Impact-free charging method and device for super capacitor in network-forming static synchronous phase modifier

Abstract

The invention provides a non-impact charging method and a non-impact charging device for a super capacitor in a network-forming static synchronous phase modifier. And controlling the direct current side actual voltage of the modular multilevel converter valve according to the direct current side reference voltage of the modular multilevel converter valve. And controlling the actual voltage of the direct current side to rise to a preset first voltage threshold according to a preset first rising slope, and carrying out uncontrolled rectification charging on the super capacitor converter valve. And controlling the actual voltage of the direct current side to rise to a preset second voltage threshold according to a preset second rising slope, and performing non-impact charging on the super capacitor converter valve according to a preset duty ratio. According to the method, the super capacitor converter valve is charged in different modes by controlling the actual voltage of the direct current side, so that the charging efficiency of the super capacitor converter valve is improved, the starting efficiency of the network-forming type static synchronous phase modifier is further improved, no impact is generated on an alternating current system, and that is, no-impact charging of the super capacitor converter valve is realized.

Description

Technical Field

[0001] The present application relates to the field of flexible power transmission technology, and in particular to a method and device for charging a supercapacitor in a grid-connected static synchronous phase condenser without impact. Background Art

[0002] As the construction of power systems accelerates, new energy sources are gradually becoming the main source of new installed capacity and new power generation. As the penetration rate of new energy sources continues to increase, the power system is gradually showing a trend of high power electronics, and the operating mechanism and safety and stability characteristics of the power system based on synchronous machines are undergoing profound changes.

[0003] In order to improve the reactive voltage control capability of the power system including new energy (referred to as the new power system), a grid-forming static synchronous compensator (STATCOM) is usually installed in the new energy station and AC collection station. STATCOM is a reactive power compensation device whose main function is to provide or absorb reactive power to improve the power factor of the new power system and maintain the voltage stability of the new power system.

[0004] The voltage and inertia support device provided by the related art may include a modular multilevel converter valve (MMC) and an energy storage converter valve. The AC side of the MMC is connected to the AC power grid, and the DC side of the MMC is connected to the energy storage converter valve. The energy storage converter valve includes a plurality of submodules, each of which may include a battery and a slow-start resistor. Due to the energy loss of the slow-start resistor, the charging efficiency of the energy storage converter valve is low, which in turn leads to low starting efficiency of the voltage and inertia support device. Summary of the invention

[0005] In order to solve the problem of low starting efficiency in the prior art, the present application provides a method for charging supercapacitors in a grid-type static synchronous condenser without impact, wherein the grid-type static synchronous condenser is a voltage and inertia support device, and the grid-type static synchronous condenser may include a modular multilevel converter valve and a supercapacitor converter valve. The AC side of the modular multilevel converter valve can be connected to the AC power grid, and the DC side of the modular multilevel converter valve can be connected to the supercapacitor converter valve through a DC switch. The supercapacitor converter valve may include multiple submodules connected in series. Each submodule may include a supercapacitor.

[0006] The impact-free charging method provided by the present application may include:

[0007] The actual DC side voltage of the modular multilevel converter valve in the grid-type static synchronous condenser is controlled according to the DC side reference voltage of the modular multilevel converter valve.

[0008] The actual voltage on the DC side is controlled to increase to a preset first voltage threshold according to a preset first rising slope, and uncontrolled rectification and charging are performed on the supercapacitor converter valve in the grid-type static synchronous phase regulator.

[0009] The actual voltage on the DC side is controlled to increase to a preset second voltage threshold according to a preset second rising slope, and the supercapacitor converter valve is charged without impact according to a preset duty cycle.

[0010] The preset second voltage threshold is greater than the preset first voltage threshold.

[0011] In some possible implementations, controlling the actual DC side voltage of the modular multilevel converter valve according to the DC side reference voltage of the modular multilevel converter valve in the grid-type static synchronous condenser includes:

[0012] According to the DC side reference voltage, the actual DC side voltage is proportionally and integrally controlled to make the actual DC side voltage 0.

[0013] In some other possible implementations, controlling the actual voltage on the DC side to increase to a preset first voltage threshold according to a preset first rising slope, and performing uncontrolled rectification and charging on the supercapacitor converter valve in the grid-type static synchronous phase condenser include:

[0014] All submodules in the supercapacitor converter valve are turned off, and the DC switch between the modular multi-level converter valve and the supercapacitor converter valve is closed.

