CN106711992A - Permanent-magnet DC fan cluster system topological structure - Google Patents

Abstract

The present invention provides a permanent magnet DC fan cluster system topology, including a plurality of permanent magnet DC fan parallel branches, wherein each permanent magnet DC fan parallel branch includes a plurality of permanent magnet DC fan components connected in parallel, multiple The parallel branches of the permanent magnet DC fans are connected in parallel to form a closed-loop structure; each of the permanent magnet DC fan components outputs high-voltage DC, and the closed-loop structure is provided with a high-voltage DC convergence point. Aiming at the defects of complex series and parallel control of DC fans and difficult fault handling, the present invention uses magnetically integrated high-frequency transformers and high-frequency high-voltage rectifiers to solve the problem of high-voltage DC generated by DC fans, multi-fan cluster system topology and fault tolerance, and avoids problems caused by DC fans. The additional electrical insulation problem caused by series connection overcomes the fan power distribution and complex voltage stability control caused by different wind speeds or faults.

Description

A cluster system topology of permanent magnet DC fans

technical field

The present invention relates to the technical field of DC fans, in particular to a cluster system topology structure of permanent magnet DC fans, specifically, a low-voltage multi-module multi-phase permanent magnet generator modular power conversion high-voltage DC fan and its high-voltage DC cluster system structure .

Background technique

DC transmission in offshore wind farms has more advantages than AC transmission, so various series-parallel structures of DC fans in offshore wind farms have been proposed.

Existing offshore wind farms usually adopt a series structure of multiple DC fans, as shown in Fig. 1 . This structure usually has the following defects:

1. The series connection of DC fans makes the electrical withstand voltage of each DC fan increase in direct proportion to the number of fans in series, and puts forward higher requirements for the electrical insulation of generators and power converters.

2. Due to the uneven distribution of wind speed and the same limitation of the series branch current, the outlet voltage of each DC fan in the series branch needs to be adjusted to meet the total voltage balance and power transmission, which makes the control system complex and difficult, and there are Wind phenomenon reduces the utilization of wind resources.

Do not find description or report similar to the present invention at present, also do not collect similar data both at home and abroad.

Contents of the invention

In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a permanent magnet DC fan cluster system topology, which ensures that each DC fan is independent, the output voltage is the same, and the ring network structure is reliable High reliability, the internal modular structure of DC fans simplifies the complexity of electrical control, low-voltage permanent magnet synchronous generators and power converters do not require additional insulation requirements, effectively solving many problems caused by series-parallel DC fans.

To achieve the above object, the present invention is achieved through the following technical solutions:

A permanent magnet DC fan cluster system topology, including a plurality of permanent magnet DC fan parallel branches, wherein each permanent magnet DC fan parallel branch includes a plurality of permanent magnet DC fan components connected in parallel, and a plurality of permanent magnet DC fans The parallel connection of the fan parallel branches forms a closed-loop structure; each of the permanent magnet DC fan components outputs high-voltage DC, and the closed-loop structure is provided with a high-voltage DC convergence point.

Preferably, each of the permanent magnet direct current blower assemblies includes: a wind turbine and a permanent magnet direct current blower connected to each other; the permanent magnet direct current blower includes a permanent magnet synchronous generator, an AC/DC rectifier, a DC/ AC high frequency inverter, AC/AC magnetic integrated high frequency transformer and AC/DC high frequency high voltage rectifier.

Preferably, the permanent magnet synchronous generator is provided with N-phase windings, the AC/DC rectifier includes N unidirectional controllable rectifier modules corresponding to the N-phase windings, and the DC/AC high-frequency inverter includes N bidirectional inverter modules corresponding to N unidirectional controllable rectifier modules, the AC/AC magnetically integrated high-frequency transformer is provided with N low-voltage winding terminals corresponding to N bidirectional inverter modules and 1 A high-voltage winding end; where:

The two output terminals of each phase winding of the permanent magnet synchronous generator are respectively connected to the input terminals of a corresponding unidirectional controllable rectifier module, and the output terminals of each unidirectional controllable rectifier module are respectively connected to a corresponding bidirectional The input terminal of the inverter module is connected, and the output terminal of each bidirectional inverter module is connected to a corresponding low-voltage winding terminal. N low-voltage winding terminals are integrated and share one high-voltage winding terminal, and the high-voltage winding terminal is connected to the AC/DC high AC side connection of high frequency and high voltage rectifier.

