Variable-frequency power supply with multiple parallel power modules

Abstract

The utility model provides a variable-frequency power supply with multiple parallel power modules, which belongs to the technical field of electronics and electrics and comprises a rectifying loop, a first alternating-current quick fuse module, a second alternating-current quick fuse module and a third alternating-current quick fuse module, the three-phase input ends of the AC / DC power modules are controllably connected to the first AC fast fuse module through the first filtering module, and the two-phase output ends of the AC / DC power modules are connected with the DC output end; the inversion loop comprises a plurality of DC / AC power modules, two-phase input ends of the DC / AC power modules are respectively connected with a DC output end, three-phase output ends of the DC / AC power modules are respectively connected with a second filtering module, and the second filtering module is connected with a three-phase voltage output end through a second AC fast fuse module; and the third filtering module is connected with the three-phase voltage output end. The beneficial effects are that the AC / DC power modules and the DC / AC power modules are used in parallel, so that the output rated current and rated capacity of the variable-frequency power supply are improved, and the requirements of high-capacity shore-based power supply facilities such as wharfs and ports can be met.

Description

Technical Field

[0001] This utility model relates to the field of electronic and electrical technology, and in particular to a frequency converter power supply with multiple parallel power modules. Background Technology

[0002] If ships continue to rely on their onboard diesel generators for power while berthed, they will generate large amounts of pollutants such as sulfur oxides, nitrogen oxides, and particulate matter, causing serious harm to the environment. Therefore, the "Decision of the Ministry of Transport on Amending the 'Administrative Measures for Shore Power to Ports and Ships'" explicitly requires local transportation (port) authorities at all levels to actively seek policies from local governments to support the upgrading of shore power facilities at wharves and the installation of power receiving facilities on ships, and to encourage ships to prioritize the use of shore power while berthed.

[0003] Currently, the capacity of mainstream low-voltage shore power inverters on the market is generally below 2MW, which is sufficient for small and medium-sized ports. However, with the increase in port throughput, the use of shore power is gradually increasing, and the capacity requirements are also gradually increasing. Especially for large coastal ports, the demand for shore power is often above 8MVA, or even higher. Existing single-module low-voltage shore power inverters are difficult to meet the large capacity requirements. Utility Model Content

[0004] To solve the above technical problems, this utility model provides a frequency converter power supply with multiple parallel power modules.

[0005] The technical problem solved by this utility model can be achieved by the following technical solution:

[0006] A frequency converter power supply with multiple parallel power modules, comprising:

[0007] A rectifier circuit, comprising:

[0008] The first AC fast fuse module, one end of which is connected to the three-phase voltage input terminal;

[0009] Multiple AC / DC power modules, each AC / DC power module has its three-phase input terminals connected to one end of a first filter module, the other end of the first filter module being controllably connected to a first AC fast fuse module, and each AC / DC power module has its two-phase output terminals connected to a DC output terminal;

[0010] Inverter circuit, the inverter circuit comprising:

[0011] Multiple DC / AC power modules are provided, with the two-phase input terminals of each DC / AC power module connected to the DC output terminal, and the three-phase output terminals of each DC / AC power module connected to one end of a second filter module. The other end of the second filter module is connected to the three-phase voltage output terminal through a second AC fast fuse module.

[0012] The third filtering module is connected to the three-phase voltage output terminal.

[0013] Preferably, a grid-side surge protection module is connected between the three-phase voltage input terminal and the grounding terminal, and the grid-side surge protection module includes:

[0014] Three first fuses, one end of each of the three first fuses being connected to one of the three-phase voltage input terminals;

[0015] The grid-side surge protector has its three-phase input terminals connected one-to-one with the other ends of the three first fuses, its three-phase output terminals connected to the grounding terminal, and the other ends of the three first fuses connected to the grounding terminal.

[0016] Preferably, the first AC fast fuse module includes:

[0017] Three second fuses, one end of each of the three second fuses being connected to one of the three-phase voltage input terminals respectively;

[0018] The main circuit contactor has one of its three-phase terminals connected to the other terminals of the three second fuses, and the other three-phase terminal is connected to all the first filter modules.

[0019] Preferably, the plurality of AC / DC power modules includes five; and / or

[0020] The plurality of DC / AC power modules includes five modules.