[0015] The actual voltage on the DC side is controlled to gradually increase according to a preset first rising slope, and the supercapacitor in the submodule is charged by uncontrolled rectification through the anti-parallel diode of the power device in the submodule.

[0016] When the actual voltage on the DC side rises to a preset first voltage threshold, all submodules are powered on for self-checking. If any submodule fails, all submodules stop uncontrolled rectification and charging, and are repaired.

[0017] Exemplarily, the preset first voltage threshold satisfies:

[0018] U dcset1 =N·U dc_start

[0019] Among them, U dcset1 represents the preset first voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U dc_start Indicates the starting voltage of the driver module used to send a driving signal to the submodule.

[0020] In some other possible implementations, controlling the actual voltage on the DC side to increase to a preset second voltage threshold according to a preset second rising slope, and performing impact-free charging on the supercapacitor converter valve according to a preset duty cycle, includes:

[0021] The actual voltage on the DC side is controlled to gradually increase according to the preset second rising slope, and the supercapacitor converter valve is charged without impact according to the preset duty cycle.

[0022] The DC voltages of all the shut-off submodules and all the bypassed submodules are collected, and the maximum DC voltage of the shut-off submodule and the minimum DC voltage of the bypassed submodule are selected.

[0023] When the voltage difference between the maximum DC voltage of the shut-down submodule and the minimum DC voltage of the bypassed submodule is greater than a preset third voltage threshold, the submodule corresponding to the minimum DC voltage of the bypassed submodule is shut down, and the submodule corresponding to the maximum DC voltage of the shut-down submodule is bypassed.

[0024] When the actual voltage on the DC side rises to the preset second voltage threshold, if the DC voltage of the submodule is within the preset voltage range, the supercapacitor converter valve completes impact-free charging. Otherwise, the supercapacitor converter valve continues to be impact-free charged according to the preset duty cycle until the DC voltage of the submodule is within the preset voltage range.

[0025] Optionally, the preset second voltage threshold satisfies:

[0026] U dcset2 =(N-1)U scn

[0027] Among them, U dcset2 represents the preset second voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U scn Indicates the rated voltage of the submodule.

[0028] Exemplarily, the preset duty cycle satisfies:

[0029]

[0030] Wherein, D represents a preset duty cycle, and N represents the number of submodules in the supercapacitor converter valve.

[0031] Furthermore, the impact-free charging method provided by the present application also includes:

[0032] All submodules in the supercapacitor converter valve are turned off, and the actual voltage on the DC side is controlled to drop to the rated voltage on the DC side of the modular multilevel converter valve through the modular multilevel converter valve.

[0033] On the other hand, the present application also provides a non-impact charging device for supercapacitors in a network-building static synchronous condenser, comprising:

[0034] The control module is used to control the actual DC side voltage of the modular multilevel converter valve according to the DC side reference voltage of the modular multilevel converter valve in the grid-type static synchronous phase regulator.

[0035] The first charging module is used to control the actual voltage on the DC side to increase to a preset first voltage threshold according to a preset first rising slope, and to perform uncontrolled rectification and charging on the supercapacitor converter valve in the grid-type static synchronous phase regulator.

[0036] The second charging module is used to control the actual voltage on the DC side to increase to a preset second voltage threshold according to a preset second rising slope, and to perform impact-free charging on the supercapacitor converter valve according to a preset duty cycle.

[0037] The preset second voltage threshold is greater than the preset first voltage threshold.

[0038] In a possible implementation, the control module is specifically used to:

[0039] According to the DC side reference voltage, the actual DC side voltage is proportionally and integrally controlled to make the actual DC side voltage 0.

[0040] In another possible implementation, the first charging module is specifically configured to:

[0041] All submodules in the supercapacitor converter valve are turned off, and the DC switch between the modular multi-level converter valve and the supercapacitor converter valve is closed.

[0042] The actual voltage on the DC side is controlled to gradually increase according to a preset first rising slope, and the supercapacitor in the submodule is charged by uncontrolled rectification through the anti-parallel diode of the power device in the submodule.

[0043] When the actual voltage on the DC side rises to a preset first voltage threshold, all submodules are powered on for self-checking. If any submodule fails, all submodules stop uncontrolled rectification and charging, and are repaired.

[0044] Exemplarily, the preset first voltage threshold satisfies:

[0045] U dcset1 =N·U dc_start

[0046] Among them, U dcset1 represents the preset first voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U dc_start Indicates the starting voltage of the driver module used to send a driving signal to the submodule.

