CN101403391B - Novel duplicate-power double-fan intelligent monitoring protection device - Google Patents

Abstract

A new type of intelligent measurement and control protection device with dual power sources and dual fans, which is an embedded system including a micro-controller processor, and also includes a data acquisition module, a serial communication module, an auxiliary hardware module, and a human-computer interaction module to complete data sampling, The tasks of protection judgment, fan control, serial communication and man-machine interface interactive processing are carried out uninterrupted ventilation and state detection. Two microcomputer intelligent measurement, control and protection devices are used to control two fans powered by different power sources, namely the master and the slave, so as to control the continuous operation of the intelligent measurement, control and protection device. The invention can not only detect the current and voltage of the fan in real time, and provide timely protection for the faults that occur, but also use complementary control strategies to ensure that the ventilation system can continuously supply air and ensure the safety of mine production; it also has a communication function and can be used as a mine A functional module in the electrical automation system, which realizes the integration of dual power supply and dual fan monitoring, control, protection, communication and other functions.

Description

New dual power supply dual fan intelligent measurement and control protection device

technical field

The invention relates to an intelligent measurement, control and protection device for dual power sources and dual fans, in particular to a device capable of realizing automatic monitoring, control and protection of dual power sources and dual fans. the

Background technique

In the process of mine production, whether the ventilation system can work effectively is directly related to the safety of mine production. As the control unit of the ventilation system, dual power supply and dual fans are a more efficient and safer form of fan composition. The dual power supply and dual fan automatic switching device is the key equipment in the system, which is directly related to the safe operation of the entire system. Therefore, the rationality and reliability of the protection and control methods of the dual power supply and dual fan automatic switching device are crucial to its safe operation. At present, the intelligent dual-power dual-fan system based on embedded microprocessor control is still blank. Most of the dual-power dual-fan systems that have been in operation are controlled by PLC or relays, which have few functions, poor reliability, and low control accuracy, especially when accidents occur on site. Emergency measures cannot be taken automatically, seriously affecting the safe operation of the power grid and equipment. the

Contents of the invention

In order to overcome the deficiencies in reliability, control accuracy and function of the existing dual-power supply dual-fan control device, the present invention provides a new type of dual-power supply dual-fan intelligent measurement and control protection device, which can not only detect the current and voltage of the fan in real time, The faults can be protected in time, and the complementary control strategy can be used to ensure the continuous and uninterrupted air supply of the ventilation system to ensure the safety of mine production. At the same time, the device also has a communication function, which can be used as a functional module in the mine electrical automation system to realize the integration of dual power supply and dual fan monitoring, control, protection, communication and other functions. the

For achieving above object, the solution that the present invention adopts is:

An intelligent measurement and control protection device with dual power sources and dual fans, which is an embedded system including a micro-control processor, and also includes a data acquisition module, a serial communication module, an auxiliary hardware module, and a human-computer interaction module to complete data sampling, protection Judgment, fan control, serial communication and man-machine interface interactive processing tasks to carry out uninterrupted ventilation and status detection. the

The data acquisition module, the serial communication module and the auxiliary hardware module are arranged on the same printed circuit board (PCB). the

The data acquisition module includes an analog signal conditioning circuit, an A/D conversion circuit, and the analog signal conditioning circuit includes a voltage transformer, a current transformer, an operational amplifier, a Zener diode, a differential mode protection diode and a high-precision resistor; the A/D conversion circuit includes The sample-and-hold device, the A/D converter, and the resistor and capacitor adopt the bipolar A/D converter to collect 7 channels of analog signals. the

The serial communication module includes a standard RS485 interface to realize connection with other terminals, transmit data and exchange information. the

Auxiliary hardware modules include a hardware watchdog circuit, a self-contained battery calendar clock module, and a small relay control module that controls the start and stop of dual fans. The hardware watchdog circuit forces the system to reset when the embedded system falls into an endless loop; self-contained battery The calendar clock module maintains the normal operation of the embedded system when the embedded system is powered off, and provides the failure time point of the double fan; the small relay control module uses a double NAND gate to accurately control the start and stop of the double fan. the

