阅读说明：本技术 一种高压隔离变送器全自动校准方法及系统 (Full-automatic calibration method and system for high-voltage isolation transmitter ) 是由 管怀军 吕华平 吴圣帆 郭志奇 于 2020-07-01 设计创作，主要内容包括：本发明提供了一种高压隔离变送器全自动校准方法及系统,该方法由主处理器控制高压隔离变送器全自动校准装置对高压隔离变送器各档量程进行零点偏移校准和增益校准。高压隔离变送器全自动校准检测系统由高压隔离变送器全自动校准装置、高压隔离变送器组成。高压隔离变送器全自动校准装置由DC/DC高压电源模块、第一高精度直流电源、第二高精度直流电源、高压闭环实时调节电路、高压取样电路、主处理器、数字隔离电路、ADC电路、输入/输出取样选择电路、电压/电流取样电路组成。(The invention provides a full-automatic calibration method and a full-automatic calibration system for a high-voltage isolation transmitter. The full-automatic calibration and detection system of the high-voltage isolation transmitter consists of a full-automatic calibration device of the high-voltage isolation transmitter and the high-voltage isolation transmitter. The full-automatic calibration device of the high-voltage isolation transmitter comprises a DC/DC high-voltage power supply module, a first high-precision direct-current power supply, a second high-precision direct-current power supply, a high-voltage closed-loop real-time adjusting circuit, a high-voltage sampling circuit, a main processor, a digital isolation circuit, an ADC circuit, an input/output sampling selection circuit and a voltage/current sampling circuit.)

1. A full-automatic calibration method for a high-voltage isolation transmitter comprises the steps of carrying out zero offset calibration and gain calibration on each range of the high-voltage isolation transmitter; the method is characterized in that: the method comprises the following steps:

Step 1, setting a range gear of a high-voltage isolation transmitter;

step 2, the DC/DC high-voltage power supply module generates 0V voltage and adds the voltage to the detection input end of the high-voltage isolation transmitter;

step 3, performing AD conversion on the signal of the isolation output end of the high-voltage isolation transmitter to obtain a zero offset error;

step 4, if the zero point error is smaller than a set first threshold value, turning to step 5, otherwise, performing coarse zero point offset adjustment, and turning to step 3;

step 5, if the zero offset error is smaller than a set second threshold value, turning to step 6, otherwise, performing zero fine adjustment, and turning to step 3;

step 6, the DC/DC high-voltage power supply module generates a standard voltage of the high-voltage isolation transmitter in the range gear and transmits the standard voltage to the detection input end of the high-voltage isolation transmitter;

step 7, performing AD conversion on the signal at the isolation output end of the high-voltage isolation transmitter and comparing the signal with a standard voltage value to generate a gain error;

step 8, if the gain error is smaller than a set third threshold value, turning to step 9, otherwise, carrying out coarse gain adjustment, and turning to step 7;

and 9, finishing the gear calibration if the gain error is smaller than a set fourth threshold, otherwise, performing fine gain adjustment, and turning to the step 7.

2. The method of claim 1 for fully automatic calibration of a high voltage isolation transmitter, comprising: the first threshold value is 1%, the second threshold value is 0.05%, the third threshold value is 1%, and the fourth threshold value is 0.05%.

3. A full-automatic calibration device for a high-voltage isolation transmitter is used for carrying out zero offset calibration and gain calibration on each measuring range of the high-voltage isolation transmitter; the method is characterized in that:

the method comprises the following steps:

a main processor;

the main processor controls the DC/DC high-voltage power supply module to generate a standard voltage signal which is connected with the input end of the isolation high-voltage isolation transmitter;

the ADC is used for performing AD conversion on an analog signal at the output end of the high-voltage isolation transmitter corresponding to a signal at the input end of the high-voltage isolation transmitter, and is connected with the main processor through a digital isolation circuit;

the main processor also generates a control signal to control the high-voltage isolation transmitter MCU to carry out coarse zero offset adjustment, fine zero offset adjustment, coarse gain adjustment and fine gain adjustment.

