Voltage stabilizer for low-voltage line

Abstract

The invention discloses a voltage stabilizing device for a low-voltage line, and relates to the technical field of power grid voltage balancing equipment, the voltage stabilizing device comprises a lower shell and an upper shell, the upper shell is fixedly mounted at the top of the lower shell, a plurality of groups of capacitors are fixedly arranged in the lower shell, a plurality of groups of switches are fixedly arranged in the upper shell, and the plurality of groups of switches correspond to the plurality of groups of capacitors. The group of switches and the group of capacitors are connected in series, a controller is fixedly arranged in the upper shell and is electrically connected with the plurality of groups of switches, a voltage measuring element and a current measuring element are fixedly arranged in the upper shell and are electrically connected with the controller, a wiring part is fixedly arranged at one end of the outer part of the upper shell, and the wiring part is electrically connected with the controller. The wiring part is electrically connected with the power grid, and a touch screen is fixedly arranged on one side of the outer portion of the upper shell and electrically connected with the controller. The voltage drop at the tail end of the low-voltage line can be improved, the power factor is improved, and the voltage at the tail end of the low-voltage line is balanced and supported.

Description

Technical Field

[0001] The invention relates to the technical field of power grid voltage balancing equipment, and in particular to a voltage stabilizing device for a low-voltage line. Background Art

[0002] In recent years, China's social economy has developed rapidly, and the material living standards of residents in rural areas have continued to improve. Household appliances have become more and more abundant, and the electricity consumption in rural areas has also been rising steadily. Many rural-urban areas are full of small and micro processing and production enterprises and breeding bases, and the power consumption has increased dramatically. Due to the large rural area and sparse population distribution, the early construction of the power grid is simple and weak, with high load dispersion and obvious seasonal and time characteristics, resulting in increasingly serious problems such as low voltage at the end of the line and three-phase imbalance.

[0003] At present, the methods to solve the voltage problem at the end of low-voltage lines include adding voltage regulators in medium-voltage or low-voltage lines, adding reactive power compensation equipment in lines or substations, etc. The medium voltage line voltage regulation achieves the purpose of regulating the incoming line voltage of the transformer in the substation by adjusting the autotransformer through the tap switch. The 10kV line compensation also achieves the purpose of increasing the line voltage by compensating the reactive load of the line. These two types of equipment will simultaneously raise the outlet voltage of the regulated substation, covering a wide area of ​​action and having a significant effect on the voltage regulation. However, in the case of serious imbalance of the three-phase load in the substation, it may cause the voltage of one or two phases of the low-voltage line to be seriously high, posing a risk to the power safety of the equipment. Since the reactive compensation of the low-voltage substation is installed on the outlet side of the distribution transformer, it cannot balance the reactive load of the load on the spot, causing reactive current to flow in the low-voltage line, aggravating the problem of low voltage at the end caused by the line voltage drop, and cannot balance the three-phase load. Then, the low-voltage line voltage regulator is installed in the middle and rear sections of the line, which is a series type device, which can improve the voltage at the rear end of the equipment installation point, but when the rear end load increases, it will cause the voltage at the front end of the installation point to decrease, and it cannot handle the imbalance and reactive problems of the load at the installation point. Finally, these devices have the defects of heavy weight, inconvenient installation and high cost. Therefore, it is necessary to provide a technical solution to improve the voltage drop of the line and balance the terminal voltage. Summary of the invention

[0004] The object of the present invention is to provide a voltage stabilizing device for a low voltage line in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A voltage stabilizing device for a low-voltage line comprises a lower shell and an upper shell, wherein the upper shell is fixedly mounted on the top of the lower shell, wherein a plurality of groups of capacitors are fixedly arranged in the lower shell, wherein a plurality of groups of switches are fixedly arranged in the upper shell, wherein the plurality of groups of switches correspond to the plurality of groups of capacitors, wherein a group of switches is connected in series with a group of capacitors, wherein a controller is fixedly arranged in the upper shell, wherein the controller is electrically connected to the plurality of groups of switches respectively, wherein a voltage measuring element and a current measuring element are fixedly arranged in the upper shell, wherein the voltage measuring element and the current measuring element are both electrically connected to the controller, wherein a wiring portion is fixedly arranged at one end of the outer portion of the upper shell, wherein the wiring portion is electrically connected to a power grid, wherein a touch screen is fixedly arranged at one side of the outer portion of the upper shell, wherein the touch screen is electrically connected to the controller.

[0007] Preferably, the number of the capacitors is 2 to 6 groups.

[0008] Preferably, the capacitances of the multiple groups of capacitors are different.

[0009] Preferably, the lower shell and the upper shell are both made of stainless steel.

[0010] Preferably, an insulating layer is fixedly provided on the inner side wall and the bottom of the lower shell.

[0011] Preferably, an insulating medium is filled in the lower shell between the insulating layer and the plurality of groups of capacitors.