[0047] In yet another possible implementation, the second charging module is specifically configured to:

[0048] The actual voltage on the DC side is controlled to gradually increase according to the preset second rising slope, and the supercapacitor converter valve is charged without impact according to the preset duty cycle.

[0049] The DC voltages of all the shut-off submodules and all the bypassed submodules are collected, and the maximum DC voltage of the shut-off submodule and the minimum DC voltage of the bypassed submodule are selected.

[0050] When the voltage difference between the maximum DC voltage of the shut-down submodule and the minimum DC voltage of the bypassed submodule is greater than a preset third voltage threshold, the submodule corresponding to the minimum DC voltage of the bypassed submodule is shut down, and the submodule corresponding to the maximum DC voltage of the shut-down submodule is bypassed.

[0051] When the actual voltage on the DC side rises to the preset second voltage threshold, if the DC voltage of the submodule is within the preset voltage range, the supercapacitor converter valve completes impact-free charging. Otherwise, the supercapacitor converter valve continues to be impact-free charged according to the preset duty cycle until the DC voltage of the submodule is within the preset voltage range.

[0052] Optionally, the preset second voltage threshold satisfies:

[0053] U dcset2 =(N-1)U scn

[0054] Among them, U dcset2 represents the preset second voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U scn Indicates the rated voltage of the submodule.

[0055] Exemplarily, the preset duty cycle satisfies:

[0056]

[0057] Wherein, D represents a preset duty cycle, and N represents the number of submodules in the supercapacitor converter valve.

[0058] Furthermore, the control module is also used for:

[0059] All submodules in the supercapacitor converter valve are turned off, and the actual voltage on the DC side is controlled to drop to the rated voltage on the DC side of the modular multilevel converter valve through the modular multilevel converter valve.

[0060] On the other hand, the present application also provides a computer device, including: one or more processors.

[0061] A processor is used to execute one or more programs.

[0062] When one or more programs are executed by one or more processors, the impact-free charging method described above is implemented.

[0063] In another aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the impact-free charging method described above is implemented.

[0064] Compared with the prior art, the beneficial effects of this application are:

[0065] In the impact-free charging method of supercapacitors in a grid-type static synchronous condenser provided in the present application, the actual voltage on the DC side of the modular multilevel converter valve is controlled according to the DC side reference voltage of the modular multilevel converter valve in the grid-type static synchronous condenser. The actual voltage on the DC side is controlled to increase to a preset first voltage threshold according to a preset first rising slope, and the supercapacitor converter valve in the grid-type static synchronous condenser is charged with uncontrolled rectification. The actual voltage on the DC side is controlled to increase to a preset second voltage threshold according to a preset second rising slope, and the supercapacitor converter valve is charged impact-free according to a preset duty cycle. It can be seen that the present application improves the charging efficiency of the supercapacitor converter valve by controlling the actual voltage on the DC side to charge the supercapacitor converter valve in different ways, thereby improving the starting efficiency of the grid-type static synchronous condenser.

[0066] In the present application, when the actual voltage on the DC side is 0, closing the DC switch between the modular multilevel converter valve and the supercapacitor converter valve will cause no voltage shock or current shock to the supercapacitor converter valve and the AC system connected to the modular multilevel converter valve, that is, it will not affect the normal operation of the AC system, and will not affect the subsequent uncontrolled rectification charging and impact-free charging of the supercapacitor converter valve.

[0067] In the present application, when the voltage difference between the maximum DC voltage of the shut-off submodule and the minimum DC voltage of the bypassed submodule is greater than a preset third voltage threshold, the submodule corresponding to the minimum DC voltage of the bypassed submodule is shut down, and the submodule corresponding to the maximum DC voltage of the shut-off submodule is bypassed, so that the DC voltage balance between the submodules can be controlled, and there is no impact on the AC system during the entire charging process of the supercapacitor converter valve, that is, impact-free charging of the supercapacitor converter valve is achieved.