4. The full automatic calibration device of high pressure isolation transmitter of claim 3, characterized in that: the DC/DC high-voltage power supply module comprises a high-voltage power supply module U3 with the model number of KDHM-E-12S5000P-2, and standard voltage output is generated under the control of a high-voltage closed-loop real-time adjusting circuit controlled by a main processor.

5. The full automatic calibration device of high pressure isolation transmitter of claim 4, characterized in that: the high-voltage closed-loop real-time adjusting circuit comprises a coarse adjusting circuit, a fine adjusting circuit and a closed-loop comparison circuit;

the coarse tuning circuit comprises a digital potentiometer U1 controlled by a main processor, a follower consisting of an operational amplifier U2A, a resistor R2, a resistor R3, a resistor R4, a resistor R6 and a capacitor C2; the output end (W1) of a digital potentiometer U1 controlled by a main processor is connected with the non-inverting input end of an operational amplifier U2A through a resistor R2, and the non-inverting input end of the operational amplifier U2A is connected with the output end through a capacitor C2; the output end of the operational amplifier U2A is connected in series through a resistor R3 and a resistor R4 to form the output end of the coarse tuning circuit, and the common end connected with the resistor R3 and the resistor R4 is connected with the out-phase input end of the operational amplifier U2A through a resistor R6;

the fine tuning circuit is controlled and generated by a PWM signal generated by a main processor and comprises a follower consisting of an operational amplifier U2B, a resistor R7, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R17, a resistor R18, a capacitor C6 and a capacitor C5; the PWM signal generated by the main processor is connected with the non-inverting terminal of the operational amplifier U2B through a resistor R13, a resistor R12 and a resistor R11; the capacitor C5 is arranged between the common end of the resistor R13 and the resistor R12 and the ground; the common end connected with the resistor R12 and the resistor R11 is connected with a +5V working power supply through a resistor R9 and is grounded through a resistor R17; the capacitor C6 is arranged between the out-phase input end and the output end of the operational amplifier U2B, the operational amplifier U2B is connected in series through a resistor R14 and a resistor R7 to form the output end of the fine tuning circuit, and the common end connected with the resistor R14 and the resistor R17 is connected with the out-phase input end of the operational amplifier U2B through a resistor R18;

The closed loop comparison circuit synthesizes output end signals of the coarse tuning circuit and the fine tuning circuit and compares the synthesized output end signals with the output of the sampled DC/DC high-voltage power supply module to generate a control signal for controlling the output of the DC/DC high-voltage power supply module; the circuit comprises a comparator consisting of an operational amplifier U4, a resistor R5, a resistor R1 and a capacitor C1; the output end of the coarse tuning circuit and the output end of the fine tuning circuit are respectively connected with the in-phase end of the operational amplifier U4, the output of the sampled DC/DC high-voltage power supply module is connected with the out-phase end of the operational amplifier U4 through a resistor R5, and the out-phase end and the output end of an operational amplifier U4 formed by connecting a resistor R1 and a capacitor C1 in series are arranged between the out-phase end and the output end.

6. The full automatic calibration device of high pressure isolation transmitter of claim 5, characterized in that: the sampling circuit for sampling the DC/DC high-voltage power supply module comprises a resistor R16, a resistor R15 and a capacitor C15; the output of the DC/DC high-voltage power supply module is sequentially connected with the ground in series through a resistor R16 and a resistor R15, a capacitor C4 is connected in parallel at two ends of a resistor R15, and the output end of the sampling output circuit is formed by the common end of the resistor R16 connected with the resistor R15.

7. The full automatic calibration device of high pressure isolation transmitter of claim 5, characterized in that: the high-voltage closed-loop real-time regulating circuit and the ADC are respectively powered by a first high-precision direct-current power supply and a second high-precision direct-current power supply.

8. The full automatic calibration device of the high voltage isolation transmitter of any one of claims 3 to 7, wherein: the digital isolation circuit is also included, and the output signal and the input signal of the main processor are isolated by the digital isolation circuit.

9. A full-automatic calibration and transmission system for a high-voltage isolator is characterized in that: comprising a high-voltage isolation transmitter and a fully automatic calibration device for the high-voltage isolation transmitter according to claims 3, 4, 5, 6, 7 and 8.

Technical Field

The invention relates to a calibration and detection device of a high-voltage isolation transmitter, in particular to a full-automatic calibration method and system of the high-voltage isolation transmitter.