Preferably, the permanent magnet synchronous generator includes 8 armature modules, wherein each armature module is 3 phases, and each phase is provided with 1 winding, a total of 24 windings, wherein each winding includes 12 a series coil.

Preferably, the unidirectional controllable rectifier module includes: uncontrollable device D _1n , uncontrollable device D _2n , uncontrollable device D _3n , uncontrollable device D _4n , controllable device S _1n , controllable device S _2n and filter The capacitor C _1n , the uncontrollable devices D _1n to D _4n are connected in parallel in twos to form an H bridge a, the controllable device S _1n and the controllable device S _2n are respectively connected in parallel with the two lower bridge arms of the H bridge a, The filter capacitor _C1n is connected in parallel with the output end of the H bridge a, and the two output ends of each phase winding of the permanent magnet synchronous generator are respectively connected to two series branches forming the H bridge a, and the filter capacitor C _1n serves as the input DC power supply of the bidirectional inverter module and is connected in parallel with the input end of the bidirectional inverter module.

Preferably, the bidirectional inverter module includes: uncontrollable device D _5n , uncontrollable device D _6n , uncontrollable device D _7n , uncontrollable device D _8n , controllable device S _3n , controllable device S _4n , controllable device The device S _5n , the controllable device S _6n , the terminal LW _n1 and the terminal LW _n2 , the uncontrollable devices D _5n ~ D _8n are connected in parallel in pairs to form an H-bridge b, and the controllable devices S _3n ~ S _6n They are respectively connected in parallel with the uncontrollable devices D _5n ~ D _8n ; the lead-out LW _n1 and lead-out LW _n2 are respectively connected to the two series branches forming the H-bridge b, and the output ends of the lead-out LW _n1 and lead-out LW _n2 are respectively Connect to the terminal at the low voltage winding end.

Preferably, the AC/AC magnetically integrated high-frequency transformer includes N low-voltage windings, N iron cores and one high-voltage winding, and the N low-voltage windings are respectively wound on N iron cores to form N low-voltage winding ends , the N iron cores are integrated and share one high-voltage winding to form one high-voltage winding end;

Each iron core includes an even number of separable magnetic cores, and the even number of separable magnetic cores is arranged in an axisymmetric space; wherein, the even number of separable magnetic cores is divided into a magnetic core with an upward opening and a magnetic core with a downward opening. The upward magnetic cores are arranged and fixed, and the high-voltage coils forming the high-voltage windings are set on the magnetically integrated magnetic core columns in the middle of the upward-opening magnetic cores, and the low-voltage coils forming the low-voltage windings are set on the magnetic cores around the downward-opening magnetic cores. The core with the opening down is placed on top of the core with the opening up.

Preferably, the terminals of the low-voltage coil are drawn out from the side of the AC/AC magnetically integrated high-frequency transformer, and the outlets of the high-voltage coil are drawn out from the middle of the AC/AC magnetically integrated high-frequency transformer.

Preferably, the iron core further includes a lower insulating pressing plate and an upper insulating pressing plate, and the lower insulating pressing plate and the upper insulating pressing plate are arranged between the magnetic core with the opening upward and the magnetic core with the opening downward .

Preferably, the AC/DC high frequency high voltage rectifier includes uncontrollable device D ₁ , uncontrollable device D ₂ , uncontrollable device D ₃ , uncontrollable device D ₄ , uncontrollable device D ₅ , uncontrollable device D ₆ , Controllable device S ₁ , controllable device S ₂ and high-voltage filter capacitor _CHv , the uncontrollable devices D ₁ to D ₄ are connected in parallel in pairs to form an H-bridge c, and the uncontrollable device D ₅ and uncontrollable device D ₆ The controllable device S ₁ and the controllable device S ₂ are respectively connected in series and anti-parallel to form the AC side of the AC/DC high-frequency high-voltage rectifier. The input end of the AC side is connected to the two outlet ends of the high-voltage winding end. The output terminals on the side are respectively connected to the two series branches forming the H-bridge c, and the two output DC terminals of the H-bridge c are connected to both ends of the high-voltage filter capacitor _CHV .

