CN202351323U

CN202351323U - Electric power digital meter adopting Rogowski coil current transformer

Info

Publication number: CN202351323U
Application number: CN2011204662205U
Authority: CN
Inventors: 李云宏; 吴柏胜
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-11-22
Filing date: 2011-11-22
Publication date: 2012-07-25
Anticipated expiration: 2021-11-22

Abstract

The utility model relates to an electric power digital meter adopting a Rogowski coil current transformer. The electric power digital meter comprises Rogowski coil current transformers (1), an integrating circuit (2), an amplifying circuit (3), a CPU (Central Processing Unit) circuit (4) and a display and operation circuit (5), wherein the Rogowski coil current transformers (1), the integrating circuit (2), the amplifying circuit (3), the CPU circuit (4) and the display and operation circuit (5) are sequentially connected; and the CPU circuit (4) is also connected with a voltage sampling circuit (6), a communication circuit (7) and an analog quantity output circuit (8). The electric power digital meter adopting the Rogowski coil current transformer has a simple structure and high precision.

Description

Adopt the electric power digital instrument of Luo-coil current transformer

Technical field

The utility model relates to a kind of electric power digital instrument, especially relates to a kind of electric power digital instrument that adopts the Luo-coil current transformer as signal pickup assembly, belongs to the electric instrument technical field.

Background technology

At present, in the power measurement system, the electric power digital instrument adopts iron core current transformer as signal pickup assembly more, adopts iron core current transformer that following shortcoming is arranged:

At first, the iron core mutual inductor is because its Secondary Winding is in the short circuit duty, thereby energy consumption is higher; The power consumption of a general iron core mutual inductor nominal operation state reaches more than the 15W, and electric energy loss is very big;

Secondly, the iron core mutual inductor is prone to saturated, and the range of linearity is little, thereby its specification China, has 27 specifications at least from 1A ~ 10KA iron core mutual inductor, thereby makes the user when measuring, and the instrument that needs to be equipped with different model is in order to being applied to different occasions;

Moreover, use the electric power digital instrument of iron core mutual inductor, owing to receive the influence of mutual inductor precision, the system accuracy of whole instrument and mutual inductor is very low, the system accuracy that has is less than 1%.

Summary of the invention

The purpose of the utility model is to overcome above-mentioned deficiency, provides a kind of simple in structure, the electric power digital instrument of the employing Luo-coil current transformer that precision is high and energy-saving and cost-reducing.

The purpose of the utility model is achieved in that a kind of electric power digital instrument that adopts the Luo-coil current transformer; Said instrument includes Luo-coil current transformer, integrating circuit, amplifying circuit, cpu circuit and display operation circuit; Said Luo-coil current transformer, integrating circuit, amplifying circuit, cpu circuit and display operation circuit are connected successively; Said Luo-coil current transformer includes the tubular support; Be wound with Luo-coil on the said tubular support, the extension line of said Luo-coil links to each other with integrating circuit, is serially connected with a plurality of screws on the circle wall of said tubular support.

A kind of electric power digital instrument that adopts the Luo-coil current transformer of the utility model also connects voltage sampling circuit, communicating circuit and analogue quantity output circuit on the said cpu circuit.

Compared with prior art, the beneficial effect of the utility model is:

The utility model is owing to adopt Luo-coil as current transformer, thus structure more simple, install and use more conveniently, the while measuring accuracy is also higher and energy-saving and cost-reducing.

Description of drawings

Fig. 1 adopts the electric power digital instrument of Luo-coil current transformer for the utility model.

Fig. 2 is the structural representation of the utility model Luo-coil current transformer.

Wherein:

Luo-coil current transformer 1, integrating circuit 2, amplifying circuit 3, cpu circuit 4, display operation circuit 5, voltage sampling circuit 6, communicating circuit 7, analogue quantity output circuit 8, extension line 9, measured conductor 10, tubular support 11, Luo-coil 12, screw 13.

Embodiment

Referring to Fig. 1; A kind of electric power digital instrument that adopts the Luo-coil current transformer that the utility model relates to; Said instrument includes Luo-coil current transformer 1, integrating circuit 2, amplifying circuit 3, cpu circuit 4 and display operation circuit 5; Said Luo-coil current transformer 1, integrating circuit 2, amplifying circuit 3, cpu circuit 4 are connected with display operation circuit 5 successively; The current transformer of said Luo-coil current transformer 1 for adopting Luo-coil to process, during use, said Luo-coil current transformer 1 is wound on the conductor to be measured; The induction current that measures transfers to cpu circuit 4 through integrating circuit 2 and amplifying circuit 3, and cpu circuit 4 is handled the back and realized through display operation circuit 5;

Referring to Fig. 2, said Luo-coil current transformer 1 includes tubular support 11, is wound with Luo-coil 12 on the said tubular support 11; The extension line 9 of said Luo-coil 12 links to each other with integrating circuit 2, is serially connected with a plurality of screws 13 on the circle wall of said tubular support 11, during use; Tubular support 11 is sleeved on the measured conductor 10; Rotary screw 13 then, make screw 13 tighten measured conductors 10, thereby realized the fastening of Luo-coil current transformer 1 and measured conductor 10.

Adopt the advantage of Luo Shi mutual inductor to be: mutual inductor adopts the Luo-coil of plastic type; In the mutual inductor shell, twine multiturn; Make Luo-coil more press close to tested lead and have more that multiturn coil is centered around around the tested electric current; Induce higher voltage, tested current i (t) is the alternating cycles ripple, momentary current i (t)=I sin (ω t); The transformer induced voltage V of Luo-coil (t)

Figure 2011204662205100002DEST_PATH_IMAGE002

θ j is the differential instantaneous flow of the j circle of coil total number of turns N circle; The transformer induced voltage V of Luo-coil (t) is reduced to and the linear voltage signal of tested current i (t) through differentiating circuit i ∫ sin (θ) dt like this, by the digital displaying meter calculation display.Can reach 0.5 grade through the actual measurement system precision, system accuracy can reach 0.2 grade under certain range of linearity, thereby precision is higher;

The utility model also can be according to the actual requirements; On cpu circuit 4, connect voltage sampling circuit 6, communicating circuit 7 and analogue quantity output circuit 8; Said voltage sampling circuit 6 is used to obtain the voltage signal on the measured conductor; Said communicating circuit 7 is used for linking to each other with external communication apparatus, and said analogue quantity output circuit 8 is used for the output of analog quantity.

Claims

1. electric power digital instrument that adopts the Luo-coil current transformer; It is characterized in that: said instrument includes Luo-coil current transformer (1), integrating circuit (2), amplifying circuit (3), cpu circuit (4) and display operation circuit (5); Said Luo-coil current transformer (1), integrating circuit (2), amplifying circuit (3), cpu circuit (4) and display operation circuit (5) are connected successively; Said Luo-coil current transformer (1) includes tubular support (11); Be wound with Luo-coil (12) on the said tubular support (11); The extension line (9) of said Luo-coil (12) links to each other with integrating circuit (2), is serially connected with a plurality of screws (13) on the circle wall of said tubular support (11).

2. a kind of according to claim 1 electric power digital instrument that adopts the Luo-coil current transformer is characterized in that: also connect voltage sampling circuit (6), communicating circuit (7) and analogue quantity output circuit (8) on the said cpu circuit (4).