[0012] Preferably, the insulating medium is in solid state.

[0013] Preferably, multiple groups of capacitors are connected in parallel on the power grid; and multiple groups of capacitors are connected in parallel.

[0014] Preferably, the voltage measuring element is connected in parallel to the power grid; and the current measuring element is connected in series to the power grid.

[0015] The beneficial effects of the present invention are as follows: (1) the present invention can improve the voltage drop at the end of the low-voltage line, improve the power factor, and balance and support the end voltage of the low-voltage line; (2) multiple groups of capacitors form multiple independent single-phase capacitors, each group of single-phase capacitors is connected to the corresponding switch, to achieve single-phase reactive power balance and balance the end voltage of the low-voltage line. When the voltage of the power grid is lower than 197V, one group of single-phase capacitors is put into use. If the voltage of the power grid is still low, another group of single-phase capacitors is put into use until multiple groups of single-phase capacitors are put into use. When the voltage of the power grid is higher than 236V, Cut off one group of single-phase capacitors. If the voltage of the power grid is still too high, continue to cut off another group of single-phase capacitors until multiple groups of single-phase capacitors are cut off. The controller automatically controls the sampling response time to be completed within 0.1mS and the rapid cycle switching within 0.2mS. (3) The upper shell and the lower shell are made of stainless steel material with strong protective performance and can be directly installed outdoors. (4) The cost of the entire voltage stabilizing device is low, the overall weight is light, and the installation and maintenance are convenient. It is convenient to flexibly select the installation point according to the load distribution of the power grid, and multiple installations can be performed to achieve a more ideal regulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional diagram of the overall structure of the present invention;

[0017] Figure 2 It is a schematic diagram of the internal structure of the lower shell of the present invention;

[0018] Figure 3 It is a schematic diagram of the working principle of the present invention.

[0019] Description of reference numerals:

[0020] 11. Lower shell; 111. Insulating layer; 112. Insulating medium; 12. Upper shell; 121. Wiring portion; 122. Touch screen; 21. First capacitor; 22. Second capacitor; 23. Third capacitor; 24. Fourth capacitor; 3. Controller; 4. Voltage measuring element; 5. Current measuring element; 61. First switch; 62. Second switch; 63. Third switch; 64. Fourth switch. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings:

[0022] like Figure 1 , Figure 2 and Figure 3As shown, the present invention provides a voltage stabilizing device for low-voltage lines, including a lower housing 11 and an upper housing 12, wherein the upper housing 12 is fixedly mounted on the top of the lower housing 11 by screws. Multiple groups of capacitors are fixedly arranged in the lower housing 11, and multiple groups of switches are fixedly arranged in the upper housing 12, wherein the multiple groups of switches correspond to the multiple groups of capacitors, and one group of switches is connected in series with one group of capacitors by wires. A controller 3 is fixedly mounted in the upper housing 12 by screws, and the controller 3 can be a single-chip microcomputer. The controller 3 is respectively connected to the multiple groups of switches by signal lines, and the switches can be phase-selective switches. A voltage measuring element 4 and a current measuring element 5 are fixedly arranged in the upper housing 12, and both the voltage measuring element 4 and the current measuring element 5 are connected to the controller 3 by signal lines, such as the voltage measuring element 4 can be a voltage transformer, and the current measuring element 5 can be a current transformer. A wiring portion 112 is fixedly arranged at one end of the outer portion of the upper housing 12, and the wiring portion 112 is connected to the power grid by wires. A touch screen 122 is fixedly arranged on one side of the outer portion of the upper housing 12, and the touch screen 122 is connected to the controller 3 by signal lines. Among them, multiple groups of capacitors are connected in parallel to the power grid; multiple groups of capacitors are connected in parallel; voltage measuring element 4 is connected in parallel to the power grid; current measuring element 5 is connected in series to the power grid. This voltage stabilizing device can improve the voltage drop at the end of the low-voltage line, improve the power factor, and balance and support the end voltage of the low-voltage line.

[0023] like Figure 2 and Figure 3 As shown, the number of capacitors is 2 to 6 groups, and the number of capacitor groups can be selected according to actual needs. In this embodiment, the number of capacitors is 4 groups, namely the first capacitor 21, the second capacitor 22, the third capacitor 23 and the fourth capacitor 24. Correspondingly, the multiple groups of switches include the first switch 61, the second switch 62, the third switch 63 and the fourth switch 64. The capacitances of the multiple groups of capacitors are different. For example, in this embodiment, the capacitance of the first capacitor 21 is greater than the capacitance of the second capacitor 22, the capacitance of the second capacitor 22 is greater than the capacitance of the third capacitor 23, and the capacitance of the third capacitor 23 is greater than the capacitance of the fourth capacitor 24. Multiple groups of capacitors form multiple independent single-phase capacitors, and each group of single-phase capacitors is connected to the corresponding switches to achieve single-phase reactive balance and balance the terminal voltage of the low-voltage line.