The permanent magnet DC fan cluster system topology provided by the present invention adopts low-voltage permanent magnet wind power generators (permanent magnet synchronous generators) with any number of phases and modules, modular winding controllable rectifiers (AC/DC rectifiers), modular DC/AC high frequency inverter (DC/AC high frequency inverter), magnetic integrated high frequency transformer (AC/AC magnetic integrated high frequency transformer), high frequency high voltage controllable rectifier (AC/DC high frequency high voltage rectifier) , forming a permanent magnet DC fan assembly.

The permanent magnet DC fan cluster system topology structure provided by the present invention, each permanent magnet DC fan component outputs high-voltage DC parallel connection, several permanent magnet DC fan components form a permanent magnet DC fan parallel branch, and multiple permanent magnet DC fan parallel branch The fields form a radial converging topology and the ends form a closed loop structure. The components of each permanent magnet DC fan are independent and have the same voltage, which avoids the need for additional insulation requirements for series DC fans to increase the electrical withstand voltage level. If any permanent magnet DC fan component fails, it can be removed from the system without affecting the operation of other units, which increases the reliability of the system.

The topology structure of the permanent magnet DC fan cluster system provided by the present invention adopts a modular low-voltage permanent magnet generator PMSG, each module unidirectional controllable rectifier, each DC module DC/AC high-frequency inverter, and an independent magnetic circuit integrated high-frequency transformer , High-frequency and high-voltage controllable rectifier, in which the high-voltage and low-voltage are electrically isolated, and the thickness of the low-voltage insulation material of the permanent magnet generator is thin, which can improve the heat dissipation effect; each DC branch is independent, and the independent magnetic circuit integrated high-frequency transformer can pass the cross-sectional area of the magnetic circuit and The number of coil turns forms a high-ratio boost; the controllable rectification can not only realize power control, but also simplify the control of the high-voltage side of the system.

Compared with the prior art, the present invention has the following beneficial effects:

First, in view of the complexity of the control of series-parallel DC fans, the independence of DC fan control and the consistency of output high-voltage DC are solved.

Second, the multi-pole, low-speed, low-voltage, multi-module and multi-phase independent magnetic circuit structure of the permanent magnet synchronous generator solves the direct mechanical coupling between the wind turbine and the generator, eliminates the fault problem caused by the gearbox, and provides modular power Transformation and fault-tolerant control create favorable conditions.

Third, the windings of each phase of the permanent magnet synchronous generator are individually connected to the controllable rectifier, filter, and bidirectional inverter to form a power conversion, which increases the independence of the winding control and enhances the fault tolerance of the winding.

Fourth, the magnetically integrated high-frequency transformer achieves double voltage multiplication by doubling the cross-sectional area of the magnetic circuit and the number of turns of the high and low voltage windings, which solves the limitation of the boost ratio of the general boost circuit and the common magnetic circuit transformer.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Figure 1 is a schematic diagram of the traditional series-parallel DC fan cluster topology;

Fig. 2 is a schematic diagram of the topology structure of the permanent magnet DC fan cluster system of the present invention;

Fig. 3 is a structural block diagram of the permanent magnet DC fan assembly of the present invention;

Fig. 4 is the structure schematic diagram of AC/DC rectifier of the present invention;

Fig. 5 is a schematic structural diagram of the DC/AC high-frequency inverter of the present invention;

Fig. 6 is a structural schematic diagram of the AC/AC magnetic integrated high-frequency transformer of the present invention;

Fig. 7 is a schematic structural diagram of the AC/DC high-frequency high-voltage rectifier of the present invention.

detailed description

The following is a detailed description of the embodiments of the present invention: this embodiment is implemented on the premise of the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Example

FIG. 2 is a schematic diagram of the topology structure of the permanent magnet DC fan cluster system provided in this embodiment, and FIG. 3 is a structural block diagram of the permanent magnet DC fan assembly provided in this embodiment.

in:

The permanent magnet DC fan cluster system topology provided in this embodiment includes multiple permanent magnet DC fan parallel branches, wherein each permanent magnet DC fan parallel branch includes multiple permanent magnet DC fan components connected in parallel, and multiple The parallel branches of the permanent magnet DC fan are connected in parallel to form a closed-loop structure; each of the permanent magnet DC fan components outputs high-voltage DC, and the closed-loop structure is provided with a high-voltage DC convergence point.

