WO2019184880A1

WO2019184880A1 - Wind power converter and control system and control method for wind power converter

Info

Publication number: WO2019184880A1
Application number: PCT/CN2019/079555
Authority: WO
Inventors: 危由青; 喻俊鹏; 周党生; 吕一航; 王琰
Original assignee: 深圳市禾望电气股份有限公司
Priority date: 2018-03-29
Filing date: 2019-03-25
Publication date: 2019-10-03

Abstract

Disclosed are a converter and a control method. The converter comprises a machine-side assembly, a power unit assembly and a grid-side assembly, sequentially disposed in a cabinet from top to bottom, wherein an input port of the power unit assembly is close to an output port of the machine-side assembly and is electrically connected to the output port by means of a conductor; and an input port of the grid-side assembly is close to an output port of the power unit assembly and is electrically connected to the output port by means of a conductor. According to the present application, by means of the main circuit layout, a power unit assembly is located in the middle, a machine-side assembly is located above a power unit, and a grid-side inductor and a grid-side switch are located below the power unit, wherein a complete machine uses a top-to-bottom layout mode, and input and output ports of adjacent devices are disposed close to each other, so that a direct electrical connection can be realized, the connection length is reduced, the whole connection is smooth, the usage amount, bending and electrical lap points of electrical conductors are reduced, a switching operation can be performed without shutting down, online rapid switching is realized, the operating efficiency is optimized, and an applicability requirement for high and low voltage ride through is met.

Description

Wind power converter and control system and control method thereof

Technical field

The invention relates to the technical field of wind power, and particularly relates to a wind power converter and a control system and a control method thereof.

Background technique

The main circuit part of the converter is mainly divided into three parts: 1 machine side interface to power unit part, which can be called machine side component; 2 power module and its subsidiary structural parts, which can be called power unit components; 3 power unit The end-to-network side interface can be called a network side component. Electrical connections are required between the machine side components, power unit components, and grid side components, and the layout of the different components determines the length of the electrical connection distance.

As shown in Figure 1, the cable enters the line from the machine side, and then goes up to the power unit through the inductor. Through the shared busbar, the power unit on the machine side and the power unit on the network side are connected into one unit, and then the power unit from the network side goes down to the inductor. . After the convergence, the entire inductor cabinet is connected to the network side switch and then to the grid. In the process of the grid side inductor to the grid side switch, since the inductor and the grid side switch are both three-dimensional, and the maintenance needs, the connecting copper strip can only be wound from the front end of the inductor to the rear end of the switch, in the turn and the connection. The process requires more bending, turning, and lap jointing, and the amount of copper platoon is larger. Together with the previous confluence and reciprocating connection, the whole machine has a larger amount of copper platoon. The power flow goes from bottom to top, then from top to bottom, then from right to left, back and forth, and the power flow bypasses more.

2 is a schematic diagram of a main circuit connection and a power flow of a back-to-back converter of a single-phase power unit, wherein a is an appearance view of the whole machine, b is a schematic diagram of a power unit side of the machine side, and c is a schematic diagram of a power unit side of the network side; As shown, the back-to-back machine side enters the line, descends through the machine side switch, and then connects to the machine side inductance through horizontal bending. The machine side inductor copper row is connected to the AC side of the machine side module, and the network side power module is reached through the connection of the common bus bar. The grid side module is further down, connected to the grid side inductor, and then horizontally bent to the grid side circuit breaker, and the circuit breaker lower outlet is connected to the grid. The connection of the back-to-back model main circuit reciprocates back and forth many times, and the copper row overlaps and bends more. Similar to the connection of Figure 1, the back-to-back layout mode has a larger amount of copper bus and connection points.

Figure 3a, b, c are the main circuit connection and power flow diagram of the latest converter (three-phase power unit back-to-back converter) of a large foreign enterprise. Figure 3a is the schematic diagram of the main circuit layout of the converter, Figure 3b is Power flow diagram of the power unit side of the main circuit of the converter, 3c is a power flow diagram of the power unit side of the main circuit of the converter; as shown in Figures 3a, b and c, the electrical components between the components The connections and their power flow are mainly as follows. First, the machine enters the line, the cable passes through the top entry hole, reaches the machine side wiring to connect the copper bar 7, and then directly connects directly to the machine side inlet port of the machine side power unit 5, and the DC port connection of the machine side power unit 5 The DC busbar is shared with the machine side. The common DC busbar connected to the power supply unit on the machine side and the common DC busbar of the power supply unit on the rear side are connected by copper bars extending through the depth direction of the cabinet. The network side shares the DC busbar directly. To the network side power unit 10, and the AC output end of 10 is connected to the bus bar. The bus bar extends to reach one connection port of the network side inductance after all AC output is completed, and the other port and the port point of the network side switch 8 The other port of the connection 8, is connected to the network side wiring port 9. The whole connection and power flow are relatively smooth. Since the single-machine side or the network-side three-phase power unit is used, the amount of the common busbar in the middle is relatively large and the number of overlapping points is large; and the grid-side inductance and power unit are basically in one Water level, need bus and

