CN206226265U - A kind of LCL filtration modules and the photovoltaic DC-to-AC converter using the filtration module - Google Patents

Abstract

The utility model provides an LCL filter module and a photovoltaic inverter using the filter module, wherein the LCL filter module includes a fixed frame, and a primary reactance, a secondary reactance, and a filter capacitor are fixedly installed in the fixed frame, and the primary reactance It is arranged side by side with the secondary reactance horizontally, the filter capacitor is arranged on the upper side of the primary reactance, and an AC output contactor is installed above the secondary reactance in the fixed frame. This LCL filter module is designed as a whole, which can be easily disassembled and maintained. At the same time, the reactance and capacitance of such a modular LCL filter structure are reasonably arranged, and the volume is small. When installed in a photovoltaic inverter, it is more discrete than each filter component. set, saving space.

Description

An LCL filter module and a photovoltaic inverter using the filter module

technical field

The utility model relates to an LCL filter module and a photovoltaic inverter using the filter module.

Background technique

The LCL filter structure in the grid-connected inverter is mainly used for LCL filtering the AC power converted by the power module. It can suppress the excessive fluctuation of the output current, reduce the surge impact, and filter out the high-frequency current generated by the switching action of the inverter. , Adjust the power output, which is convenient for the design of the control system and EMC function. The LCL filter structure mainly includes two reactors and filter capacitors. After the conversion of DC to AC by the photovoltaic inverter power module, the three-phase current is filtered by the primary reactance, and then filtered again by the filter capacitor and the secondary reactance. Filtering to reduce the output harmonics of the inverter current and improve power quality.

The two-stage reactance and filter capacitor of the existing LCL filter structure are generally directly and discretely installed in the box of the photovoltaic inverter, and arranged in sequence, resulting in an unreasonable structural layout of the entire photovoltaic inverter and occupying a large number of boxes. space. In addition, when the LCL filter structure is overhauled in the later stage, the two-stage reactance and capacitor need to be overhauled separately, which is very inconvenient to operate.

Utility model content

The purpose of the utility model is to provide an LCL filter module, which is used to solve the problems of insufficient space utilization and inconvenient maintenance caused by scattered arrangement of various parts of the existing LCL filter structure in the photovoltaic inverter. Meanwhile, the utility model also aims to provide a photovoltaic inverter using the LCL filter module.

The first technical scheme of the LCL filter module of the utility model includes a fixed frame, and a primary reactance, a secondary reactance and a filter capacitor are fixedly installed in the fixed frame, the primary reactance and the secondary reactance are arranged side by side, and the filter capacitor is arranged in the primary reactance On the upper side, an AC output contactor is installed above the secondary reactance in the fixed frame. This LCL filter module is designed as a whole, which can be easily disassembled and maintained. At the same time, the reactance and capacitance of such a modular LCL filter structure are reasonably arranged, and the volume is small. When installed in a photovoltaic inverter, it is more discrete than each filter component. set, saving space.

On the basis of the technical solution 1 of the LCL filter module, the technical solution 2 is further optimized, that is, the primary reactance includes three single-phase reactors arranged in groups, and the three single-phase reactors are arranged horizontally and stacked in the vertical direction. Such an arrangement reduces the volume of the fixed frame as much as possible.

On the basis of the technical solution 1 or the technical solution 2 of the LCL filter module, the technical solution 3 is further optimized, that is, the secondary reactance adopts a three-phase reactor. Such primary and secondary reactances adopt single-phase and three-phase reactance respectively, and the filtering effect is better.

Furthermore, on the basis of technical solution 1, technical solution 2 or technical solution 3 of the LCL filter module, it is preferable to set the fixed frame as a rectangular frame, and the rectangular frame is provided between the primary reactance and the secondary reactance The fourth technical solution of the LCL filter module is obtained by using the support column. In this way, the structural strength of the fixed frame is ensured through the strengthening effect of the supporting columns, and at the same time, the setting of the supporting columns also facilitates the cascading and fixed installation of the three single-phase reactances in the upper and lower directions.

In addition, it can be further improved on the basis of any one of the above four technical solutions of the LCL filter module. The specific means of improvement is to set the guide column on the rear side of the fixed frame for guiding with the rear wall of the photovoltaic inverter box. Matching guide holes, when the fixed frame is installed into the photovoltaic inverter, it can facilitate the positioning of the fixed frame and the photovoltaic inverter box, which is convenient for installation.