The human-computer interaction module includes a liquid crystal display and a keyboard, and the liquid crystal display is drawn out from the printed circuit board through a cable. the

The auxiliary hardware module also includes a hardware communication module that can communicate with the complementary device. Through the communication module, the two dual-power dual-fan intelligent measurement, control and protection devices respectively control the two dual-fans powered by different power sources to realize uninterrupted ventilation. the

The data acquisition module also includes a leakage blocking circuit to detect the analog signal of the leakage fault of the double fan. the

Its software part includes data acquisition and protection judgment analysis module, human-computer interaction drive module, network drive module, control function module, data acquisition and protection judgment analysis module collects and analyzes the phase current, leakage voltage and common line voltage of the dual fans, and judges the current Status; the human-computer interaction driver module displays the results of calculation, analysis and processing of the data collected by the data acquisition and protection judgment module; the network driver module sends function codes to perform corresponding actions; the control function module detects the switch relay of the double fan, and controls the different operation modes of the double fan . the

Due to the adoption of the above scheme, the present invention has the following characteristics: the present invention utilizes an embedded system based on a microprocessor chip, and realizes the integration of functions such as monitoring, control, protection, and communication of dual power sources and dual blowers. Using the powerful computing performance of the processor, it is possible to analyze and record the daily operation data of the fan, which is convenient for future management and analysis; use mature algorithms to judge, protect and record various common faults of the fan; use intrinsically safe hardware communication modules , relying on a reasonable control strategy to control the start and stop of the dual fans and their complementary fans, to ensure the continuity of underground air supply and improve the safety of mine production; to use communication buses and protocols to realize remote monitoring and control of devices, which is also convenient for mine electrification in the future The network operation of the device. the

Description of drawings

Figure 1 is a schematic diagram of a voltage signal conditioning circuit. the

FIG. 2 is a schematic diagram of a current signal conditioning circuit. the

FIG. 3 is a schematic diagram of a leakage voltage detection circuit. the

Figure 4 is a schematic diagram of the fan relay control circuit. the

Fig. 5 is a schematic diagram of the hardware circuit of the A/D converter. the

Fig. 6 is a schematic diagram of the peripheral circuit of the calendar clock. the

FIG. 7 is a schematic diagram of a hardware communication circuit with a complementary device. the

FIG. 8 is a schematic diagram of a liquid crystal hardware interface circuit. the

Fig. 9 is the general flow chart of the software of the dual power supply and dual blower fan measurement, control and protection device. the

Fig. 10 is a schematic diagram of the keyboard hardware circuit. the

Figure 11 is a block diagram of the dual-power supply dual-fan monitoring and protection system. the

Detailed ways

The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings. the

The intelligent measurement, control and protection device with dual power supply and dual fan is an embedded system with ATmega128 microcontroller of ATMEL company as the processor. ATmega128 is based on AVR core, adopts RISC structure, 8-bit microcontroller with low power consumption CMOS. the

Microcontroller ATmega128 is mainly responsible for tasks such as data sampling, protection judgment, fan control, serial communication and man-machine interface interaction processing. In order to complete the above functions, there are other important hardware modules around ATmega128: data acquisition module, serial communication module, auxiliary hardware module and human-computer interaction module. The first three of these four major hardware modules are distributed on the same PCB (Printed Circuit Board, printed circuit board), which is a necessary hardware part of every dual-power dual-fan intelligent measurement, control and protection device. The last module, the human-computer interaction module, is mainly composed of a small LCD liquid crystal display and a small six-key keyboard. Among them, the small LCD liquid crystal display is drawn from the printed circuit board through a cable, so that it can be placed at a designated position on the casing. the

The LCD used in the human-computer interaction module adopts a 128×64 dot-matrix liquid crystal display, which is clear and convenient. The input keyboard has six keys: increase key (forward key), decrease key (backward key), confirmation key, reset key, start key, and stop key. These six keys cooperate with the well-designed menu mode to meet the application requirements of the whole device well. the