Connected, the cost of the bus is more, resulting in more overlapping points. As the power of the whole machine increases, the amount of busbars and the number of overlapping points will increase. Moreover, the main circuit connection and power flow of the whole machine, from top to bottom, through the cabinet in the depth direction, and then from the bottom to the top, directly horizontally converge across the entire power cabinet. Although the height of the power module is high, the connection length of the upper and lower sides is saved, but the back and forth and the connection still consume more bus bars and increase the connection point, resulting in increased cost and excessive loss.

Comprehensively available, the main circuit of the existing model has more round-trip reciprocating, bending, and confluence connections. The amount of connecting copper bars and the number of overlapping points are large, and the internal power flow of the converter is not smooth, and the cost is high. The line loss is large.

Summary of the invention

A brief summary of embodiments of the invention is set forth below in order to provide a basic understanding of certain aspects of the invention. It should be understood that the following summary is not an exhaustive overview of the invention. It is not intended to identify key or critical aspects of the invention, and is not intended to limit the scope of the invention. Its purpose is to present some concepts in a simplified form as a pre-

According to an aspect of the present application, a main circuit layout of a current transformer is provided, including a machine side component, a power unit component, and a mesh side component that are sequentially disposed from top to bottom in a cabinet; an input port and a machine side of the power unit component The output port of the component is adjacent, and the input port of the power unit component and the output port of the machine side component are electrically connected through a conductor; the input port of the network side component and the output port of the power unit component are adjacent, and the input port and power unit of the network side component The output ports of the components are electrically connected by conductors. The grid side component includes a grid side inductor and a grid side switch, the grid side inductor is disposed under the power unit assembly, the grid side inductor and the power unit component are electrically connected through the conductor; and the grid side switch is disposed on one side of the grid side inductor. The output port of the grid side inductor is disposed adjacent to the input port of the grid side switch, and is electrically connected through a conductor.

Wherein, the machine side component, the power unit component and the net side component are arranged in the upper, middle and lower modes in the vertical direction, but are not limited to the same vertical line, and the devices are in front and rear, left and right in the respective upper, middle and lower regions. The position of the upper and lower can be adjusted according to actual needs. The application passes the above main circuit layout, the power unit assembly is centered, the machine side component is located above the power unit, the grid side inductance and the grid side switch are located below the power unit, and the whole machine adopts a top to bottom layout mode, and is adjacent The input and output ports of the device are placed adjacent to each other, which can realize electrical direct connection, reduce the connection length, smooth the entire connection, and reduce the amount of electrical conductors, bends and electrical junctions.

Further, the power unit assembly includes at least one integrated single-phase module including a machine side module, a network side module, and a bus capacitor integrated together, wherein the machine side module and the network side module are respectively disposed at Both sides of the bus capacitor. Preferably, the machine side module, the bus bar capacitor and the network side module are longitudinally distributed, that is, the machine side module, the bus bar capacitor, and the network side module are upper middle and lower structures, and the machine side module and the network side module are respectively disposed on the bus bar capacitor. The upper and lower sides. Of course, the machine side module, the bus bar capacitor, and the grid side module may also be left center right structures.

The power unit assembly further includes a driving board, a module bus, and an AC outlet port. The bus capacitor is mounted on the module bus, and the module AC port is near the line.

When a plurality of single-phase modules are integrated, the power unit assembly further includes a shared busbar, and a side outlet of the module busbar is connected to the shared busbar.

Preferably, the network side module is disposed adjacent to the mesh side component. The switch on the machine side is electrically connected to the inductor on the machine side, and the inductance on the machine side is connected to the machine side module in the power unit assembly.

Similarly, the machine side module is disposed adjacent to the machine side assembly. The network side module in the power unit assembly is electrically connected to the grid side inductor, and the grid side inductor is electrically connected to the grid side switch.