[0021] Preferably, the first filtering module includes multiple modules, each of which is connected to one of the AC / DC power modules. Each first filtering module includes:

[0022] The first filter reactor, the three-phase output terminals of the first filter reactor are respectively connected to the three-phase input terminals of the corresponding AC / DC power module;

[0023] A first filter capacitor, the first filter capacitor comprising:

[0024] The first sub-filter capacitor is connected between the first phase and the second phase of the first filter reactance;

[0025] The second sub-filter capacitor is connected between the second and third phases of the first filter reactance;

[0026] The third sub-filter capacitor is connected between the first phase and the third phase of the first filter reactance.

[0027] Preferably, a pre-charge module is connected between the first AC fast fuse module and the DC output terminal, the pre-charge module comprising:

[0028] A pre-charge branch contactor is connected between the first AC fast-fuse module and the pre-charge resistor, wherein the pre-charge resistor comprises:

[0029] The first resistor is connected between the first phase of the pre-charge branch contactor and the first phase of the uncontrolled rectifier.

[0030] The second resistor is connected between the second phase of the pre-charge branch contactor and the second phase of the uncontrolled rectifier;

[0031] The third resistor is connected between the third phase of the pre-charge branch contactor and the third phase of the uncontrolled rectifier, and the two-phase output terminals of the uncontrolled rectifier are connected to the DC output terminal.

[0032] Preferably, the second filtering module includes multiple modules, each of which is connected to a DC / AC power module in a one-to-one correspondence. Each second filtering module includes:

[0033] The second filter reactor, the three-phase output terminals of the second filter reactor are respectively connected to the three-phase output terminals of the corresponding DC / AC power modules;

[0034] The second filter capacitor includes:

[0035] The fourth sub-filter capacitor is connected between the first and second phases of the second filter reactance;

[0036] The fifth sub-filter capacitor is connected between the second and third phases of the second filter reactance;

[0037] The sixth sub-filter capacitor is connected between the first and third phases of the second filter reactance.

[0038] Preferably, the second AC fast fuse module includes:

[0039] Three third fuses, one end of which is connected to all the second filter modules, and the other end of which is connected to the three-phase voltage output terminals respectively.

[0040] Preferably, the third filtering module includes three filtering branches, one end of each of the three filtering branches is connected to one-to-one with the three phases of the three-phase voltage output terminal, and the other end is connected together.

[0041] Each filter branch is formed by connecting the third filter reactance, the third filter capacitor, and the filter resistor in series.

[0042] Preferably, it further includes a frequency converter power supply cabinet, the frequency converter power supply cabinet comprising:

[0043] A control cabinet, wherein the control cabinet is provided with an incoming copper busbar and the first AC fast fuse module, and the incoming copper busbar is connected to the three-phase voltage input terminal;

[0044] The rectifier cabinet includes three rectifier cabinets, each of which is equipped with the AC / DC power module, the filter reactance of the first filter module, and a first connecting copper busbar. The first connecting copper busbar connects the input copper busbar and the rectifier circuit.

[0045] The inverter cabinet includes three inverter cabinets, each of which is equipped with the DC / AC power module, the filter reactance of the second filter module, and the second connecting copper busbar. The second connecting copper busbar connects the first connecting copper busbar and the inverter circuit.

[0046] The outgoing line cabinet is equipped with the filter capacitors of the rectifier circuit and the inverter circuit, the second AC fast fuse module, and the third connecting copper busbar. The third connecting copper busbar is connected to the second connecting copper busbar and the three-phase voltage output terminal.

[0047] The advantages or beneficial effects of this utility model's technical solution are as follows:

[0048] This invention uses multiple AC / DC power modules and DC / AC power modules in parallel to rectify AC power from the power grid into DC power and invert DC power into constant voltage and constant frequency AC power to provide power to other equipment. This improves the rated output current and rated capacity of the frequency converter, and can meet the needs of large-capacity shore-based power supply facilities such as docks and ports. Attached Figure Description

[0049] Figure 1 This is a structural block diagram of a frequency converter power supply with multiple parallel power modules in a preferred embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram of the rectifier topology of the frequency converter power supply with multiple parallel power modules in a preferred embodiment of the present invention.

[0051] Figure 3 This is a schematic diagram of the inverter topology of the frequency converter power supply with multiple parallel power modules in a preferred embodiment of the present invention.