[0024] In this embodiment, the lower shell 11 and the upper shell 12 are both made of stainless steel. Stainless steel has strong protective performance and can be directly installed outdoors.

[0025] like Figure 2 As shown, in this embodiment, the inner side wall and the bottom of the lower shell 11 are fixedly provided with an insulating layer 111, and the insulating layer 111 can be made of mica. The lower shell 11 is filled with an insulating medium 112 between the insulating layer 111 and the plurality of capacitors. The insulating medium 112 is solid, and the insulating medium 112 can be made of silica gel.

[0026] like Figures 1 to 3 As shown, when working, (1) first, the connection part 112 of the voltage stabilizer is connected to the power grid through wires to connect the voltage stabilizer to the power grid. Then, the voltage stabilizer is powered on and initialized, including hardware initialization and self-test. The voltage parameter range value is set through the touch screen 122 to set the action conditions of the voltage stabilizer. (2) The voltage value of the power grid is collected through the voltage measuring element 4, and the current measuring element 5 collects the current value of the power grid. The voltage value and current value information are transmitted to the controller 3. The controller 3 calculates the active power and reactive power parameters of the power grid. Then, the controller 3 calculates the voltage compensation demand of the power grid (i.e., the end of the low-voltage line) according to the set voltage stabilization parameters and controls the on and off of multiple sets of switches to perform voltage compensation. First, according to the power and current conditions of the power grid, the gap that needs to be compensated for the phase is calculated, and compensation and removal are performed according to the actual gap. Specifically, when the voltage of the power grid is lower than 197V, a group of single-phase capacitors is put into use. If the voltage of the power grid is still low, another group of single-phase capacitors is put into use until multiple groups of single-phase capacitors are put into use; when the voltage of the power grid is higher than 236V, a group of single-phase capacitors is cut off. If the voltage of the power grid is still high, another group of single-phase capacitors is cut off until multiple groups of single-phase capacitors are cut off. The controller 3 automatically controls so that the sampling response time is completed within 0.1mS and the 0.2mS rapid cycle switching. The voltage stabilizing device automatically tracks the power grid voltage and the zero potential point of multiple groups of capacitors to find the appropriate action time and complete the response of the execution command.

[0027] The present invention solves the problem of low voltage at the end of a low-voltage line. The voltage stabilizing device has low cost, light overall weight, and is easy to install and maintain. It is convenient to flexibly select installation points in combination with the load distribution of the power grid, and can be installed at multiple points to achieve a more ideal regulation effect.

[0028] The above are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereby. It should be understood by those skilled in the art that various changes, modifications, substitutions and deformations may be made to these embodiments without departing from the principles and purposes of the present invention, and all of them should be included in the protection scope of the present invention. The protection scope of the present invention is defined by the claims and their equivalents.

Claims

1. A voltage stabilizing device for a low voltage line, characterized in that: It comprises a lower shell and an upper shell, wherein the upper shell is fixedly mounted on the top of the lower shell, a plurality of groups of capacitors are fixedly arranged in the lower shell, a plurality of groups of switches are fixedly arranged in the upper shell, the plurality of groups of switches correspond to the plurality of groups of capacitors, a group of switches is connected in series with a group of capacitors, a controller is fixedly arranged in the upper shell, the controller is electrically connected to the plurality of groups of switches respectively, a voltage measuring element and a current measuring element are fixedly arranged in the upper shell, the voltage measuring element and the current measuring element are both electrically connected to the controller, a wiring portion is fixedly arranged at one end of the outer side of the upper shell, the wiring portion is electrically connected to the power grid, a touch screen is fixedly arranged at one side of the outer side of the upper shell, the touch screen is electrically connected to the controller.

2. A voltage stabilizing device for a low voltage line according to claim 1, characterized in that: The number of the capacitors is 2 to 6 groups.

3. A voltage stabilizing device for a low voltage line according to claim 1, characterized in that: The capacitances of the plurality of groups of capacitors are different.

4. A voltage stabilizing device for a low voltage line according to claim 1, characterized in that: The lower shell and the upper shell are both made of stainless steel.

5. A voltage stabilizing device for a low voltage line according to claim 1, characterized in that: The inner side wall and the bottom of the lower shell are both fixedly provided with an insulating layer.

6. A voltage stabilizing device for a low voltage line according to claim 5, characterized in that: The lower shell is filled with an insulating medium between the insulating layer and the plurality of groups of capacitors.

7. A voltage stabilizing device for a low voltage line according to claim 6, characterized in that: The insulating medium is in solid state.

8. A voltage stabilizing device for a low voltage line according to claim 1, characterized in that: Multiple groups of capacitors are connected in parallel on the power grid; multiple groups of capacitors are connected in parallel.

9. A voltage stabilizing device for a low voltage line according to claim 1, characterized in that: The voltage measuring element is connected in parallel to the power grid; and the current measuring element is connected in series to the power grid.

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