CN210244135U

CN210244135U - Analog signal acquisition circuit of distribution automation terminal

Info

Publication number: CN210244135U
Application number: CN201921635070.9U
Authority: CN
Inventors: Liuchao Zhang; 张留朝; Jin Gao; 高进
Original assignee: Weifang University
Current assignee: Weifang University
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2020-04-03
Anticipated expiration: 2029-09-29

Abstract

The utility model relates to an analog signal acquisition circuit of a distribution automation terminal, which comprises m multi-channel analog switches, a multi-channel synchronous sampling A/D unit and 1 DSP, wherein m is an integer larger than 1; the multi-path synchronous sampling A/D unit is connected with the DSP; each multi-channel analog switch comprises 1 enabling end EN, n switch channels and a plurality of control ends; the multi-path synchronous sampling A/D unit comprises n A/D converters; the output ends of n switch channels in each multi-channel analog switch are correspondingly connected with the input ends of n A/D converters; controlling the start and stop of n switch channels by a plurality of control ends, wherein n is a positive integer; and each control terminal and the enable terminal EN are connected with the DSP. The utility model discloses simplify circuit design, improved the analog signal volume that acquisition circuit gathered, can reduce the quantity of AD converter simultaneously, reduced the cost input of AD converter.

Description

Analog signal acquisition circuit of distribution automation terminal

Technical Field

The utility model relates to a distribution automation terminal's analog signal acquisition circuit belongs to the electric wire netting and measures collection technical field.

Background

The comprehensive automation technology of the power distribution network is a power measurement and control technology developed along with the development of communication and computer technologies in recent years, and has important significance for improving power supply reliability, expanding power supply capacity, reducing line loss and lightening labor intensity.

To realize real-time monitoring and control of the power grid, firstly, the analog signal quantity on the power grid needs to be acquired. The traditional semaphore acquisition methods have two types:

(1) as shown in FIG. 1, the traditional analog Signal acquisition circuit combining an eight-way (one-out-of-one) analog switch and an A/D converter has the limitation that ① semaphore acquisition cannot be synchronized, and software complexity is increased ② has a limited number of acquired analog semaphores due to speed limitation of A/D and DSP (Digital Signal Processing).

(2) The conventional analog signal acquisition circuit, in which an analog signal is used in combination with an a/D converter, uses a plurality of a/ds, as shown in fig. 2. The limitations of this analog semaphore acquisition method are: too many a/D conversion chips are used, increasing the cost.

Disclosure of Invention

Not enough to prior art, the utility model provides a distribution automation terminal's analog signal acquisition circuit.

The technical scheme of the utility model is that:

an analog signal acquisition circuit of a distribution automation terminal comprises m multi-channel analog switches, a multi-channel synchronous sampling A/D unit and 1 DSP, wherein m is an integer larger than 1;

the multi-path synchronous sampling A/D unit is connected with the DSP;

each multi-channel analog switch comprises 1 enabling end EN, n switch channels and a plurality of control ends; the multi-path synchronous sampling A/D unit comprises n A/D converters; the output ends of n switch channels in each multi-channel analog switch are correspondingly connected with the input ends of n A/D converters; controlling the start and stop of n switch channels by a plurality of control ends, wherein n is a positive integer; and each control end and each enable end EN are connected with the DSP.

The acquisition circuit can realize synchronous acquisition of analog signals, and the number of the acquired analog signals is greatly increased; the number of A/D converters is reduced, the cost of the acquisition circuit is reduced, and the circuit design is simplified. The DSP transmits an enabling signal to the enabling end EN, and the enabling signal selects a switch channel in the multi-channel analog switch; the control end is used for controlling the start and stop of a corresponding switch channel, the switch channel transmits an analog signal to the A/D converter, the A/D converter converts the analog signal into a digital signal and transmits the digital signal to the DSP; and the DSP performs calculation analysis processing on the received digital signals to realize real-time monitoring control on the power grid.

According to the utility model discloses it is preferred, the number of control end is n, corresponds opening of controlling n switch passageways by n control ends. The consistency of the design is good, the starting speed of the switch is high, and the anti-interference performance is strong. Compared with the three control end of conventionality, the conventional control method can only select to switch on all the way at every turn, the utility model discloses can realize that the multichannel switches on.

