in series 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 double frequency on the DC side of the H-bridge circuit, and the second filter inductor L2 can mainly filter the double 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 charging and starting method for a cascaded supercapacitor energy storage device, which is applied to the charging and starting system for the cascaded supercapacitor energy storage device described in the above embodiment. Figure 6 is a flow chart of a charging start-up method for a cascaded supercapacitor energy storage device provided by an embodiment of the present invention, such as Figure 6 As shown, the method comprises the following steps:

[0076] S110. When the output voltage of each power module on any phase is less than the first preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to be disconnected, and controls each power module to enter an uncontrolled rectification mode so that each power module charges each supercapacitor cluster in the uncontrolled rectification mode.

[0077] S120. When the output voltage of each power module is less than the second preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to be disconnected, and controls each power module to enter the voltage equalization charging stage mode so that each power module charges each supercapacitor cluster in the voltage equalization charging stage mode.

[0078] S130. When the output voltage of each power module 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 power module to enter a controllable charging mode so that each power module charges each supercapacitor cluster in a controllable charging mode.

[0079] In the embodiment of the method, each power module meets the high-voltage direct-mounted energy storage demand of the cascaded supercapacitor on each phase through different charging stages; and in the soft start stage, charging is performed in a mixed charging mode of an uncontrolled rectification mode and a voltage equalization charging stage mode, and combined with an uncontrollable charging mode, different charging stages are charged in different charging modes, thereby shortening the charging time of the cascaded high-voltage energy storage device as a whole.

[0080] Optionally, based on the above method embodiment, further refine and optimize, Figure 7 FIG. 1 is a flow chart of a charging start method of a cascade type supercapacitor energy storage device provided by an embodiment of the present invention, such as Figure 7 As shown, the method specifically comprises the following steps:

[0081] S210, after controlling the closing of any phase contact of the first three-phase bypass switch and the opening of the corresponding phase contact of the second three-phase bypass switch, the control module determines whether the power modules and supercapacitors of the corresponding phases are disconnected according to whether the operating status signals sent by the power controllers are received within a preset time.

[0082] Among them, refer to Figure 3-Figure 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 be powered when any phase contact of the first three-phase bypass switch is in a normally closed state and the corresponding phase contact of the second three-phase bypass switch is in a normally closed state, and when the DC side output voltage of the H-bridge circuit reaches the starting voltage at a first preset time, and starts to receive the operating status signal output by each power module 30;

[0083] After the control module of 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 be disconnected, 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 operating status signal sent by the power controller is received within the second preset time, it can be determined that the power modules of the corresponding phase are disconnected from the supercapacitor clusters; when the operating 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 of the corresponding phase are not disconnected from the supercapacitor clusters C0; in this way, before the high-power direct-hanging energy storage of the cascaded supercapacitor, the connection detection of each power module and each supercapacitor cluster is realized, thereby ensuring the subsequent normal energy storage of the cascaded supercapacitor.

[0084] S220. When the output voltage of each power block is less than the first preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to be disconnected, and controls each power module to enter an uncontrolled rectification mode so that each power module charges each supercapacitor cluster in the uncontrolled rectification mode.

[0085] S230. When the output voltage of each power module is less than the second preset voltage, the control module controls the corresponding phase contacts of the first three-phase bypass switch to be disconnected, and controls each power module to enter the voltage equalization charging stage mode so that each power module charges each supercapacitor cluster in the voltage equalization charging stage mode.

[0086] Among them, continue to refer to Figure 3-Figure 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 a voltage-balanced charging stage mode, including: when the DC-side output voltage of each H-bridge circuit is less than a second preset voltage, the DC-side output voltage of each H-bridge circuit is sorted; according to the DC-side output voltage of each H-bridge circuit after sorting and the rated voltage of the AC side of each H-bridge circuit, the preset bypass control switch is controlled to close so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors;