Preferably, the power unit assembly is located at a lower portion of the machine side assembly, the input port of the power unit assembly is disposed at a top portion thereof, and the output port of the machine side assembly is disposed at a lower portion thereof to enable an input port of the power unit assembly and the machine side assembly The output port is adjacent. The mesh side component is located at a lower portion of the power unit assembly, the input port of the mesh side component is disposed at an upper portion thereof, and the output port of the power unit component is disposed at a bottom thereof, so that an input port of the mesh side component and an output port of the power unit component are adjacent to each other .

The machine side component is a circuit connector, or a combination of a circuit connector and a machine side switch, or a combination of a circuit connector and a machine side inductance, or the machine side component is a circuit connector, a machine side switch, and A combination of machine side inductances. When the machine side component is a combination of a circuit connector, a machine side switch and a machine side inductance, the machine side inductance is disposed above the power unit component, and the machine side inductance and the power unit component are electrically connected through the conductor; the machine side switch setting On one side of the machine-side inductor, the output port of the machine-side inductor is placed adjacent to the input port of the machine-side switch, and is electrically connected through a conductor.

By adopting the above-mentioned new main circuit layout scheme, the power flow in the converter is smooth, the input port is adjacent to the output port of the output end, and can be directly connected, and the internal connection has no reciprocating back and forth, a wide range of bending, and a long distance. Confluence connection, less steering or bending between electrical points, reducing the use of electrical conductors and electrical junctions of the main circuit, smooth power flow of the whole machine, reducing the cost of the whole machine, reducing the loss in the circuit, and improving the whole machine Cost-effective, can perform switching operation without stopping, not only realizes online fast switching, but also optimizes operating efficiency, and can also meet the needs of different occasions, including real-time changes in operating conditions and can not be interrupted; Under this control method, even if the machine-side converter of a part of the wind power converter stops running, its grid-side converter throws and keeps running online, so that when high and low voltage crossing occurs, the semi-offline wind power converter Still has the function of reactive power support, so this control method can also meet the applicability requirements of high and low voltage crossing and other power grids.

DRAWINGS

The invention may be better understood by referring to the following description in conjunction with the drawings, wherein the same or similar reference numerals are used throughout the drawings. The drawings, which are included in the specification, and in the claims In the drawing:

Figure 1 is a schematic diagram of the main loop connection of a single-phase power unit in-line converter and its power flow.

2 is a schematic diagram of a main circuit connection and a power flow of a back-to-back converter of a single-phase power unit, wherein a is an appearance view of the whole machine, b is a schematic diagram of a power unit side of the machine side, and c is a schematic diagram of a power unit side of the network side.

3a is a schematic diagram of the main circuit layout of the back-to-back converter of the three-phase power unit, FIG. 3b is a power flow diagram of the power unit side of the main circuit of the converter, and 3c is the power of the power unit side of the main circuit of the converter. Flow diagram.

4a is a schematic diagram of the main circuit connection and power flow of the whole machine of the present application, FIG. 4b is a view taken along line A in FIG. 4a, and FIG. 4c is a view taken along line B in FIG. 4a.

5a is a schematic diagram of power flow of the main circuit of the whole machine of the present application, and FIG. 5b is a schematic diagram of power flow of the other side of the main circuit of the whole application.

6 is a schematic diagram of communication of a wind turbine main controller, a general dispatch module, and each wind power converter controller according to the present invention.

7 is a schematic diagram of a multi-winding, multi-wind power converter parallel system in a semi-offline mode according to the present invention.

detailed description

Embodiments of the present invention will be described below with reference to the drawings. Elements and features described in one of the figures or one embodiment of the invention may be combined with elements and features illustrated in one or more other figures or embodiments. It should be noted that, for the sake of clarity, representations and descriptions of components and processes known to those of ordinary skill in the art that are not related to the present invention are omitted from the drawings and the description.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", " The orientation or positional relationship of the indications of "upright", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present invention and The simplification of the description is not intended to limit or imply that the device or component that is referred to has a particular orientation, is constructed and operated in a particular orientation, and thus is not to be construed as limiting. Moreover, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that the terms "installation", "connected", and "connected" are to be understood broadly, and may be fixed or detachable, for example, unless otherwise explicitly defined and defined. Connected, or integrally connected; can be mechanical or electrical; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of the two components. The specific meaning of the above terms in the present invention can be understood in a specific case by those skilled in the art.

