CN-122017328-A - Current monitoring method for multipath intrinsic safety actuator

CN122017328ACN 122017328 ACN122017328 ACN 122017328ACN-122017328-A

Abstract

The application provides a current monitoring method of a multi-channel intrinsic safety actuator, which comprises the steps of acquiring analog signals of the currents of the multi-channel intrinsic safety actuator through a plurality of non-invasive Hall current sensors sleeved on power lines of the multi-channel intrinsic safety actuator, electrically isolating primary sides from secondary sides of the Hall current sensors, enabling the internal resistances of the primary sides to be extremely small, inputting output signals of the Hall current sensors into a multi-channel signal acquisition and processing mainboard, enabling a multi-channel signal conditioning circuit to be integrated with the mainboard to filter and amplify the analog signals, enabling an analog-to-digital converter of the mainboard to conduct digital conversion on the conditioned multi-channel signals, enabling a microprocessor of the mainboard to process the digital signals and generate fault state marks of each channel based on preset thresholds, enabling the microprocessor to package the multi-channel current values and the corresponding fault state marks into standard industrial protocol data frames, and enabling the isolated digital communication interfaces of the mainboard to be sent to an upper control system through a single digital bus.

Inventors

WANG ZHENGYUN
LI WANCUN
YANG PENG
LI WEI
FENG YANAN
MA SHOUGANG

Assignees

新疆晶诺新能源产业发展有限公司

Dates

Publication Date: 20260512
Application Date: 20260129

Claims (8)

1. A current monitoring method for a multi-channel intrinsic safety actuator is characterized by comprising the steps of obtaining analog signals of the currents of the multi-channel intrinsic safety actuator through a plurality of non-invasive Hall current sensors sleeved on power lines of the multi-channel intrinsic safety actuator, enabling primary sides and secondary sides of the Hall current sensors to be electrically isolated and enabling primary sides to have minimum internal resistance, inputting output signals of the Hall current sensors into a multi-channel signal acquisition and processing main board, enabling a multi-channel signal conditioning circuit to be integrated with the main board to conduct filtering and amplifying on the analog signals, enabling an analog-to-digital converter of the main board to conduct digital conversion on the conditioned multi-channel signals, enabling a microprocessor of the main board to conduct processing on the digital signals and generating fault state marks of each channel based on preset thresholds, enabling the multi-channel current values and the corresponding fault state marks to be packaged into standard industrial protocol data frames, and enabling the multi-channel current values and the fault state marks to be sent to an upper control system through a single digital bus through an isolated digital communication interface of the main board.
2. The method of claim 1, wherein the plurality of non-invasive hall current sensors are sleeved on a plurality of intrinsically safe actuator power lines to obtain analog signals of the currents of the intrinsically safe actuators, and the method comprises the steps of enabling the hall current sensors to be of a perforated structure, enabling a primary side to be perforated through the intrinsically safe actuator power lines, enabling the internal resistance of the primary side to be kept in milliohm level to minimize the influence on the loop voltage drop of the intrinsically safe actuator, enabling secondary sides of the hall current sensors to output voltage signals corresponding to the current range of the intrinsically safe actuator and transmitting the voltage signals to input ends of a multi-channel signal acquisition and processing main board through short-distance shielding cables, determining secondary side output polarity according to the current direction of the primary side for each hall current sensor, and enabling direct current components to be contained in the analog signals to represent the working state of the intrinsically safe actuator.
3. The method of claim 1 wherein said motherboard integrated multi-channel signal conditioning circuit filters and amplifies said analog signal, including an RC low pass filter for each channel, said RC low pass filter cut-off frequency suppressing high frequency interference components in said analog signal, followed by a programmable gain amplifier for adjusting said Hall current sensor output voltage to said analog to digital converter input range, said microprocessor controlling said programmable gain amplifier gain via a digital potentiometer, said gain dynamically adjusted according to the analog signal amplitude for each channel.
4. The method of claim 1, wherein the microprocessor of the motherboard processes the digital signal and generates each path of fault status flag based on a preset threshold, comprising powering up the microprocessor to load zero calibration coefficients and fullness calibration coefficients for each channel in a nonvolatile memory, applying a linear correction to the digitized converted signal to obtain a calibration current value, comparing the calibration current value to a first preset threshold, generating an open-circuit fault status flag if the calibration current value is below the first preset threshold, comparing the calibration current value to a second preset threshold, generating an overcurrent fault status flag if the calibration current value is above the second preset threshold, and storing the fault status flag in association with the corresponding calibration current value to the microprocessor register.
5. The method of claim 1 wherein said microprocessor encapsulating multiple current values and corresponding fault status flags into a standard industrial protocol data frame comprises said microprocessor mapping each of said calibrated current values to a standard industrial protocol hold register address, mapping each of said fault status flags to a standard industrial protocol coil address or a discrete input register address, constructing said standard industrial protocol data frame comprising multiple of said hold registers and said coil address contents as slave stations responding to master station polls of a higher control system.
6. The method of claim 1, wherein the isolated digital communication interface of the motherboard is transmitted to an upper control system via a single digital bus, and comprises isolating the microprocessor serial port from the RS485 transceiver via a high-speed optocoupler, wherein the motherboard isolated power module obtains isolated power from an external power source to provide the microprocessor and the signal conditioning circuit operating voltage, and wherein the standard industrial protocol data frame is periodically transmitted to the upper control system via the single digital bus.
7. The method of claim 1, wherein the standard industrial protocol data frame is sent to an upper control system via a single digital bus through an isolated digital communication interface of the motherboard, comprising the microprocessor acting as a Modbus RTU slave, returning multiple paths of the calibration current values in response to the upper control system master read register command, returning multiple paths of the fault status flags in response to the upper control system master read coil command, and the RS485 transceiver driving the single digital bus A, B differential signal line to transmit the Modbus RTU data frame.
8. The method of claim 3 wherein the motherboard integrated multi-channel signal conditioning circuit filters and amplifies the analog signal, comprising the RC low pass filter resistor-capacitor parameters configured for the frequency characteristics of the analog signal, the programmable gain amplifier output connected to a multi-channel analog-to-digital converter input, the analog-to-digital converter synchronously or time-division sampling the amplified analog signal, the microprocessor obtaining a sequence of digital samples from the analog-to-digital converter, and averaging the filtered digital signal.

