CN211669278U

CN211669278U - Thermal power generating unit excitation coil voltage integrated monitoring system

Info

Publication number: CN211669278U
Application number: CN201922487560.5U
Authority: CN
Inventors: 余俐敏
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-10-13
Anticipated expiration: 2029-12-31

Abstract

The utility model discloses a thermal power generating unit excitation coil voltage integrated monitoring system, the monitoring system comprises a monitoring upper computer for acquiring signals and monitoring and displaying in real time and a router connected with the monitoring upper computer through a network cable; the router is simultaneously connected with a plurality of voltage acquisition devices for acquiring the voltages of the excitation coils through network cables, the voltage acquisition devices are communicated with the monitoring upper computer through a network, and the voltage acquisition devices transmit monitoring data to the monitoring upper computer; the voltage acquisition device is also connected with the divider resistance sensor through a cable; the divider resistance sensor is connected with the detected magnet exciting coil, and transmits the acquired voltage of the magnet exciting coil to the voltage acquisition device after dividing the voltage.

Description

Thermal power generating unit excitation coil voltage integrated monitoring system

Technical Field

The utility model relates to a thermal power unit excitation coil voltage integrated monitoring system belongs to thermal power generation technical field.

Background

The excitation coil passes through changed current in the coil, and magnetic lines of force pass through the center of the coil, and the larger the current is, the more the magnetic lines of force are, and the magnetic lines of force disappear until the current is cut off in a saturated mode. The current-carrying coil used to excite the magnetic flux in the magnetic circuit is called an excitation coil (or excitation winding), and the current in the excitation coil is called an excitation current (or excitation current). If the exciting current is direct current, the magnetic flux in the magnetic circuit is constant and does not change along with time, and the magnetic circuit is called a direct current magnetic circuit; the magnetic circuit of a dc motor belongs to this category. If the exciting current is alternating current, the magnetic flux in the magnetic circuit changes alternately along with time, and the magnetic circuit is called an alternating current magnetic circuit; ac core coils, transformers and magnetic circuits of induction machines all belong to this category. In the thermal power generating unit, the instantaneous voltage measurement of the excitation coil can provide important reference value for monitoring the running state of the thermal power generating unit, and the excitation coil voltage comprehensive monitoring system can monitor a plurality of paths of voltage signals in real time and display and monitor the signals, so that important guarantee is provided for the normal running of the thermal power generating unit.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: the utility model aims to solve the technical problem that a thermal power unit excitation coil voltage integrated monitoring system is provided, this monitored control system carries out instantaneous measurement to excitation coil's voltage through voltage acquisition device, gives the control host computer and reports an emergency and asks for help or increased vigilance communication device with data through network transmission simultaneously to monitored control system can real time monitoring multichannel voltage signal and show.

In order to achieve the above purpose, the utility model adopts the technical scheme that:

a thermal power generating unit magnet exciting coil voltage comprehensive monitoring system comprises a monitoring upper computer and a router, wherein the monitoring upper computer is used for acquiring signals and monitoring and displaying in real time, the router is connected with a plurality of voltage acquisition devices used for acquiring magnet exciting coil voltages through network cables, and the voltage acquisition devices are communicated with the monitoring upper computer through a network and send monitoring data to the monitoring upper computer; the voltage acquisition device is also connected with the divider resistance sensor through a cable; the voltage dividing resistance sensor is connected with the excitation coil to be detected, and transmits the acquired excitation coil voltage to the voltage acquisition device after dividing the voltage; the alarm communication device is communicated with the voltage acquisition device, acquires the abnormal signals acquired by the voltage acquisition device and communicates with an external mobile phone terminal in a wireless mode.

The alarm communication device comprises a central processing unit, and the central processing unit is respectively connected with a network communication module, a storage module, a GPRS communication module and an acousto-optic alarm module; the central processing unit is in network communication with the router through the network communication module; the central processing unit acquires the voltage signal acquired by the voltage acquisition device through the network communication module, judges the abnormal signal, stores the abnormal signal through the storage module and sends an acousto-optic alarm to field personnel through the acousto-optic alarm module; the GPRS communication module is also connected with a communication antenna, the central processing unit is in wireless communication with a remote mobile phone terminal through the GPRS communication module and the communication antenna, and sends the alarm signal to the mobile phone terminal in a wireless mode.