The data acquisition module is one of the important modules on the PCB, which is composed of two parts: an analog signal conditioning circuit and an A/D conversion circuit. The analog signal conditioning circuit is mainly composed of voltage transformer SPT204, current transformer SCT214, operational amplifier OP07, 10V Zener diode, differential mode protection diode and a series of high-precision resistors. The data acquisition module needs to sample seven analog quantities through the A/D chip: (1) Phase A current of fan 1; (2) Phase B current of fan 1; (3) Phase C current of fan 1; (4) Phase A current of fan 1; 2 phase A current; (5) fan 2 phase B current; (6) fan 2 phase C current; (7) fan AC phase line voltage. The A/D conversion circuit is mainly composed of a sample-and-hold device LF398, an A/D converter, and a series of resistors and capacitors. In order to ensure the measurement accuracy, the A/D conversion chip uses a bipolar 12-bit A/D converter TLC2578, its signal input range can reach -10V ~ 10V, and the average conversion time is only 2us, which can have enough time to complete seven One-channel analog quantity acquisition realizes the sampling of 12 signal points per power frequency cycle. TLC2578 has 8 built-in sampling channels, so the above seven analog quantities can be sampled and held at the same time, and then A/D conversion is performed separately, which not only ensures the acquisition accuracy, but also improves the acquisition efficiency. In addition, there are two analog signals used to judge whether the fan has a leakage fault—the leakage voltage of the fan 1 and the leakage voltage of the fan 2. Since the accuracy requirements are not very high, they are passed through a series of resistors and regulator tubes. The leakage blocking circuit composed of a diode and a diode enters the internal A/D of the ATmega128 microcontroller for conversion. the

The auxiliary hardware modules on the PCB include a hardware watchdog circuit, a self-contained battery calendar clock module, a small relay control module to control the start and stop of the fan, and a hardware communication module responsible for communicating with complementary devices, etc. The watchdog circuit is an indispensable part of the embedded system. When the program falls into an endless loop and the embedded system enters a "crash" state, it can automatically send a hardware reset signal to force the system to reset, and the program starts running from the startup code again. The self-contained battery calendar clock can still work normally when the system is powered off. It can not only record the specific time when the fan fails, but also provide some special calculation data. For example: provide a time scale for calculating the operating electricity consumption of the fan. In the process of mine production, safety has always been put in the first place. The small relay module that controls the start and stop of the fan must be very reliable, and the phenomenon of false start and stop is not allowed. Therefore, the module uses a double NAND gate to control the start and stop of the fan, so as to ensure that the fan will not cause malfunction of the fan when the system is reset or other uncertain situations occur. the

The working environment of dual power sources and dual fans requires that the measurement, control and protection devices must work reliably and strictly ensure the continuity of underground air supply. Therefore, the device is specially equipped with an intrinsically safe hardware communication module responsible for communicating with complementary devices to complete this function. In order to ensure the continuity of the underground air supply, the system must be redundant to prevent the air supply from stopping when a fan fails. Therefore, now two microcomputer intelligent measurement and control protection devices are used to control two fans powered by different power sources, which are called master and slave respectively. There is no hard and fast rule on which wind turbine controlled by the measurement, control and protection device is the master or the slave. It can be set through the human-computer interaction module to determine whether it is the master or the slave. This hardware communication module is mainly responsible for the state communication between the master and the slave, which judges the state of the complementary device through a pair of handshaking nodes; when the device is in the running state, the pair of nodes is in the closed state, otherwise it is in the disconnected state. So that the master or slave understands the state of its complementary device - running or stopping. When the state of the complementary device changes, the device must adjust the state of the device according to the principle of ensuring the continuity of the air supply. the

The serial communication module mainly provides a standard RS485 interface, which is convenient for the network operation of various equipment in the mine, and it is convenient for the staff to monitor the equipment and perform remote control in the background.

