阅读说明：本技术 一种高精度高动态隔离型电压变送器 (High-precision high-dynamic isolation type voltage transmitter ) 是由 冯广义 张巨龙 潘亚菲 赵盼 李宁斌 于 2020-11-11 设计创作，主要内容包括：本发明涉及一种高精度高动态隔离型电压变送器,以解决传统隔离型电压变送器采用霍尔或磁阻元件实现隔离,在需要高精度、高动态的场合无法满足要求的问题。该电压变送器包括隔离供电单元,以及依次电连接的电阻分压单元、信号调理单元、AD转换单元、数字转换单元、数字隔离单元、数字信号解析单元。电阻分压单元将输入的高电压等比例缩小,信号调理单元对缩小后的电压信号进行调理,AD转换单元将电压信号转换为数字信号,数字转换单元将数字信号转换为高速串行数字信号,数字隔离单元将高速串行数字信号转换为数字光信号并进行传输,再将数字光信号转换为数字电信号,数字信号解析单元对接收的数字电信号进行解析,并输出供用户直接使用。(The invention relates to a high-precision high-dynamic isolation type voltage transmitter, which aims to solve the problem that the traditional isolation type voltage transmitter adopts a Hall or a magnetic resistance element to realize isolation and cannot meet the requirement in the occasions requiring high precision and high dynamics. The voltage transducer comprises an isolation power supply unit, and a resistance voltage division unit, a signal conditioning unit, an AD conversion unit, a digital isolation unit and a digital signal analysis unit which are electrically connected in sequence. The resistance voltage dividing unit reduces input high voltage in an equal proportion, the signal conditioning unit conditions the reduced voltage signal, the AD conversion unit converts the voltage signal into a digital signal, the digital conversion unit converts the digital signal into a high-speed serial digital signal, the digital isolation unit converts the high-speed serial digital signal into a digital optical signal and transmits the digital optical signal, the digital optical signal is converted into a digital electric signal, and the digital signal analysis unit analyzes the received digital electric signal and outputs the digital electric signal for direct use by a user.)

1. A high dynamic isolation type voltage transmitter of high accuracy which characterized in that:

the device comprises an isolation power supply unit, and a resistance voltage division unit, a signal conditioning unit, an AD conversion unit, a digital isolation unit and a digital signal analysis unit which are electrically connected in sequence;

the isolation power supply unit is used for supplying power to the signal conditioning unit, the AD conversion unit, the digital isolation unit and the digital signal analysis unit;

the resistance voltage division unit is used for reducing the input voltage in an equal proportion and transmitting the voltage to the signal conditioning unit;

the signal conditioning unit is used for conditioning the reduced voltage signal to obtain a voltage signal matched with the AD conversion unit and transmitting the voltage signal to the AD conversion unit;

the AD conversion unit is used for converting the received voltage signal into a digital signal and transmitting the digital signal to the digital conversion unit;

the digital conversion unit is used for converting the received digital signals into high-speed serial digital signals and transmitting the high-speed serial digital signals to the digital isolation unit;

the digital isolation unit is used for converting the received high-speed serial digital signals into digital optical signals for transmission, converting the digital optical signals into digital electric signals and transmitting the digital electric signals to the digital signal analysis unit;

the digital signal analysis unit is used for analyzing the received digital electric signal and outputting the digital electric signal for direct use by a user.

2. The high-precision high-dynamic isolation type voltage transmitter of claim 1, wherein:

the resistance voltage division unit comprises a plurality of resistors connected in series, and the resistance voltage division unit takes a voltage value on one of the resistors and transmits the voltage value to the signal conditioning unit in a differential mode;

the signal conditioning unit is a signal conditioning circuit formed by an operational amplifier for an instrument;

the AD conversion unit comprises an AD converter and a voltage reference, wherein the voltage reference provides a voltage reference for the AD converter;

the digital isolation unit comprises an optical fiber driver, an optical fiber transmitter, an optical cable and an optical fiber receiver; the input end of the optical fiber driver is connected with the output end of the digital conversion unit, the output end of the optical fiber driver is connected with the input end of the optical fiber transmitter, the output end of the optical fiber transmitter is connected with the input end of the optical fiber receiver through an optical cable, and the output end of the optical fiber receiver is connected with the input end of the digital signal analysis unit;

and the digital signal analysis unit analyzes and restores the received digital electric signal and outputs the restored digital electric signal in a standard SPI interface mode.

