CN102289924B - An overhead transmission line temperature measuring device - Google Patents

Abstract

The invention discloses a temperature measurement device for an overhead power transmission line. The temperature measurement device comprises an intelligent sensor and a data acquiring unit communicated with the intelligent sensor through a standard communication interface, wherein the intelligent sensor comprises a sensing terminal for acquiring the temperature of a power transmission conductor and a management terminal arranged on a tower. Only one lithium battery is used for supplying power on the basis of a clock synchronous working mode; therefore, the state of the overhead power transmission line can be monitored for a long term, the power consumption of a device for monitoring the state of the power transmission line is reduced, and the reliability of the system is improved; the standard communication interface is provided for the external so that the temperature measurement device can be conveniently accessed into the data acquiring unit with a standard communication interface, thus strong generality and expandability can be achieved; a chip-level wireless SoC (system on chip) is adopted between the management terminal and the sensing terminal; therefore, the temperature measurement device is small in volume, low in power consumption and long in communication distance, meets the communication requirement for state monitoring of power transmission line state, and reduces the unreliability factor caused by an externally integrated wireless communication module.

Description

An overhead transmission line temperature measuring device

technical field

The invention relates to a temperature measuring device for an overhead power transmission line, which belongs to the technical field of electric power.

Background technique

Transmission lines generally have large spans and wide coverage, and they operate under complex and changeable conditions for a long time. Therefore, it is very important to detect potential accidents early and eliminate them in time to keep them running in a good state. The existing wire temperature measurement device is generally composed of a sensing terminal (Smart Sensor Terminal, referred to as SST) and a data collection unit (Data Collection Unit, referred to as DCU). The DCU directly collects data from the SST, and the communication interface between the DCU and the SST is an external dedicated wireless communication module. When working, the command is issued from the DCU to the SST in a downlink manner. When the SST receives the command, it sends the data back to the DCU through its externally integrated wireless communication module. The sensing terminal SST is usually in the state of waiting to receive, and cannot enter the sleep state to save power consumption. Therefore, its operating current is relatively large, which makes the power consumption of the wire temperature measurement device relatively large, and the battery or online power is often used to maintain its operation. . On the other hand, the existing wire temperature sensor and the data collector use a wireless communication module for communication, which has poor versatility and openness, and is inconvenient to connect to other types of interface data collectors. At the same time, the wire temperature sensor integrates a wireless module to communicate with the data collector, which has a large volume and power consumption, which increases the burden on the power supply of the transmission line status monitoring system and reduces its operational reliability.

Contents of the invention

The technical problem to be solved by the present invention is to provide a temperature measuring device for overhead power transmission wires, which has low power consumption, does not need battery power supply, is more versatile, and is convenient to connect to data collectors with various types of interfaces.

In order to solve the above technical problems, the present invention provides a temperature measuring device for overhead transmission lines, which is characterized in that it includes

An intelligent sensor, the intelligent sensor includes a sensing terminal for collecting the temperature of the transmission wire and a management terminal installed on the tower,

A data acquisition unit that communicates with the smart sensor through a standard communication interface.

The standard communication interface is either an RS485 interface, an RS232 interface, or an SDI-12 bus interface.

The sensing terminal is arranged on the power transmission wire.

The data acquisition unit is arranged on the tower.

The clocks of the sensing terminal, the management terminal and the data acquisition unit are synchronized.

The sensing terminal includes a wireless SOC, a radio frequency impedance matching circuit, a watchdog circuit, a program emulation JTAG interface, a lithium battery, a low dropout linear voltage regulator, an external crystal oscillator, and a temperature measurement chip.

The temperature sensing surface of the temperature measuring chip is attached to the surface of the power transmission wire.

The management terminal includes a wireless SOC microprocessor, a radio frequency impedance matching circuit, a watchdog circuit, a program emulation JTAG interface, a low-dropout linear voltage regulator, and an external crystal oscillator.

One end of the standard communication interface circuit is connected to the wireless SOC microprocessor, and the other end is connected to the data acquisition unit.

The input end of the low dropout linear regulator is connected to an external power supply, and the output end is connected to the power bus of the management terminal.