According to the utility model discloses preferred, multichannel analog switch is the multichannel analog switch of integration in multichannel synchronous sampling AD unit. The multi-path synchronous sampling A/D unit becomes a multi-path synchronous sampling A/D unit with a multi-path programmable configuration analog switch, and the control end O1-On is used for selectively controlling the corresponding switch channel to be conducted so as to output analog signals I1-In for output.

According to the present invention, the a/D converter is preferably of the type ADS 8556.

According to the present invention, preferably, each of the a/D converters is connected to the DSP through a serial data output port for data output from the a/D converter to the DSP; each A/D converter is connected with the DSP through a serial data input port and used for outputting data from the DSP to the A/D converter.

According to the present invention, preferably, each of the a/D converters is connected to the DSP through a serial data clock port; each A/D converter is also connected with the DSP through a starting conversion pin (AD _ CONVT) and used for controlling the A/D converter to carry out analog-to-digital conversion by the DSP.

The working method of the analog signal acquisition circuit comprises the following steps: when the analog signal acquisition circuit works, an enabling signal provided by the DSP is transmitted to an enabling end EN of the multi-channel analog switch to select a switch channel in each multi-channel analog switch, a control end of the multi-channel analog switch controls the start and stop of the corresponding switch channel, and the analog signal is transmitted to an A/D converter of the multi-channel synchronous sampling A/D unit;

the DSP controls an A/D converter in the multi-path synchronous sampling A/D unit to perform analog-to-digital conversion through an enable signal output end, the A/D converter converts an analog signal into a digital signal and transmits the digital signal to the DSP through a serial data input end AD _ MISO;

and the DSP performs calculation analysis processing on the received digital signals to realize real-time monitoring control on the power grid.

The utility model has the advantages that:

1. the utility model provides a synchronous AD unit that samples of multichannel includes a n AD converter, and every AD converter all is connected with a switch channel among every multichannel analog switch, corresponds an AD converter for a traditional switch channel, and this design can realize the synchronous collection of multichannel synchronous AD unit to multichannel analog switch's signal, has improved the analog signal volume that acquisition circuit gathered.

2. The utility model discloses can reduce the quantity of AD converter, reduce the cost input of AD converter.

3. The utility model provides an analog signal acquisition circuit uniformity is good, and the start-up speed of switch is fast, and interference immunity is strong.

4. The utility model discloses circuit design has been simplified.

Drawings

Fig. 1 is a schematic structural diagram of an analog signal acquisition circuit combining an analog switch and an a/D converter for selecting one of eight paths in a conventional manner;

FIG. 2 is a schematic diagram of an analog signal acquisition circuit for use with a conventional analog signal and A/D converter;

fig. 3 is a schematic structural diagram of an analog signal acquisition circuit provided in embodiment 1 of the present invention;

fig. 4 is a schematic structural diagram of an analog signal acquisition circuit provided in embodiment 2 of the present invention.

Detailed Description

The present invention will be further described with reference to the following examples and drawings, but is not limited thereto.

Example 1

An analog signal acquisition circuit of a distribution automation terminal, as shown in fig. 3, includes m multi-channel analog switches, a multi-channel synchronous sampling a/D unit, and 1 DSP; m is an integer greater than 1; the multi-path synchronous sampling A/D unit is connected with the DSP; each multi-channel analog switch comprises 1 enabling end EN, n switch channels and a plurality of control ends; the multi-path synchronous sampling A/D unit comprises n A/D converters; the output ends of n switch channels in each multi-channel analog switch are correspondingly connected with the input ends of n A/D converters; controlling the start and stop of the n switch channels by a plurality of control ends; n is a positive integer; and each control end O and the enable end EN are connected with the DSP. And O1-On is used for controlling whether the signals I1-In are output or not, when the output of the DSP is at a high level, the corresponding control end O controls the corresponding switch channel to be conducted, for example, O1 is at a high level, then the switch corresponding to I1 is conducted, the signal of the I1 port can be sent to the output end, and so On.

The acquisition circuit can realize synchronous acquisition of analog signals and increase the number of the acquired analog signals; the number of A/D converters is reduced, the cost of the acquisition circuit is reduced, and the circuit design is simplified.

