CN209929740U - Electric structure of filtering loop of power grid side frequency converter and integrated machine for wind generating set - Google Patents

Abstract

The utility model discloses a filter circuit of a power grid side frequency converter, which comprises a fuse for a frequency conversion circuit, a contactor for the frequency conversion circuit and three filter capacitors which are used for being connected with the three-phase input of the power grid side frequency converter in a one-to-one correspondence manner; the method is characterized in that: the fuse for the frequency conversion loop is a three-phase fuse; the input side of the fuse for the variable frequency loop is connected with the output loop of the generator stator; the number of the contactors for the variable frequency circuit is one, and the input side of a normally open contact of the contactor for the variable frequency circuit is electrically connected with the output side of the fuse for the variable frequency circuit; a three-phase current transformer is arranged on a three-phase cable on the output side of a normally open contact of the contactor for the variable frequency circuit, and three filtering capacitors are correspondingly connected to the three phases on the output side of the normally open contact of the contactor for the variable frequency circuit one by one; and the control coil of the contactor for the frequency conversion loop is connected with a corresponding output interface on the PLC. The utility model also discloses an all-in-one electrical structure for wind turbine generator system who adopts above-mentioned filter circuit.

Description

Electric structure of filtering loop of power grid side frequency converter and integrated machine for wind generating set

Technical Field

The utility model belongs to the wind generating set field, concretely relates to electric structure of regulator cubicle that is used for wind generating set's tower footing interior to use.

Background

A wind generating set (wind generating set for short) is a device for converting clean, environment-friendly and renewable wind energy into electric energy.

The wind turbine mainly comprises a tower, a cabin and a wind wheel (the wind wheel comprises blades and a hub), the tower is fixed on the ground, and the whole wind wheel is rotatably arranged on the cabin through a main shaft and a bearing and is connected with a rotating shaft of a generator fixed in the cabin through a gearbox; the whole cabin can be horizontally and rotatably arranged on the top of the tower. An engine room control cabinet (used for yaw control, safety monitoring, tower footing control cabinet communication and the like) is installed in the engine room, and a tower footing control cabinet (used for data acquisition, power parameter monitoring, communication with the engine room control cabinet and the like) and a frequency conversion cabinet (internally comprising a grid-connected circuit, used for being connected with a power grid and a generator rotor through a transformer, power control and the like) are installed in the tower footing.

At present, in a tower footing, a tower footing control cabinet and a frequency conversion cabinet have the following defects:

1. the field installation is time-consuming and labor-consuming, and the installation efficiency is low; the installation costs and material costs are high.

Because the tower footing control cabinet and the frequency conversion cabinet are two cabinets which are independent from each other and are produced by different manufacturers, when the tower footing (the bottom of the tower barrel) is installed, the tower footing control cabinet and the frequency conversion cabinet need to be respectively and sequentially sent into the tower footing, and then corresponding interfaces on the two cabinet bodies are connected through cables to complete installation.

2. The volume and the occupied area are larger.

The size of the tower footing control cabinet is about (in millimeters): 600 deep × 1200 wide × 2200 high; the size of the frequency conversion cabinet is about (unit millimeter): 600 deep x 2300 wide x 2375 high. Therefore, the total width of the tower footing control cabinet and the frequency conversion cabinet arranged in the tower footing is about 3 m 5, so that the residual space in the tower footing is more tense.

Based on this, the applicant considers designing an all-in-one machine integrating grid connection, master control power distribution and frequency conversion devices in a cabinet body, but before the design, how to design an all-in-one machine electrical structure with a simpler structure, safety and reliability needs to be considered firstly.

Disclosure of Invention

To the not enough of above-mentioned prior art, the utility model aims to solve the technical problem that: how to provide a structure is simpler, safe and reliable's electric structure of filtering circuit and wind-driven generator group of electric wire netting side converter.

In order to solve the technical problem, the utility model discloses a following technical scheme:

the filter circuit of the power grid side frequency converter comprises a fuse for the frequency conversion circuit, a contactor for the frequency conversion circuit and three filter capacitors which are used for being connected with the three-phase input of the power grid side frequency converter in a one-to-one correspondence manner;

the method is characterized in that: the fuse for the frequency conversion loop is a three-phase fuse; the input side of the fuse for the variable frequency loop is connected with the output loop of the generator stator;

the number of the contactors for the variable frequency circuit is one, and the input side of a normally open contact of the contactor for the variable frequency circuit is electrically connected with the output side of the fuse for the variable frequency circuit; a three-phase current transformer is arranged on a three-phase cable on the output side of the normally open contact of the contactor for the frequency conversion loop, and the three filtering capacitors are correspondingly connected to the three phases on the output side of the normally open contact of the contactor for the frequency conversion loop one by one; and the frequency conversion loop is connected with a corresponding output interface on the PLC by a control coil of the contactor.

The filter circuit of the existing grid-side frequency converter is provided with a fuse with the fusing current of 550A in a main circuit where the fuse for the frequency conversion circuit is located, a fuse with the fusing current of 300A is installed in a branch of three filter capacitors, and the two fuses are more easily disconnected when being smaller than the rated fusing current in a high-temperature environment, so that the failure rate is higher, and the maintenance workload is increased. In addition, a plurality of contactors are arranged in a frequency conversion loop and a loop where a filter capacitor is located in a filter loop of the existing power grid side frequency converter, so that the device cost is high, a PLC output control interface is occupied, and the control difficulty is increased.

According to the technical scheme, the contactor and the fuse are arranged on the main loop, so that the circuit structure is simplified, and the device cost is reduced; meanwhile, a current transformer is additionally arranged on the main loop, so that the current parameters of the main loop are collected in real time and can be monitored in time, and the safety and the reliability are improved.

The integrated machine electrical structure for the wind turbine generator set comprises a filter circuit of the power grid side frequency converter.

Therefore, the integrated machine for the wind turbine generator set has the advantages of simpler circuit structure, lower device cost and higher reliability of the filter circuit.

Drawings

Fig. 1 is a schematic view of the three-dimensional structure of the integrated machine for wind turbine generator system according to the present invention (the front door panel of the main control distribution area and the rear door panel of the main control distribution area are both opened).