[0068] In the present application, the supercapacitor converter valve of the grid-type static synchronous phase condenser does not need to be separately provided with a slow-start resistor, thereby avoiding the power loss of the slow-start resistor and further improving the starting efficiency of the grid-type static synchronous phase condenser. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0070] Figure 1 A schematic structural diagram of a networked static synchronous condenser in an embodiment of the present application;

[0071] Figure 2 A schematic structural diagram of a submodule in an embodiment of the present application;

[0072] Figure 3 Another schematic structural diagram of a submodule in an embodiment of the present application;

[0073] Figure 4 A schematic flow chart of a method for charging a supercapacitor without impact in an embodiment of the present application;

[0074] Figure 5 This is a schematic structural diagram of a non-impact charging device for a supercapacitor in an embodiment of the present application. DETAILED DESCRIPTION

[0075] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0076] The terms "first", "second", etc. in the specification embodiments, claims, and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product, or device is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0077] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0078] Embodiment 1:

[0079] The present application embodiment provides a non-impact charging method for supercapacitors in a networked static synchronous condenser. Figure 1 As shown, a grid-type static synchronous condenser (i.e., STATCOM) may include a modular multilevel converter valve 1 and a supercapacitor converter valve 2. The AC side of the modular multilevel converter valve 1 may be connected to the AC grid G ​​through an AC switch QFac, and the DC side of the modular multilevel converter valve 1 may be connected to the supercapacitor converter valve 2 through a DC switch QF1dc and a DC switch QF2dc. The supercapacitor converter valve 2 may include a plurality of submodules connected in series. The plurality of submodules connected in series include Figure 1 There are N sub-modules in total, including sub-module SC-SM1, sub-module SC-SM2,..., sub-module SC-SMN-1, and sub-module SC-SMN.

[0080] The modular multilevel converter valve 1 includes an A-phase bridge arm, a B-phase bridge arm and a C-phase bridge arm. Each phase bridge arm includes an upper bridge arm and a lower bridge arm, and the upper bridge arm and the lower bridge arm each include a plurality of submodules connected in series. For example, the A-phase bridge arm includes submodules SMa1 to SMa2N, the B-phase bridge arm includes submodules SMb1 to SMb2N, and the C-phase bridge arm includes submodules SMc1 to SMc2N. Figure 1 In the equation, L is the bridge arm reactance. dc Indicates the actual voltage on the DC side of the modular multilevel converter valve 1.

[0081] like Figure 2As shown, each submodule can be a half-bridge structure, including a power device T1, a power device T2 and a super capacitor SC. Both the power device T1 and the power device T2 can be an insulated gate bipolar transistor (IGBT), and the IGBT is anti-parallel with a diode. The first pole of the power device T1 is connected to the first pole of the super capacitor SC, the second pole of the power device T1 is connected to the first pole of the power device T2, as the first end of the submodule, and the second pole of the power device T2 is connected to the second pole of the super capacitor SC, as the second end of the submodule.

[0082] like Figure 3 As shown, each submodule can be a full-bridge structure, including a power device T1, a power device T2, a power device T3, a power device T4 and a super capacitor SC. The power device T1, the power device T2, the power device T3 and the power device T4 can all be an insulated-gate bipolar transistor (IGBT), and the IGBT has a diode in anti-parallel connection.

[0083] like Figure 4 As shown, the impact-free charging method 100 provided in the embodiment of the present application includes the following steps:

[0084] Step S1: Based on the DC side reference voltage of the modular multi-level converter valve 1 (which can be represented by U ref The actual voltage U on the DC side of the modular multi-level converter valve 1 is represented by dc .

[0085] Step S2: Control the actual DC side voltage U according to a preset first rising slope (which can be represented by k1). dc Increase to the preset first voltage threshold (U dcset1 Indicated), and the supercapacitor converter valve 2 is charged by uncontrolled rectification.

[0086] Step S3: Control the actual DC side voltage U according to the preset second rising slope (which can be represented by k2). dc Increase to the preset second voltage threshold (U dcset2 The supercapacitor converter valve 2 is charged without impact according to a preset duty cycle (which can be represented by D).

[0087] The preset second voltage threshold U dcset2 Greater than a preset first voltage threshold U dcset1 The first rising slope and the second rising slope may be the same or different, which is not limited in the embodiment of the present application.

[0088] In some embodiments, in step S1, the DC side reference voltage U of the modular multi-level converter valve 1 is ref Control the actual DC side voltage U of the modular multilevel converter valve dc ,include:

[0089] According to the DC side reference voltage U ref , the actual voltage U on the DC side dc Proportional integral control (PI control) is performed to make the actual DC side voltage U dc is 0.

[0090] In some other embodiments, in step S2, the actual DC side voltage U is controlled according to the preset first rising slope k1. dc Increases to the preset first voltage threshold U dcset1 , and uncontrolled rectification and charging of the supercapacitor converter valve 2, including:

[0091] All submodules in the supercapacitor converter valve 2 are turned off, and the DC switch QF1dc and the DC switch QF2dc between the modular multilevel converter valve 1 and the supercapacitor converter valve 2 are closed.