Example 1

The embodiment discloses a wind power converter. According to the characteristics of the nacelle in the fan system, the converter is on the tower base platform, the box is changed to the outdoor ground or the base layer of the tower, the main loop device inside the converter is arranged reasonably. . Referring to Figures 4a, 4b and 4c, the converter comprises a machine side switch 1, a machine side inductor 2, a power unit assembly 3, a grid side inductor 4, a grid side switch 5, a machine side port 6, a network side port 7, and others. Auxiliary device 12. The power unit component 3 integrates a machine side module, a network side module, a bus capacitor, a driving board, a module bus, a shared bus, and an AC outlet port in a single module. That is, the power unit assembly 3 includes at least one integrated single-phase module, each single-phase module including an integrated side-side module, a grid-side module, and a bus capacitor. When multiple integrated single-phase modules are employed, multiple single-phase modules are connected by a common busbar. The bus capacitance of each integrated single-phase module is centrally mounted on the module busbar, and the machine-side module, the busbar capacitor and the grid-side module are vertically distributed, that is, the machine-side module, the busbar capacitor, and the grid-side module are upper-lower and lower-structure. The machine side module and the network side module are respectively disposed on the upper and lower sides of the bus capacitor; the module bus side outlet of the power module is connected with the internal shared bus, and the module AC port is outgoing. The grid side module is disposed adjacent to the grid side inductor 4.

In other embodiments, the machine side module, the bus capacitor, and the network side module may also be horizontally distributed, that is, the machine side module, the bus line capacitor, and the network side module are left center right and right side structures, and the machine side module and the network side module are respectively set. On the left and right sides of the bus capacitor.

The machine side switch 1 is connected to the machine side inductor 2 through the first conductor 8, and the machine side inductor 2 is connected through the second conductor 9 and the machine side module in the power unit assembly 3, and the mesh side module in the power unit assembly 3 passes through the third conductor. 10 is connected to the grid side inductor 4, and the grid side inductor 4 is connected to the grid side switch 5 via the fourth conductor 11.

First, the machine side port 6 of the whole machine is connected to one end of the machine side switch 1, the machine side switch 1 is placed beside the machine side inductor 2, and the other end of the machine side switch 1 is close to a port of the machine side inductor 2, and passes through the first conductor 8 connection.

The power unit assembly 3 is centered and located below the machine side inductance 2. In the power unit assembly 3, the machine side module is on the upper side and the network side module is on the lower side. Since the machine-side inductor 2 and the machine-side switch 1 have a certain depth dimension, the other port of the machine-side inductor 2 is substantially in the same vertical line as the AC port of the machine-side module, and the port is adjacent, and is connected through the second conductor 9. .

The grid side inductor 4 is placed below the power unit assembly 3. The grid side module of the power unit assembly 3 is adjacent to one port of the inductor, and may be connected by the third conductor 10. The grid side switch 5 is placed beside the grid side inductor 4, and the other port of the grid side inductor 4 is adjacent to one port of the grid side switch 5, connected by the fourth conductor 11, and the other port of the grid side switch 5 is connected. Then connect to the grid.

The main circuit layout scheme of the present application has a smooth power flow inside the converter, and the input port is adjacent to the output port of the output terminal, and can be directly connected, and the internal connection has no reciprocating back and forth, a wide range of bending, a long distance confluence connection, and electrical There is less steering or bending between the points, which reduces the use of the main circuit conductor and the electrical connection point, and the power flow of the whole machine is smooth, which reduces the cost and loss of the whole machine and improves the cost performance of the whole machine.

The schematic diagram of the power flow of the whole machine is shown by the arrows in FIG. 5a and FIG. 5b, FIG. 5a is a side view of the whole machine, and FIG. 5b is another side view of the whole machine. The whole machine connection and its power flow are input from the machine side port 6, vertically downward, and connected to one end of the machine side switch 1, passing the machine side switch 1, the other port of the machine side switch 1 and one port of the machine side inductance 2 The other port of the machine-side inductor 2 is connected to the machine-side module AC port of the power unit assembly 3 to complete the connection of the machine-side component to the power unit assembly 3. The network side module AC port of the power unit component 3 is connected to one port of the grid side inductor 4, the other port of the grid side inductor 4 is connected to one end of the grid side switch 5, and the other port of the grid side switch 5 can be connected to the grid. connection. The connection distance between the whole device is short, the power flow is smooth, and there is no electrical connection point for reciprocating connection, long distance convergence, turning or bending.