Fig. 2 is a front view (the door panel is opened before the main control distribution area) of the integrated machine for wind turbine generator system according to the present invention.

Fig. 3 is a front view of the main control power distribution area of fig. 2 (with the front door panel of the main control power distribution area open).

Fig. 4 is a rear view (the back door panel of the main control distribution area is opened) of the wind turbine generator integrated machine according to the present invention.

Fig. 5 is a rear view of the main control power distribution area in fig. 4 (the rear door panel of the main control power distribution area is opened).

Fig. 6 is a left side view of the merging area (left side panel removed).

FIG. 7 is a schematic diagram of the structure of the arc protector.

Fig. 8 is a schematic circuit diagram of a filter loop of a conventional grid-side converter.

Fig. 9 is a schematic circuit diagram of the filtering loop of the power grid side converter of the present invention.

Fig. 10 is the electrical structure schematic diagram of the integrated machine for wind turbine generator system of the present invention.

Fig. 11 is an enlarged view at I of fig. 10.

Fig. 12 is an enlarged view of fig. 10 at II.

Fig. 13 is an enlarged view at III of fig. 10.

Fig. 14 is an enlarged view at IV of fig. 10.

Labeled as:

grid-connected area (grid-connected unit):

100 main circuit breakers;

an arc protector: 101 transverse plates, 102 vertical plates and 103 support fixing plates;

an x exhaust fan;

a y louver port;

z a local heat dissipation fan;

s an electric heater;

104 a stator contactor;

105 current transformer.

Master power distribution area (master power distribution unit):

200 three-phase transformers;

201 a temperature sensor;

202 PLC；

203, controlling a front door panel of a power distribution area;

204, separating the board: 2041230V mounting region, 204224V mounting region;

205 switch (encryptor);

206 IBOX；

207 UPS；

208 supporting the plate;

209 a filter capacitor;

an x exhaust fan;

a y louver port;

s an electric heater;

a 210 fuse;

211 a rotor contactor;

212 single-phase transformer.

Frequency conversion region (frequency conversion unit):

an x exhaust fan;

and a y shutter air port.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 to 14:

the integrated machine for the wind turbine generator comprises a cabinet body, wherein a grid-connected unit, a master control power distribution unit and a frequency conversion unit are installed in the cabinet body;

the grid-connected unit comprises a main circuit breaker 100, wherein the input side of the main circuit breaker 100 is used for being connected with a stator winding of a generator of a wind turbine generator, and the output side of the main circuit breaker 100 is used for being connected with an alternating current power grid;

the main control power distribution unit comprises a three-phase transformer 200 and a PLC 202, wherein the input side of the three-phase transformer 200 is electrically connected with any side of a main breaker 100 of the grid-connected unit, and the output side of the three-phase transformer 200 forms a power supply of each power distribution loop; each input interface of the PLC is used for receiving various parameters, and each output interface of the PLC is used for being electrically connected with a control coil of a contactor in each power distribution loop;

the frequency conversion unit comprises a power grid side frequency converter, wherein the input side of the power grid side frequency converter is electrically connected with the alternating current power grid, and the output side of the power grid side frequency converter is connected with the input side of the rotor side three-phase frequency converter.

The output side of the rotor side three-phase frequency converter is used for being connected with a rotor winding of a wind turbine generator, and the power grid side frequency converter and the rotor side three-phase frequency converter jointly realize control over the rotating speed of a rotating magnetic field in the wind turbine generator in the engine room. The operation of the double-fed wind generating set is divided into three states of synchronization (the rotating speed of a rotor is 50 revolutions per second), subsynchronous rotor rotating speed is lower than 50 revolutions per second) and supersynchronous (the rotating speed of the rotor is higher than 50 revolutions per second); the operation and control principle of the grid-side frequency converter and the rotor-side three-phase frequency converter in each state is common knowledge of those skilled in the art, and will not be described herein.

Compared with the prior art, the integrated machine for the wind turbine generator has the advantages that:

1. on-site arrangement and installation are more efficient

In the prior art, 2 cabinets (a tower footing control cabinet and a frequency conversion cabinet (including a grid-connected cabinet)) are adopted in a tower footing; the integrated machine integrates a grid-connected unit, a main control power distribution unit and a frequency conversion unit into a cabinet body; thus, a whole cabinet can be directly assembled in a workshop; on the spot, the wind turbine generator is lifted in place by the integrated machine once, and then the distribution is finished, so that the carrying process and the process of communicating the corresponding interfaces of the tower footing control cabinet and the frequency conversion cabinet on the spot are saved, the arrangement and installation efficiency on the spot is greatly improved, the installation difficulty of the cabinet body in the tower footing is reduced, and the accuracy of the one-time installation in place can be effectively ensured.

2. Has more compact structure and lower manufacturing cost

In the prior art, a frequency conversion cabinet supplies power to a main control power distribution cabinet (various power supply interfaces are arranged on two corresponding cabinets, and a connecting cable is required to be adopted between the power supply interfaces), and a can bus is required to be adopted between the frequency conversion cabinet and the main control power distribution cabinet for communication connection (a communication interface is arranged correspondingly, and a communication cable is adopted between the communication interfaces).

According to the technical scheme, the grid-connected unit, the main control power distribution unit and the frequency conversion unit are integrated in one cabinet body, so that an interface between the tower footing control cabinet and the frequency conversion cabinet can be eliminated; and the mutual connection distance is shorter, so that the consumption of the cable can be saved, the whole manufacturing cost is saved, and the benefit is improved.

Meanwhile, compared with the prior tower footing control cabinet and the prior frequency conversion cabinet which are exposed outside the cabinets, the integrated machine for the wind turbine generator is directly connected in the cabinet, so that the shell of the cabinet can be directly utilized to form protection, the fault caused by gnawing of the cable mouse is avoided, and the reliability of internal wiring is better ensured.

The width of the cabinet body is greater than the depth, the grid-connected unit, the master control power distribution unit and the frequency conversion unit are arranged along the width direction of the cabinet body in sequence, and the cabinet body is sequentially a grid-connected area, a master control power distribution area and a frequency conversion area along the width direction.