3. The high-precision high-dynamic isolation type voltage transmitter of claim 2, wherein:

the input voltage of the resistance voltage division unit is larger than 1000V, and the number of the resistors is larger than or equal to 7.

4. The high-precision high-dynamic isolation type voltage transmitter of claim 2, wherein:

the precision error of the resistor is not more than 0.1%, and the temperature drift is-5 ppm/DEG C;

the voltage offset of the operational amplifier for the instrument is not more than 25uV, the offset drift is not more than 0.3 uV/DEG C, the bias current is not more than 0.4nA, the slew rate is not less than 2V/us, the bandwidth is not less than 800kHz, and the common mode rejection ratio is not less than 90 dB;

the resolution of the AD converter is not less than 18 bits, the signal-to-noise ratio is not less than 95dB, and the conversion rate is not less than 1 Msps;

the precision error of the voltage reference is not more than 0.02%, and the temperature drift is not more than 1 ppm/DEG C.

5. The high accuracy high dynamic isolation type voltage transmitter of claim 4, wherein:

the baud rate of serial digital communication performed by the digital conversion unit is not lower than 30 Mbps;

the baud rate of signals carried by the optical fiber driver, the optical fiber transmitter, the optical cable and the optical fiber receiver is not lower than 50 Mbps.

6. The high accuracy high dynamic isolation type voltage transmitter of any one of claims 1 to 5, wherein:

the isolation power supply unit comprises two groups of outputs which are isolated from each other, and one group of the outputs supplies power for the signal conditioning unit, the AD conversion unit, the digital conversion unit and the digital isolation unit; and the other group supplies power to the digital isolation unit and the digital signal analysis unit.

Technical Field

The invention relates to a high-precision high-dynamic isolation type voltage transmitter.

Background

The traditional isolation type voltage transmitter usually adopts a Hall or a magnetic resistance element to realize isolation, has the defects of low precision, large temperature drift, poor analog signal output index and dynamic index and the like, and can not meet the requirements in occasions requiring high precision and high dynamic.

Disclosure of Invention

The invention aims to solve the problems that the traditional isolation type voltage transmitter in the prior art adopts a Hall or a magnetic resistance element to realize isolation, has the defects of low precision, large temperature drift, poor analog signal output index and dynamic index and the like, and cannot meet the requirements in occasions requiring high precision and high dynamics, and provides the high-precision and high-dynamic isolation type voltage transmitter.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a high-precision high-dynamic isolation type voltage transmitter is characterized in that:

the device comprises an isolation power supply unit, and a resistance voltage division unit, a signal conditioning unit, an AD conversion unit, a digital isolation unit and a digital signal analysis unit which are electrically connected in sequence;

the isolation power supply unit is used for supplying power to the signal conditioning unit, the AD conversion unit, the digital isolation unit and the digital signal analysis unit;

the resistance voltage division unit is used for reducing the input voltage in an equal proportion and transmitting the voltage to the signal conditioning unit;

the signal conditioning unit is used for conditioning the reduced voltage signal to obtain a voltage signal matched with the AD conversion unit and transmitting the voltage signal to the AD conversion unit;

the AD conversion unit is used for converting the received voltage signal into a digital signal and transmitting the digital signal to the digital conversion unit;

the digital conversion unit is used for converting the received digital signals into high-speed serial digital signals and transmitting the high-speed serial digital signals to the digital isolation unit;

the digital isolation unit is used for converting the received high-speed serial digital signals into digital optical signals for transmission, converting the digital optical signals into digital electric signals and transmitting the digital electric signals to the digital signal analysis unit;

the digital signal analysis unit is used for analyzing the received digital electric signal and outputting the digital electric signal for direct use by a user.