Most of the functions of the dual-power supply dual-fan measurement and control protection device are realized by software. The microcontroller ATmega128 has relatively ample on-chip RAM and Flash resources, and uses pipeline technology. Considering the efficiency of software development and the powerful function of ATmega128 chip, a high-level programming language C language is used for programming. the

The entire software system can be called a front/background system or a hyperloop system. The application is an infinite loop, and the corresponding function is called in the loop to complete the corresponding operation. This part is called background behavior. The system continuously detects flags such as "analog calculation", "analog acquisition", "failure status", "RS485 communication processing", "response keyboard input", "refresh liquid crystal display", "complementary system status" and so on. If it is set, the corresponding service module unit is called, and then the flag is cleared. The interrupt service routine handles asynchronous events, which are considered as foreground activities. It is a series of discrete and asynchronously executed interrupt processing modules, including triggering A/D interrupt, A/D conversion completion interrupt, RS485 receiving and sending completion request interrupt, etc. The system runs in each module of the background service program, and may be suspended by the foreground interrupt processing module at any time. In the foreground processing program, return to the background service module immediately after performing necessary processing and setting the corresponding flag. the

Similar to the hardware structure, the software is also divided into four modules accordingly:

(1) Data acquisition and protection judgment analysis module. The data acquisition module has a total of nine input analog quantities, among which the AC phase voltage of the fan is the external grid line voltage shared by the two fans. By collecting and analyzing the three phase currents, one leakage voltage, and one common line voltage of each fan, the software can use various algorithms to determine whether the fan has failed: use the current mutation algorithm to determine whether a short-circuit fault occurs; use the over-current feedback The time limit algorithm is used to judge whether the fan has an overload fault; the three-phase current balance rate is used to judge whether the fan has a phase failure fault; the line voltage is used to judge whether the fan has an overvoltage or undervoltage fault; the leakage voltage is used to judge whether the fan has a leakage fault. After detecting the failure of the fan, the measurement, control and protection device will send out a trip signal immediately or after a delay according to the protection requirements of different fault types to cut off the faulty fan; The drive module uploads fault information to the remote monitoring host. For example, after the protection analysis algorithm judges an undervoltage fault through calculation, according to the undervoltage fault protection requirements, the device will automatically trip after a delay of 5 seconds, and cut off the fan to protect the fan; at the same time, the control function module The corresponding start-stop control is carried out in the mode. If it is in the online operation mode, another fan will be automatically started after the set delay. the

(2) Human-computer interaction driver module. After calculation, analysis and processing, the data obtained by the data acquisition module needs to be displayed on the LCD, and at the same time, the setting values of various parameters of the system need to be input by the keyboard. The human-computer interaction module mainly has the following functions: (a) Dynamically refresh and display real-time monitoring data. The physical quantities to be displayed include the current voltage of the power grid and the effective value of the single-phase current of the fan. (b) Dynamically refresh and display the working state of the device, and display the fault category when a fault occurs. (c) Fault information recall function. The device can not only provide fault information in real time, but also can recall the category of historical fault information, parameter values and specific time of fault occurrence. (d) The operator can set the action thresholds of various fault protection functions through the keyboard, adjust the real-time clock, and set password protection for various control functions of the device, etc. the

(3) Network driver module. It is mainly the realization of RS485 communication protocol. The protocol adopts the query mode, the upper computer sends a specific frame to the device, and the device completes a specific operation according to the function code of the upper computer frame. The communication protocol has a unified format when the system is developed, and its basic frame format is sequentially composed of device address, frame length, function code, type code, user data, and check code. For example, a message frame of a confirmation command is composed of device address 03 (device preset), frame length 02, function code 01, and check code 06, which together form a confirmation message frame of 03020106. the