By adopting the structure cabinet body structure, the grid-connected unit, the main control power distribution unit and the frequency conversion unit can be rapidly installed in the cabinet body during production, and the production efficiency of the all-in-one machine for the wind turbine generator is effectively ensured.

And the position between two adjacent areas in the grid-connected area, the master control power distribution area and the frequency conversion area is fixed with an isolation plate inside the cabinet body.

The setting of above-mentioned division board not only can make and net district, master control distribution district and frequency conversion district independently open and protect respectively, can also effectively reduce the influence of electromagnetic interference and temperature or humidity between two adjacent regions, better ensures the security and the reliability of this regional environment.

Wherein, the depth of the cabinet body is 500 to 650 millimeters, the width is 2500 to 2650 millimeters, and the height is 2200 millimeters to 2400 millimeters.

By adopting the cabinet body with the optimal size, the width and the size of the cabinet body can be reduced, the compactness is improved, and the occupied area in the tower footing is reduced, so that the size required by the tower footing can be reduced, the wind turbine generator set is helped to reduce the manufacturing cost and the cost, and the better cost performance is achieved.

The existing tower footing control cabinet and frequency conversion cabinet which are arranged in the tower footing are approximately 600 mm in depth, 3500 mm in width and 2200 and 2375 mm in height.

In practice, the depth of the cabinet is preferably 600 mm, the width is 2600 mm, and the height is 2375 mm (without a binding wire frame). Therefore, the integrated machine for the wind turbine generator set can obviously shorten the width of the cabinet body (by about 0.9 m), effectively reduce the occupied area of the cabinet body in the tower footing, further help to reduce the size of the tower footing, reduce the overall cost of the tower footing and improve the economic benefit.

The master power distribution unit is shown in fig. 1 to 5:

the area where the main control power distribution unit is located in the width direction of the cabinet body is a main control power distribution area;

a main control power distribution area front door panel 203 is arranged at the position of the main control power distribution area on the front panel of the cabinet body;

the main control power distribution unit further comprises a partition plate 204, the partition plate 204 is vertically fixed in the cabinet body and is integrally located in the middle position of the depth direction of the cabinet body, and the depth direction of the interior of the cabinet body of the main control power distribution area is divided into a front side installation space and a rear side installation space by the partition plate 204;

the front side installation space is provided with a PLC, and the rear side installation space is provided with a three-phase transformer 200.

The advantage of adopting above-mentioned main control distribution district and main control power supply and distribution unit is "optimize the inside spatial structure and the device overall arrangement in main control distribution district, promote convenience and the security of using", and concrete reason is:

1. the space is separated, thereby being beneficial to fully utilizing the space and optimizing the layout of various devices

The main control power distribution unit includes a partition plate 204, and the partition plate 204 can perform a partition function and partition "the depth direction in the cabinet body of the main control power distribution area into a front side installation space and a rear side installation space".

Adopt "front side installation space to install PLC, rear side installation space installs three-phase transformer 200"'s structure for PLC department is in front side installation space, and front side installation space is closer apart from main control distribution district front door plant 203, so can open main control distribution district front door plant 203 after realize PLC's quick dimension and examine, improve the speed of troubleshooting of trouble.

2. Improve the convenience and the safety of use

Through division board 204, after the front side installation space and the rear side installation space that separate into, the overall arrangement has fully considered strong, weak electric subregion, each control function subregion, and the cable is walked the line convenience, pleasing to the eye aspect etc.. Meanwhile, the three-phase transformer 200 with higher voltage level is placed in the rear mounting space, and the partition plate 204 can also prevent human bodies from touching the three-phase transformer 200 by mistake, so that the use safety is improved.

In practice, the capacity of the three-phase transformer 200 is preferably 90 kVA. In the prior art, the three-phase transformer 200 is enough to adopt the capacity of 130 kVA; after the technical scheme is optimized, the power supply requirement can be met only by adopting the three-phase transformer 200 with the capacity of 90kVA, so that the volume of the three-phase transformer 200 can be reduced, the purchase cost of the three-phase transformer 200 can also be reduced, the manufacturing cost of the whole machine is reduced, and better benefits are obtained.

Wherein the PLC is fixedly installed at a front side surface of the partition plate 204.

Thus, the partition plate 204 has a partition function and also forms a mounting plate, so that a larger mounting area is formed in the cabinet body where the main control power distribution area is located, the space in the cabinet body can be utilized more fully, and the size of the cabinet body is effectively reduced.

Meanwhile, the front side surface of the partition plate 204 faces and faces the front door plate 203 of the main control power distribution area, so that the PLC can be visually seen by opening the door plate, and the maintenance inspection, the detection or the setting can be conveniently carried out, and the maintenance inspection and the use efficiency can be improved.

A single-phase transformer 212 is also fixedly installed in the rear-side installation space, the input side of the single-phase transformer 212 is connected with any two phases of the three-phase transformer 200, and the output side of the single-phase transformer 212 has an output voltage level of 230V and is used for supplying power to the PLC and the low-voltage power supply circuit.

In practice, the single-phase transformer 212 preferably has a capacity of 3kVA, and the single-phase transformer 212 is mainly used for supplying power to the PLC and for supplying power to the UPS 207 (uninterruptible power supply) that ensures reliable power supply to the PLC.

Therefore, the power supply loop of the PLC is simpler, and the PLC can be normally used without an external power supply cable.

The front side surface of the partition plate 204 is sequentially provided with a 230V installation area 2041 and a 24V installation area 2042 from left to right in the transverse direction, wherein the PLC is located in the 230V installation area 2041, a switch 205 is fixedly installed in the 24V installation area 2042, and the switch 205 is used for being in communication connection with the PLC.

The wiring and usage of the switch 205 are well known to those skilled in the art and will not be described herein.

In practice, a monitor (IBOX 206) of the fan control system is also fixedly mounted in the 24V mounting area 2042, and is connected between the PLC and the switch 205, and is used to have a higher data collection frequency, so that richer data can be obtained from the PLC, thereby helping to realize faster fault diagnosis. The monitor of the fan control system (IBOX 206) is prior art, see publication (bulletin) No.: CN205036506U, CN207470355U and CN 105134493B. And will not be described in detail herein.