The voltage acquisition device comprises an electromagnetic shielding box and an acquisition circuit board positioned in the electromagnetic shielding box; the collecting circuit board is connected with the electromagnetic shielding box through the metal fixing column; a power interface, a signal acquisition interface and a network communication interface are fixed on the side edge of the electromagnetic shielding box; the acquisition circuit board comprises a signal sampling module and a signal processing module, the signal sampling module comprises an FPGA chip and an A/D conversion chip connected with the FPGA chip, and a sampling end of the A/D conversion chip is connected with the signal conditioning circuit; the signal processing module comprises a DSP chip, and an SDRAM (synchronous dynamic random access memory) memory, a FLASH memory and an Ethernet interface module which are connected with the DSP chip; the DSP chip comprises an EMIFA interface, the DSP chip is connected with the FPGA through the EMIFA interface, and sampling data acquired by the FPGA is transmitted to the DSP chip through the EMIFA interface; the input end of the signal conditioning circuit is connected with the signal acquisition interface through a cable; the Ethernet interface is connected with the network communication interface through a cable; the acquisition circuit board is connected with an external power supply through a power interface.

The signal acquisition interface is connected with a divider resistance sensor, the divider resistance sensor comprises divider resistances R1 and R2 which are connected IN series, two ends of R1 and R2 are respectively connected with a voltage acquisition input end IN and a ground, and a connection point OUT of R1 and R2 is connected with the signal acquisition interface of the voltage acquisition device; the voltage acquisition input end IN is connected with the voltage acquisition point of the excitation coil.

The signal conditioning circuit comprises an attenuation circuit, an impedance conversion circuit, an amplification circuit and an ADC (analog to digital converter) driving circuit which are connected in sequence; the input end of the attenuation circuit is connected with an external voltage sensor; the output end of the ADC driving circuit is connected with the sampling input end of the A/D conversion chip.

The attenuation circuit is passive attenuation and comprises voltage division resistors R10 and R13; the voltage dividing resistors R10 and R13 are connected in parallel with a capacitor and a resistor for high-frequency compensation, respectively.

The impedance transformation circuit comprises a voltage follower circuit, the voltage follower circuit comprises a transport amplifier OPA656, the positive input end of the transport amplifier OPA656 is connected with the output end of the attenuation network, and the reverse input end of the transport amplifier OPA656 is directly connected with the output end.

The amplifying circuit comprises an operational amplifier AD8009, and the positive input end of the operational amplifier AD8009 is connected with the output end of the impedance conversion circuit; the inverting input is connected to the output through a resistor R32.

The ADC driving circuit comprises a high-speed differential amplifier AD8138, wherein a forward input end of the high-speed differential amplifier AD8138 is connected with an output end of the amplifying circuit and is simultaneously connected with a differential signal reverse output end, and the reverse input end of the high-speed differential amplifier AD8138 is respectively connected with a zero potential point and the differential signal forward output end through a resistor; the level reference end of the high-speed differential amplifier AD8138 is connected with the level reference end of the A/D conversion chip; and the differential signal output end of the high-speed differential amplifier AD8138 is connected with the input end of the A/D conversion chip.

Compared with the prior art, the utility model discloses the beneficial effect who has is:

the utility model discloses a network communication mode realizes voltage acquisition device and the interconnection of control host computer, realizes that thermal power generating unit excitation coil voltage gathers in real time and realizes the remote monitoring. The voltage acquisition device can be expanded as required, and multi-point comprehensive monitoring is realized. Meanwhile, an alarm communication device is adopted to monitor and judge the abnormal signals, so that the abnormal signals can be timely alarmed and recorded. The voltage acquisition device adopts a high-speed signal sampling module and a signal processing module to acquire and process the voltage signal of the magnet exciting coil. The signal conditioning circuit equally processes the voltage to reduce the distortion of the signal, and the sampling of the signal adopts a high-speed A/D conversion chip, so that the instantaneous waveform of the voltage signal can be measured, and the voltage waveform state can be more accurately restored. The signals are processed in sequence through the FPGA and the DSP, and the processing and storage speed of the signals is improved.