Example 2

Referring to FIG. 2, the embodiment discloses a control system for a wind power converter according to Embodiment 1. The control system of the wind power converter includes N wind power converters according to Embodiment 1 in parallel. Each of the wind power converters includes a serially connected machine side converter and a grid side converter, and the other side of the machine side converter of the N wind power converters is connected to the motor. The other side of the grid-side converter is connected to the power grid, the power unit assembly 3 includes a machine-side power unit and a network-side power unit, and the machine-side converter includes a machine-side component and a machine-side power unit, The grid-side converter includes a grid side component and a grid side power unit, the power unit component is located at a lower portion of the machine side component, and an input port of the power unit component 3 and an output port of the machine side component are electrically connected through a conductor, The mesh side component is located at a lower portion of the power unit assembly 3, and the input port of the mesh side component and the output port of the power unit component 3 are electrically connected by a conductor, and the mesh side component includes a mesh side inductor 4 and a mesh side switch 5, and the mesh side The inductor 4 is disposed below the power unit assembly 3 The grid side inductor 4 and the power unit assembly 3 are electrically connected by a conductor; the grid side switch 5 is disposed at one side of the grid side inductor 4, and is electrically connected by a conductor, and the control system of the wind power converter further includes a total a scheduling module, each of the wind power converters has a built-in controller, and each controller of the wind power converter communicates with the total dispatching module, and each of the wind power converters is controlled Communicating with the total dispatching module, each controller of the wind power converter transmits information to the total dispatching module, and the total dispatching module calculates the required investment according to the current real-time power generation or the demand of the generated current The number of wind turbine converters that are operating.

Example 3

Referring to FIG. 7, the embodiment discloses a control method for a wind power converter control system according to Embodiment 2. The control system of the wind power converter includes N wind power converters according to Embodiment 1 in parallel. Each of the wind power converters includes a serially connected machine side converter and a grid side converter, and the power unit assembly 3 includes a machine side power unit and a grid side power unit, and the machine side converter The utility model comprises a machine side component and a machine side power unit, the grid side converter comprises a grid side component and a grid side power unit, the power unit component 3 is located at a lower part of the machine side component, and the input port and the machine side component of the power unit component 3 The output port is electrically connected by a conductor, the mesh side component is located at a lower portion of the power unit assembly 3, and the input port of the mesh side component and the output port of the power unit component 3 are electrically connected by a conductor, the mesh side component including The grid side inductor 4 and the grid side switch 5, the grid side inductor 4 is disposed below the power unit assembly 3, the grid side inductor 4 and the power unit assembly 3 are electrically connected by a conductor; and the grid side switch 5 is disposed at the grid side inductor 4 Side, and through the conductor The electrical connection is realized, the other side of the machine-side converter of the N wind power converters is connected to the motor, and the other side of the grid-side converter is connected to the power grid, and the parallel type converter is connected The control method comprises the following steps: setting the X1 wind power converter to the online mode, the X2 wind power converter to the semi-offline mode, and X1+X2≦N; wherein the online mode is the mesh side change of the wind power converter Both the flow device and the machine-side converter are operated online, the semi-offline mode is the grid-side converter of the wind power converter running online, and the machine-side converter of the wind power converter is stopped for offline operation.

The second step is to calculate the number of wind power converters to be put into operation according to the real-time power generation or the current demand of the power generation, and determine whether the number of the wind power converters is consistent with the current number of wind power converters in the online mode. If they are inconsistent, it is determined that the input needs to be increased. The number Y of the wind power converters in the semi-offline mode or the number Z of wind power converters that need to be cut out in the online mode.

The third step is to increase the wind power converter that is put into the Y-semi-offline mode, or cut out the wind turbine converter that operates in Z.

The machine-side converter of the wind power converter of the Y-semi-offline mode is activated and put into the control system of the wind power converter, and the wind power converter of the Y-semi-offline mode is switched to the online mode, thereby realizing the Y New investment in wind power converters with semi-offline mode.

Or, the machine-side converter of the wind power converter that controls the cut-off Z-line mode is stopped, and the grid-side converter of the Z wind power converter is kept running online, and the wind power of the Z-line online mode is changed. The streamer is switched to the semi-offline mode, thereby realizing the cutting out of the Z-line online mode wind power converter.

As described above, the X1 wind power converter is in the online mode, and the X2 wind power converter is in the semi-offline mode, so that the wind power converter is formed in a semi-offline mode as a whole. In this mode, it is only necessary to start the machine-side converter of the wind power converter in the semi-offline mode to complete the input operation, and only need to control the machine-side converter of the wind power converter in the online mode to stop. The cut-out operation means that the input and cut-out operation can be performed without stopping the machine, thereby realizing the fast online switching function, ensuring the continuity of the operation, optimizing the operation efficiency, and satisfying the needs of different occasions, including operation. In the case where the working condition changes in real time and cannot be interrupted; in addition, in this mode, even if the machine-side converter of a part of the wind power converter stops operating, the net-side converter throws and keeps running online, so that when When the high and low voltages pass through, the semi-offline wind power converter still has the function of reactive power support, so it can meet the applicability requirements of high and low voltage crossing and other power grids.