The beneficial effect that the present invention reaches:

1) The present invention is a low-power transmission wire temperature measuring device based on a clock synchronous working mode. It can be used for long-term monitoring of the status of overhead power transmission and transformation lines by only using one lithium battery for power supply, which greatly reduces the power transmission The power consumption of the line state monitoring device reduces the requirement of the system on the power supply and improves the reliability of the system.

2) The present invention includes a smart sensor integrated with the sensing terminal SST and the management terminal SSC, which provides a standard communication interface to the outside, and can be easily connected to the data acquisition unit DCU with a standard communication interface, and its versatility and scalability very strong.

3) The present invention adopts a chip-level wireless system-on-chip between the management terminal SSC and the sensing terminal SST, which has small volume, low power consumption, and long communication distance, which satisfies the communication requirements of transmission line status monitoring. It is easy to use and reduces the unreliability factors caused by the external integrated wireless communication module.

Description of drawings

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

Fig. 2 is the functional block diagram of SST;

Fig. 3 is the circuit schematic diagram of SSC.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

As shown in Figure 1, a low-power wire temperature measuring device of the present invention includes a sensing terminal SST1 (Smart Sensor Terminal) installed on a power transmission wire, a management terminal SSC2 (Smart Sensor Controller) installed on a tower, and Data collection unit DCU3 (Data Collection Unit). Among them, SST1 is powered by lithium battery, regularly collects sensor values, and sends them to SSC2 through wireless; SSC2 is powered by data acquisition unit DCU3, regularly receives data from SST1 and sends SST1 data to the data acquisition unit through RS485 bus.

SST1 and SSC2 form an intelligent sensor, SST1 is responsible for the collection of temperature data, SSC2 is responsible for the transmission of temperature data and external communication with the data acquisition unit DCU3 through the standard SDI-12 protocol.

DCU3, SST1, and SSC2 realize micro-power consumption data collection and transmission on the basis of clock synchronization. The specific working method is as follows: when the device is initialized and running, first, DCU3 and SSC2 perform time synchronization to complete the clock synchronization of DCU3 and SSC2. Then SSC2 and SST1 perform time synchronization to complete the clock synchronization between SSC2 and SST1; after the synchronization is completed, DCU3, SST1, and SSC2 are usually in a sleep state with extremely low power consumption, and work synchronously according to a certain wake-up interval (default minimum wake-up The interval is 5 minutes, which can be set according to the actual working conditions); when SST1 is working, collect sensor data, open the wireless radio frequency RF interface, send data to SSC2 wirelessly, and wait for a response or control command, and enter sleep immediately after the waiting time expires State; when SSC2 is working, start the wireless radio frequency circuit, wait to receive the data from SST1 and reply, if it receives the command sent by DCU3, it will forward the command to SST1 through wireless, and enter the sleep state immediately after the waiting time expires; when DCU3 is working, Wake up SSC2 through the 485 bus, and send commands to obtain and save SST1 data from SSC2, and enter the sleep state immediately if no remote command is received.

The key to realize the low power consumption temperature measurement device is to keep DCU3, SST1, SSC2 three clock synchronization, must give full consideration to the reliability of clock synchronization, the specific design technical scheme is as follows: DCU3, SSC2, SST1 three wake-up cycle It must be an integer multiple of the measurement interval to ensure that the three can wake up at the same time; after SSC2 receives the SST1 data, if it finds that SST1 has not completed the synchronization, it will perform a clock synchronization on SST1; DCU3, SSC2, and SST1 will be performed once a day after a certain time interval The clock is synchronized to ensure that the clock will not be out of sync due to the drift of the external clock.

The following is a specific description of each sub-item in the invention in conjunction with the accompanying drawings.

