CN201766368U - Low-voltage reactive power compensation device - Google Patents

Abstract

The utility model relates to a low-voltage reactive power compensation device, which is provided with a cabinet for placing components. A circuit breaker, a controller, a lightning arrester and a plurality of capacitor compensation circuits are contained inside the cabinet, and a fuse, a throw switch and a compensation capacitor are sequentially connected onto each capacitor compensation circuit. The device is characterized in that the circuit breaker is connected with a power grid via a copper bar, an output end of the circuit breaker is connected with the capacitor compensation circuits and the lightning arrester, the throw switches in the capacitor compensation circuits are thyristors in back-to-back parallel connection, and the controller acquiring three-phase current and voltage of a power grid system is connected with the throw switches. The low-voltage reactive power compensation device has the advantages that the device does not generate extremely large impact current when throwing, and does not generate harmonic interference.

Description

Low-voltage reactive power compensation device

technical field

The utility model relates to a power grid equipment, in particular to a low-voltage reactive power compensation device with automatic compensation function

Background technique

At present, traditional low-voltage reactive power compensation equipment generally collects a single signal, uses three-phase capacitors, and three-phase common compensation. This compensation method is suitable for occasions where the load is mainly three-phase loads (motors); but if the current load is mainly For residential users, the three-phase load is likely to be unbalanced, so the reactive power demand of each phase is also different. Using this compensation method will cause over-compensation or under-compensation to varying degrees; moreover, AC contactors are mostly used for switching switches. The reactive power compensation capacitor switched by the AC contactor will generate a large inrush current, which will not only cause interference to the power grid, but also affect the service life of the capacitor. Not only that, most of the controlled physical quantities are voltage, power factor, and reactive current; the switching methods are cycle switching and code switching. This strategy does not consider the balance relationship of voltage and reactive power optimization of the area.

Utility model content

In order to solve the deficiencies of the prior art, the purpose of this utility model is to provide a low-voltage reactive power compensation device capable of realizing zero-crossing switching and intelligently collecting three-phase electrical parameters.

In order to achieve the above object, the utility model is achieved through the following technical solutions:

The low-voltage reactive power compensation device is equipped with a cabinet for placing components. The cabinet includes circuit breakers, controllers, lightning arresters and multiple capacitor compensation circuits. Each capacitor compensation circuit is connected with a fuse, switching switch and compensation capacitor in turn. , characterized in that the above-mentioned circuit breaker is connected to the power grid through a copper bar, and its output terminal is connected to the above-mentioned multiple capacitance compensation circuits and lightning arresters, the switching switches in the above-mentioned capacitance compensation circuits are thyristors connected in reverse parallel, and the above-mentioned controller collects and Detect the three-phase current and voltage of the power grid system, and connect with the above switching switch.

The above-mentioned low-voltage reactive power compensation device is characterized in that the above-mentioned cabinet further includes a comprehensive display device for displaying the detection results of the above-mentioned controller.

The aforementioned low-voltage reactive power compensation device is characterized in that the above-mentioned cabinet is also equipped with a cooling fan, a temperature controller responsible for temperature measurement and control, and a switch for manual and automatic conversion. The above-mentioned temperature controller is connected to the above-mentioned fan , the above-mentioned transfer switch is connected with the above-mentioned temperature controller and the fan.

The aforementioned low-voltage reactive power compensation device is characterized in that the above-mentioned cabinet is divided into upper and lower layers, and the front side of the upper layer is an operation panel, in which the above-mentioned controller, integrated display device, temperature controller, transfer switch and fan are arranged. The fan is arranged on the top of the above cabinet, the above-mentioned integrated display device is arranged on the above-mentioned operation panel, and the operation parts of the above-mentioned controller, temperature controller and transfer switch are arranged on the above-mentioned operation panel; the lower layer is divided into a front room and a back room, the front room The side is a box door that can be opened and closed. There is an indicator light on the box door. The above-mentioned circuit breaker, lightning arrester, fuse, and switching switch are installed in the above-mentioned front room. The above-mentioned compensation capacitor is installed in the above-mentioned rear room. switch connected. The utility model is beneficial in that: the thyristor is used as the switching switch, because it is a non-contact switch, switching at the zero-crossing voltage point does not generate a large impact current and does not generate harmonic interference; the fan installed on the top And temperature controller and changeover switch, which can realize forced ventilation and realize automatic control of ventilation by the temperature controller, prolonging the service life.

Description of drawings

Fig. 1 is the schematic diagram of the connection relationship of the main circuit of the low-voltage reactive power compensation device of the present invention;

Fig. 2 is the front view of the low-voltage reactive power compensation device of the present invention;

Fig. 3 is the structural representation of the low-voltage reactive power compensation device of the present invention after removing the front side box door;

Fig. 4 is a side view internal structure diagram of the low-voltage reactive power compensation device of the present invention.

In the figure: 1 is the controller, 2 is the comprehensive display device, 3 is the temperature control instrument, 4 is the transfer switch, 5 is the indicator light, 6 is the circuit breaker, 7 is the lightning arrester, 8 is the fuse, 9 is the switching switch, 10 is a compensation capacitor.

Detailed ways

The specific embodiment of the utility model is described in detail below in conjunction with accompanying drawing.

Fig. 1 is a schematic diagram of the main circuit connection relationship of the low-voltage reactive power compensation device of the present invention; Fig. 2 is a front view of the low-voltage reactive power compensation device of the present invention; Fig. 3 is a low-voltage reactive power compensation device of the present invention Figure 4 is a schematic diagram of the internal structure of the side view of the low-voltage reactive power compensation device of the present invention.