Description

Current monitoring method for multipath intrinsic safety actuator Technical Field The invention relates to the technical field of information, in particular to a current monitoring method of a multipath intrinsic safety actuator. Background In the environments with explosive gas hazards such as underground coal mines and chemical production, a plurality of intrinsically safe actuators bear key control tasks such as valve opening and closing, adjustment and the like, and the devices are directly related to safe operation and accident prevention of the production process, so that the real-time monitoring of the operation state of the devices is extremely high in necessity. The current common monitoring mode mostly depends on that an ammeter or a shunt resistor is connected in series in a loop for measurement, the access mode can directly change the electrical parameters of the original intrinsic safety loop, the loop resistance is increased or extra inductance and capacitance are introduced, the safety margin of explosion-proof authentication is easily destroyed, the whole equipment is not in accordance with the intrinsic safety requirement any more, and the equipment cannot be used in dangerous places legally. In addition, some schemes adopting parallel shunt or sampling resistors have smaller access resistance values, but the circuit is inevitably influenced, and particularly when a multi-path actuator works simultaneously, accumulated interference introduced by a plurality of monitoring points can offset an originally weak current signal, so that the monitoring precision is seriously reduced. The core requirement of the intrinsically safe loop is to severely limit the energy output, any monitoring means must ensure that no additional energy is injected into the loop, the loop impedance characteristics are not changed, and independent parallel acquisition of multiple actuator currents is achieved. Often, dozens of or even dozens of actuators are deployed on an actual production site, and the current change of each path may reflect different problems such as valve blocking, coil aging, poor cable contact or failure of the actuators, and if all loops cannot be monitored continuously at the same time, it is difficult to find abnormality at the initial stage of failure. For example, a sudden drop in one actuator current to a near zero value may mean that the valve is not in place, while an abnormal rise in the other current may be a coil short or a load stuck, the different manifestations being immediately distinguishable only by continuous, independent current collection. However, the existing method is limited by the constraint that the loop integrity must be maintained, and cannot realize multi-channel synchronous high-precision monitoring on the premise of not influencing safety parameters, so that once an abnormality of an actuator occurs on site, the abnormality can be discovered only by means of manual inspection or shutdown inspection after production interruption, and the fault response time is delayed. Therefore, on the premise of not changing at all and damaging the electrical characteristics of the original intrinsic safety loop, the parallel, real-time and independent current monitoring is realized on the multi-path intrinsic safety actuator, and the running state of each path is accurately identified, so that the method becomes a key problem for guaranteeing the production continuity of dangerous places and the safe running of equipment. Disclosure of Invention The invention provides a current monitoring method of a multipath intrinsic safety actuator, which mainly comprises the following steps: The method comprises the steps of acquiring analog signals of multiple paths of intrinsic safety executors through a plurality of non-invasive Hall current sensors sleeved on power lines of the multiple paths of intrinsic safety executors, electrically isolating primary sides and secondary sides of the Hall current sensors, enabling primary side internal resistances to be extremely small, inputting output signals of the multiple Hall current sensors into a multi-channel signal acquisition and processing main board, enabling a multi-channel signal conditioning circuit to conduct filtering and amplification on the analog signals, enabling an analog-to-digital converter of the main board to conduct digital conversion on the conditioned multiple paths of signals, enabling a microprocessor of the main board to conduct processing on the digital signals and generating fault state marks of each path based on preset thresholds, enabling the microprocessor to package the multiple paths of current values and the corresponding fault state marks into standard industrial protocol data frames, and enabling the isolated digital communication interfaces of the main board to be sent to an upper control system through a single digital bus. The method comprises the steps of enabling a primary side of a Hall current sensor t