Preferably, at the initial startup, only one side converter and a grid side converter of the wind power converter can be activated, and all other wind power converters only start the grid side converter, and the machine side changes. The flow devices are not started, and the input and cut operations are performed as needed during the subsequent operation. This way, you can save energy.

In this embodiment, the number of converters that are put into operation is controlled according to the real-time power generation demand. When the power demand decreases, part of the wind power converter is cut out; when the power demand rises, the input part of the wind power converter is increased.

Calculate the number of wind turbine converters that need to be put into operation according to the real-time power or current demand of wind power generation, taking real-time power as an example (current demand is the same):

In theory, the number of single machines that need to be put into operation N

= (current real-time power generation / stand-alone power rating)

The “current real-time power generation” is the current real-time power generation detected, and “single-machine rated power” means the rated power of a single wind power converter.

In fact, preferably, when calculating the number of wind power converters to be put into operation, the calculation is performed according to the input logic and the cutting logic, wherein

The formula for calculating the number of wind power converters to be put into operation according to the input logic is:

N ₁ = [(current real-time power generation + ΔP ₁ ) / stand-alone power] take +1

The formula for calculating the number of wind turbine converters to be put into operation according to the cut-out logic is:

N ₂ = [(current real-time power generation + ΔP ₂ ) / stand-alone power] take +1

Where: ΔP ₁ , ΔP ₂ both refer to fixed compensation, and ΔP ₂ > ΔP ₁ >0, the rated power of a single machine refers to the rated power of a single back-to-back converter.

Among them, the result calculated according to the input logic is only used as a reference for increasing the input, and the result of the logical calculation is only used as a cut-off reference. That is to say, the input logic only manages the input, regardless of the cut-out; the logic is cut out only, regardless of the input, so that the repetition of the input and the cut-out can be avoided, and the backlash can be guaranteed.

Specifically, according to the above two formulas, since ΔP ₂ > ΔP ₁ > 0, N ₂ ≥ N ₁ , that is, the number of inputs required to calculate the logic according to the cut-out logic must be more than the number of stages calculated according to the input logic. In order to avoid frequent switching, a hysteresis must be made, and only when X>N2, the cutting action is performed. For example, if there are 3 wind power converters running online, according to the input logic calculation, only 2 units need to be put into operation, and according to the cutting logic calculation, 3 units must be put in. At this time, according to the cutting logic, Cut out; or, if there are 4 wind power converters running online, according to the input logic calculation, only 2 units need to be put into operation, and according to the cutting logic, 3 units should be put into operation. At this time, according to the cutting logic Counting, only one set is cut out; if three wind power converters are running online, according to the input logic calculation, only 4 units need to be put into operation, and according to the cut-out logic, 5 units must be put in, at this time, according to the input Logically, only one input is added.

In the input logic, when calculating the number of wind power converters that need to be put into operation, add a fixed compensation ΔP ₁ to the “current real-time power generation” to ensure early input and avoid the overload operation of the online single machine when the power rises rapidly; In the cutting logic, when calculating the number of wind power converters that need to be put into operation, a larger fixed compensation ΔP _{2 is} added to the “current real-time power generation demand” to further ensure the return difference.

In the present embodiment, the torque of each of the machine-side converters of the Y-type wind power converters that are originally in the standby state is gradually increased in the process of being put into operation; the X1 station originally in the online mode The torque reference of the machine-side converter of the wind power converter gradually becomes smaller until the torque reference of the machine-side converter of each of the X1+Y wind-electric converters is equal to the total torque The fixed 1/(X1+Y); during the input process, the torque given by the machine-side converter of the X1+Y wind turbine converter is always equal to the total torque reference. This setting allows for no impact during the input process.

Preferably, during the input process, the torque reference of the machine-side converter of each of the X1 wind power converters is always equal during the reduction process, and is equal to (total torque reference - Y The torque of the machine-side converter of the wind power converter that is added to the input is given) / X1; the torque of the machine-side converter of each of the Y wind power converters is given during the increase process It is always equal.