(4) Control function modules. The control function of the dual-power supply dual-fan monitoring and protection device is required to be very reliable. Therefore, the switch relay of the fan should be detected in real time in the control module. After any opening and closing command is sent, the control module must immediately check whether the fan can be opened and closed as required after a delay of several hundred milliseconds. If any abnormality occurs, an alarm must be issued immediately. On this basis, the control function module must also adapt to the operation requirements of the fan in various modes. First of all, this device can control and protect the operation of double fans, and can also control and protect the operation of a single fan. The operation of double fans is called the counter-rotation mode, and the operation of a single fan is called the independent mode. Among them, when running in counter-rotation mode, in order to avoid the impact of two fans starting at the same time on the power grid, an adjustable value is set, which is called counter-rotation delay, that is, after the first fan starts, after the counter-rotation delay After the time set in the hour, the second fan will start. Secondly, this device not only supports the operation of two devices as a complementary system, which is called online operation, but also supports the self-operation of a single device, which is called independent operation. In the same way, in order to avoid the impact caused by the simultaneous start of multiple fans, an online delay is also set to control the start time of the complementary system. the

An intelligent measurement, control and protection device with dual power supplies and dual fans is responsible for the measurement, control and protection of a dual fan. The two devices control the two dual fans as complements, and they use reliable internal communication methods to exchange their status information. At the same time, each device is equipped with RS485 standard communication interface, which can carry out data transmission, information exchange and remote control with PC or communication substation at any time. the

The above description of the embodiments is for those of ordinary skill in the art to understand and apply the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention should fall within the protection scope of the present invention.

Claims (4)

1. duplicate-power double-fan intelligent monitoring protection device; It is the embedded system that comprises the microcontroller processor; It is characterized in that: it also comprises data acquisition module, serial communication module, ancillary hardware module, human-computer interaction module, thereby uninterruptedly ventilates and state-detection with the task of accomplishing data sampling, protection judgement, blower fan control, serial communication and man-machine interface interaction process;

Said data acquisition module, serial communication module, ancillary hardware module are arranged on the same printed circuit board (PCB);

This data acquisition module comprises analog signal conditioner circuit, A/D change-over circuit, and the analog signal conditioner circuit comprises voltage transformer, current transformer, operational amplifier, reference diode, differential mode protection diode and precision resister; The A/D change-over circuit comprises sampling holder, A/D converter and resistance capacitance, and it adopts ambipolar this A/D converter to gather 7 road analog signalses;

This serial communication module comprises the RS485 interface of standard, realizes being connected with other-end transmission exchanges data information;

This ancillary hardware module comprises the miniature relay control module of hardware watchdog circuit, self-contained battery calendar clock module, the two blower fan start and stop of control, and forced system resetted when the hardware watchdog circuit was absorbed in the endless loop state in this embedded system; Self-contained battery calendar clock module keeps the normal operation of the embedded system under this embedded system power down situation, and two fan trouble time points are provided; The miniature relay control module adopts the accurately start and stop of the two blower fans of control of mode of two AND NOT gates;

This human-computer interaction module comprises liquid crystal display, keyboard, and liquid crystal display is drawn from printed circuit board (PCB) through winding displacement.

2. duplicate-power double-fan intelligent monitoring protection device as claimed in claim 1; It is characterized in that: its ancillary hardware module also comprises the hardware communications module that can communicate by letter with compensation device; Control two two blower fans respectively through two duplicate-power double-fan intelligent monitoring protection devices of this communication module realization, realize uninterruptedly ventilating by the different electrical power power supply.

3. duplicate-power double-fan intelligent monitoring protection device as claimed in claim 1 is characterized in that: this data acquisition module also comprises the earth leakage search/lockout circuit, detects the analog signals of two blower fan leak current faults.

4. duplicate-power double-fan intelligent monitoring protection device as claimed in claim 1; It is characterized in that: its software section comprises data capture and protection discriminatory analysis module, man-machine interaction driver module, network-driven module, control function module; Current state is judged in data capture and phase current, electrical leakage voltage and the bridging line voltage of protecting the two blower fans of discriminatory analysis module collection analysis; Man-machine interaction driver module video data is gathered the result after the data of gathering with protection discriminatory analysis module are handled through computational analysis; Network-driven module sending function sign indicating number is carried out corresponding actions; The control function module detects two fan switch relays, the different operating modes of the two blower fans of control.

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