Drawings

Fig. 1 is a schematic structural view of the field coil voltage comprehensive monitoring system of the thermal power generating unit of the present invention;

fig. 2 is a schematic structural view of the alarm communication device of the field coil voltage comprehensive monitoring system of the thermal power generating unit of the utility model;

fig. 3 is a schematic structural diagram of the voltage acquisition device of the integrated monitoring system for the excitation coil voltage of the thermal power generating unit of the utility model;

fig. 4 is a schematic circuit diagram of the voltage acquisition device of the integrated monitoring system for the exciting coil voltage of the thermal power generating unit of the utility model;

fig. 5 is a schematic diagram of a signal conditioning circuit of the voltage acquisition device of the field coil voltage comprehensive monitoring system of the thermal power generating unit of the utility model;

fig. 6 is an attenuation circuit of the voltage acquisition device of the field coil voltage comprehensive monitoring system of the thermal power generating unit of the utility model;

fig. 7 is an impedance conversion circuit of the voltage acquisition device of the integrated monitoring system for the exciting coil voltage of the thermal power unit of the utility model;

fig. 8 is an amplifying circuit of the voltage collecting device of the field coil voltage comprehensive monitoring system of the thermal power generating unit of the utility model;

fig. 9 is an ADC driving circuit of the voltage collecting device of the field coil voltage comprehensive monitoring system of the thermal power generating unit of the present invention;

fig. 10 is the utility model discloses the schematic diagram is received to thermal power unit excitation coil voltage integrated monitoring system divider resistance sensor.

Detailed Description

The invention is further described with reference to the accompanying drawings.

As shown in fig. 1-10, the utility model discloses thermal power generating unit excitation coil voltage integrated monitoring system, including the router that is used for the control host computer that the real time monitoring of signal shows and passes through the net twine with the control host computer and be connected, the router is connected with a plurality of voltage acquisition device that are used for gathering excitation coil voltage through the net twine simultaneously, and voltage acquisition device passes through network and control host computer communication, sends the control data for the control host computer.

The voltage acquisition device is also connected with the divider resistance sensor through a cable; the voltage dividing resistance sensor is connected with the excitation coil to be detected, divides the acquired voltage of the excitation coil and transmits the divided voltage to the voltage acquisition device; the alarm communication device is communicated with the voltage acquisition device, acquires the acquired abnormal signals and communicates with an external mobile phone terminal in a wireless mode.

The alarm communication device comprises a central processing unit which is respectively connected with the network communication module, the storage module, the GPRS communication module and the acousto-optic alarm module; the central processing unit is in network communication with the router through the network communication module; the central processing unit acquires the voltage signal acquired by the voltage acquisition device through the network communication module, judges the abnormal signal, stores the abnormal signal through the storage module and sends an acousto-optic alarm to field personnel through the acousto-optic alarm module; the GPRS communication module is also connected with a communication antenna, the central processing unit is in wireless communication with a remote mobile phone terminal through the GPRS communication module and the communication antenna, and sends the alarm signal to the mobile phone terminal in a wireless mode.

The comprehensive monitoring system for the voltage of the excitation coil of the thermal power generating unit comprises an electromagnetic shielding box 1 and a collecting circuit board 2 positioned in the electromagnetic shielding box 1. The collection circuit board 2 is connected with the electromagnetic shielding box 1 through the metal fixing column 3. The side of the electromagnetic shielding box 1 is fixed with a power interface 6, a signal acquisition interface 4 and a network communication interface 5.

The electromagnetic shielding box 1 is of a metal structure and is connected with the ground wire of the acquisition circuit board 2 through the metal fixing column 3, so that the electromagnetic interference resistance of the device is effectively improved.

The acquisition circuit board 2 includes a signal sampling module and a signal processing module. The signal sampling module comprises an FPGA chip and an A/D conversion chip connected with the FPGA chip, and a sampling end of the A/D conversion chip is connected with the signal conditioning circuit. The signal processing module comprises a DSP chip, and an SDRAM memory, a FLASH memory and an Ethernet interface module which are connected with the DSP chip. The DSP chip contains the EMIFA interface, and the DSP chip passes through the EMIFA interface to be connected with FPGA, and the sampling data that FPGA obtained passes through the EMIFA interface and transmits for the DSP chip.