In implementation, an encryption machine is further fixedly installed in the 24V installation area 2042, and the encryption machine is connected to the switch 205 through network cable communication. The encryptor is an existing device, and the usage thereof is the prior art, which is not described herein in detail.

This may have the advantage of:

1. after the mounting regions of the two voltage classes are formed, firstly, various devices are difficult to mount incorrectly, and the accuracy of device mounting is better ensured. Secondly, make the installation overall arrangement more reasonable regular, optimize the outward appearance.

2. During maintenance, fault points or devices can be found and positioned quickly, and therefore troubleshooting and troubleshooting efficiency is improved.

Wherein, door plant 203 is two open door structures before the main control distribution area.

Therefore, the external space required by opening the cabinet door can be reduced, and the cabinet door is more suitable for being used in a narrow space.

And a button and/or a display panel which is connected with a PLC signal are/is arranged on the left door plate in the double-door structure.

Therefore, the wiring distance between the button and/or the display panel and the PLC is shorter, the using length of a connecting cable is reduced, and the cost is reduced.

And a PCB control panel of the power grid side frequency converter is fixedly arranged on the inner side of the right door panel in the double-door structure.

The PCB control board is used for controlling the power module in the frequency conversion unit. In the prior art, a PCB control panel is arranged in a frequency conversion cabinet.

In this technical scheme, the inner space of the cabinet body that not only can more abundant utilization main control distribution district belongs to also can help reducing the volume of frequency conversion unit place cabinet body part, effectively helps reducing the cabinet body size of all-in-one for the wind turbine generator system. Meanwhile, the power module in the PCB control board adjacent to the frequency conversion unit can be ensured by adopting the method, the wiring length of the required cable is reduced, and the cost control effect is ideal.

The master control power distribution area further comprises a UPS 207 and a support panel 208;

the internal portion of cabinet at master control distribution district place is located division board 204 top position department fixed mounting has one support flat board 208, UPS 207 fixed mounting be in support flat board 208's upper surface, just UPS 207 electric connection be in single phase transformer 212 with on the return circuit between the PLC.

The UPS 207 and the supporting flat plate 208 have the advantages that:

1. the reliability of the PLC power supply, and thus the reliability of the PLC control functions, may be ensured through the UPS 207 without interruption.

2. The supporting plate 208 is integrally positioned above the partition plate 204, so that heat generated by the UPS 207 in operation and use cannot be conducted and radiated downwards, and a better temperature control effect is obtained; and ensures that the devices in the space in front of and behind the partition plate 204 can be always in a more proper temperature range, thereby better ensuring the operation reliability of all the devices.

The UPS 207 is a mature product, and its structure and use are known to those skilled in the art, and will not be described herein.

The main control power distribution area further comprises a filter, and the filter comprises three filter capacitors 209 which are connected with three-phase inputs of the power grid side frequency converter in a one-to-one correspondence manner; the filter is fixedly mounted on the upper plate surface of the support plate 208.

In the prior art, the filter is also assembled in the frequency conversion cabinet.

By adopting the arrangement scheme of the filter, the filter can be used for filtering high-frequency harmonic waves in an alternating current power grid; the space required by the frequency conversion cabinet can be effectively reduced; in addition, the wave filter can generate heat in the in-service use process, and after the wave filter is installed on the upper plate surface of the supporting flat plate 208, the heat emitted by the wave filter in the operation use process can not be conducted and radiated downwards, so that the temperature rise degree in the cabinet is avoided, and the operation reliability of all devices is better ensured.

The main control power distribution area further comprises a main control power distribution area heat dissipation structure, and the main control power distribution area heat dissipation structure comprises an exhaust fan x and a louver port y;

the louver air inlet y is fixedly arranged at the bottom position of the front door panel 203 of the main control power distribution area, and the exhaust fan x is fixedly arranged at the top position of the front door panel 203 of the main control power distribution area.

In the heat dissipation structure, the bottom of the door panel is provided with the louver air port y, and the top of the door panel is provided with the exhaust fan x, so that the airflow in the main control power distribution area flows from bottom to top; and the cold air entering through the louver port y can form sufficient heat exchange along the airflow direction, gradually becomes lighter hot air with higher rising speed after absorbing the heat of various devices, and finally forms negative pressure in the cabinet body after being exhausted from the exhaust fan x in an accelerated manner, so that the air inlet speed at the louver port y is increased, and finally, the cabinet body can be maintained in a proper temperature range, and the operation reliability of various devices is ensured.

During implementation, louver air openings y (with filter screens) are fixedly arranged at the bottoms of the double door panels of the front door panel 203 of the main control power distribution area; and the exhaust fan x is arranged on one of the double door plates of the front door plate 203 of the main control power distribution area, which is opposite to the filter. Therefore, heat emitted by the filter can be removed as soon as possible, and heat extraction and heat dissipation effects inside the cabinet body are better guaranteed.

When the cabinet is implemented, a main control power distribution area rear door plate is arranged at the position of the main control power distribution area on the rear panel of the cabinet body, and the main control power distribution area rear door plate is of a double-door structure; similarly, the exhaust fan x is also installed at the top of the rear door panel of the main control power distribution area, and the louver air opening y is installed at the bottom of the rear door panel of the main control power distribution area.

In practice, the louver opening y and the exhaust fan x are preferably provided with filter screens. Like this, can avoid the dust to get into cabinet body inside and consequently reduce the insulating properties and the heat dispersion of cabinet body inside device, ensure operational reliability better.

When the main control power distribution unit is implemented, the main control power distribution unit further includes a fuse 210, the fuse 210 is a fuse 210 for a variable frequency circuit, the fuse 210 is a three-phase fuse 210 of 630A, the fuse 210 is fixedly installed on the rear side surface of the partition plate 204, and the fuse 210 is connected between an alternating current power grid and the filter. In the prior art, a 550A fuse 210 is adopted, and the fuse 210 is installed in a frequency conversion cabinet; in the technical scheme, after the fuse 210 is integrated into the main control power distribution area, the rated current is increased by one gear (from 550A to 630A), and the short-circuit protection capability of the loop is not influenced; in addition, the 630A fuse 210 can better adapt to a high-temperature environment (with more devices, larger heat generation amount during the operation of the devices) in the cabinet of the master control power distribution area, and the use reliability is improved.