Background

A transducer is a transducer that converts the output signal of a sensor into a signal that can be recognized by a controller (or a signal source that converts the non-electrical quantity input by the sensor into an electrical signal while amplifying it for remote measurement and control). The sensor and the transmitter together form a monitoring signal for automatic control. Different physical quantities require different sensors and corresponding transmitters. The types of transmitters are various, and the transmitters used on the industrial control instrument mainly comprise a temperature transmitter, a pressure transmitter, a flow transmitter, a current transmitter, a voltage transmitter and the like.

The voltage transducer is an instrument which can convert the tested AC and DC voltage into AC and DC current or voltage which is output according to linear proportion. And the corresponding indicating instrument or device is matched, so that the measurement and control of voltage and current can be realized in alternating current and direct current circuits of the power system.

In high-power equipment such as rail transit, power grids, industrial control, new energy and the like, a higher-voltage driving mode is adopted for optimizing energy efficiency. For the detection and control of these high-voltage systems, the isolation voltage must be very high to ensure personal safety, for example, the subway traction system requires a working voltage of 3.6kV and an isolation voltage of more than 15 kV. This necessitates a high-voltage isolation transmitter, a high-isolation, high-reliability, high-precision monitoring device.

In a rail transit high-voltage traction system, the wide input range of a voltage signal of a high-voltage isolation transmitter is as follows: unipolar or bipolar voltage of +/-60 mV to +/-3600V is isolated by high voltage and then output and converted into +/-20 mA, 4-20 mA and +/-10V standard current and voltage range.

At present, the calibration and detection of the high-voltage isolation transmitter has no special detection equipment, and the high-voltage power supply, the high-voltage meter, the ammeter and a plurality of connecting pieces are connected for manual calibration and detection. The existing calibration detection mode is complex in operation and poor in calibration precision, and has high requirements on detection personnel. Especially, when the multi-range high-voltage isolation transmitter is calibrated and detected, a lot of manpower and time are needed. The high-voltage isolation transmitter has high detection voltage, can cause serious accidents by slight negligence, and is not beneficial to safe, quick and efficient production.

Disclosure of Invention

The invention provides a full-automatic calibration method and a full-automatic calibration system for a high-voltage isolation transmitter, aiming at the problems existing in the calibration and detection of the high-voltage isolation transmitter and the potential safety hazard of the high voltage to personal safety.

The invention realizes the full-automatic calibration and detection of the high-voltage isolation transmitter, does not need manual intervention in the test process, and greatly reduces the requirements on the quality of detection personnel.

The technical scheme adopted by the invention for realizing the technical purpose is as follows: a full-automatic calibration method for a high-voltage isolation transmitter comprises the steps of carrying out zero offset calibration and gain calibration on each range of the high-voltage isolation transmitter; the method comprises the following steps:

step 1, setting a range gear of a high-voltage isolation transmitter;

step 2, the DC/DC high-voltage power supply module generates 0V voltage and adds the voltage to the detection input end of the high-voltage isolation transmitter;

step 3, performing AD conversion on the signal of the isolation output end of the high-voltage isolation transmitter to obtain a zero offset error;

step 4, if the zero point error is smaller than a set first threshold value, turning to step 5, otherwise, performing coarse zero point offset adjustment, and turning to step 3;

step 5, if the zero offset error is smaller than a set second threshold value, turning to step 6, otherwise, performing zero fine adjustment, and turning to step 3;

Step 6, the DC/DC high-voltage power supply module generates a standard voltage of the high-voltage isolation transmitter in the range gear and transmits the standard voltage to the detection input end of the high-voltage isolation transmitter;

step 7, performing AD conversion on the signal at the isolation output end of the high-voltage isolation transmitter and comparing the signal with a standard voltage value to generate a gain error;

step 8, if the gain error is smaller than a set third threshold value, turning to step 9, otherwise, carrying out coarse gain adjustment, and turning to step 7;

and 9, finishing the gear calibration if the gain error is smaller than a set fourth threshold, otherwise, performing fine gain adjustment, and turning to the step 7.

Further, in the above full-automatic calibration method: the first threshold value is 1%, the second threshold value is 0.05%, the third threshold value is 1%, and the fourth threshold value is 0.05%.