[0092] Control the actual DC side voltage U according to the preset first rising slope k1 dc Gradually increases, the super capacitor SC in the submodule is charged by uncontrolled rectification through the anti-parallel diode of the power device in the submodule.

[0093] The actual voltage U on the DC side dc Increases to the preset first voltage threshold U dcset1 In this case, all submodules are powered on for self-checking. If any submodule fails, all submodules stop uncontrolled rectification and charging and carry out maintenance.

[0094] Exemplarily, the preset first voltage threshold U dcset1 satisfy:

[0095] U dcset1 =N·U dc_start

[0096] Among them, U dcset1 represents the preset first voltage threshold, N represents the number of submodules in the supercapacitor converter valve 2, and U dc_start Indicates the starting voltage of the driver module used to send the driving signal to the submodule. The driver module usually uses DC power.

[0097] In some other embodiments, in step S3, the actual DC side voltage U is controlled according to the preset second rising slope k2. dc Increases to the preset second voltage threshold U dcset2, and charging the supercapacitor converter valve 2 without impact according to the preset duty cycle D, including:

[0098] Control the actual DC side voltage U according to the preset second rising slope k2 dc The voltage gradually increases, and the supercapacitor converter valve 1 is charged without impact according to the preset duty cycle D.

[0099] Collect all the shut-off submodules and all the bypassed submodules (which can be turned on Figure 3 The DC voltage of the power device T2 bypass submodule in the power device T2 bypass submodule) is selected, and the maximum DC voltage of the shutdown submodule is selected (which can be used to sc_max and the minimum DC voltage of the bypassed submodule (which can be represented by U sc_min express).

[0100] When the DC voltage maximum value U of the shutdown submodule sc_max (The corresponding submodule can be recorded as submodule SC-SM j ) and the minimum DC voltage U of the bypassed submodule sc_min (The corresponding submodule can be recorded as submodule SC-SM k ) (which can be expressed as ΔU sc If the DC voltage of the bypassed submodule is greater than a preset third voltage threshold (such as 20V), the DC voltage minimum value U of the bypassed submodule is turned off. sc_min The corresponding submodule (i.e. shut down submodule SC-SM k ), and bypass the maximum DC voltage U of the shutdown submodule sc_max The corresponding submodule (i.e. bypass submodule SC-SM j ).

[0101] The actual voltage U on the DC side dc Increases to the preset second voltage threshold U dcset2 In the case of a submodule, if the DC voltage is within the preset voltage range (which can be 0.95U scn ~1.05U scn , where U scn If the DC voltage of the submodule is within the preset voltage range, the supercapacitor converter valve 2 completes the impact-free charging. Otherwise, the supercapacitor converter valve 2 continues to be charged without impact according to the preset duty cycle D until the DC voltage of the submodule is within the preset voltage range.

[0102] Optionally, the preset second voltage threshold satisfies:

[0103] U dcset2 =(N-1)U scn

[0104] Among them, U dcset2represents the preset second voltage threshold, N represents the number of submodules in the supercapacitor converter valve 2, and U scn Indicates the rated voltage of the submodule.

[0105] Exemplarily, the preset duty cycle satisfies:

[0106]

[0107] Wherein, D represents a preset duty cycle, and N represents the number of submodules in the supercapacitor converter valve.

[0108] Furthermore, the impact-free charging method 100 provided in the embodiment of the present application further includes:

[0109] All submodules in the supercapacitor converter valve 2 are turned off, and the actual DC side voltage U is controlled by the modular multilevel converter valve 1. dc Drop to the rated voltage of the DC side of the modular multilevel converter valve 1.

[0110] In summary, the charging method provided in the embodiment of the present application does not involve the addition or change of hardware and has strong engineering practicality.

[0111] Embodiment 2:

[0112] Based on the same inventive concept, the embodiment of the present application also provides a non-impact charging device for supercapacitors in a network-building static synchronous condenser. The relevant introduction of the network-building static synchronous condenser can be referred to above and the relevant drawings, and the embodiment of the present application will not be repeated.

[0113] like Figure 5 As shown, the charging device 200 includes:

[0114] The control module 21 is used to control the DC side reference voltage U of the modular multi-level converter valve 1 according to the DC side reference voltage U ref Control the actual DC side voltage U of the modular multilevel converter valve 1 dc .