With reference to Fig. 1, the utility model comprises circuit breaker 6, controller 1, lightning arrester 7 and a plurality of capacitance compensation loops, is connected with fuse 8, switching switch 9 and compensation capacitor 10 successively on each capacitance compensation loop, and capacitance compensation loop The number of capacitors can be determined according to specific conditions, and the fuse 8 can protect the safety of each capacitance compensation circuit. As a preferred solution of the present invention, the number of capacitor compensation circuits can be three. The circuit breaker 6 is connected to the power grid through copper bars, and its output is connected to the above-mentioned multiple capacitor compensation circuits and the lightning arrester 7. The main function of the circuit breaker 6 is to break the connection with the power grid to protect the safety of all circuits. The lightning arrester 7 is mainly to prevent lightning The intrusion of waves, the reverse parallel thyristor is used as the switching switch 9 in the capacitor compensation circuit, the controller 1 is responsible for collecting the three-phase current and voltage of the power grid system, and is connected with the above switching switch 9, and the user sets it through the controller 1 A target power factor, the system power factor is compared with the set target power factor: if it is within the threshold, no action will be taken; if it exceeds the threshold, corresponding switching measures will be taken to keep the power factor within the set limit band. Since the sampling current is a three-phase current, when the power factors of the three phases are different, the controller 1 switches single-phase capacitors according to compensation requirements to realize phase-separated compensation. Controller 1 chooses to switch capacitors when the system voltage crosses zero to reduce impact voltage and avoid harmonics.

Referring to Fig. 2 and Fig. 3, as a preferred solution of the present invention, an integrated display device 2 for displaying the detection result of the controller 1 may also be provided. In addition, the cabinet is also provided with a cooling fan, a temperature controller 3 responsible for temperature measurement and control, and a transfer switch 4 responsible for manual and automatic conversion. The temperature controller 3 is connected to the fan, and the transfer switch 4 is connected to the temperature controller. 3 is connected with the fan. As a preferred solution, the fan can be arranged on the top of the cabinet.

The temperature controller 3 is responsible for detecting the temperature in the cabinet. When the temperature reaches a certain value, the temperature controller 3 starts the fan to dissipate heat. Change-over switch 4 can switch blower fan to manual mode and automatic mode.

As a preferred embodiment of the present utility model, the cabinet body is divided into upper and lower layers, and the front side of the upper layer is an operation panel, in which the aforementioned controller 1, integrated display device 2, temperature controller 3, transfer switch 4 and fan are placed. The operation parts of the above-mentioned controller 1, temperature controller 3, and transfer switch 4 are set on the above-mentioned operation panel, and the integrated display device 2 can be set on the operation panel; The box door, the above-mentioned front chamber is provided with the above-mentioned circuit breaker 6, lightning arrester 7, fuse 8, switching switch 9, the above-mentioned rear chamber is provided with the above-mentioned compensation capacitor 10, and the above-mentioned indicator light 5 is connected with the above-mentioned switching switch 9. As a preferred solution, the compensation capacitors 10 are layered in the rear chambers of the upper and lower layers.

When in use, the user sets a target power factor through the controller 1, and the system power factor is compared with the set target power factor: if it is within the threshold, no action will be taken; if it exceeds the threshold, the switching switch 9 will be controlled accordingly. Take all measures to keep the power factor within the set limit band. Since the sampling current is a three-phase current, when the power factors of the three phases are different, the controller 1 switches single-phase capacitors according to compensation requirements to realize phase-separated compensation.

The above-mentioned embodiments do not limit the utility model in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the utility model.

Claims (4)

1. The low-voltage reactive power compensation device is equipped with a cabinet for placing components. The cabinet includes circuit breakers, controllers, lightning arresters and multiple capacitor compensation circuits. Each capacitor compensation circuit is connected in turn with fuses, switching switches and The compensation capacitor is characterized in that the above-mentioned circuit breaker is connected to the power grid through a copper bar, and its output terminal is connected to the above-mentioned multiple capacitance compensation circuits and lightning arresters. The switching switches in the above-mentioned capacitance compensation circuits are thyristors connected in reverse parallel. Collect and detect the three-phase current and voltage of the grid system, and connect with the switching switch mentioned above. 2. The low-voltage reactive power compensation device according to claim 1, characterized in that, the cabinet further includes a comprehensive display device for displaying the detection results of the controller. 3. The low-voltage reactive power compensation device according to claim 1 or 2, characterized in that, the above-mentioned cabinet is also provided with a cooling fan, a temperature controller responsible for temperature measurement and control, and a changeover switch responsible for manual and automatic conversion, The above-mentioned temperature controller is connected with the above-mentioned fan, and the above-mentioned transfer switch is connected with the above-mentioned temperature controller and the fan respectively. 4. The low-voltage reactive power compensation device according to claim 3, wherein the above-mentioned cabinet body is divided into upper and lower layers, and the front side of the upper layer is an operation panel, in which the above-mentioned controller, integrated display device, and temperature controller are arranged. , switch and fan, the fan is set on the top of the cabinet, the comprehensive display device is set on the operation panel, the controller, temperature controller, and the operation part of the switch are set on the operation panel; the lower layer is divided into The front room and the back room, the front side is a box door that can be opened and closed, the box door is equipped with an indicator light, the above-mentioned front room is equipped with the above-mentioned circuit breaker, lightning arrester, fuse, switching switch, and the above-mentioned back room is equipped with the above-mentioned compensation capacitor , the above-mentioned indicator light is connected with the above-mentioned switching switch. the

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