[0052] Figure 4 This is a schematic diagram of the rectifier structure layout of the frequency converter power supply with multiple parallel power modules in a preferred embodiment of the present invention.

[0053] Figure 5 This is a schematic diagram of the inverter structure layout of a frequency converter power supply with multiple parallel power modules in a preferred embodiment of the present invention. Detailed Implementation

[0054] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0055] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0056] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0057] See Figure 1 , Figure 2 and Figure 3 In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a frequency converter power supply with multiple parallel power modules is provided, comprising:

[0058] Rectifier circuit 100 is connected between three-phase voltage input terminal 1 and DC output terminals (DC+, DC-). Rectifier circuit 100 includes:

[0059] First AC fast fuse module 2, one end of the first AC fast fuse module 2 is connected to the three-phase voltage input terminal 1;

[0060] Multiple AC / DC power modules 4, each AC / DC power module 4 has its three-phase input terminals connected to one end of the first filter module 3, and the other end of the first filter module 3 is controllably connected to the first AC fast fuse module 2. Each AC / DC power module 4 has its two-phase output terminals connected to the DC output terminals (DC+, DC-).

[0061] Inverter circuit 200 is connected between the DC output terminal (DC+, DC-) and the three-phase voltage output terminal 11. Inverter circuit 200 includes:

[0062] Multiple DC / AC power modules 7, with two-phase input terminals of each DC / AC power module 7 connected to the DC output terminal respectively, and three-phase output terminals of each DC / AC power module 7 connected to one end of the second filter module 8 respectively, and the other end of the second filter module 8 connected to the three-phase voltage output terminal 11 through the second AC fast fuse module 9;

[0063] The third filter module 10 is connected to the three-phase voltage output terminal 11.

[0064] Specifically, in response to the problem that existing single-module low-voltage shore power frequency converters cannot meet the large capacity requirements, in this embodiment, the frequency converter is divided into two parts: a rectifier circuit 100 and an inverter circuit 200. The rectifier circuit 100 is used to rectify the AC power from the grid side into DC power. The inverter circuit 200 is connected to the rectifier circuit 100 and inverts the DC power into constant voltage and constant frequency AC power to provide power to other equipment.

[0065] This frequency converter uses multiple power modules connected in parallel, with five power modules connected in parallel for both rectification and inversion. This improves the rated output current and rated capacity of the frequency converter, meeting the needs of large-capacity shore-based power supply facilities such as docks and ports.

[0066] In a preferred embodiment, a grid-side surge protection module 5 is connected between the three-phase voltage input terminal 1 and the grounding terminal. The grid-side surge protection module 5 includes:

[0067] Three first fuses, one end of each of the three first fuses is connected to the three-phase voltage input terminal 1 in a one-to-one correspondence;

[0068] The grid-side surge protector E1 has its three-phase input terminals connected one-to-one with the other ends of the three first fuses. The three-phase output terminals of the grid-side surge protector E1 are connected to the grounding terminal, and the other ends of the three first fuses are connected to the grounding terminal.

[0069] Furthermore, such as Figure 2 As shown, the three first fuses are implemented using a first sub-fuse FU1, a second sub-fuse FU2, and a third sub-fuse FU3. The first sub-fuse FU1 is connected between phase A of the three-phase voltage input terminal and the grid-side surge protector E1. The second sub-fuse FU2 is connected between phase B of the three-phase voltage input terminal and the grid-side surge protector E1. The third sub-fuse FU3 is connected between phase C of the three-phase voltage input terminal and the grid-side surge protector E1.

[0070] The grid-side surge protector E1 is a three-phase surge protector with protective grounding, thus protecting the equipment.

[0071] In a preferred embodiment, the first AC fast-melting module 2 includes:

[0072] Three second fuses, one end of each of the three second fuses is connected to a corresponding three-phase voltage input terminal;

[0073] The main circuit contactor QF1 has three-phase terminals on one side connected to the other ends of the three second fuses, and three-phase terminals on the other side connected to all three phases of the first filter module.