The invention also provides a full-automatic calibration device of the high-voltage isolation transmitter, which is used for carrying out zero offset calibration and gain calibration on each range of the high-voltage isolation transmitter;

the method comprises the following steps:

a main processor;

the DC/DC high-voltage power supply module generates a standard voltage signal under the control of the main processor and is connected with the input end of the high-voltage isolation transmitter;

the ADC performs AD conversion on an analog signal at the output end of the high-voltage isolation transmitter corresponding to a signal at the input end of the high-voltage isolation transmitter, and the ADC and the main processor are connected;

The main processor also generates a control signal to control the high-voltage isolation transmitter MCU to carry out coarse zero offset adjustment, fine zero offset adjustment, coarse gain adjustment and fine gain adjustment.

Further, in the above full-automatic calibration device: the DC/DC high-voltage power supply module comprises a high-voltage power supply module U3 with the model number of KDHM-E-12S5000P-2, and standard voltage output is generated under the control of a high-voltage closed-loop real-time adjusting circuit controlled by a main processor.

Further, in the above full-automatic calibration device: the high-voltage closed-loop real-time adjusting circuit comprises a coarse adjusting circuit, a fine adjusting circuit and a closed-loop comparison circuit;

the coarse tuning circuit comprises a digital potentiometer U1 controlled by a main processor, a follower consisting of an operational amplifier U2A, a resistor R2, a resistor R3, a resistor R4, a resistor R6 and a capacitor C2; the output end (W1) of a digital potentiometer U1 controlled by a main processor is connected with the non-inverting input end of an operational amplifier U2A through a resistor R2, and the non-inverting input end of the operational amplifier U2A is connected with the output end through a capacitor C2; the output end of the operational amplifier U2A is connected in series through a resistor R3 and a resistor R4 to form the output end of the coarse tuning circuit, and the common end connected with the resistor R3 and the resistor R4 is connected with the out-phase input end of the operational amplifier U2A through a resistor R6;

The fine tuning circuit is controlled and generated by a PWM signal generated by a main processor and comprises a follower consisting of an operational amplifier U2B, a resistor R7, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R17, a resistor R18, a capacitor C6 and a capacitor C5; the PWM signal generated by the main processor is connected with the non-inverting terminal of the operational amplifier U2B through a resistor R13, a resistor R12 and a resistor R11; the capacitor C5 is arranged between the common end of the resistor R13 and the resistor R12 and the ground; the common end connected with the resistor R12 and the resistor R11 is connected with a +5V working power supply through a resistor R9 and is grounded through a resistor R17; the capacitor C6 is arranged between the out-phase input end and the output end of the operational amplifier U2B, the operational amplifier U2B is connected in series through a resistor R14 and a resistor R7 to form the output end of the fine tuning circuit, and the common end connected with the resistor R14 and the resistor R17 is connected with the out-phase input end of the operational amplifier U2B through a resistor R18;

the closed loop comparison circuit synthesizes signals at the output ends of the coarse tuning circuit and the fine tuning circuit and compares the synthesized signals with the output of the sampled DC/DC high-voltage power supply module to generate a control signal for controlling the output of the DC/DC high-voltage power supply module; the circuit comprises a comparator consisting of an operational amplifier U4, a resistor R5, a resistor R1 and a capacitor C1; the output end of the coarse tuning circuit and the output end of the fine tuning circuit are respectively connected with the in-phase end of the operational amplifier U4, the output of the sampled DC/DC high-voltage power supply module is connected with the out-phase end of the operational amplifier U4 through a resistor R5, and the out-phase end and the output end of an operational amplifier U4 formed by connecting a resistor R1 and a capacitor C1 in series are arranged between the out-phase end and the output end.

Further, in the above-mentioned full automatic calibration device of high pressure isolation transmitter: the sampling output circuit for sampling the DC/DC high-voltage power supply module comprises a resistor R16, a resistor R15 and a capacitor C15; the output of the DC/DC high-voltage power supply module is sequentially connected with the ground in series through a resistor R16 and a resistor R15, a capacitor C4 is connected in parallel at two ends of a resistor R15, and the output end of the sampling output circuit is formed by the common end of the resistor R16 connected with the resistor R15.