Further, each permanent magnet DC fan assembly includes: a wind turbine and a permanent magnet DC fan connected to each other; the permanent magnet DC fan includes a permanent magnet synchronous generator, an AC/DC rectifier, a DC/ AC high frequency inverter, AC/AC magnetic integrated high frequency transformer and AC/DC high frequency high voltage rectifier.

Further, the permanent magnet synchronous generator is provided with N-phase windings, the AC/DC rectifier includes N unidirectional controllable rectifier modules corresponding to the N-phase windings, and the DC/AC high-frequency inverter includes N bidirectional inverter modules corresponding to N unidirectional controllable rectifier modules, the AC/AC magnetically integrated high-frequency transformer is provided with N low-voltage winding terminals corresponding to N bidirectional inverter modules and 1 A high-voltage winding end; where:

The two output terminals of each phase winding of the permanent magnet synchronous generator are respectively connected to the input terminals of a corresponding unidirectional controllable rectifier module, and the output terminals of each unidirectional controllable rectifier module are respectively connected to a corresponding bidirectional The input terminal of the inverter module is connected, and the output terminal of each bidirectional inverter module is connected to a corresponding low-voltage winding terminal. N low-voltage winding terminals are integrated and share one high-voltage winding terminal, and the high-voltage winding terminal is connected to the AC/DC high AC side connection of high frequency and high voltage rectifier.

Further, the permanent magnet synchronous generator includes 8 armature modules, wherein each armature module is 3 phases, and each phase is provided with 1 winding, a total of 24 windings, wherein each winding includes 12 a series coil.

Further, the unidirectional controllable rectifier module includes: uncontrollable device D _1n , uncontrollable device D _2n , uncontrollable device D _3n , uncontrollable device D _4n , controllable device S _1n , controllable device S _2n and filter The capacitor C _1n , the uncontrollable devices D _1n to D _4n are connected in parallel in twos to form an H bridge a, the controllable device S _1n and the controllable device S _2n are respectively connected in parallel with the two lower bridge arms of the H bridge a, The filter capacitor _C1n is connected in parallel with the output end of the H bridge a, and the two output ends of each phase winding of the permanent magnet synchronous generator are respectively connected to two series branches forming the H bridge a, and the filter capacitor C _1n serves as the input DC power supply of the bidirectional inverter module and is connected in parallel with the input end of the bidirectional inverter module.

Further, the bidirectional inverter module includes: uncontrollable device D _5n , uncontrollable device D _6n , uncontrollable device D _7n , uncontrollable device D _8n , controllable device S _3n , controllable device S _4n , controllable device The device S _5n , the controllable device S _6n , the terminal LW _n1 and the terminal LW _n2 , the uncontrollable devices D _5n ~ D _8n are connected in parallel in pairs to form an H-bridge b, and the controllable devices S _3n ~ S _6n They are respectively connected in parallel with the uncontrollable devices D _5n ~ D _8n ; the lead-out LW _n1 and lead-out LW _n2 are respectively connected to the two series branches forming the H-bridge b, and the output ends of the lead-out LW _n1 and lead-out LW _n2 are respectively Connect to the terminal at the low voltage winding end.

Further, the AC/AC magnetically integrated high-frequency transformer includes N low-voltage windings, N iron cores and one high-voltage winding, and the N low-voltage windings are respectively wound on N iron cores to form N low-voltage winding ends , the N iron cores are integrated and share one high-voltage winding to form one high-voltage winding end;

Each iron core includes an even number of separable magnetic cores, and the even number of separable magnetic cores is arranged in an axisymmetric space; wherein, the even number of separable magnetic cores is divided into a magnetic core with an upward opening and a magnetic core with a downward opening. The upward magnetic cores are arranged and fixed, and the high-voltage coils forming the high-voltage windings are set on the magnetically integrated magnetic core columns in the middle of the upward-opening magnetic cores, and the low-voltage coils forming the low-voltage windings are set on the magnetic cores around the downward-opening magnetic cores. The core with the opening down is placed on top of the core with the opening up.

Further, the terminals of the low-voltage coil are drawn out from the side of the AC/AC magnetically integrated high-frequency transformer, and the outlets of the high-voltage coil are drawn out from the middle of the AC/AC magnetically integrated high-frequency transformer.