[0087] Delay for a preset time to determine whether the DC side output voltage of each H-bridge circuit is greater than the second preset voltage; if the DC side output voltage of each H-bridge circuit is greater than the second preset voltage, return to sort 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. Since the preset bypass control switch K is closed during the process of entering the voltage-equalizing charging stage mode, the DC side output voltage of each other H-bridge circuit is increased, shortening the charging time; in addition, in the voltage-equalizing charging stage mode, the preset bypass control switch K is closed cyclically, so that the difference between the output voltage of the H-bridge circuit corresponding to the closing of the preset bypass control switch K and the output voltage of other H-bridge circuits corresponding to the disconnection of the preset bypass control switch K is guaranteed to be within the balance value, ensuring charging safety, and avoiding the problem of unsafe charging caused by the continuous closure of the preset bypass control switch K, resulting in a large difference between the output voltage of the H-bridge circuit corresponding to the closing of the preset bypass control switch K and the output voltage of other H-bridge circuits corresponding to the disconnection of the preset bypass control switch K.

[0088] Of course, in other embodiments, when entering the equalizing charging stage mode, the DC side output voltages of each H-bridge circuit are first sorted, and then the H-bridge circuit corresponding to the preset bypass control switch can be controlled to be disconnected according to 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, so that the other H-bridge circuits corresponding to the remaining bypass control switches can charge the remaining supercapacitors. After a preset delay time, 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 each H-bridge circuit are less than the second preset voltage V2, the DC side output voltages of each H-bridge circuit are returned to be sorted until it is determined that the DC side output voltage of each H-bridge circuit is greater than the second preset voltage V2.

[0089] S240: When the output voltage of each power module is less than the third preset voltage, the control module controls the first circuit breaker to close, and controls each power module to enter a controllable charging mode so that each power module charges each supercapacitor cluster in the controllable charging mode.

[0090] Based on the above method embodiment, this embodiment further detects the connection between each power module of any phase and each supercapacitor cluster before the normal high-voltage energy storage of the cascaded supercapacitor energy storage device charging start system; and refines the charging of the supercapacitor cluster in the voltage-equalizing charging stage mode, thereby 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 are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection 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, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A cascade type supercapacitor energy storage device charging start-up system, characterized in that: include: A first three-phase bypass switch, a three-phase soft-start resistor, power modules and a control module that are cascade-connected on the three phases; the three-phase soft-start resistor is 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 that are cascade-connected 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; The control module is used for controlling the corresponding phase contact of the first three-phase bypass switch to be disconnected when the output voltage of each power module on any phase is less than a first preset voltage, so that each power module enters an uncontrolled rectification mode so that each power module charges each supercapacitor cluster in the uncontrolled rectification mode; The control module is used to control the corresponding phase contacts of the first three-phase bypass switch to be disconnected when the output voltage of each power module is less than the second preset voltage, and control each power module to enter the voltage-balanced charging stage mode so that each power module charges each supercapacitor cluster in the voltage-balanced charging stage mode; The control module is used to control the corresponding phase contacts of the first three-phase bypass switch to close when the output voltage of each power module is less than a third preset voltage, and control each power module to enter a controllable charging mode so that each power module charges each supercapacitor cluster in the controllable charging mode.

2. The charging start-up system of the cascade type supercapacitor energy storage device according to claim 1, characterized in that: Each of the power modules comprises an H-bridge circuit, a support capacitor and 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 H-bridge circuit is electrically connected in parallel with the supercapacitor cluster through the support capacitor; The control module is used to control each of the power modules to enter a voltage-balanced charging stage mode when the output voltage of each of the power modules is less than a second preset voltage, and includes: The control module is used to sort the DC side output voltages of the H-bridge circuits in order of high and low when the DC side output voltages of the H-bridge circuits are all less than a second preset voltage; According to the sorted DC side output voltages of the H-bridge circuits and the rated voltages of the AC side of the H-bridge circuits, the preset bypass control switches are controlled to close, so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors; Delaying a preset time to determine whether the DC side output voltage of each H-bridge circuit is greater than the second preset voltage; If the DC side output voltages of the H-bridge circuits are all less than the second preset voltage, return to sorting the DC side output voltages of the H-bridge circuits until it is determined that the DC side output voltages of the H-bridge circuits are greater than the second preset voltage.

3. The charging start-up system of the cascade type supercapacitor energy storage device according to claim 2, characterized in that: The control module is also used to control the H-bridge circuit corresponding to the preset bypass control switch to disconnect according to the DC side output voltage of each H-bridge circuit after high and low sorting, so that the other H-bridge circuits corresponding to the remaining bypass control switches charge the remaining supercapacitors.