Fig. 2 is the functional block diagram of SST of the present invention, and SST1 mainly comprises wireless SOC11, radio frequency impedance matching circuit 14, watchdog circuit 13, program emulation JTAG interface is called for short JTAG interface 12, lithium battery 17, low dropout linear voltage stabilizer is called for short LDO16 , external crystal oscillator 15 and temperature measurement chip 10, VCC and the I2C part in the I2C interface 18 are connected with the wireless SOC11; VCC and the VCC part in the I2C interface 18 are connected with the VCC output by the LDO16 module; The wire is connected with the VCC of the temperature measurement chip 10 and the I2C interface 19, provides power for the temperature measurement chip 10 and connects the temperature conversion signal to the wireless SOC11.

Among them, the temperature measurement chip 10 is a key chip for wire temperature measurement, its output is connected with the wireless SOC11, responsible for obtaining the analog signal of the wire temperature and converting the signal into a digital signal for the wireless SOC11 to collect. When installed and used, its temperature-sensing surface is closely attached to the surface of the wire to ensure the accuracy of the measured wire temperature. In this embodiment, the ADT7410 chip is used as the temperature measurement chip 10. The AD7410 chip has a very wide measurement range, the temperature range is: -55°C-150°C, and the absolute accuracy can reach ±1°C, which can well meet the requirements of wire temperature measurement. Require.

The external crystal oscillator 15 is the clock reference source for the entire SST1 operation, and the output is connected to the internal timing counter of the wireless SOC11. When the counter reaches the wake-up cycle value, the SST1 enters the wake-up state from the sleep state and starts to collect temperature signals. After the collection is completed, the wireless radio frequency interface is turned on. , and send the collected temperature data to the SSC wirelessly; when the counter reaches the wake-up waiting time (generally no more than 5 seconds), SST1 turns off the wireless radio frequency interface, and enters the sleep state from the wake-up state. It can be seen that the time of SST1 in the wake-up state is very short, generally at the second level, and it is in the sleep state of micro-power consumption most of the time.

Wireless SOC11 is a wireless system-on-chip with extremely low power consumption, small size, and 51-type single-chip microcomputer as the core. As the core component of SST1, it is responsible for collecting the signal of the temperature measurement chip 10 and communicating with the SSC through the wireless radio frequency interface. When the chip works in the sleep state, it only draws about 1 microampere. It has wireless transmission modulation methods such as FSK, GFSK, and OOK. The maximum output power reaches 20dBm, the receiving sensitivity is -121dBm, and the maximum transmission distance can reach 2000 meters.

The power supply of SST1 is composed of lithium battery 17 and 3.3V LDO16. LDO (low dropout regulator) is a low dropout linear regulator. V voltage to power the entire SST1 circuit. The lithium battery 17 is small in size, light in weight, easy to install, reduces the load on the transmission line, and has a large capacity, which can meet the power demand of SST1 for long-term monitoring on the transmission line.

The input and output of the watchdog circuit 13 of SST1 are all connected to the external pins of the wireless SOC11, its input is used as the dog feeding signal given by the wireless SOC11, and the output is used as the reset signal of the wireless SOC11. When the SST1 wakes up, the wireless SOC11 must output the dog feeding signal at an interval, otherwise, the watchdog circuit 13 will output a reset signal to reset the SST11 after a given interval. The watchdog circuit 13 is mainly for preventing the SST1 from crashing during operation, and ensuring the reliability of the long-term operation of the SST1.

The radio frequency impedance matching circuit 14 is a peripheral matching circuit for wireless communication, and it is connected with the wireless peripheral channel inside the wireless SOC 11 . When the SST1 enters the dormant state, the circuit does not work, and is only turned on when the SST1 wakes up, and the radio frequency interface provided by the radio frequency impedance matching circuit 14 can communicate with the SSC wirelessly. JTAG interface 12 is the interface of the program emulation of wireless SOC11 single-chip microcomputer, program download.

3 is a schematic block diagram of the circuit of SSC2, which mainly includes a wireless SOC microprocessor 21, a radio frequency impedance matching circuit 25, a watchdog circuit 23, a program emulation JTAG interface 22, an LDO 27, an external crystal oscillator 26, and an RS485 interface circuit 24. On the whole, the functional block diagrams of SSC and SST are very similar, in which wireless SOC microprocessor 21, radio frequency impedance matching circuit 25, watchdog circuit 23, program emulation JTAG interface 22, external crystal oscillator 26 are the same as the wireless SOC in Fig. 2 SST The characteristics and functions of the SOC, RF impedance matching circuit, watchdog circuit, JTAG interface, and external crystal oscillator are the same, and will not be repeated here.