Further, the iron core also includes a lower insulating pressing plate and an upper insulating pressing plate, and the lower insulating pressing plate and the upper insulating pressing plate are arranged between the magnetic core with the opening upward and the magnetic core with the opening downward .

Further, the AC/DC high frequency high voltage rectifier includes uncontrollable device D ₁ , uncontrollable device D ₂ , uncontrollable device D ₃ , uncontrollable device D ₄ , uncontrollable device D ₅ , uncontrollable device D ₆ , Controllable device S ₁ , controllable device S ₂ and high-voltage filter capacitor C _HV , the uncontrollable devices D ₁ to D ₄ are connected in parallel in pairs to form an H-bridge c, and the uncontrollable device D ₅ and uncontrollable device D _{6 The} controllable device S1 and the controllable device S2 are respectively connected in series and antiparallel to form the AC side of the AC/DC high _- frequency high-voltage rectifier, and the input terminal of the AC side is connected to the outlet terminal HW1 and the outlet terminal HW2 of the high-voltage winding end, The output terminals of the AC side are respectively connected to two series branches forming the H-bridge c, and the output DC terminals HV _1n and _{HV 2n} of the H-bridge c are connected to both ends of the high-voltage filter capacitor CHV.

In this example:

The topology of the permanent magnet DC fan cluster system adopts each permanent magnet DC fan component to output high-voltage DC, several units are connected in parallel to form a branch circuit, and several branches are connected in parallel to form a ring structure, and a high-voltage DC convergence point is selected on the ring. The convergence point may be a direct current converter station or a direct current transmission terminal.

The permanent magnet DC fan components are independently controlled, the output DC voltage is the same, and the power is determined according to the utilization rate of wind resources. Its ring network structure can improve the utilization rate of wind resources and enhance the reliability of power supply. Even if there is a DC fan failure, as long as the fan is removed Without affecting other wind turbines and transmission voltage.

The permanent magnet direct current blower assembly includes an interconnected wind turbine and a permanent magnet direct current blower (including a permanent magnet synchronous generator (PMSG), an AC/DC rectifier, a DC/AC high frequency inverter, an AC/AC magnetic integrated high frequency Transformer, AC/DC high-frequency high-voltage rectifier), converts the output low-voltage AC of the permanent magnet synchronous generator into high-voltage direct current, and the electrical insulation of each winding of the permanent magnet synchronous generator maintains a low voltage state, and passes through multiple low-voltage direct current and high-frequency alternating current in the middle , High-frequency magnetic integrated transformer step-up and high-frequency rectification to achieve high-voltage DC output.

The permanent magnet synchronous generator is a multi-pole low-speed wind turbine directly driven by a low-voltage, multi-module, multi-phase structure. Each module contains the same number of phases, and the magnetic circuit of each phase is relatively independent. Between modules and between phases The electrical and magnetic circuits are independent and not coupled to each other.

Each phase winding (outlet L _1n , L _2n ) of the permanent magnet synchronous generator adopts an independent power unidirectional controllable rectification module, as shown in Figure 3, the rectification module includes four uncontrollable devices (D _1n ~ D _4n ), and two controllable devices (S _1n and S _2n ) connected in parallel with the two lower bridge arms (D _3n and D _4n ), so that the winding current can be controlled in both directions, and the AC/DC is formed by using the winding's own inductance The step-up rectification module outputs a parallel filter capacitor C _1n to stabilize the DC voltage. Since the multi-module, multi-phase permanent magnet synchronous generator has N windings in total, there are N rectifier modules.

The unidirectional controllable rectifier module (hereinafter referred to as the rectifier module) outputs a DC voltage through a bidirectional H-bridge bidirectional inverter module (hereinafter referred to as the inverter module), as shown in Figure 4, the inverter module includes four The uncontrollable device (D _5n ～D _8n ) is composed of a controllable device (S _3n ～S _6n ) connected in parallel with it, and controls the output square wave voltage (outlet LW _n1 , LW _n2 ), which is input into the high-frequency transformer low-voltage Coil (LW _n ). Since there are N rectifier modules in total, there are N independent inverter modules and N independent AC/AC magnetically integrated high-frequency transformers (hereinafter referred to as high-frequency transformers) low-voltage coils. When the permanent magnet synchronous generator winding in the permanent magnet DC fan fails and needs to cut off the working state of the winding, on the one hand, the AC/DC rectifier side is disconnected, and on the other hand, the controllable devices S _4n and S of the lower bridge arm of the bidirectional inverter module The _6n conduction short-circuits the corresponding low-voltage coil (constituting the low-voltage winding) in the AC/AC magnetically integrated high-frequency transformer, eliminating the magnetic flux of the magnetic circuit, and avoiding the reverse magnetic flux caused by the high-voltage coil (constituting the high-voltage winding) when the low-voltage coil is open. Voltage intrusion into low voltage circuits. Other windings and systems of the permanent magnet synchronous generator can work normally. When the fault is serious, the high-voltage DC side can be disconnected from the DC grid, and the entire permanent magnet DC fan can be disconnected from the grid.