[0115] The first charging module 22 is used to control the actual DC side voltage U according to a preset first rising slope k1. dc Increases to the preset first voltage threshold U dcset1 , and perform uncontrolled rectification and charging on the supercapacitor converter valve 2.

[0116] The second charging module 23 is used to control the actual DC side voltage U according to the preset second rising slope k2 dc Increases to the preset second voltage threshold U dcset2 , and the supercapacitor converter valve 2 is charged without impact according to the preset duty cycle D.

[0117] The preset second voltage threshold Udcset2 Greater than a preset first voltage threshold U dcset1 The first rising slope and the second rising slope may be the same or different, which is not limited in the embodiment of the present application.

[0118] In some embodiments, the control module 21 is specifically used to:

[0119] According to the DC side reference voltage U ref , the actual voltage U on the DC side dc Proportional integral control is performed to make the actual DC side voltage U dc is 0.

[0120] In some other embodiments, the first charging module 22 is specifically used for:

[0121] All submodules in the supercapacitor converter valve 2 are turned off, and the DC switch QF1dc and the DC switch QF2dc between the modular multilevel converter valve 1 and the supercapacitor converter valve 2 are closed.

[0122] Control the actual DC side voltage U according to the preset first rising slope k1 dc Gradually increases, the super capacitor SC in the submodule is charged by uncontrolled rectification through the anti-parallel diode of the power device in the submodule.

[0123] The actual voltage U on the DC side dc Increases to the preset first voltage threshold U dcset1 In this case, all submodules are powered on for self-checking. If any submodule fails, all submodules stop uncontrolled rectification and charging and carry out maintenance.

[0124] Exemplarily, the preset first voltage threshold U dcset1 satisfy:

[0125] U dcset1 =N·U dc_start

[0126] Among them, U dcset1 represents the preset first voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U dc_start Indicates the starting voltage of the driver module used to send a driving signal to the submodule.

[0127] In some further embodiments, the second charging module 23 is specifically used for:

[0128] Control the actual DC side voltage U according to the preset second rising slope k2 dc The voltage gradually increases, and the supercapacitor converter valve 1 is charged without impact according to the preset duty cycle D.

[0129] Collect all the shut-off submodules and all the bypassed submodules (which can be turned on Figure 3 The DC voltage of the power device T2 bypass submodule in the power device T2 bypass submodule) is selected, and the maximum DC voltage of the shutdown submodule is selected (which can be used to sc_max and the minimum DC voltage of the bypassed submodule (which can be represented by U sc_min express).

[0130] When the DC voltage maximum value U of the shutdown submodule sc_max (The corresponding submodule can be recorded as submodule SC-SM j ) and the minimum DC voltage U of the bypassed submodule sc_min (The corresponding submodule can be recorded as submodule SC-SM k ) (which can be expressed as ΔU sc If the DC voltage of the bypassed submodule is greater than a preset third voltage threshold (such as 20V), the DC voltage minimum value U of the bypassed submodule is turned off. sc_min The corresponding submodule (i.e. shut down submodule SC-SM k ), and bypass the maximum DC voltage U of the shutdown submodule sc_max The corresponding submodule (i.e. bypass submodule SC-SM j ).

[0131] The actual voltage U on the DC side dc Increases to the preset second voltage threshold U dcset2 In the case of a submodule, if the DC voltage is within the preset voltage range (which can be 0.95U scn ~1.05U scn , where U scn If the DC voltage of the submodule is within the preset voltage range, the supercapacitor converter valve 2 completes the impact-free charging. Otherwise, the supercapacitor converter valve 2 continues to be charged without impact according to the preset duty cycle D until the DC voltage of the submodule is within the preset voltage range.

[0132] Optionally, the preset second voltage threshold satisfies:

[0133] U dcset2 =(N-1)U scn

[0134] Among them, U dcset2 represents the preset second voltage threshold, N represents the number of submodules in the supercapacitor converter valve 2, and U scn Indicates the rated voltage of the submodule.

[0135] Exemplarily, the preset duty cycle satisfies:

[0136]

[0137] Wherein, D represents a preset duty cycle, and N represents the number of submodules in the supercapacitor converter valve.

[0138] Furthermore, the control module 21 is also used for:

[0139] All submodules in the supercapacitor converter valve 2 are turned off, and the actual DC side voltage U is controlled by the modular multilevel converter valve 1. dc Drop to the rated voltage of the DC side of the modular multilevel converter valve 1.