In implementation, the main control power distribution unit further includes a rotor contactor 211 (ABB model AX 370) fixedly installed on the rear side surface of the partition plate 204, and the rotor contactor 211 is a contactor for a variable frequency loop; the rotor contactor 211 is connected between the input side of the grid-side frequency converter and the ac grid. Therefore, the using quantity of the contactors (2 contactors are arranged in a loop of the filter capacitor 209) can be reduced, the setting space required by devices in a frequency conversion area is reduced, and the heat resistance and the reliability of the integrated machine can be improved.

In implementation, a temperature sensor 201 is fixedly installed at a position above the rear side surface of the partition plate 204, and the temperature sensor 201 is connected with a PLC signal.

As fig. 6 and 7 show arc protection and grid connection units:

the arc protector comprises a transverse plate 101 and two vertical plates 102 made of insulating materials, wherein the transverse plate 101 and the vertical plates 102 can be fixedly connected and jointly form an -shaped structure, the -shaped structure is formed with three input compartments at the upper part and three output compartments at the lower part, and the three input compartments and the three output compartments are used for isolating three input busbars and three output busbars at the back part of the circuit breaker from each other.

The wind turbine generator is often installed in a region with high altitude, high air humidity and much wind, air with high humidity is broken down by voltage, so that electric arcs are easily formed between any adjacent busbars on the back of the circuit breaker due to the fact that the air breaks down an air layer by the voltage, when the electric arcs are formed, a large amount of electrons are generated by the air, the electric conductivity is rapidly improved, and the electric arcs cannot be extinguished even if the distance between two conductors is continuously increased (the phenomenon is also called as arc discharge); the generation of electric arcs easily causes short circuit, causes electrical accidents and has high harmfulness.

After the arc protector is adopted, the transverse plate 101 and the vertical plates 102 can be fixed into the -shaped structure to separate the busbars on the back of the circuit breaker, so that the generation of electric arcs is effectively avoided, and the safety and the reliability are better ensured.

Wherein, the horizontal plate 101 and the two vertical plates 102 are made of mica plates.

The mica plate has the advantages that the temperature resistance of the mica plate reaches 500 ℃, the voltage breakdown resistance index reaches 20kV/mm, and therefore, the mica plate has excellent high-temperature-resistant insulating property.

Vertical plate clamping grooves are formed in the surface of the transverse plate 101 in a penetrating mode, two vertical plate clamping grooves are formed in the length direction of the transverse plate 101 at intervals, and the width of each vertical plate clamping groove is close to the thickness of each vertical plate 102;

the face of each vertical plate 102 is provided with a transverse plate clamping groove in a penetrating manner, the transverse plate clamping groove is located in the middle of the vertical plate 102 in the height direction, and the width of the transverse plate clamping groove is close to the thickness of the transverse plate 101.

When the transverse plate 101 and the two vertical plates 102 are used:

firstly, a transverse plate 101 is horizontally placed, and a vertical plate clamping groove on the transverse plate 101 faces outwards;

then, each vertical plate 102 is vertically placed one by one, and the notches of the transverse plate clamping grooves on the vertical plates 102 are opposite to the notches of the vertical plate clamping grooves on the transverse plates 101 and are inserted, so that the vertical plates 102 and the transverse plates 101 are spliced and fixed together to form a structure shaped like ''.

As can be seen, the assembly between the transverse plate 101 and the vertical plate 102 is very simple and fast; meanwhile, the transverse plate 101 and the vertical plate 102 which are not assembled are of an integral thin plate structure, are easy to stack and occupy less space, and the storage effect is good.

The arc protector also comprises a supporting and fixing plate 103, the supporting and fixing plate 103 is integrally of a long strip plate-shaped structure, and two ends of the supporting and fixing plate 103 in the length direction can be fixed on the inner side surface of the cabinet body through connecting pieces;

the upper ends of the two vertical plates 102 are fixedly connected with the supporting and fixing plate 103.

In this way, the two vertical plates 102 and the horizontal plate 101 can be fixedly mounted only by the fixing support fixing plate 103, and the mounting is simple and efficient.

Each vertical plate 102 is of an inverted L-shaped structure, and the outer end of the transverse edge part of the inverted L-shaped structure is clamped and fixed in a clamping groove correspondingly arranged on the surface of the supporting and fixing plate 103.

In this way, the assembling structure between the vertical plate 102 and the supporting and fixing plate 103 is also very simple, convenient and fast, and the arrangement and installation speed of the arc protector is further improved.

The grid-connected unit comprises a main circuit breaker 100 fixedly installed in a cabinet body, wherein the input side of the main circuit breaker 100 is used for being connected with a stator winding of a generator of a wind turbine generator, and the output side of the main circuit breaker 100 is used for being connected with an alternating current power grid; the arc protector is also included.

By adopting the grid-connected unit of the arc protector, the electric arc between two adjacent busbars on the back of the circuit breaker is avoided, and the safety and reliability of the grid-connected unit can be further improved.

The grid-connected unit also comprises an exhaust fan x and a louver port y, and the exhaust fan x is fixedly installed on a front panel of the cabinet body where the grid-connected unit is located; and the louver air opening y is fixed on the front and rear panels of the cabinet body where the grid-connected unit is located.

After adopting above-mentioned structure, can be in high temperature season or when the internal temperature of cabinet is too high, start exhaust fan x and come the internal gas flow of cabinet with higher speed to promote the internal heat dispersion of cabinet, locate in the suitable temperature range better to ensure in the cabinet.

The exhaust fans x are respectively and fixedly installed at the top and the bottom of the front panel of the cabinet body where the grid-connected unit is located.

Therefore, the heat dissipation efficiency in the cabinet body where the grid-connected unit is located can be accelerated through the two exhaust fans x; and, two exhaust fan x position are close to top cable junction room and bottom cable junction room to can strengthen the air current intensity of two cable junction rooms, effectively prevent the node intensification, better ensure the reliability of node connection.