The input end of the signal conditioning circuit is connected with the signal acquisition interface 4 through a cable. The ethernet interface is connected to the network communication interface 5 by a cable. The acquisition circuit board 2 is connected with an external power supply through a power interface 6.

The signal conditioning circuit comprises an attenuation circuit, an impedance conversion circuit, an amplification circuit and an ADC (analog-to-digital converter) driving circuit which are sequentially connected; the input end of the attenuation circuit is connected with an external voltage sensor; the output end of the ADC driving circuit is connected with the sampling input end of the A/D conversion chip.

The attenuation network is passive attenuation and comprises voltage dividing resistors R10 and R13; the voltage dividing resistors R10 and R13 are connected in parallel with a capacitor and a resistor for high-frequency compensation, respectively. As can be seen from the figure, the attenuation network has a voltage division ratio of

Wherein the content of the first and second substances,

when the optimum compensation is satisfied, i.e. Z₁R₁₀＝Z₂R₁₃When the voltage is divided, the imaginary part in the voltage dividing ratio can be eliminated to obtain

It can be seen that by selecting R₁₀、R₁₃The resistance value of the pressure-dividing valve can meet the requirement of the pressure-dividing coefficient. When the signal channel is accessed, the influence of the attenuation part on the circuit impedance can be ignored due to the larger resistance of the impedance transformation part.

The impedance transformation circuit comprises a voltage follower circuit comprising a transport amplifier OPA656, the forward input of the transport amplifier OPA656 being connected to the output of the attenuation network, the inverting input of the transport amplifier OPA656 being directly connected to the output.

The OPA656 is a JFET input type operational amplifier with high input impedance and a bandwidth of up to 500 MHz. Considering its high input impedance, and the resistor R in the figure₂₁The parallel connection can be ignored, and is equivalent to the open circuit of the preceding stage circuit. Capacitor C₂₁To compensate for the capacitance, the input impedance of the circuit is therefore approximately R₂₀And R₂₁Series resistance of 1M omega

The conversion rate of the operational amplifier AD8009 can reach 5500V/mus, and the unit gain bandwidth of a minus 3dB small signal is 1 GHz. The circuit controls the S3 switch in a jumper mode to select the signal to be amplified by 2 times or not. Resistance R in FIG. 3.5₃₁And R₃₂The resistance of (2) is 499 Ω. When the switch of S3 is closed, the voltage at

points

3 and 4 is the same according to the 'virtual short' principle, and the output voltage of the amplifying circuit is twice of the input voltage at the moment. When the S3 switch is turned on, the output voltage of the amplifying circuit is equal to the input voltage

The ADC driving circuit comprises a high-speed differential amplifier AD8138, wherein a forward input end of the high-speed differential amplifier AD8138 is connected with an output end of the amplifying circuit and is simultaneously connected with a differential signal reverse output end, and a reverse input end of the high-speed differential amplifier AD8138 is respectively connected with a zero potential point and the differential signal forward output end through a resistor; the level reference end of the high-speed differential amplifier AD8138 is connected with the level reference end of the A/D conversion chip; and the differential signal output end of the high-speed differential amplifier AD8138 is connected with the input end of the A/D conversion chip. The gain bandwidth of AD8138 is 320MHz, V_comLevel reference terminal V of terminal and ADC_cmThe common mode voltage of the output differential signal is set up in connection. Differential signal input range (A)_in+-A_in-) Is optional from +/-0.5V to +/-1V.

The DSP chip adopts C6455, and the communication between the C6455 and the FPGA adopts an External Memory Interface (EMIF) mode. The EMIF is an important external expansion interface in a DSP embedded system, and is often connected with a large-capacity high-speed memory, a parallel AD/DA (analog-to-digital) and external expansion special function chip and a CPLD (complex programmable logic device)/FPGA (field programmable gate array) or ASIC (application specific integrated circuit). EMIF enables the communication channel between DMA channels and peripheral devices. The system adopts a highest support 64-bit EMIFA interface of the C6455, and can enable the C6455 to realize seamless connection with a Synchronous Dynamic Random Access Memory (SDRAM), a Synchronous Burst Static Random Access Memory (SBSRAM), an asynchronous memory (comprising FIFO, SRAM and the like) and the like. The schematic structure of EMIFA inside C6455 is shown in fig. 3.12. The EMIFA module mainly communicates with an on-chip enhanced direct memory access controller (EDMA) and an off-chip shared memory controller to realize the operation of external data.