A technical solution of the photovoltaic inverter of the present utility model: it includes a box body, and an LCL filter module is installed in the box body, and the LCL filter module includes a fixed frame connected with the box body, and the fixed frame is fixed The primary reactance, secondary reactance and filter capacitor are installed, the primary reactance and secondary reactance are arranged side by side, the filter capacitor is arranged on the upper side of the primary reactance, and an AC output contactor is installed above the secondary reactance in the fixed frame. The LCL filter module is installed in the box of this photovoltaic inverter. As a whole, the LCL filter module can reduce the output harmonics of the inverter current in function. The layout is optimized, and the internal space of the photovoltaic inverter box can be used reasonably.

The utility model also provides the second technical solution of the photovoltaic inverter, which is an improvement on the basis of the above-mentioned first technical solution of the photovoltaic inverter. Specifically, the primary reactance includes three For single-phase reactors, three single-phase reactors are placed horizontally and stacked up and down. Such an arrangement can reduce the volume of the fixed frame as much as possible.

The utility model also provides a third technical solution of the photovoltaic inverter, which can be improved on the basis of the above-mentioned first technical solution of the photovoltaic inverter, or can be improved on the basis of the above-mentioned second Improvements are made on the basis of the technical scheme of a photovoltaic inverter, specifically, a three-phase reactor is used for the secondary reactance. Such primary and secondary reactances adopt single-phase and three-phase reactance respectively, and the filtering effect is better.

Further, the utility model also provides a fourth improvement scheme of the photovoltaic inverter, which is essentially a further improvement on the basis of the above three technical schemes of the photovoltaic inverter Specifically, the rear side of the box body is provided with a guide post extending forward, and the rear side of the fixed frame is provided with a guide hole that guides and cooperates with the guide post. In this way, when the fixed frame is installed into the photovoltaic inverter, the positioning of the fixed frame and the photovoltaic inverter box can be facilitated, and installation is facilitated.

Furthermore, the photovoltaic inverter of the present utility model can also be improved and deformed on top of any of the above-mentioned technical solutions of the photovoltaic inverter, that is, support guide rails are set on the box body of the photovoltaic inverter, and the fixed The frame is installed in the box through the supporting guide rail, which facilitates the disassembly and assembly of the LCL filter module.

Description of drawings

Fig. 1 is the structural representation of the photovoltaic inverter of the present utility model;

Fig. 2 is the perspective view of the LCL filter module of the present utility model;

Fig. 3 is the front view of the LCL filtering module of the present utility model;

Fig. 4 is a right side view of Fig. 3 .

detailed description

Embodiments of the present utility model will be further described below in conjunction with the accompanying drawings.

The first specific embodiment of the photovoltaic inverter of the present utility model, as shown in Fig. 1-4, includes a box body 9, and an LCL filter module 90 is installed in the box body. Wherein, the LCL filter module includes a fixed frame 1 , and a primary reactance 2 , a secondary reactance 4 and a filter capacitor 3 are installed in the fixed frame 1 . The primary reactance 2 and the secondary reactance 4 are arranged horizontally side by side, and the filter capacitor 3 is arranged above the primary reactance 2 . In addition, an AC output contactor 5 is arranged above the secondary reactance 4 in the fixed frame 1 . The layout of the LCL filter module primary reactance, secondary reactance, filter capacitor and AC output contactor in the photovoltaic inverter of this embodiment makes the entire LCL filter module rectangular, which can make rational use of space and minimize The overall volume of the LCL filter module, and this modular design is also convenient for disassembly and maintenance of the LCL filter module.

The photovoltaic inverter of the present invention also provides a second embodiment, which is further optimized on the basis of the first embodiment. The specific technical solution is to further define that the primary reactance in the first embodiment is composed of three three-phase reactors arranged in groups, and the three reactors are all placed horizontally and stacked in the vertical direction. This setting is designed considering the volume of the secondary reactance, filter capacitor and AC output contactor, which can make the shape of the LCL filter module regular, which is conducive to reducing the occupied space when installed in the photovoltaic inverter.

The photovoltaic inverter of the present invention is further optimized on the basis of the technical solution of the first embodiment to obtain the third embodiment. The difference between the third embodiment and the first embodiment is that the secondary reactance is preferably a three-phase reactor.

The photovoltaic inverter of the present invention also provides a fourth embodiment, which is an optimization scheme of the first embodiment. In the fourth embodiment, the fixed frame of the LCL filter module adopts a rectangular frame, and the frame body of the rectangular frame is provided with support columns supporting the upper and lower sides of the fixed frame at the position between the primary reactance and the secondary reactance. The structural strength of the fixed frame can be improved through the supporting columns, and the rectangular fixed frame is divided into left and right parts through the supporting columns, which is also convenient for the partition installation of the primary reactance and the secondary reactance.