The magnetic circuits of the low-voltage windings of the high-frequency transformer are independent of each other, and the low _- voltage windings are coupled with the high _- voltage windings through magnetic integration. As shown in FIG. ) The magnetic flux caused by the magnetic circuit is superimposed and enhanced by magnetic integration, so that the magnetic flux after magnetic integration is multiplied on the high-voltage winding side (HW), so that high voltage is generated through the combined action of magnetic flux multiplication and high-frequency transformer high-voltage and low-voltage winding turn ratio multiplication.

The high-frequency transformer output (outlets HW ₁ , HW ₂ ) undergoes controllable high-voltage rectification to form a high-voltage AC/DC boost, and is filtered by a high-voltage filter capacitor C _HV to form a stable high-voltage DC voltage, as shown in FIG. 6 . The AC/DC high-frequency high-voltage rectifier adopts an H-bridge arm composed of four uncontrollable devices (D ₁ to D ₄ ), and an AC/DC boost circuit (anti-parallel S ₁ and D ₅ , S ₂ and D ₆ ).

The topology of the permanent magnet direct current fan cluster system provided in this embodiment adopts the parallel connection of the permanent magnet direct current fan components to form a multi-circuit ring cluster system topology, which improves the reliability of the system.

Taking the permanent magnet synchronous generator with 24 windings as an example, the specific description is as follows:

Permanent magnet synchronous generator 5MW, speed 10rpm, 280 poles, divided into 8 armature modules, each armature module has 3 phases, each phase has a winding, that is, 24 windings, each winding has 12 coils in series , Winding voltage 960V. Each permanent magnet DC fan assembly has 24 AC/DC rectifier modules as shown in Figure 4, 24 bidirectional inverter modules as shown in Figure 5, 24 low-voltage windings of AC/AC magnetic integrated high-frequency transformers and Iron core, each iron core is composed of an even number of separable magnetic cores, 24 iron cores are integrated and share one high-voltage winding, the AC/AC magnetic integrated high-frequency transformer high-voltage and low-voltage winding schematic diagram is shown in Figure 6, and one such The AC/DC high-frequency high-voltage rectifier shown in Figure 7.

The two outgoing terminals (L _1n and L _2n ) of each winding of the permanent magnet synchronous generator are connected to the input terminal of the corresponding unidirectional controllable rectifier module, and the output terminal of each unidirectional controllable rectifier module is connected in parallel with a filter capacitor C _1n to stabilize Voltage, the filter capacitor C _1n is also used as the input DC power supply of the bidirectional inverter module, the output AC square wave of the bidirectional inverter module and the low-voltage coil (constituting the low-voltage winding) terminal (LW _n1 and LW _n2 ), the outlet terminals (HW ₁ and HW ₂ ) of the high-voltage coil (constituting the high-voltage winding) of the AC/AC magnetically integrated high-frequency transformer are connected to the AC side of the AC/DC high-frequency high-voltage rectifier, and the AC/DC high-frequency The high-voltage rectifier output DC terminals (HV _1n and HV _2n ) are connected with a high-voltage filter capacitor C _HV .

The separable magnetic cores of the AC/AC magnetic integrated high-frequency transformer are arranged according to the axisymmetric space. The opening of the magnetic core is upward or downward. Put the insulated low-voltage coils on the surrounding magnetic cores, place the upper insulating compression plate, and place the downward-opening magnetic core on the upward-opening magnetic core. Finally, the magnetic core with the opening downward is fixed, the low-voltage coil is drawn out from the side of the AC/AC magnetically integrated high-frequency transformer, and the high-voltage coil is drawn out from the middle of the AC/AC magnetically integrated high-frequency transformer.