Preferably, the torque reference of the machine-side converter of each of the Y wind power converters is gradually increased from 0 to 1/(X1+Y) given by the total torque according to the set slope. In the cut-out process of the Z wind power converters originally in the online mode, the torque given by each machine-side converter is gradually reduced to 1 by the total torque given 1/X1, and the remaining The torque reference of the machine-side converter of the X1-Z stage of the wind power converter still in the online mode is gradually increased until the X1-Z stage is in the on-line converter of the wind power converter in the online mode. The moment given by the moment is equal to the total torque given, and the machine-side converter of each unit is equal to 1/(X1-Z) of the total torque given; during the cutting process, the Z-stage is cut out The torque of the machine-side converter of the wind power converter is given and the torque of the machine-side converter of the remaining X1-Z stage is still in the online mode. The sum of the torques is always equal to the total torque. set. This setting allows for no impact during the input process. When the torque reference is reduced to 0, the Z-stage cut-off wind-driven converter's machine-side converter stops running, but its grid-side converter remains online, so that when high and low voltage crossing occurs The semi-offline wind power converter still has reactive power support.

In other embodiments of the present invention, the starting point of the torque reference is not limited to 0, and may be 1% or other values.

Preferably, during the cutting process, the torque reference of the machine-side converter of each of the X1-Z stages still in the online mode is always equal in the process of increasing, equal to (Total torque is given - the torque of the machine-side converter of the wind turbine converter that is cut out is given) / (X1-Z); the Z-stage is cut out of the wind power converter The torque reference of the machine-side converter of the station is also always equal during the reduction process.

Preferably, the torque reference of the machine-side converter of each of the Z wind power converters is gradually reduced to 0 by a given gradient from 1/X given by the total converter. The specific control method of switching is explained below in two different embodiments.

The invention reduces the distance of the electrical connection and reduces the connection point of the electrical connection by reducing the power flow of the whole device from top to bottom by reasonable layout between the devices, thereby reducing the cost of the whole machine, reducing the line impedance and reducing Loss, improve efficiency, and can perform the switching operation without stopping the operation. It not only realizes online fast switching, but also optimizes the operating efficiency, and can also meet the needs of different occasions, including real-time changes in operating conditions and cannot be interrupted. In this case, in addition, under this control method, even if the machine-side converter of a part of the wind power converter stops running, the net-side converter throws and keeps running online, so that when high and low voltage crossing occurs, the semi-offline The wind power converter still has the function of reactive power support, so this control method can also meet the applicability requirements of high and low voltage crossing power grids.

While the invention has been described by the foregoing embodiments of the present invention, it should be understood that Various modifications, improvements or equivalents of the invention may be devised by those skilled in the art. Such modifications, improvements, or equivalents are also considered to be included within the scope of the present invention.

Claims

A wind power converter, characterized in that: the wind power converter comprises a wind power converter cabinet, a machine side component, a power unit assembly and a net side component arranged in the cabinet from top to bottom;

The power unit assembly is located at a lower portion of the machine side assembly, and an input port of the power unit assembly and an output port of the machine side assembly are electrically connected through a conductor;

The mesh side component is located at a lower portion of the power unit assembly, and an input port of the mesh side component and an output port of the power unit component are electrically connected through a conductor;