4. The charging start-up system of the cascade supercapacitor energy storage device according to claim 2 or 3, characterized in that: Also 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; Each of the power modules further comprises: a DC / DC switching power supply and a power controller; each of the power controllers is connected in parallel with the H-bridge circuit via the DC / DC switching power supply; the power controller is configured to be powered when the DC side output voltage of the H-bridge circuit reaches the starting voltage at a first preset time, and start sending the operating status signal of each of the power modules; The control module is also used to determine whether the power modules and supercapacitor clusters of the corresponding phases are disconnected according to whether an operating status signal sent by each power controller is received within a second preset time after controlling the corresponding phase contacts of the first three-phase bypass switch to close and the corresponding phase contacts of the second three-phase bypass switch to open.

5. The charging start-up system of the cascade supercapacitor energy storage device according to claim 4, characterized in that: Each of the power modules further includes a circuit breaker, a first unidirectional diode and a second unidirectional diode; Each of the H-bridge circuits is connected in parallel with each of the supercapacitor clusters through the circuit breaker; the first end of the support capacitor is electrically connected to the first end of the first unidirectional diode; the second end of the first unidirectional diode is electrically connected to the first input end of the DC / DC switching power supply; the second end of the support capacitor is electrically connected to the second input end of the DC / DC switching power supply; the output end of the DC / DC switching power supply is electrically connected to the power controller; The second end of the circuit breaker is electrically connected to the first end of the second unidirectional diode; the second end of the second unidirectional diode is electrically connected to the first input end of the DC / DC switching power supply.

6. The charging start-up system of the cascade supercapacitor energy storage device according to claim 4, characterized in that: The power controller is also used 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.

7. The charging start-up system of the cascade supercapacitor energy storage device according to claim 5, characterized in that: Also includes: A three-phase first filter inductor; each of the power modules also includes a second filter inductor; 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 inductors of the three-phase first filter inductors; the first end of the support capacitor is electrically connected to the first end of the second filter inductor; and the second end of the second filter inductor is electrically connected to the circuit breaker.

8. A charging start-up method for a cascade type supercapacitor energy storage device, characterized in that: The charging start-up system for the cascade supercapacitor energy storage device according to any one of claims 1 to 7 comprises: When the output voltage of each of the power modules in any phase is less than the first preset voltage, the control module controls the corresponding phase contact 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; 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 be disconnected, and controls each of the power modules to enter the voltage-balanced charging stage mode so that each of the power modules charges the supercapacitor cluster in the voltage-balanced 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 contacts of the first three-phase bypass switch to close, and controls each of the power modules to enter a controllable charging mode so that each of the power modules charges the supercapacitor in the controllable charging mode.

9. The charging start-up method of the cascade type supercapacitor energy storage device according to claim 8, characterized in that: Each of the power modules comprises an H-bridge circuit, a support capacitor and a bypass control switch; The control module controls each of the power modules to enter a voltage-balanced charging stage mode, including: When the DC side output voltages of the H-bridge circuits are all less than the second preset voltage, the DC side output voltages of the H-bridge circuits are sorted in order of high and low; According to the sorted DC side output voltages of the H-bridge circuits and the rated voltages of the AC side of the H-bridge circuits, a preset bypass control switch is controlled to close so that the other H-bridge circuits corresponding to the other bypass control switches charge the other supercapacitors; Delaying a preset time to determine whether the DC side output voltage of each H-bridge circuit is greater than the second preset voltage; If the DC side output voltage of each H-bridge circuit is greater than the second preset voltage, return 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.

10. The charging start-up method of the cascade type supercapacitor energy storage device according to claim 9, characterized in that: The cascade type supercapacitor energy storage device charging start-up 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; When the output voltage of each power module in any phase is less than the first preset voltage, the control module controls the corresponding phase contact of the first three-phase bypass switch to be disconnected, and controls each power module to enter the uncontrolled rectification mode, and further includes: After controlling the corresponding phase contacts of the first three-phase bypass switch to close and the corresponding phase contacts of the second three-phase bypass switch to open, the control module determines whether the power modules and supercapacitor clusters of the corresponding phases are disconnected according to whether an operating status signal sent by each power controller is received within a preset time.

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