Embodiment 5 of the photovoltaic inverter of the present utility model: This embodiment provides a relatively complete photovoltaic inverter, and the photovoltaic inverter of this embodiment is not only included in Embodiment 2, Embodiment 3 or Embodiment 4 In view of the improvement or optimization scheme proposed in the first embodiment, the problems encountered in the disassembly and assembly of the LCL filter module of the photovoltaic inverter are also optimized. Specifically, the rear side wall of the box body of the photovoltaic inverter is provided with a guide column extending forward, the front end of the guide column is a tapered tip, and the rear side of the fixed frame of the LCL filter module is provided with a guide hole. When installing into the box, the positioning between the filter module and the photovoltaic inverter box is facilitated through the guiding cooperation between the guide hole and the guide column.

Embodiment 6 of the photovoltaic inverter of the present utility model: On the basis of Embodiment 1, the fixed frame of the LCL filter module adopts a rectangular frame, and the frame body of the rectangular frame is set at the position between the primary reactance and the secondary reactance. There are support columns supporting the upper and lower sides of the fixed frame. A crossbeam is arranged between the support column and one vertical side of the fixed frame, and there are three crossbeams. The primary reactance is composed of three three-phase reactors arranged in groups. The three reactors are placed horizontally on the beam. The rear side wall of the photovoltaic inverter box is provided with a guide post extending forward. It is a tapered tip, and the three beams of the fixed frame are provided with guide holes matched with the guide posts.

Embodiment 7 of the photovoltaic inverter of the present utility model: this embodiment further provides an installation method of the LCL filter module on the basis of the above-mentioned embodiment 1, embodiment 2 or embodiment 3. Specifically, the photovoltaic inverter box is provided with supporting rails, and the bottom of the fixed frame of the LCL filter module is provided with rollers or sliders that cooperate with the supporting rails. The LCL filter module is installed on the photovoltaic inverter through the supporting rails in the box. inside the box of the device. In this way, the disassembly and assembly of the LCL filter module is more convenient.

In addition, the utility model also provides an LCL filter module for the above-mentioned photovoltaic inverter. The specific structure of the filter module is the same as that of the LCL filter module in the embodiment of the above-mentioned photovoltaic inverter, and will not be repeated here. repeat.

Claims (10)

1. a kind of LCL filtration modules, it is characterized in that, including fixed frame, be installed with the fixed frame one-level reactance, Two grades of reactance and filter capacitor, one-level reactance and two grades of reactance horizontal Tiles are set, and filter capacitor is located at one-level reactance upside, Exchange output contactor also is installed above two grades of reactance in fixed frame.

2. LCL filtration modules according to claim 1, it is characterized in that, the one-level reactance includes three single-phase reactors, Three single-phase reactors are horizontal and are stacked in above-below direction.

3. LCL filtration modules according to claim 1, it is characterized in that, two grades of reactance are three-phase reactor.

4. LCL filtration modules according to claim 1, it is characterized in that, the fixed frame is rectangle support body, the rectangle Support body is provided with support column between one-level reactance and two grades of reactance.

5. LCL filtration modules according to claim 1-4 any one, it is characterized in that, set on rear side of the fixed frame Have for being oriented to the pilot hole for coordinating with the lead column on photovoltaic DC-to-AC converter casing rear surface.

6. a kind of photovoltaic DC-to-AC converter, including casing, it is characterized in that, LCL filtration modules, the LCL filters are installed in the casing Ripple module includes the fixed frame being connected with the casing, and one-level reactance, two grades of reactance are installed with the fixed frame And filter capacitor, one-level reactance and two grades of reactance horizontal Tiles settings, filter capacitor is located at one-level reactance upside, fixed frame Exchange output contactor also inside is installed above two grades of reactance.

7. photovoltaic DC-to-AC converter according to claim 6, it is characterized in that, the one-level reactance includes three single-phase reactors, Three single-phase reactors are horizontal and are stacked in above-below direction.

8. photovoltaic DC-to-AC converter according to claim 6, it is characterized in that, two grades of reactance are three-phase reactor.

9. the photovoltaic DC-to-AC converter according to claim 6-8 any one, it is characterized in that, it is provided with forward on rear side of the casing The lead column of extension, is provided with the pilot hole for being oriented to lead column and being coordinated on rear side of the fixed frame.

10. the photovoltaic DC-to-AC converter according to claim 6-8 any one, it is characterized in that, the casing is provided with support and leads Rail, the fixed frame is arranged in casing by the supporting guide.