The grid side component includes a grid side inductor and a grid side switch, the grid side inductor is disposed under the power unit assembly, the grid side inductor and the power unit component are electrically connected through the conductor; and the grid side switch is disposed on one side of the grid side inductor. And electrical connection is made through the conductor.
The wind power converter according to claim 1, wherein said power unit assembly comprises at least one integrated single-phase module, said integrated single-phase module comprising integrated machine side modules, grid side modules and bus bars Capacitor, wherein the machine side module and the network side module are respectively disposed on both sides of the bus capacitor.
The wind power converter according to claim 2, wherein the machine side module, the bus bar capacitor and the net side module are longitudinally distributed, and the machine side module and the net side module are respectively disposed on upper and lower sides of the bus capacitor.
The wind power converter according to claim 2, wherein the machine side module is disposed adjacent to the machine side assembly.
The wind power converter according to claim 2, wherein the power unit assembly further comprises a driving single board, a module bus bar and an AC outlet port, wherein the bus bar capacitor is mounted on the module bus bar, and the module AC port is adjacent to the line.
The wind power converter according to claim 1 or 2, characterized in that the input port of the power unit assembly is provided at the top thereof, and the output port of the machine side assembly is provided at the lower portion thereof.
The wind power converter according to claim 1 or 2, wherein the input port of the mesh side component is disposed at an upper portion thereof, and the output port of the power unit assembly is disposed at a bottom thereof.
The wind power converter according to claim 1 or 2, wherein the machine side component is a circuit connector, or a combination of a circuit connector and a machine side switch, or a circuit connector and a machine side inductance. combination.
The wind power converter according to claim 1 or 2, wherein the machine side component is a combination of a circuit connector, a machine side switch, and a machine side inductance.
The wind power converter according to claim 9, wherein the machine side inductance is disposed above the power unit assembly, the machine side inductance and the power unit assembly are electrically connected through the conductor; and the machine side switch is disposed on the machine side inductance. On one side, the output port of the machine side inductor is disposed adjacent to the input port of the machine side switch, and is electrically connected through a conductor.
A control system for a wind power converter according to claim 1, comprising: N sets of wind power converters according to claim 1 in parallel, each of said wind power converters comprising a serial connection The machine side converter and the grid side converter, the other side of the machine side converter of the N wind power converters are connected to the motor, and the other side of the grid side converter is connected to the power grid. The power unit assembly includes a machine side power unit and a network side power unit, the machine side converter includes a machine side component and a machine side power unit, and the grid side converter includes a network side component and a network side power unit. The power unit assembly is located at a lower portion of the machine side assembly, and an input port of the power unit assembly and an output port of the machine side assembly are electrically connected by a conductor, the grid side assembly is located at a lower portion of the power unit assembly, and an input port of the grid side assembly And the output port of the power unit component is electrically connected by a conductor, the grid side component includes a grid side inductor and a grid side switch, the grid side inductor is disposed under the power unit component, and the grid side inductor and the power unit component pass through the conductor Connected; the network side switch is disposed on one side of the grid side inductor, and is electrically connected by a conductor. The control system of the wind power converter further includes a total dispatching module, and each of the wind power converters has a built-in a controller, each controller of the wind power converter is in communication with the total dispatching module, and each controller of the wind power converter communicates with the total dispatching module, each of the wind power The controller of the converter transmits information to the total dispatching module, and the total dispatching module calculates the number of wind power converters to be put into operation according to the current real-time power generation or the demand of the generated current.
A control method applied to the wind power converter control system according to claim 11, characterized in that:

The control system of the wind power converter comprises N sets of wind power converters according to claim 1 in parallel, each of the wind power converters comprises a serially connected machine side converter and a grid side converter The power unit assembly includes a machine side power unit and a network side power unit, the machine side converter includes a machine side component and a machine side power unit, and the grid side converter includes a network side component and a network side power a unit, the power unit assembly is located at a lower portion of the machine side assembly, and an input port of the power unit assembly and an output port of the machine side assembly are electrically connected by a conductor, the mesh side assembly is located at a lower portion of the power unit assembly, and the mesh side assembly The input port and the output port of the power unit component are electrically connected by a conductor, the grid side component includes a grid side inductor and a grid side switch, the grid side inductor is disposed under the power unit component, and the grid side inductor and the power unit component pass the conductor Electrical connection; the network side switch is disposed on one side of the grid side inductor, and is electrically connected by a conductor, and the other side of the machine side converter of the N wind power converters is connected to the motor, The other side by the converter are connected to the power control method of the parallel type converter comprising:

The first step is to set the X1 wind power converter to the online mode, the X2 wind power converter to the semi-offline mode, and X1+X2≦N; wherein the online mode is the grid side converter and the machine of the wind power converter. The side converters are all running online, the semi-offline mode is the grid side converter of the wind power converter running online, and the machine side converter of the wind power converter is stopped in the offline operation state;

The second step is to calculate the number of wind power converters to be put into operation according to the real-time power generation or the current demand of the power generation, and determine whether the number of the wind power converters is consistent with the current number of wind power converters in the online mode. If they are inconsistent, it is determined that the input needs to be increased. The number of wind power converters in the semi-offline mode or the number of wind power converters in the online mode that need to be cut out Z;

The third step is to increase the wind power converter that is put into the Y-semi-offline mode, or cut out the Z-line wind power converter.

The machine-side converter of the wind power converter of the Y-semi-offline mode is activated and put into the control system of the wind power converter, and the wind power converter of the Y-semi-offline mode is switched to the online mode, thereby realizing the Y New investment in wind power converters with semi-offline mode;

Or, the machine-side converter of the wind power converter that controls the cut-off Z-line mode is stopped, and the grid-side converter of the Z wind power converter is kept running online, and the wind power of the Z-line online mode is changed. The streamer is switched to the semi-offline mode, thereby realizing the cutting out of the Z-line online mode wind power converter.