And 2 louver air openings y are arranged on the right rear panel of the cabinet body where the grid-connected unit is positioned and at intervals at the positions of the breaker chamber and below the breaker chamber.

Therefore, cold air sucked by the louver air opening y can be blown from the lower part of the circuit breaker and the back part of the circuit breaker, and the whole circuit breaker obtains a more ideal heat dissipation effect.

Meanwhile, the louver port y in the breaker chamber is matched with the exhaust fan x on the front panel of the cabinet body, so that cold air entering through the louver port y in the breaker chamber can rise after absorbing heat and is exhausted through the exhaust fan x on the front panel of the cabinet body.

In implementation, a three-phase transformer 200 in the main control power distribution unit is correspondingly connected with an input side bus of the circuit breaker; a local heat radiation fan z is fixedly arranged above the breaker chamber and below the top cable wiring chamber; the air outlet of the local cooling fan z faces the junction between the three-phase transformer 200 and the input-side bus of the circuit breaker. Thus, the heat dissipation effect at the connection node between the three-phase transformer 200 and the input-side bus of the circuit breaker can be ensured by the local heat dissipation fan z, and the reliability of the connection at the connection node can be ensured.

The grid-connected unit further comprises an electric heater s, the electric heater s is provided with an exhaust fan x, and the electric heater s is fixed on a front panel of the cabinet body where the grid-connected unit is located and located at a position below the circuit breaker.

In this way, in cold or humid weather, the electric heater s emits hot air and causes the hot air to rise and be discharged from the top exhaust fan x. The electric heater s can prevent condensation phenomenon, avoid short circuit easily caused by condensation, and better ensure the reliability of the grid-connected unit for durable use.

In practice, the air exhausting direction of the electric heater s is from top to bottom. Therefore, the hot air heated by the heater can be quickly filled in the cabinet body, and a better condensation preventing effect is obtained.

Fig. 8 to 14 show the utility model discloses the electric structure of the filtering circuit of grid side converter and wind generating set all-in-one machine:

the filter circuit comprises a fuse 210 for the frequency conversion circuit, a contactor for the frequency conversion circuit and three filter capacitors 209 which are used for being connected with the three-phase input of the frequency converter on the power grid side in a one-to-one correspondence manner;

the method is characterized in that: the fuse 210 for the frequency conversion loop is a three-phase fuse 210; the input side of the variable frequency loop fuse 210 is connected with the generator stator output loop;

the number of the frequency conversion loop contactors is one, and the input sides of the normally open contacts of the frequency conversion loop contactors are electrically connected with the output side of the frequency conversion loop fuse 210; a three-phase current transformer 105 is arranged on a three-phase cable on the output side of the normally open contact of the contactor for the variable frequency circuit, and the three filtering capacitors 209 are correspondingly connected to the three phases on the output side of the normally open contact of the contactor for the variable frequency circuit one by one; and the frequency conversion loop is connected with a corresponding output interface on the PLC by a control coil of the contactor.

In the filter circuit of the existing grid-side frequency converter, a fuse 210 with the fusing current of 550A is arranged in a main circuit where a fuse 210 for the frequency conversion circuit is located, a fuse 210 with the fusing current of 300A is arranged in a branch of three filter capacitors 209, and the two fuses 210 are more easily disconnected when being smaller than the rated fusing current in a high-temperature environment, so that the failure rate is higher, and the maintenance workload is increased. In addition, a plurality of contactors are arranged in a frequency conversion loop and a loop where a filter capacitor 209 is located in a filter loop of the existing power grid side frequency converter, so that the cost of devices is high, and a PLC output control interface is occupied, and the control difficulty is increased.

According to the technical scheme, the contactor and the fuse 210 are arranged on the main circuit, so that the circuit structure is simplified, and the device cost is reduced; meanwhile, a current transformer 105 is additionally arranged on the main loop, so that the current parameters of the main loop can be acquired in real time and can be monitored in time, and the safety and the reliability are improved.

In practice, the grid-side filter (i.e. the three filter capacitors 209) of the grid-side frequency converter and its wiring are known to those skilled in the art and will not be described herein.

The blowing current of the inverter circuit fuse 210 is 630A.

Because the all-in-one machine for the wind turbine generator in the technical scheme transfers some devices (such as the UPS 207, the transformer and the filter capacitor 209) originally arranged in the frequency converter into the cabinet body where the main control power distribution area is located. Therefore, devices in the main control power distribution area are increased and concentrated, and the heat productivity in the cabinet is also obviously increased.

Therefore, the 550A fuse 210 used in the filter circuit of the conventional grid-side inverter has a high failure rate in a high-temperature environment (high heat generation amount). After the fuse 210 with the fusing current of 630A is adopted in the technical scheme, the use reliability of the fuse 210 can be improved; and the rated current is only increased by one gear, so that the short-circuit protection capability of the loop is not influenced, and the use safety is ensured.

In practice, the contactor has a rated operating current of 370A.

The fuse 210 for the frequency conversion loop, the contactor for the frequency conversion loop and the three filter capacitors 209 are all fixedly installed inside a cabinet body where the main control power distribution area is located.

Therefore, the occupied space required by the devices in the frequency conversion area can be reduced, the space of the master control power distribution area is fully utilized, and the size and the volume of the all-in-one machine for the wind turbine generator are effectively reduced.

Two normally open stator contactors 104 are connected in parallel between the input side of the fuse 210 and the output loop of the generator stator, and the control coils of the two stator contactors 104 are connected to corresponding output interfaces on the PLC.

The two stator contactors 104 are arranged, so that the grid connection safety and reliability of the wind generating set can be improved, and adverse effects on an alternating current power grid are avoided; the safety of the power grid is better ensured.

The integrated machine electrical structure for the wind turbine generator comprises a filter circuit of the power grid side frequency converter.

Therefore, the integrated machine for the wind turbine generator set has the advantages of simpler circuit structure, lower device cost and higher reliability of the filter circuit.