[0074] Furthermore, the three second fuses are implemented using a fourth sub-fuse FU4, a fifth sub-fuse FU5, and a sixth sub-fuse FU6. The fourth sub-fuse FU4 is connected between phase A of the three-phase voltage input terminal and terminal 2 of the main circuit contactor QF1. The fifth sub-fuse FU5 is connected between phase B of the three-phase voltage input terminal and terminal 4 of the main circuit contactor QF1. The sixth sub-fuse FU6 is connected between phase C of the three-phase voltage input terminal and terminal 6 of the main circuit contactor QF1.

[0075] The equipment is protected by connecting the fourth to sixth sub-fuse FU4 to FU6 in series in the main circuit.

[0076] In a preferred embodiment, such as Figure 2 As shown, there are multiple AC / DC power modules, including 5.

[0077] Specifically, the rectifier uses five power modules connected in parallel, including the first AC / DC power module UI1.1, the second AC / DC power module UI1.2, the third AC / DC power module UI1.3, the fourth AC / DC power module UI1.4, and the fifth AC / DC power module UI1.5.

[0078] In a preferred embodiment, the first filtering module 3 includes multiple modules, and each of the multiple first filtering modules 3 is connected to an AC / DC power module in a corresponding manner.

[0079] Each first filtering module 3 includes:

[0080] The first filter reactor, the three-phase output terminals of the first filter reactor are respectively connected to the three-phase input terminals of the corresponding AC / DC power modules;

[0081] The first filter capacitor includes:

[0082] The first sub-filter capacitor is connected between the first phase and the second phase of the first filter reactance;

[0083] The second sub-filter capacitor is connected between the second and third phases of the first filter reactance;

[0084] The third sub-filter capacitor is connected between the first phase and the third phase of the first filter reactance.

[0085] Specifically, the first filter module 3 also includes 5 modules, and the 5 first filter modules 3 are connected one-to-one with the first to fifth AC / DC power modules mentioned above.

[0086] The five first filter modules 3 have the same structure. Taking the first filter module connected to the first AC / DC power module UI1.1 as an example, it includes the first filter reactance L1.1 and the first filter capacitor C1.1. The first filter capacitor C1.1 consists of three filter sub-capacitors connected in a delta configuration.

[0087] The capacitance value of the first filter capacitor C1.1 is preferably 55.7uF.

[0088] In a preferred embodiment, a pre-charge module 6 is connected between the first AC fast fuse module 2 and the DC output terminal. The pre-charge module 6 includes:

[0089] The pre-charge branch contactor KM1 is connected between the first AC fast fuse module 2 and the pre-charge resistor, which includes:

[0090] The first resistor R1 is connected between the first phase of the pre-charge branch contactor KM1 and the first phase of the uncontrolled rectifier MDS.

[0091] The second resistor R2 is connected between the second phase of the pre-charge branch contactor KM1 and the second phase of the uncontrolled rectifier MDS.

[0092] The third resistor R3 is connected between the third phase of the pre-charge branch contactor KM1 and the third phase of the uncontrolled rectifier MDS. The two-phase output terminals of the uncontrolled rectifier are connected to the DC output terminals.

[0093] Specifically, the pre-charging branch contactor KM1 consists of three on / off switches and has six connection terminals. The second terminal of the pre-charging branch contactor KM1 is connected to the second terminal of the main circuit contactor QF1, the fourth terminal of the pre-charging branch contactor KM1 is connected to the fourth terminal of the main circuit contactor QF1, and the sixth terminal of the pre-charging branch contactor KM1 is connected to the sixth terminal of the main circuit contactor QF1.

[0094] Furthermore, the pre-charge module 6 also includes three fuses: a first pre-charge fuse F1, a second pre-charge fuse F2, and a third pre-charge fuse F3. The first pre-charge fuse F1 is connected between the first terminal of the pre-charge branch contactor KM1 and one end of the first resistor R1. The second pre-charge fuse F2 is connected between the third terminal of the pre-charge branch contactor KM1 and one end of the second resistor R2. The third pre-charge fuse F3 is connected between the fifth terminal of the pre-charge branch contactor KM1 and one end of the third resistor R3.