[0140] Embodiment 3:

[0141] Based on the same inventive concept, an embodiment of the present application also provides a computer device, which includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in a computer storage medium to implement the corresponding method flow or corresponding functions, so as to implement the steps of the impact-free charging method provided in the above embodiment.

[0142] Embodiment 4:

[0143] Based on the same inventive concept, the embodiment of the present application also provides a computer-readable storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of the impact-free charging method provided in the above embodiment.

[0144] Those skilled in the art will appreciate that the embodiments of the application may be provided as methods, systems, or computer program products. Therefore, the application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0145] The application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0146] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0147] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0148] The above are merely embodiments of the application and are not intended to limit the application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the application are included in the scope of the claims of the pending application.

Claims

1. A non-impact charging method for supercapacitors in a network-building static synchronous condenser, characterized in that: include: Controlling the actual DC side voltage of the modular multilevel converter valve in the grid-type static synchronous condenser according to the DC side reference voltage of the modular multilevel converter valve; Controlling the actual voltage on the DC side to increase to a preset first voltage threshold according to a preset first rising slope, and performing uncontrolled rectification and charging on the supercapacitor converter valve in the grid-type static synchronous phase regulator; Controlling the actual voltage on the DC side to increase to a preset second voltage threshold according to a preset second rising slope, and performing impact-free charging on the supercapacitor converter valve according to a preset duty cycle; Wherein, the preset second voltage threshold is greater than the preset first voltage threshold.

2. The impact-free charging method according to claim 1, characterized in that: The controlling of the actual DC side voltage of the modular multilevel converter valve according to the DC side reference voltage of the modular multilevel converter valve in the grid-type static synchronous condenser comprises: According to the DC side reference voltage, proportional-integral control is performed on the DC side actual voltage so that the DC side actual voltage is 0.

3. The impact-free charging method according to claim 1, characterized in that: The method of controlling the actual voltage on the DC side to increase to a preset first voltage threshold according to a preset first rising slope, and performing uncontrolled rectification and charging on the supercapacitor converter valve in the grid-type static synchronous phase regulator, comprises: Turning off all submodules in the supercapacitor converter valve, and closing the DC switch between the modular multi-level converter valve and the supercapacitor converter valve; The actual voltage on the DC side is controlled to gradually increase according to the preset first rising slope, and the supercapacitor in the submodule is charged by uncontrolled rectification through the anti-parallel diode of the power device in the submodule; When the actual voltage on the DC side rises to the preset first voltage threshold, all submodules are powered on for self-inspection. If any submodule fails, all submodules stop uncontrolled rectification and charging, and are repaired.

4. The impact-free charging method according to claim 1, characterized in that: The preset first voltage threshold satisfies: U dcset1 =N·U dc_start Among them, U dcset1 represents the preset first voltage threshold, N represents the number of submodules in the supercapacitor converter valve, U dc_start Indicates the starting voltage of the driving module used to send a driving signal to the submodule.

5. The impact-free charging method according to claim 1, characterized in that: The step of controlling the actual DC side voltage to increase to a preset second voltage threshold according to a preset second rising slope, and performing impact-free charging on the supercapacitor converter valve according to a preset duty cycle, comprises: Controlling the actual voltage on the DC side to gradually increase according to the preset second rising slope, and performing impact-free charging on the supercapacitor converter valve according to the preset duty cycle; Collecting the DC voltages of all shutdown submodules and all bypassed submodules, and selecting the maximum DC voltage of the shutdown submodule and the minimum DC voltage of the bypassed submodule; When the voltage difference between the maximum DC voltage of the shut-down submodule and the minimum DC voltage of the bypassed submodule is greater than a preset third voltage threshold, the submodule corresponding to the minimum DC voltage of the bypassed submodule is shut down, and the submodule corresponding to the maximum DC voltage of the shut-down submodule is bypassed; When the actual voltage on the DC side rises to the preset second voltage threshold, if the DC voltage of the submodule is within the preset voltage range, the supercapacitor converter valve completes impact-free charging; otherwise, the supercapacitor converter valve continues to be impact-free charged according to the preset duty cycle until the DC voltage of the submodule is within the preset voltage range.

6. The impact-free charging method according to claim 1, characterized in that: The preset second voltage threshold satisfies: U dcset2 =(N-1)U scn Among them, U dcset2 represents the preset second voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U scn Indicates the rated voltage of the submodule.