The electrical structure of the all-in-one machine for the wind turbine generator further comprises a main circuit breaker 100 and a three-phase transformer 200, wherein the input side of the main circuit breaker 100 is connected with the output sides of the two normally-open stator contactors 104, and the output side of the main circuit breaker 100 is connected with the input side of the three-phase transformer 200;

the all-in-one electrical structure for the wind turbine generator further comprises a heating loop, wherein the heating loop comprises a plurality of electric heaters s which are arranged in a grid-connected area, a master control power distribution area and a frequency conversion area in the cabinet body respectively and connected in parallel, and the plurality of electric heaters s are electrically connected with the single phase of the three-phase transformer 200.

After the heating loop is adopted, the electric heater s can be started to heat and dehumidify in a low-temperature or high-humidity environment, and the temperature and humidity environment in the integrated cabinet for the wind turbine generator set are adjusted so that various devices can be operated and used durably and reliably.

Wherein, all-in-one electrical structure for wind turbine generator system still includes heat dissipation loop, heat dissipation loop includes and sets up respectively and a plurality of exhaust fan x that connect in grid-connected area, main control distribution district and the frequency conversion district that the cabinet is internal, a plurality of exhaust fan x with three-phase transformer 200's single-phase electric connection, and be provided with at least one and one at the cabinet body that grid-connected area, main control distribution district and frequency conversion district located respectively the tripe wind gap y that exhaust fan x corresponds.

After the heat dissipation loop is adopted, the exhaust fan x can be started to accelerate the air flow speed in the cabinet body when the heat productivity in the cabinet body is large, and the heat dissipation effect is improved; the environment of the devices in the cabinet body is ensured to be more suitable.

The 230V power supply loop comprises a single-phase transformer 212 and a UPS 207, the output side of the single-phase transformer 212 is connected with any two phases of the three-phase transformer 200, the input side of the single-phase transformer 212 is connected with the input interface of the UPS 207, the input interface of the UPS 207 is connected with the input interface of a switching power supply, and the output of the switching power supply is 24V direct-current power supply.

In practice, the UPS 207 is preferably a tower type, and the storage battery of the UPS 207 is located outside the tower type.

By adopting the 230V power supply loop, reliable power supply of the PLC, various sensors and the circuit board can be effectively ensured, and the use safety and reliability are improved.

The all-in-one machine electrical structure for the wind turbine generator further comprises a main control distribution area maintenance detection loop, the main control distribution area maintenance detection loop comprises a power interface, and the power interface is supplied by the single-phase power supply of the three-phase transformer 200.

When the maintenance detection circuit is implemented, the maintenance detection circuit of the master control power distribution area further comprises an illuminating lamp connected with the power interface in parallel, and the illuminating lamp is arranged in the front side installation space of the cabinet body where the master control power distribution area is located.

Above-mentioned main control distribution district dimension is examined and is used return circuit setting, is convenient for obtain power supply interface when examining and repairing the main control distribution district and supplies to examine and repair the device or maintainer to use, promotes the practicality.

The main control power distribution area dimension detection loop further comprises a flashlight charging seat, the flashlight charging seat is connected with the power interface in parallel, the flashlight charging seat is fixed in the front side installation space of the cabinet body where the main control power distribution area is located, and the flashlight charging seat is provided with a rechargeable flashlight.

After the flashlight charging seat and the rechargeable flashlight are adopted, good illumination can be obtained through the rechargeable flashlight when the flashlight is overhauled, and then maintenance efficiency is improved.

During implementation, the all-in-one machine electrical structure for the wind turbine generator further comprises a tower power distribution loop which is connected with the main control power distribution area dimension detection loop in parallel, and the tower power distribution loop comprises a tower elevator power supply loop, a tower illumination control loop, a tower foundation fire-fighting system power supply loop and a tower foundation video system power supply loop.

To sum up, this wind turbine generator system uses all-in-one has the advantage to be:

1. reduce cost and sum more than 2 ten thousand yuan

Compared with the original tower footing control cabinet and the frequency conversion cabinet, the integrated machine has two cabinets, non-standard sheet metal parts such as mounting plates, cross beams and the like in the cabinets are correspondingly reduced, and equipment such as heaters, filtering fans, temperature control and the like for heating and radiating the cabinets are also correspondingly reduced; through the fusion optimization design, interfaces (such as an auxiliary power supply 690V interface, a current measurement interface, a communication interface between cabinet bodies, a frequency converter 400V power supply interface, a frequency converter UPS230V power supply interface, a frequency converter emergency stop button loop interface and the like) used for connecting the original tower footing control cabinet and the frequency conversion cabinet are greatly reduced, and devices and terminals of the part are correspondingly reduced; only one set of lightning protection device (in a grid-connected unit) is needed after circuit integration, the 100-F1 fuse is reserved, and a 300-F1 filter fuse and the like are eliminated, so that a part of electric components are saved.

Besides the direct reduction of material purchasing and cost reduction, a series of advantages are brought, wherein the production and assembly processes are fewer; lower logistics transportation cost; faster debugging, hoisting, etc.

Compared with a tower foundation control cabinet and a frequency conversion cabinet, the integrated structure design of the wind turbine generator system enables the number of cabinet bodies to be reduced from 5 to 3, and the use amount of the cabinet is directly reduced; a large number of standard mounting accessories and non-standard sheet metal parts in the cabinet are reduced; the number of the mounting plates in the cabinet is reduced from 3 to 2; the accessories such as a large cradle with higher cost and the like are eliminated; the packaging box is changed into a set from 2 sets.

In summary, compared with the original tower footing control cabinet and the original frequency conversion cabinet, the integrated machine for the wind turbine generator set has the advantage that the comprehensive cost is reduced by not less than 2 ten thousand yuan.

2. The equipment is miniaturized and the total volume of the product is reduced

The integrated machine grid-connected region for the wind turbine generator has the overall dimension of 500(W) × 600(D) × 2200(H), is mainly used for installing a main breaker and a busbar for connecting a stator and a power grid, and needs to keep the complete function of a left cabinet grid-connected cabinet of an original power cabinet; the overall dimension of the frequency conversion zone of the integrated machine for the wind turbine generator is 1200(W) × 600(D) × 2200(H), and the grid side IGBT power module, the machine side IGBT power module, the reactor and the fault crossing module are mainly installed, so that the complete functions of the original right cabinet power cabinet are required to be kept, and the two cabinets have single functions and compact layout.