Further, in the above-mentioned full automatic calibration device of high pressure isolation transmitter: the high-voltage closed-loop real-time regulating circuit and the ADC are respectively powered by a first high-precision direct-current power supply and a second high-precision direct-current power supply.

Further, in the calibration apparatus for a high-voltage isolation transmitter described above: the digital isolation circuit is also included, and the output signal and the input signal of the main processor are isolated by the digital isolation circuit.

The invention also provides a full-automatic calibration and transmission system of the high-voltage isolation transformer, which comprises the high-voltage isolation transmitter and a full-automatic calibration device of the high-voltage isolation transmitter. The full-automatic calibration device of the high-voltage isolation transmitter consists of a DC/DC high-voltage power supply module, a first high-precision direct-current power supply, a second high-precision direct-current power supply, a high-voltage closed-loop real-time adjusting circuit, a high-voltage sampling circuit, a main processor, a digital isolation circuit, an ADC (analog-to-digital converter) circuit, an input/output sampling selection circuit and a voltage/current sampling circuit, wherein the high-voltage isolation transmitter consists of an input circuit, a high-voltage isolation circuit, an output circuit, a transmitter MCU (microprogrammed control unit) and a range switch.

The invention provides a full-automatic calibration method and a full-automatic calibration system for a high-voltage isolation transmitter, which are used for realizing full-automatic calibration and detection of the high-voltage isolation transmitter, and greatly reducing the requirements on the quality of detection personnel without manual intervention in the test process.

The invention is further described with reference to the following figures and detailed description.

Drawings

FIG. 1 is a block diagram of a full-automatic calibration and detection system for a high-voltage isolation transmitter according to the present invention.

Fig. 2 is a circuit schematic diagram corresponding to the high-voltage closed-loop real-time regulating circuit.

Fig. 3 is a flow chart of the full-automatic calibration software of the high-voltage isolation transmitter in embodiment 1 of the invention.

Detailed Description

Embodiment 1, as shown in fig. 1, this embodiment is a system for calibrating a high voltage isolation transmitter that detects input voltages up to several thousand volts, consisting of a multi-range high voltage isolation transmitter full automatic calibration device and a 16-step high voltage isolation transmitter. The full-automatic calibration device of the multi-range high-voltage isolation transmitter comprises a DC/DC high-voltage power supply module, a first high-precision direct-current power supply, a second high-precision direct-current power supply, a high-voltage closed-loop real-time adjusting circuit, a high-voltage sampling circuit, a main processor, a digital isolation circuit, an ADC circuit, an input/output sampling selection circuit and a voltage/current sampling circuit. The 16-gear multi-range high-voltage isolation transmitter comprises an input circuit, a high-voltage isolation circuit, an output circuit, a high-voltage isolation transmitter MCU, a range selection switch and the like.

The high-voltage input signal of the high-voltage isolation transmitter is output and generated by the DC/DC high-voltage power supply module. The high-voltage output is controlled by the main processor MCU to the coarse tuning circuit and the fine tuning circuit of the high-voltage closed-loop real-time adjusting circuit, and a standard high-voltage signal is generated. The main controller MCU generates 2 paths of control signals, and the high-voltage closed-loop real-time regulating circuit controls the DC/DC high-voltage power supply module to output high-voltage signals and controls the high-voltage isolation transmitter MCU after the control signals pass through the digital isolation circuit respectively. The high-voltage signal output by the DC/DC high-voltage power supply is sampled by the high-voltage sampling circuit and then is sent to the ADC circuit through the input/output sampling selection circuit. The main processor can measure the amplitude of the current output high-voltage signal through the ADC, so that the self calibration of the high-voltage signal output by the DC/DC high-voltage power supply module is realized before the high-voltage isolation transmitter is calibrated, and the precision of the high-voltage signal output by the DC/DC high-voltage power supply module is guaranteed.

The high-voltage closed-loop real-time adjusting circuit is shown in fig. 2 and comprises a coarse adjusting circuit, a fine adjusting circuit and a closed-loop comparison circuit. The +5V, 5V and +15V power supplies of the closed-loop real-time regulating circuit are provided by a first high-precision direct-current power supply.