7. The impact-free charging method according to claim 1, characterized in that: The preset duty cycle satisfies: Wherein, D represents the preset duty cycle, and N represents the number of submodules in the supercapacitor converter valve.

8. The impact-free charging method according to claim 1, characterized in that: The impact-free charging method further comprises: All submodules in the supercapacitor converter valve are turned off, and the actual voltage on the DC side is controlled to drop to the rated voltage on the DC side of the modular multilevel converter valve through the modular multilevel converter valve.

9. A non-impact charging device for supercapacitors in a network-building static synchronous condenser, characterized in that: include: A control module, used for controlling the actual DC side voltage of the modular multilevel converter valve in the grid-type static synchronous condenser according to the DC side reference voltage of the modular multilevel converter valve; A first charging module, used for controlling the actual voltage on the DC side to increase to a preset first voltage threshold according to a preset first rising slope, and performing uncontrolled rectification charging on the supercapacitor converter valve in the grid-type static synchronous phase regulator; A second charging module, used for controlling the actual voltage of the DC side to increase to a preset second voltage threshold according to a preset second rising slope, and performing impact-free charging on the supercapacitor converter valve according to a preset duty cycle; Wherein, the preset second voltage threshold is greater than the preset first voltage threshold.

10. The impact-free charging device according to claim 9, characterized in that: The control module is specifically used for: According to the DC side reference voltage, proportional-integral control is performed on the DC side actual voltage so that the DC side actual voltage is 0.

11. The impact-free charging device according to claim 9, characterized in that: The first charging module is specifically used for: Turning off all submodules in the supercapacitor converter valve, and closing the DC switch between the modular multi-level converter valve and the supercapacitor converter valve; The actual voltage on the DC side is controlled to gradually increase according to the preset first rising slope, and the supercapacitor in the submodule is charged by uncontrolled rectification through the anti-parallel diode of the power device in the submodule; When the actual voltage on the DC side rises to the preset first voltage threshold, all submodules are powered on for self-inspection. If any submodule fails, all submodules stop uncontrolled rectification and charging, and are repaired.

12. The impact-free charging device according to claim 9, characterized in that: The preset first voltage threshold satisfies: U dcset1 =N·U dc_start Among them, U dcset1 represents the preset first voltage threshold, N represents the number of submodules in the supercapacitor converter valve, U dc_start Indicates the starting voltage of the driving module used to send a driving signal to the submodule.

13. The impact-free charging device according to claim 9, characterized in that: The second charging module is specifically used for: Controlling the actual voltage on the DC side to gradually increase according to the preset second rising slope, and performing impact-free charging on the supercapacitor converter valve according to the preset duty cycle; Collecting the DC voltages of all shutdown submodules and all bypassed submodules, and selecting the maximum DC voltage of the shutdown submodule and the minimum DC voltage of the bypassed submodule; When the voltage difference between the maximum DC voltage of the shut-down submodule and the minimum DC voltage of the bypassed submodule is greater than a preset third voltage threshold, the submodule corresponding to the minimum DC voltage of the bypassed submodule is shut down, and the submodule corresponding to the maximum DC voltage of the shut-down submodule is bypassed; When the actual voltage on the DC side rises to the preset second voltage threshold, if the DC voltage of the submodule is within the preset voltage range, the supercapacitor converter valve completes impact-free charging; otherwise, the supercapacitor converter valve continues to be impact-free charged according to the preset duty cycle until the DC voltage of the submodule is within the preset voltage range.

14. The impact-free charging device according to claim 9, characterized in that: The preset second voltage threshold satisfies: U dcset2 =(N-1)U scn Among them, U dcset2 represents the preset second voltage threshold, N represents the number of submodules in the supercapacitor converter valve, and U scn Indicates the rated voltage of the submodule.

15. The impact-free charging device according to claim 9, characterized in that: The preset duty cycle satisfies: Wherein, D represents the preset duty cycle, and N represents the number of submodules in the supercapacitor converter valve.

16. The impact-free charging device according to claim 9, characterized in that: The control module is also used for: All submodules in the supercapacitor converter valve are turned off, and the actual voltage on the DC side is controlled to drop to the rated voltage on the DC side of the modular multilevel converter valve through the modular multilevel converter valve.

17. A computer device, characterized in that: include: one or more processors; The processor is used to store one or more programs; When the one or more programs are executed by the one or more processors, the impact-free charging method according to any one of claims 1 to 8 is implemented.

18. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, the impact-free charging method according to any one of claims 1 to 8 is implemented.

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