In order to reduce the electromagnetic interference on the control board group and reduce the interference of high-temperature devices on temperature-sensitive devices, the middle cabinet is divided into a front layer, a middle layer and a rear layer of relatively independent installation spaces in the depth direction of the main control power distribution area (see fig. 2, 3 and 5). The front layer space is mainly used for installing a core control board group, a touch screen, a cabinet door lamp and a button; the middle layer space is mainly used for installing a main installation plate, and the installation plate comprises low-voltage elements such as a PLC (programmable logic controller), an IBOX (International Business machines on ox), a switch and the like; the back layer space is mainly used for mounting an auxiliary mounting plate and a transformer, and a temperature control device, a fuse, a contactor and the like are mounted on the mounting plate. An independent space for installing a UPS, a UPS battery and a filter capacitor is designed above the inside of the cabinet. A 292 air suction fan and two filter screens are arranged on the front layer; and a 292 air suction fan, a 224 air suction fan and two filter screens are arranged on the rear layer. The temperature rise of the integrated machine is ensured to meet the requirement of the operating condition of the product at minus 35 ℃ to plus 50 ℃.

Generally, the all-in-one machine for the wind turbine generator system of the scheme is compared with an original tower footing control cabinet and a frequency conversion cabinet, and the total occupied area of equipment is reduced by not less than 20%.

3. The functions, the using environment and the technical requirements are not changed

By optimizing the spatial layout and optimizing, upgrading and changing the types of a part of devices, the functions, the use environment conditions and the technical requirements of the combined all-in-one machine are the same as those of the original tower foundation control cabinet and the original frequency conversion cabinet.

4. The system temperature rise meets the use requirement

The combined middle cabinet of the frequency conversion cabinet of the original tower footing control cabinet comprises a 90kVA transformer, a UPS battery, a PLC, a control panel group and other components, and the space is very compact. The main control power distribution area of the integrated machine for the wind turbine generator is subjected to functional partitioning and high-low temperature partitioning, so that the temperature rise of the integrated machine is effectively ensured to meet the operating condition requirements of a product at-35 ℃ to +50 ℃.

The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the technical scope of the present invention, and the technical scope of the present invention is also considered to fall into the scope of the claims.

Claims (10)

1. The filter circuit of the power grid side frequency converter comprises a fuse for the frequency conversion circuit, a contactor for the frequency conversion circuit and three filter capacitors which are used for being connected with three-phase input of the power grid side frequency converter in a one-to-one correspondence manner;

the method is characterized in that: the fuse for the frequency conversion loop is a three-phase fuse; the input side of the fuse for the variable frequency loop is connected with the output loop of the generator stator;

the number of the contactors for the variable frequency circuit is one, and the input side of a normally open contact of the contactor for the variable frequency circuit is electrically connected with the output side of the fuse for the variable frequency circuit; a three-phase current transformer is arranged on a three-phase cable on the output side of the normally open contact of the contactor for the frequency conversion loop, and the three filtering capacitors are correspondingly connected to the three phases on the output side of the normally open contact of the contactor for the frequency conversion loop one by one; and the frequency conversion loop is connected with a corresponding output interface on the PLC by a control coil of the contactor.

2. The filter circuit of a grid-side frequency converter according to claim 1, characterized in that: the fusing current of the fuse for the frequency conversion loop is 630A.

3. The filter circuit of a grid-side frequency converter according to claim 1 or 2, characterized in that: the fuse for the frequency conversion circuit, the contactor for the frequency conversion circuit and the three filter capacitors are fixedly installed inside a cabinet body where the main control power distribution area is located.

4. The filter circuit of a grid-side frequency converter according to claim 1 or 2, characterized in that: and two normally-open stator contactors are connected in parallel between the input side of the fuse and the output loop of the generator stator, and control coils of the two stator contactors are respectively connected with corresponding output interfaces on the PLC.

5. All-in-one electrical structure for wind turbine generator system, its characterized in that: filter circuit comprising a grid-side frequency converter according to claim 4.

6. The all-in-one machine electrical structure for the wind turbine generator according to claim 5, characterized in that: the input side of the main circuit breaker is connected with the output sides of the two normally-open stator contactors, and the output side of the main circuit breaker is connected with the input side of the three-phase transformer;

the cabinet is characterized by further comprising a heating loop, wherein the heating loop comprises a plurality of electric heaters which are arranged in the grid-connected area, the master control power distribution area and the frequency conversion area in the cabinet body respectively and are connected in parallel, and the electric heaters are electrically connected with the single phase of the three-phase transformer.

7. The all-in-one machine electrical structure for the wind turbine generator according to claim 6, characterized in that: still include heat dissipation loop, heat dissipation loop includes and sets up respectively and a plurality of exhaust fans that connect in the internal grid-connected region of cabinet, main control distribution district and frequency conversion district, a plurality of exhaust fans with three-phase transformer's single-phase electric connection, and be provided with at least one and one at the cabinet body that grid-connected region, main control distribution district and frequency conversion district located respectively the tripe wind gap that the exhaust fan corresponds.

8. The all-in-one machine electrical structure for the wind turbine generator according to claim 6, characterized in that: the 230V power supply circuit comprises a single-phase transformer and a UPS, the output side of the single-phase transformer is connected with any two phases of the three-phase transformer, the input side of the single-phase transformer is connected with the input interface of the UPS, the input interface of the UPS is connected with the input interface of the switching power supply, and the output of the switching power supply is 24V direct-current power supply.

9. The all-in-one machine electrical structure for the wind turbine generator according to claim 6, characterized in that: the power supply system is characterized by further comprising a main control distribution area maintenance detection loop, wherein the main control distribution area maintenance detection loop comprises a power interface, and the power interface is supplied by the single phase of the three-phase transformer.

10. The all-in-one machine electrical structure for the wind turbine generator according to claim 9, characterized in that: the main control power distribution area maintenance detection loop further comprises a flashlight charging seat, the flashlight charging seat is connected with the power interface in parallel, the flashlight charging seat is fixed in the front side installation space of the cabinet body where the main control power distribution area is located, and the flashlight charging seat is provided with a rechargeable flashlight.

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