In this embodiment, the coarse tuning circuit includes an operational amplifier U2A, a digital potentiometer U1, a resistor R2, a resistor R3, a resistor R4, a resistor R6, and a capacitor C2. Pins 1 and 2 of the digital potentiometer U1 are grounded, pins 3, 4 and 5 are connected to the MCU1 control circuit through a digital isolation circuit, pins 6 and 8 are connected to a +5V power supply, and pin 7 is connected to one end of R2. The other end of R2 is connected with the 3 feet of the operational amplifier U2A. The 4 pins of the operational amplifier U2A are connected with +5V, and the 8 pins are connected with-5V. The 2 pin of the operational amplifier U2A is connected with one end of a capacitor C2 and one end of a resistor R6, the other end of the capacitor C2 is connected with the 1 pin of the operational amplifier U2A and one end of a resistor R3, and the other end of the resistor R6 is connected with the other end of the resistor R3 and connected with one end of the resistor R4.

In this embodiment, the coarse tuning circuit includes a digital potentiometer U1 controlled by a main processor, a follower composed of an operational amplifier U2A, a resistor R2, a resistor R3, a resistor R4, a resistor R6, and a capacitor C2; the main processor controls the output end (W1) of the digital potentiometer U1 through a digital isolation circuit to be connected with the non-inverting input end of the operational amplifier U2A through a resistor R2, and the inverting input end of the operational amplifier U2A is connected with the output end through a capacitor C2; the output end of the operational amplifier U2A is connected in series through a resistor R3 and a resistor R4 to form the output end of the coarse tuning circuit, and the common end connected with the resistor R3 and the resistor R4 is connected with the out-phase input end of the operational amplifier U2A through a resistor R6.

In this embodiment, the trimming circuit includes an operational amplifier U2B, a resistor R7, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R17, a resistor R18, a capacitor C6, and a capacitor C5. One end of the resistor R13 is connected to the main processor circuit through a digital isolation circuit. The other end of the resistor R13 is connected to the resistor R12 and the capacitor C5, and the other end of the capacitor C5 is grounded. The other end of the resistor R12 is connected with one ends of a resistor R9, a resistor R11 and a resistor R17, the other end of the resistor R9 is connected with +5V, the other end of the resistor R17 is grounded, and the other end of the resistor R11 is connected with a pin 5 of the U2B. The pin 6 of the operational amplifier U2B is connected with one end of a capacitor C6 and one end of a resistor R18, the other end of the capacitor C6 is connected with the pin 7 of the operational amplifier U2B and one end of a resistor R14, and the other end of the resistor R18 is connected with the other end of the resistor R14 and connected with one end of the resistor R7.

In this embodiment, the trimming circuit is controlled and generated by a PWM signal generated by the main processor, and includes a follower composed of an operational amplifier U2B, a resistor R7, a resistor R9, a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R17, a resistor R18, a capacitor C6, and a capacitor C5; the PWM signal generated by the main processor is sent to a resistor R13 and a capacitor C5 through a digital isolation circuit to form an integral circuit, and is connected with the in-phase end of an operational amplifier U2B through a resistor R12 and a resistor R11; the capacitor C5 is arranged between the common end of the resistor R13 and the resistor R12 and the ground; the common end connected with the resistor R12 and the resistor R11 is connected with a +5V working power supply through a resistor R9 and is grounded through a resistor R17; a capacitor C6 is disposed between the out-of-phase input and output terminals of operational amplifier U2B, operational amplifier U2B is connected in series through resistor R14 and resistor R7 to form the output terminal of the trimming circuit, and the common terminal of the resistor R14 and resistor R17 is connected through resistor R18 to the out-of-phase input terminal of operational amplifier U2B.

In this embodiment, the closed-loop comparator circuit includes an operational amplifier U4, a resistor R5, a resistor R1, and a capacitor C1. The 4 pins of the operational amplifier U4 are connected with a-5V power supply, and the 7 pins of the operational amplifier U4 are connected with a +5V power supply. And the 3 pins of the operational amplifier U4 are connected to the other end of the resistor R4 and the other end of the resistor R7. The 2 pins of the op-amp are connected to one end of a resistor R1 and one end of a resistor R5. The other end of the resistor R5 is connected to one end of the high-voltage sampling circuit resistor R15, the capacitor C4 and the resistor R16. The other end of the resistor R1 is connected to the capacitor C1, and the other end of the capacitor C1 is connected to the pin 6 of the operational amplifier U4 and the pin 2 of the DC/DC high-voltage power supply module.