The DSP transmits an enabling signal to an enabling end EN, and the enabling signal selects a switch channel in the multi-channel analog switch; the control end is used for controlling the start and stop of the corresponding switch channel, the switch channel transmits the analog signal to the A/D converter, the A/D converter converts the analog signal into a digital signal and transmits the digital signal to the DSP; and the DSP performs calculation analysis processing on the received digital signals to realize real-time monitoring control on the power grid.

The number of the control ends is n, and the start and stop of the n switch channels are correspondingly controlled by the n control ends.

One of the connection modes is as follows: the output end of the 1 st switch channel of all the multi-channel analog switches is connected with the input end of the 1 st A/D converter, the output end of the 2 nd switch channel of all the multi-channel analog switches is connected with the input end of the 2 nd A/D converter, and so on, the output end of the jth switch channel of all the multi-channel analog switches is connected with the input end of the jth A/D converter, and the design can effectively reduce the number of the A/D converters, save the cost and simultaneously realize the synchronous acquisition of the multi-channel analog switches. The design has good consistency, high starting speed of the switch and strong anti-interference performance.

In this embodiment, the type of the a/D converter is ADS 8556.

The serial data output port AD _ MISO of each A/D converter is connected with the serial data output port MISO of the DSP and is used for outputting data from the A/D converter to the DSP; each A/D converter is connected with the serial data output port MOSI of the DSP through the serial data input port AD _ MOSI and is used for outputting data from the DSP to the A/D converter.

Each A/D converter is connected with the DSP through a serial data clock port AD _ CLK; each A/D converter is also connected with the DSP through a starting conversion pin AD _ CONVT and used for the DSP to output a magic conversion starting signal to control the A/D converter to carry out analog-to-digital conversion.

Each A/D converter only occupies 4I/O ports of the DSP, thereby saving resources and reducing cost.

The working method of the analog signal acquisition circuit comprises the following steps: when the analog signal acquisition circuit works, an enabling signal provided by the DSP is transmitted to an enabling end EN of the multi-channel analog switch to select a switch channel In each multi-channel analog switch, a control end O1-On of the analog switch controls the start and stop of the corresponding switch channel, and analog signals I1-In are sent to an A/D converter of the multi-channel synchronous sampling A/D unit;

Example 2

According to embodiment 1, there is provided an analog signal acquisition circuit of a distribution automation terminal, characterized in that:

one multi-channel analog switch of the m multi-channel analog switches is integrated in the multi-channel synchronous sampling A/D unit, other multi-channel analog switches are connected with the integrated multi-channel synchronous sampling A/D unit, local circuit connection is shown in figure 4, and the connection relation between other multi-channel analog switches and the multi-channel synchronous sampling A/D unit is not marked in the figure. The multi-path synchronous sampling A/D unit becomes a multi-path synchronous sampling A/D unit with a multi-path programmable configuration analog switch, and the control end O1-On is used for selectively controlling the corresponding switch channel to be conducted so as to output analog signals I1-In for output.

Claims

1. An analog signal acquisition circuit of a distribution automation terminal is characterized by comprising m multi-channel analog switches, a multi-channel synchronous sampling A/D unit and 1 DSP, wherein m is an integer greater than 1;

the multi-path synchronous sampling A/D unit is connected with the DSP;

2. The analog signal acquisition circuit of the distribution automation terminal of claim 1, wherein the number of the control terminals is n, and the n control terminals correspondingly control the on/off of the n switch channels.

3. The distribution automation terminal analog signal acquisition circuit of claim 1 wherein the multi-channel analog switch is a multi-channel analog switch integrated in a multi-channel synchronous sampling a/D cell.

4. The distribution automation terminal analog signal acquisition circuit of claim 1 wherein the a/D converter is model ADS 8556.

5. The analog signal acquisition circuit of a distribution automation terminal of claim 1 wherein each of the a/D converters is connected to the DSP through a serial data output port for data output from the a/D converter to the DSP; each A/D converter is connected with the DSP through a serial data input port and used for outputting data from the DSP to the A/D converter.

6. The distribution automation terminal analog signal acquisition circuit of any one of claims 1 to 5 wherein each of the A/D converters is connected to a DSP via a serial data clock port; each A/D converter is also connected with the DSP through a starting conversion pin and used for controlling the A/D converter to carry out analog-to-digital conversion by the DSP.