CN213813715U

CN213813715U - High-precision transient feedback power amplification circuit for relay protection tester

Info

Publication number: CN213813715U
Application number: CN202022180434.8U
Authority: CN
Inventors: 鄢振鹏; 黄俭; 艾戈韬
Original assignee: Jiangxi Huadong Electric Co ltd
Current assignee: Jiangxi Huadong Electric Co ltd
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2021-07-27
Anticipated expiration: 2030-09-28

Abstract

The utility model discloses a high accuracy transient feedback power amplifier circuit for relay protection tester belongs to the relay protection field, a high accuracy transient feedback power amplifier circuit for relay protection tester, including high performance CPU, high accuracy DA module, little analog quantity signal output circuit, power amplification module, little signal output acquisition return circuit, high accuracy AD module, its characterized in that: high accuracy DA module and high performance CPU and high accuracy AD module between be equipped with parallel bus, high accuracy DA module is connected with high performance CPU through parallel bus, high performance CPU is connected with high accuracy AD module through parallel bus, high accuracy DA module connect little analog signal output circuit, high accuracy DA module is connected with power amplification module through little analog signal output circuit, power amplification module connect little signal output and gather the return circuit, power amplification module pass through little signal output and gather the return circuit and be connected with high accuracy AD module.

Description

High-precision transient feedback power amplification circuit for relay protection tester

Technical Field

The relay protection tester is widely applied as a power supply capable of truly simulating and replaying various actual faults on site. The design of the relay protection tester is required to be provided with a high-fidelity power amplifier circuit. The power amplifier circuit generally comprises a DA chip, a power amplifying element and the like. The utility model relates to a high accuracy transient feedback power amplifier circuit for relay protection tester gathers feedback module, high performance based on high accuracy DA conversion module, high real-time AD and calculates CPU and multistage amplifier circuit constitution. The circuit has high reliability, high power waveform output precision and strong stability.

Background

The output waveform of the traditional power amplification power supply has the following problems: high distortion rate, unstable output precision and slow transient response. The main reasons for these problems are due to: the output of the power amplifying circuit lacks a closed loop feedback link, the characteristics of circuit components change along with the rise of the power output and the temperature, and the waveform computing capability and DA conversion precision are low.

The relay protection tester outputs high-precision full-range analog quantity and ensures that the amplitude, phase, frequency and other performance parameters of high-precision waveforms are output, so that a high-precision transient feedback power amplification circuit with higher performance and reliability is required.

SUMMERY OF THE UTILITY MODEL

The utility model provides a high accuracy transient feedback power amplifier circuit for relay protection tester, circuit structure is simple, the realization is convenient, measures through real-time closed loop, revises waveform output, improves the precision and the wave form performance of power amplifier circuit output.

The utility model adopts the technical proposal that:

1. and (3) realizing small analog quantity signal output: as shown in the following figure, a high-frequency point location hardcore operation is carried out on a waveform through a CPU based on a master frequency 480M in a high-performance CPU module, an operation result is transmitted to a high-precision DA module through a high-speed parallel bus, and the high-precision DA module realizes the output of a small analog quantity signal;

2. the realization of a small signal output acquisition loop: as shown in the following figure, after a small analog signal is amplified by a high-performance operational amplifier, the analog signal enters a next stage of power amplification module, a power amplifier output waveform signal is recovered, and the recovered signal is processed by a following operational amplifier and a proportional filter circuit;

3. and (3) realizing signal closed loop correction: as shown in the following figure, the processed signals enter a high-precision AD module, the AD acquisition module transmits data to a CPU in a closed loop through a high-speed parallel bus in real time, and the CPU corrects the output small analog quantity signals in real time according to the comparison relation between the analog quantity output value and the actual acquisition signals, so that high-precision transient feedback is realized, and the precision and the stability of the output waveform are improved.

The utility model has the advantages that:

1. high-precision analog quantity waveform output is realized through closed-loop feedback: the CPU compares the small analog quantity signal output value with the actual analog quantity output value amplified by the multi-stage power in real time, establishes a data model, calculates the circuit equivalent error, and then corrects and outputs the small analog quantity signal, thereby realizing high precision and high stability.

2. The circuit structure is clear and simple: the circuit structure includes: the CPU realizes the operation of waveform point values, the DA module realizes the output of small signals, the multi-stage power amplifying circuit finishes the output of large-function analog quantities, and the sampling circuit and the AD module realize the recovery of signals.