Furthermore, the resistance voltage dividing unit comprises a plurality of resistors connected in series, and the resistance voltage dividing unit takes the voltage value on one of the resistors and transmits the voltage value to the signal conditioning unit in a differential mode;

the signal conditioning unit is a signal conditioning circuit formed by an operational amplifier for an instrument;

the AD conversion unit comprises an AD converter and a voltage reference, wherein the voltage reference provides a voltage reference for the AD converter;

the digital isolation unit comprises an optical fiber driver, an optical fiber transmitter, an optical cable and an optical fiber receiver; the input end of the optical fiber driver is connected with the output end of the digital conversion unit, the output end of the optical fiber driver is connected with the input end of the optical fiber transmitter, the output end of the optical fiber transmitter is connected with the input end of the optical fiber receiver through an optical cable, and the output end of the optical fiber receiver is connected with the input end of the digital signal analysis unit;

and the digital signal analysis unit analyzes and restores the received digital electric signal and outputs the restored digital electric signal in a standard SPI interface mode.

Further, the input voltage of the resistance voltage division unit is greater than 1000V, and the number of the resistors is greater than or equal to 7.

Further, the precision error of the resistor is not more than 0.1%, and the temperature drift is-5 ppm/DEG C;

the voltage offset of the operational amplifier for the instrument is not more than 25uV, the offset drift is not more than 0.3 uV/DEG C, the bias current is not more than 0.4nA, the slew rate is not less than 2V/us, the bandwidth is not less than 800kHz, and the common mode rejection ratio is not less than 90 dB;

the resolution of the AD converter is not less than 18 bits, the signal-to-noise ratio is not less than 95dB, and the conversion rate is not less than 1 Msps;

the precision error of the voltage reference is not more than 0.02%, and the temperature drift is not more than 1 ppm/DEG C.

Furthermore, the baud rate of serial digital communication performed by the digital conversion unit is not lower than 30 Mbps;

the baud rate of signals carried by the optical fiber driver, the optical fiber transmitter, the optical cable and the optical fiber receiver is not lower than 50 Mbps.

Furthermore, the isolation power supply unit comprises two groups of outputs which are isolated from each other, and one group of the outputs supplies power for the signal conditioning unit, the AD conversion unit, the digital conversion unit and the digital isolation unit; and the other group supplies power to the digital isolation unit and the digital signal analysis unit.

Compared with the prior art, the invention has the beneficial effects that:

the high-precision high-dynamic isolation type voltage transmitter provided by the invention can directly convert an analog voltage signal into a digital signal, realizes high-precision, high-dynamic and isolation type voltage transmission in a digital isolation mode, is suitable for occasions requiring high-precision, high-dynamic and high-isolation levels, and is convenient to be directly connected with a digital microprocessor.

Drawings

FIG. 1 is a schematic block diagram of a high-precision high-dynamic isolation type voltage transmitter of the present invention.

Detailed Description

To make the objects, advantages and features of the present invention more apparent, the high-precision high-dynamic isolation type voltage transmitter proposed by the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

The high-precision high-dynamic isolation type voltage transmitter provided by the invention comprises an isolation power supply unit, and a resistance voltage dividing unit, a signal conditioning unit, an AD conversion unit, a digital isolation unit and a digital signal analysis unit which are electrically connected in sequence, wherein the working principle of the voltage transmitter is shown in figure 1.