[0095] Furthermore, the uncontrolled rectifier MDS consists of six diodes: diode D1, diode D2, diode D3, diode D4, diode D5, and diode D6. The anode of diode D1 and the cathode of diode D4 are connected together, forming the first phase of the uncontrolled rectifier and connecting to the other end of resistor R1. The anode of diode D2 and the cathode of diode D5 are connected together, forming the second phase of the uncontrolled rectifier and connecting to the other end of resistor R2. The anode of diode D3 and the cathode of diode D6 are connected together, forming the third phase of the uncontrolled rectifier and connecting to the other end of resistor R3. The cathodes of diodes D1, D2, and D3 are connected together and connected to the DC+ terminal of the DC output. The anodes of diodes D4, D5, and D6 are connected together and connected to the DC- terminal of the DC output.

[0096] The pre-charging state is controlled by the on / off state of the pre-charging branch contactor KM1.

[0097] Furthermore, the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R2 are preferably 60Ω and 500W.

[0098] In a preferred embodiment, such as Figure 3 As shown, there are five DC / AC power modules.

[0099] Specifically, the inverter also uses five power modules connected in parallel, including the first DC / AC power module UI2.1, the second DC / AC power module UI2.2, the third DC / AC power module UI2.3, the fourth DC / AC power module UI2.4, and the fifth DC / AC power module UI2.5.

[0100] In a preferred embodiment, the second filter module 8 includes multiple modules, and each of the multiple second filter modules 8 is connected to a DC / AC power module in a corresponding manner.

[0101] Each second filter module 8 includes:

[0102] The second filter reactor is connected to the three-phase output terminals of the corresponding DC / AC power modules respectively.

[0103] The second filter capacitor includes:

[0104] The fourth sub-filter capacitor is connected between the first and second phases of the second filter reactance;

[0105] The fifth sub-filter capacitor is connected between the second and third phases of the second filter reactance;

[0106] The sixth sub-filter capacitor is connected between the first and third phases of the second filter reactance.

[0107] Specifically, the second filter module 8 also includes 5 modules, and the 5 second filter modules 8 are connected one-to-one with the first to fifth DC / AC power modules mentioned above.

[0108] The five second filter modules 8 have the same structure. Taking the second filter module connected to the first DC / AC power module UI2.1 as an example, it includes a second filter reactance L2.1 and a second filter capacitor C2.1. The second filter capacitor C2.1 consists of three filter sub-capacitors connected in a delta configuration.

[0109] The capacitance value of the second filter capacitor C2.1 is preferably 55.7uF.

[0110] In a preferred embodiment, the second AC fast-melting module 9 includes:

[0111] Three third fuses, one end of each third fuse is connected to all the second filter modules 8, and the other end of each third fuse is connected to the three-phase voltage output terminals respectively.

[0112] Furthermore, the three third fuses are implemented using the seventh sub-fuse FU7, the eighth sub-fuse FU8, and the ninth sub-fuse FU9. The seventh sub-fuse FU7 is connected between the second filter module and phase A of the three-phase voltage output terminal, the eighth sub-fuse FU8 is connected between the second filter module and phase B of the three-phase voltage output terminal, and the ninth sub-fuse FU9 is connected between the second filter module and phase C of the three-phase voltage output terminal.

[0113] The equipment is protected by connecting the seventh to ninth sub-fuse FU7 to FU9 in series in the main circuit.

[0114] In a preferred embodiment, the third filtering module 10 includes three filtering branches, one end of which is connected to each of the three phases of the three-phase voltage output terminal 11, and the other end is connected together.

[0115] Each filter branch is formed by connecting the third filter reactance, the third filter capacitor, and the filter resistor in series.

[0116] Specifically, the third filter module 10 includes a first sub-filter reactor L3, a second sub-filter reactor L4, a third sub-filter reactor L5, a seventh sub-filter capacitor C3, an eighth sub-filter capacitor C4, a ninth sub-filter capacitor C5, a first sub-filter resistor R4, a second sub-filter resistor R5, and a third sub-filter resistor R6; wherein, one end of the first sub-filter reactor L3 is connected to phase A of the three-phase voltage output terminal 11, and the other end of the first sub-filter reactor L3 is connected in series with one end of the seventh sub-filter capacitor C3 and one end of the first sub-filter resistor R4; One end of the second sub-filter reactor L4 is connected to phase B of the three-phase voltage output terminal 11. The other end of the second sub-filter reactor L4 is connected in series with one end of the eighth sub-filter capacitor C4 and the second sub-filter resistor R5. One end of the third sub-filter reactor L5 is connected to phase C of the three-phase voltage output terminal 11. The other end of the third sub-filter reactor L5 is connected in series with one end of the ninth sub-filter capacitor C5 and the third sub-filter resistor R6. The other end of the second sub-filter resistor R5, the first sub-filter resistor R4, and the third sub-filter resistor R6 are connected together.