The permanent magnet DC wind turbine cluster system topology provided in this embodiment includes low-voltage permanent magnet wind turbines with any number of phases and modules, modular winding controllable rectifiers, modular DC/AC high-frequency inverters, and high magnetic integration Permanent magnet DC fan composed of frequency transformer, high frequency and high voltage controllable rectifier, and DC fan cluster topology.

The topology of the permanent magnet DC fan cluster system is shown in Figure 2. The output of each permanent magnet DC fan component is connected in parallel with high-voltage DC. Several permanent magnet DC fan components form a branch circuit, and multiple branch circuits form a radial convergence topology. Connect the ends in parallel to form a multi-loop ring structure. Each DC fan is independently controlled and the DC voltage is consistent, which avoids the need to increase the insulation requirements of the DC fan in series to increase the electrical withstand voltage level. If any DC fan fails, it can be removed from the system without affecting the operation of other units, which increases the reliability of the system.

The block diagram structure of each permanent magnet DC fan is shown in Figure 3, including the modular low-voltage permanent magnet generator PMSG, each module unidirectional controllable rectifier (unidirectional controllable rectifier module), each DC module DC/AC high frequency inverter Inverter (bidirectional inverter module), independent magnetic circuit integrated high-frequency transformer (AC/AC magnetic integrated high-frequency transformer), high-frequency high-voltage controllable rectifier (AC/DC high-frequency high-voltage rectifier). The high voltage and low voltage are electrically isolated, and the low voltage insulation material of the permanent magnet synchronous generator is thin, which can improve the heat dissipation effect. Each DC branch is independent, and the magnetically integrated high-frequency transformer can form a high voltage ratio boost through the cross-sectional area of the magnetic circuit and the number of turns of the coil. Controlled rectification can not only realize power control, but also simplify the control of the high-voltage side of the system.

To sum up, this embodiment aims at the defects of complex series-parallel control of DC fans and difficult fault handling, and uses magnetically integrated high-frequency transformers and high-frequency high-voltage rectifiers to solve the problems of high-voltage DC generated by DC fans, multi-fan cluster system topology and fault tolerance, and avoid It solves the problem of additional electrical insulation caused by the series connection of DC fans, and overcomes the fan power distribution and complex voltage stability control caused by different wind speeds or faults.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (10)

1. a kind of DC blower fan group system topological structure, it is characterised in that including a plurality of DC fan parallel-connection branch Road, each of which DC fan parallel-connection branch road include many DC fan assemblies being connected in parallel, it is a plurality of forever Composition closed loop configuration is connected in parallel between magnetic DC fan parallel branch；The each DC fan assembly exports height Straightening stream, the closed loop configuration is provided with HVDC convergent point.

2. DC blower fan group system topological structure according to claim 1, it is characterised in that described in each forever Magnetic DC fan component includes：The wind energy conversion system and DC blower fan of interconnection；The DC blower fan is included successively The magneto alternator of connection, AC/DC rectifiers, DC/AC high-frequency inverters, the integrated high frequency transformer of AC/AC magnetic and AC/DC High-frequency and high-voltage rectifier.

3. DC blower fan group system topological structure according to claim 2, it is characterised in that the permanent-magnet synchronous Generator is provided with N phase windings, and the AC/DC rectifiers include the N number of unidirectional controlled rectifier module corresponding with N phase windings, The DC/AC high-frequency inverters include the N number of two-way inverter module corresponding with N number of unidirectional controlled rectifier module, described The integrated high frequency transformer of AC/AC magnetic is provided with N number of low pressure winding end and 1 high voltage winding corresponding with N number of two-way inverter module Group end；Wherein：

Two output ends of each phase winding of the magneto alternator unidirectional controlled rectifier corresponding with respectively The input connection of module, the output end of each unidirectional controlled rectifier module two-way inverter mould corresponding with respectively The input connection of block, the output end low pressure winding end connection corresponding with respectively of each two-way inverter module is N number of Low pressure winding end is integrated to share 1 high pressure winding terminal, and high pressure winding terminal is connected with the AC of AC/DC high-frequency and high-voltage rectifiers.

4. DC blower fan group system topological structure according to claim 3, it is characterised in that the permanent-magnet synchronous Generator includes 8 armature modules, and each of which armature module is 3 phases, and each phase is equipped with 1 winding, 24 altogether Winding, each of which winding includes 12 series coils.