The resistance voltage division unit is used for reducing the high voltage in equal proportion and transmitting the high voltage to the signal conditioning unit. The resistance voltage division unit adopts a plurality of resistors with high precision and low temperature drift to be connected in series, and a voltage value on one resistor is taken and sent to the signal conditioning unit in a differential mode. Specifically, the precision error of the resistor is not more than 0.1%, and the temperature drift is-5 to 5 ppm/DEG C. If the voltage range to be collected is large, such as over 1000V, more than 7 resistors are usually required for voltage division, so as to avoid the resistor failure caused by the high voltage value on a single resistor.

The signal conditioning unit is used for conditioning the reduced voltage signal to obtain a voltage signal matched with the AD conversion unit and transmitting the voltage signal to the AD conversion unit. The signal conditioning unit adopts an operational amplifier for the instrument with the characteristics of low temperature drift, low zero bias, high dynamic and high common mode rejection ratio to form a signal conditioning circuit, and the signal conditioning circuit conditions the voltage signal output by the resistance voltage division unit to obtain a signal in a proper voltage range and reasonably match the signal with the AD converter. Specifically, the voltage offset of the operational amplifier for the instrument is not more than 25uV, the offset drift is not more than 0.3 uV/DEG C, the bias current is not more than 0.4nA, the slew rate is not less than 2V/us, the bandwidth is not less than 800kHz, and the common-mode rejection ratio is not less than 90 dB.

The AD conversion unit is used for converting the received voltage signal into a digital signal and transmitting the digital signal to the digital conversion unit. The AD conversion unit adopts an AD converter with the characteristics of high precision, high signal-to-noise ratio, high conversion rate and the like, and needs a voltage reference with high precision and low temperature drift to be matched with the AD converter for use. Specifically, the resolution of the AD converter is not less than 18 bits, the signal-to-noise ratio is not less than 95dB, and the conversion rate is not less than 1 Msps; the precision error of the voltage reference is not more than 0.02 percent, and the temperature drift is not more than 1 ppm/DEG C.

The digital conversion unit is used for converting the received digital signals into high-speed serial digital signals convenient for high-speed transmission after recombination and conversion, and transmitting the high-speed serial digital signals to the digital isolation unit. The baud rate of serial digital communication performed by the digital conversion unit is not lower than 30 Mbps.

The digital isolation unit is used for converting the received high-speed serial digital signals into digital optical signals for transmission, converting the digital optical signals into digital electric signals and transmitting the digital electric signals to the digital signal analysis unit. The digital isolation unit comprises an optical fiber driver, an optical fiber transmitter, an optical cable and an optical fiber receiver, wherein the input end of the optical fiber driver is connected with the output end of the digital conversion unit, the output end of the optical fiber driver is connected with the input end of the optical fiber transmitter, the optical fiber transmitter outputs digital optical signals, the output end of the optical fiber transmitter is connected with the input end of the optical fiber receiver through the optical cable, the optical cable transmits the digital optical signals, the optical fiber receiver converts the digital optical signals into digital electric signals, and the output end of the optical fiber receiver is connected with the input end of the digital signal analysis unit, so that the isolation transmission of the digital. The baud rate of signals carried by the optical fiber driver, the optical fiber transmitter, the optical cable and the optical fiber receiver is not lower than 50 Mbps.

The digital signal analysis unit is used for analyzing the received digital electric signal and outputting the digital electric signal for direct use by a user. The digital signal analysis unit analyzes and restores the received digital electric signal and outputs the digital electric signal in a standard SPI interface mode, so that the digital signal analysis unit is directly connected with the digital microprocessor.

The isolation power supply unit has two groups of outputs, one group supplies power for the signal conditioning unit, the AD conversion unit, the digital conversion unit and the digital isolation unit; and the other group supplies power to the digital isolation unit and the digital signal analysis unit. Since the digital isolation unit has two isolated sets of interfaces, two isolated sets of power supplies are required. The two groups of outputs of the isolated power supply unit are isolated, and the voltage-resistant requirement, such as 5000VDC, needs to be met.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.