[0117] Furthermore, the resistance values ​​of the first sub-filter resistor R4, the second sub-filter resistor R5, and the third sub-filter resistor R6 are preferably two 300W / 0.2Ω resistors connected in parallel.

[0118] In a preferred embodiment, such as Figure 4 and Figure 5 As shown, it also includes a frequency converter power supply cabinet 300, which includes:

[0119] Control cabinet 301 is equipped with an incoming copper busbar and a first AC fast fuse module. The incoming copper busbar is connected to the three-phase voltage input terminal.

[0120] The rectifier cabinet 302 includes three cabinets: the first rectifier cabinet 3021, the second rectifier cabinet 3022, and the third rectifier cabinet 3023. Each of the three rectifier cabinets is equipped with an AC / DC power module, a filter reactor of the first filter module, and a first connecting copper busbar. The first connecting copper busbar connects the incoming copper busbar and the rectifier circuit.

[0121] Inverter cabinet 303 includes three units: first inverter cabinet 3031, second inverter cabinet 3032, and third inverter cabinet 3033. Each inverter cabinet is equipped with a DC / AC power module, a filter reactor of a second filter module, and a second connecting copper busbar. The second connecting copper busbar connects to the first connecting copper busbar and the inverter circuit.

[0122] Outgoing line cabinet 304 contains filter capacitors in the rectifier circuit and inverter circuit, a second AC fast fuse module 9, and a third connecting copper busbar. The third connecting copper busbar connects to the second connecting copper busbar and the three-phase voltage output terminal.

[0123] Specifically, the shore power frequency converter cabinet in this embodiment consists of four cabinets: control cabinet 301, rectifier cabinet 302, inverter cabinet 303, and outgoing line cabinet 304.

[0124] like Figure 4 As shown, the control cabinet 301 mainly consists of a switch 305, a main control board 306, circuit breakers 307 (including QF1 and KM1), fuses 308 (including FU1~FU6, F1~F3) and incoming copper busbars (not shown in the figure), and also contains a small number of primary and secondary circuit components.

[0125] The rectifier cabinet 302 mainly consists of AC / DC power modules UI1.1 to UI1.5, filter reactors L1.1 to 1.5, and connecting copper busbars.

[0126] like Figure 5 As shown, the inverter cabinet 303 mainly consists of DC / AC power modules UI2.1 to UI2.5, filter reactors L2.1 to L2.5, and connecting copper busbars.

[0127] The outgoing line cabinet mainly consists of filter capacitors 309 (including C1.1~C1.5, C2.1~C2.5, C3~C5), fuses 310 (including FU7~FU9) and connecting copper busbars.

[0128] The advantages or beneficial effects of adopting the above technical solution are as follows: This utility model uses multiple AC / DC power modules and DC / AC power modules in parallel to rectify the AC power on the grid side into DC power and invert the DC power into constant voltage and constant frequency AC power to provide power supply for other equipment. This improves the output rated current and rated capacity of the frequency converter, which can meet the needs of large-capacity shore-based power supply facilities such as docks and ports.

[0129] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A variable frequency power supply of a plurality of parallel power modules, characterized by, Comprising: a rectification circuit, the rectification circuit comprising: a first AC fast fuse module, one end of the first AC fast fuse module being connected to a three-phase voltage input end; a plurality of AC / DC power modules, three-phase input ends of each of the AC / DC power modules being respectively connected to one end of a first filter module, the other end of the first filter module being controllably connected to the first AC fast fuse module, two-phase output ends of each of the AC / DC power modules being connected to a DC output end; an inversion circuit, the inversion circuit comprising: a plurality of DC / AC power modules, two-phase input ends of each of the DC / AC power modules being respectively connected to the DC output end, three-phase output ends of each of the DC / AC power modules being respectively connected to one end of a second filter module, the other end of the second filter module being connected to a three-phase voltage output end through a second AC fast fuse module; a third filter module connected to the three-phase voltage output end.