In this embodiment, the closed-loop comparison circuit compares the synthesized signal of the output ends of the coarse tuning circuit and the fine tuning circuit with the output of the sampled DC/DC high-voltage power supply module to generate a control signal for controlling the output of the DC/DC high-voltage power supply module; the circuit comprises a comparator consisting of an operational amplifier U4, a resistor R5, a resistor R1 and a capacitor C1; the output end of the coarse tuning circuit and the output end of the fine tuning circuit are respectively connected with the in-phase end of the operational amplifier U4, the output of the sampled DC/DC high-voltage power supply module is connected with the out-phase end of the operational amplifier U4 through a resistor R5, and the out-phase end and the output end of an operational amplifier U4 formed by connecting a resistor R1 and a capacitor C1 in series are arranged between the out-phase end and the output end.

The process of the multi-range high-voltage isolation transmitter in the embodiment during full-automatic calibration is shown in fig. 3, and the transmitter MCU performs related parameter initialization and serial port initialization. The variable N is the gear of the current multi-range high-voltage isolation transmitter, and the initial value of N is 0. All 16 gear calibrations are completed every time one gear calibration criterion N plus 1 is completed until N > 16. And if N is less than or equal to 16, the MCU is switched to a corresponding gear according to the current value of N. And reading data of the current gear gain and the zero offset. Firstly, zero offset calibration is carried out, the output of the DC/DC high-voltage power supply module is set to be 0V, and the MCU reads the value V of the ADC _ADC. Will V_ADCAnd comparing the zero offset with the standard value of the gear, calculating a zero offset error, if the error is more than or equal to 1%, sending a zero offset coarse adjustment command by the MCU, if the error is more than or equal to 0.05%, sending a zero offset fine adjustment command by the MCU, and if the error is less than 0.05%, completing zero offset calibration. And after the zero offset calibration is finished, gain calibration is carried out, and the output of the DC/DC high-voltage power supply module is set to be the full-scale input voltage of the current gear of the high-voltage isolation transmitter. At this time, the MCU reads the value V of the ADC_ADC. Will V_ADCAnd comparing the gain standard value with the gain standard value of the gear, calculating a gain error, if the error is more than or equal to 1%, sending a gain rough adjustment command by the MCU, if the error is more than or equal to 0.05%, sending a gain fine adjustment command by the MCU, and if the error is less than 0.05%, completing gain calibration. After the gear calibration is finished, the variable N plus 1 enters the next gear calibration and the next gear calibration is finishedTo complete all 16 stroke gear calibrations.

After the calibration is finished, the system detects all gears successively, rechecks errors of all gears and displays measuring range precision errors of all gears.

The multi-range high-voltage isolation transmitter after full-automatic calibration of the embodiment can reach the following main performance indexes:

input range: unipolar or bipolar voltages of + -60 mV to + -3600V,

outputting a measuring range: standard current of +/-20 mA, 4-20 mA and +/-10V and voltage range.

And (3) zero offset: less than 0.05 percent

Gain error: less than 0.05 percent

By adopting the multi-range high-voltage isolation transmitter full-automatic calibration detection system of the embodiment, multi-range high-precision high-voltage automatic calibration of the high-voltage isolation transmitter is realized, and the reliability and the calibration efficiency are remarkably improved. The calibration detection time is shortened from half an hour per unit to 3 minutes per unit, and the calibration detection efficiency is greatly improved. In the calibration and detection process, an operator does not need to contact the high-voltage circuit part, so that the potential safety hazard is fundamentally solved.

Compared with the existing high-voltage isolation transmitter calibration detection technology, the high-voltage isolation transmitter full-automatic calibration detection system of the embodiment has the following advantages: the calibration device has the advantages of high calibration precision, low cost, strong practicability, manpower and time saving, simple and convenient operation, safe use and contribution to quick and efficient work.