3. The circuit parameter configuration is flexible: the resistance value can be modified according to the parameter requirements of elements such as analog quantity amplification factor, AD and DA, and the like, so that the circuit generalization is achieved.

4. The circuit has very wide application prospect.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides a high accuracy transient feedback power amplifier circuit for relay protection tester as shown in figure 1.

Through the design of the sliding rheostat VR1, in order to guarantee high output precision, the circuit design keeps the aim of inputting offset voltage for the operational amplifier through manual adjustment, solves the problem of overall output drift, and corrects the waveform amplitude.

The CPU based on the master frequency 480M carries out high-priority communication on the operation value of the output analog high-frequency discrete point with a 16-bit high-performance DA module in real time through a high-speed parallel bus by an algorithm, and the DA module converts the operation value of the discrete point into a small analog output by real-time hard interrupt and parallel bus communication. The small analog output signal is connected to the negative input of the operational amplifier U1A through a precision resistor R3 connected in series and R4 and C1 connected in parallel with the output. The positive input signal of U1A is connected in series-parallel through a sliding resistor VR1, precision resistors R1 and R2. Analog signals are amplified by the power amplification module and then output, feedback signals are collected at the output end and are connected to the positive end of the U1B, the negative electrode of the U1B is in short circuit with the output, a voltage follower is achieved, and the signals enter the high-precision AD module after passing through series-parallel connection of C2, R5, C3, R6, R7 and R8. And after the high-precision AD module passes through the acquisition algorithm, the high-precision AD module communicates the numerical value to the high-performance CPU by using a parallel bus. And after the high-performance CPU is subjected to a comparison algorithm, correcting the numerical value.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and variations can be made in the embodiments or in part of the technical features of the embodiments without departing from the spirit and the scope of the invention.

Claims

1. The utility model provides a high accuracy transient feedback power amplifier circuit for relay protection tester, includes high performance CPU, high accuracy DA module, little analog signal output circuit, power amplification module, little signal output acquisition return circuit, high accuracy AD module, its characterized in that: high accuracy DA module and high performance CPU and high accuracy AD module between be equipped with parallel bus, high accuracy DA module is connected with high performance CPU through parallel bus, high performance CPU is connected with high accuracy AD module through parallel bus, high accuracy DA module connect little analog signal output circuit, high accuracy DA module is connected with power amplification module through little analog signal output circuit, power amplification module connect little signal output and gather the return circuit, power amplification module pass through little signal output and gather the return circuit and be connected with high accuracy AD module.

2. The high-precision transient feedback power amplifier circuit for the relay protection tester according to claim 1, wherein: the high-performance CPU is connected with a high-precision DA module and a high-precision AD module through a parallel bus, an ADIN-end and an ADIN + end are arranged on the high-precision AD module, and the ADIN-end and the ADIN + end are connected with a small-signal output acquisition loop.

3. The high-precision transient feedback power amplifier circuit for the relay protection tester according to claim 1, wherein: the small analog quantity signal output circuit is provided with an operational amplifier U1A, the operational amplifier U1A is provided with a port 1, a port 2, a port 3, a port 4 and a port 11, the port 1 is connected with a power amplification module, a precision resistor R4 and a capacitor C1, the port 2 is connected with a precision resistor R3, a precision resistor R4 and a capacitor C1 in parallel, the port 3 is connected with the precision resistor R2, the other end of the precision resistor R2 is connected with a precision resistor R1 and a movable end of a slide rheostat 1, two ends of a fixed end of the slide rheostat VR1 are respectively connected with a reference voltage negative terminal REF-10 and a reference voltage positive terminal REF +10, the other end of the R1 is connected with AGND, the port 4 is connected with a voltage of +15V, and the port 11 is connected with a voltage of-15V.

4. The high-precision transient feedback power amplifier circuit for the relay protection tester according to claim 1, wherein: the small signal output acquisition loop be equipped with operational amplifier U1B, operational amplifier U1B be equipped with 5 mouths, 6 mouths, 7 mouths, 5 mouths connect the other end of power amplification module, 6 mouths short circuit in 7 mouths, 7 mouths be connected with precision resistor R5 and electric capacity C2, precision resistor R5 be connected with resistance R6, electric capacity C3, the resistance R6 other end be connected with resistance R8, ADIN + end respectively, the resistance R8 other end be connected with resistance R7, ADIN-end respectively, resistance R7, electric capacity C3, electric capacity C2 be connected with AGND.