2. The variable frequency power supply of claim 1, wherein, A network-side lightning protection module is connected between the three-phase voltage input end and a ground end, the network-side lightning protection module comprising: three first fuses, one end of each of the three first fuses being connected to the three-phase voltage input end one by one; a network-side lightning protection device, three-phase input ends of the network-side lightning protection device being connected to the other end of each of the three first fuses one by one, three-phase output ends of the network-side lightning protection device being connected to the ground end, the other end of each of the three first fuses being connected to the ground end through the ground end.

3. The variable frequency power supply of claim 1, wherein, The first AC fast fuse module comprises: three second fuses, one end of each of the three second fuses being respectively connected to the three-phase voltage input end one by one; a main circuit contactor, three-phase ends on one side of the main circuit contactor being connected to the other end of each of the three second fuses one by one, three-phase ends on the other side of the main circuit contactor being connected to all the first filter modules.

4. The variable frequency power supply of claim 1, wherein, The plurality of AC / DC power modules comprises five; and / or The plurality of DC / AC power modules comprises five.

5. The variable frequency power supply of claim 1, wherein, The first filter module comprises a plurality, each of the first filter modules being connected to the AC / DC power module one by one, each of the first filter modules comprising: a first filter reactance, three-phase output ends of the first filter reactance being respectively connected to three-phase input ends of the corresponding AC / DC power module; a first filter capacitor, the first filter capacitor comprising: a first sub-filter capacitor connected between a first phase and a second phase of the first filter reactance; a second sub-filter capacitor connected between the second phase and a third phase of the first filter reactance; a third sub-filter capacitor connected between the first phase and the third phase of the first filter reactance.

6. The variable frequency power supply of claim 1, wherein, A pre-charging module is connected between the first AC fast fuse module and the DC output end, the pre-charging module comprising: a pre-charging branch contactor connected between the first AC fast fuse module and a pre-charging resistor, the pre-charging resistor comprising: a first resistor connected between a first phase of the pre-charging branch contactor and a first phase of a non-controlled rectifier; a second resistor connected between a second phase of the pre-charging branch contactor and a second phase of the non-controlled rectifier; A third resistor is connected between the third phase of the pre-charge branch contactor and the third phase of the uncontrolled rectifier, and two-phase output terminals of the uncontrolled rectifier are connected to the DC output terminals.

7. The variable frequency power supply of claim 1, wherein, The second filter module includes a plurality of second filter modules, each of which is connected to a corresponding DC / AC power module. A second filter reactor has three-phase output terminals connected to the three-phase output terminals of the corresponding DC / AC power module. The second filter capacitor includes: A fourth sub-filter capacitor is connected between the first phase and the second phase of the second filter reactor. A fifth sub-filter capacitor is connected between the second phase and the third phase of the second filter reactor. A sixth sub-filter capacitor is connected between the first phase and the third phase of the second filter reactor.

8. The variable frequency power supply of claim 1, wherein, The second AC fast-fuse module includes: Three third fuses, one end of each of the three third fuses being connected to all the second filter modules, and the other end of each of the three third fuses being connected to a corresponding three-phase voltage output terminal.

9. The variable frequency power supply of claim 1, wherein, The third filter module includes three filter branches, one end of each of the three filter branches being connected to a corresponding three-phase of the three-phase voltage output terminal, and the other end of each of the three filter branches being connected together. Each filter branch is connected in series by a third filter reactor, a third filter capacitor, and a filter resistor.

10. The variable frequency power supply of any of claims 1-9, wherein, The frequency conversion power supply cabinet includes: A control cabinet in which an incoming copper bar and the first AC fast-fuse module are arranged, the incoming copper bar being connected to the three-phase voltage input terminal; Three rectifier cabinets in which the AC / DC power module, the filter reactor of the first filter module, and a first connecting copper bar are arranged, the first connecting copper bar being connected to the incoming copper bar and the rectification circuit; Three inverter cabinets in which the DC / AC power module, the filter reactor of the second filter module, and a second connecting copper bar are arranged, the second connecting copper bar being connected to the first connecting copper bar and the inverter circuit; An outgoing cabinet in which the filter capacitors in the rectification circuit and the inverter circuit, the second AC fast-fuse module, and a third connecting copper bar are arranged, the third connecting copper bar being connected to the second connecting copper bar and the three-phase voltage output terminal.

Images