5. DC blower fan group system topological structure according to claim 3, it is characterised in that described unidirectional controllable Rectifier module includes：Uncontrollable device D_1n, uncontrollable device D_2n, uncontrollable device D_3n, uncontrollable device D_4n, controllable devices S_1n, controllable devices S_2nWith filter condenser C_1n, the uncontrollable device D_1n~D_4nComposition H bridges a in parallel, described after connecting two-by-two Controllable devices S_1nWith controllable devices S_2nTwo lower bridge arms respectively with H bridges a are in parallel, the filter condenser C_1nIt is defeated with H bridges a Go out end parallel connection, two output ends of each phase winding of the magneto alternator are connected to two strings for constituting H bridges a On connection branch road, the filter condenser C_1nInput DC power as two-way inverter module is defeated with two-way inverter module Enter end in parallel.

6. DC blower fan group system topological structure according to claim 3, it is characterised in that the two-way inversion Device module includes：Uncontrollable device D_5n, uncontrollable device D_6n, uncontrollable device D_7n, uncontrollable device D_8n, controllable devices S_3n、 Controllable devices S_4n, controllable devices S_5n, controllable devices S_6n, exit LW_n1With exit LW_n2, the uncontrollable device D_5n~D_8n It is in parallel after connecting two-by-two to constitute H bridges b, the controllable devices S_3n~S_6nRespectively with uncontrollable device D_5n~D_8nIt is in parallel；The extraction End LW_n1With exit LW_n2It is connected in two series arms for constituting H bridges b, exit LW_n1With exit LW_n2It is defeated Go out terminals of the end respectively with low pressure winding end to be connected.

7. DC blower fan group system topological structure according to claim 3, it is characterised in that the AC/AC magnetic Integrated high frequency transformer includes N number of low pressure winding, N number of iron core and 1 high pressure winding, and N number of low pressure winding is wound in N respectively On individual iron core, N number of low pressure winding end is formed, N number of iron core is integrated to share 1 high pressure winding, forms 1 high pressure winding terminal；

Each iron core includes that even number can be separated magnetic core, and the separable magnetic core of even number is according to axial symmetry space arrangement；Wherein, The separable magnetic core of even number is divided into the magnetic core and the magnetic core that Open Side Down of opening upwards, and the magnetic-core arranging of opening upwards is fixed, The high-tension coil for constituting high pressure winding is sleeved in the middle of the magnetic core of opening upwards on the integrated magnetic core post of magnetic, constitutes low pressure winding Low-voltage coil is sleeved on around the magnetic core that Open Side Down on each magnetic core, and the magnetic core that Open Side Down is placed on the magnetic core of opening upwards On.

8. DC blower fan group system topological structure according to claim 7, it is characterised in that low-voltage coil connects Line end is drawn from the side of the integrated high frequency transformer of AC/AC magnetic, and the leading-out terminal of high-tension coil is from the integrated high frequency transformer of AC/AC magnetic In the middle of extraction.

9. DC blower fan group system topological structure according to claim 7, it is characterised in that the iron core is also wrapped Bottom insulation pressure strip and upper portion insulating pressure strip are included, the bottom insulation pressure strip and upper portion insulating pressure strip are arranged at opening Between upward magnetic core and the magnetic core that Open Side Down.

10. the DC blower fan group system topological structure according to claim any one of 3-9, it is characterised in that institute Stating AC/DC high-frequency and high-voltages rectifier includes uncontrollable device D₁, uncontrollable device D₂, uncontrollable device D₃, uncontrollable device D₄、 Uncontrollable device D₅, uncontrollable device D₆, controllable devices S₁, controllable devices S₂With high-voltage filtering capacitor device C_Hv, the uncontrollable device Part D₁~D₄It is in parallel after connecting two-by-two to constitute H bridges c, the uncontrollable device D₅With uncontrollable device D₆Respectively with controllable devices S₁With Controllable devices S₂Inverse parallel after series connection, forms the AC of AC/DC high-frequency and high-voltage rectifiers, input and the height of the AC Two leading-out terminals connection of winding terminal is pressed, the output end of the AC is connected to two series arms for constituting H bridges c On, two output direct current termination high-voltage filtering capacitor device C of H bridges c_HVTwo ends.