The LDO27 in this embodiment adopts the input terminal of 3.3V LDO27 to connect the external power supply 4, and the output is connected to the power bus of the whole SSC2, and its function is to convert the 12V power inputted by the external power supply 4 into 3.3V output. Since the SSC2 is a device installed on the tower, the battery and solar equipment fixed on the tower are used as the external power supply 4 .

One end of the RS485 interface circuit 14 is connected to the serial peripheral of the wireless SOC microprocessor 21, and the other end is connected to the data acquisition unit DCU. This circuit is responsible for responding to the command of DCU and exchanging data with DCU. The interface circuit is only turned on when the SS2C is in the wake-up state, and is in the micro-power receiving state when the SSC1 is in the sleep state, and the DCU can send commands through the RS485 interface circuit 24 to wake up the SSC2 immediately.

The RS485 interface circuit 24 is a convenient and easy-to-use standard interface through which DCUs from various manufacturers can be connected to the SSC2.

Those skilled in the art can realize that the interface used here can not only be an RS485 interface circuit, but also can be replaced by other standard interfaces, such as RS232 standard interface, SDI-12 bus interface and so on.

The functions of the data acquisition unit DCU are relatively simple, and the implementation methods can be diversified. Here, only its external functions are described, and its internal specific circuit principles are not described. In the wire temperature measuring device, the main function of the DCU is to set the working parameters of the SST through the RS485 interface, read the temperature data of the SST, and calibrate the clock of the SSC to achieve synchronization with the clocks of the SSC and SST. In addition, the DCU is also a tower device, and its power supply method is a conventional power supply method for tower equipment, that is, batteries and solar energy.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and modifications can also be made. It should also be regarded as the protection scope of the present invention.

Claims (9)

1. a temperature measurement device for overhead power transmission line is characterized in that, comprises

Intelligence sensor, described intelligence sensor comprise the sensing terminal that gathers the transmission pressure temperature and the office terminal that is located on the shaft tower,

The data acquisition unit of communicating by letter with described intelligence sensor by standard communication interface;

Described sensing terminal comprises wireless SOC, radio-frequency (RF) impedance match circuit, watchdog circuit, procedure simulation jtag interface, lithium battery, low pressure difference linear voltage regulator, external crystal-controlled oscillation, temperature survey chip.

2. a kind of temperature measurement device for overhead power transmission line according to claim 1 is characterized in that, described standard communication interface or be the RS485 interface, or be the RS232 interface, or be the SDI-12 bus interface.

3. a kind of temperature measurement device for overhead power transmission line according to claim 1 is characterized in that, described sensing terminal is located on the transmission pressure.

4. a kind of temperature measurement device for overhead power transmission line according to claim 1 is characterized in that, described data acquisition unit is located on the shaft tower.

5. a kind of temperature measurement device for overhead power transmission line according to claim 1 is characterized in that, described sensing terminal, office terminal, data acquisition unit clock synchronous.

6. a kind of temperature measurement device for overhead power transmission line according to claim 1 is characterized in that, temperature-sensitive face and the transmission pressure surface of described temperature survey chip are affixed.

7. a kind of temperature measurement device for overhead power transmission line according to claim 1, it is characterized in that, described office terminal comprises wireless SOC microprocessor, radio-frequency (RF) impedance match circuit, watchdog circuit, procedure simulation jtag interface, low pressure difference linear voltage regulator, external crystal-controlled oscillation.

8. a kind of temperature measurement device for overhead power transmission line according to claim 7 is characterized in that, described standard communication interface circuit one end is connected with described wireless SOC microprocessor, and the other end is connected with described data acquisition unit.

9. a kind of temperature measurement device for overhead power transmission line according to claim 7 is characterized in that, the input end of described low pressure difference linear voltage regulator connects external power source, and output terminal is connected on the power bus of described office terminal.

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