The asynchronous FIFO can be prepared by using the IP (Internet protocol) of Altera company in the FPGA, so that the FPGA can be used as an external FIFO memory of C6455, and the transmission of collected data is facilitated. The FIFO input end is controlled by a data acquisition module in the FPGA to write in data, and the FIFO output end outputs the acquired data under the control of C6455.

The network transmission function of the field acquisition device mainly expands a corresponding network circuit through an EMAC interface of the C6455, and the data packet exchange between the C6455 and a network chip is realized. The EMAC interface provides an effective interface for the C6455 and an external network, conforms to an IEEE802.3 protocol and supports a Media Independent Interface (MII). The EMAC module has 8 independent transmitting and receiving channels and can support 10/100Mbit data operation and broadcasting and multi-frame transmission formats.

The system utilizes an Enhanced Direct Memory Access (EDMA) controller of C6455 to construct the high speed data channel of the L2 cache/memory and the external storage device.

The trigger mode uses an external interrupt EXTENT 5 to transfer the data at the FIFO-mapped address to the L2 memory inside the DSP. The L2 storage area is a single RAM that manages externally extended data storage. The program opens up two separate spaces in the L2 storage, L2A and L2B, as ping-pang buffers, the size of which fits the data capacity required for one data processing. The data processing is realized by a CPU according to a program algorithm, and 14-bit dual-channel data is read from an L2A space and an L2B space in sequence and is changed into 64-bit data after being split and recombined. The processed data is written into the SDRAM through the EMIFA interface of C6455.

The signal acquisition interface of the voltage acquisition device is connected with a divider resistance sensor, the divider resistance sensor comprises divider resistances R1 and R2 which are connected IN series, two ends of R1 and R2 are respectively connected with a voltage acquisition input end IN and the ground, and a connection point OUT of R1 and R2 is connected with the signal acquisition interface of the voltage acquisition device; the voltage acquisition input end IN is connected with the voltage acquisition point of the excitation coil. The voltage divider resistors R1 and R2 divide the acquired voltage of the excitation coil and then output the voltage to the voltage acquisition device for acquisition, so that the voltage range is ensured to be within the range of the voltage acquisition device.

Claims

1. The utility model provides a thermal power generating unit excitation coil voltage integrated monitoring system which characterized in that: the monitoring system comprises a monitoring upper computer for acquiring signals and monitoring and displaying in real time and a router connected with the monitoring upper computer through a network cable, wherein the router is simultaneously connected with a plurality of voltage acquisition devices for acquiring the voltage of an excitation coil through the network cable; the voltage acquisition device is also connected with the divider resistance sensor through a cable; the voltage dividing resistance sensor is connected with the excitation coil to be detected, and transmits the acquired excitation coil voltage to the voltage acquisition device after dividing the voltage; the alarm communication device is communicated with the voltage acquisition device, acquires the abnormal signals acquired by the voltage acquisition device and communicates with an external mobile phone terminal in a wireless mode.

2. The thermal power generating unit excitation coil voltage integrated monitoring system according to claim 1, characterized in that: the alarm communication device comprises a central processing unit which is respectively connected with a network communication module, a storage module, a GPRS communication module and an acousto-optic alarm module; the central processing unit is in network communication with the router through the network communication module; the central processing unit acquires the voltage signal acquired by the voltage acquisition device through the network communication module, judges the abnormal signal, stores the abnormal signal through the storage module and sends an acousto-optic alarm to field personnel through the acousto-optic alarm module; the GPRS communication module is also connected with a communication antenna, the central processing unit is in wireless communication with a remote mobile phone terminal through the GPRS communication module and the communication antenna, and sends the alarm signal to the mobile phone terminal in a wireless mode.

3. The thermal power generating unit excitation coil voltage integrated monitoring system according to claim 1, characterized in that: the voltage acquisition device comprises an electromagnetic shielding box and an acquisition circuit board positioned in the electromagnetic shielding box; the collecting circuit board is connected with the electromagnetic shielding box through the metal fixing column; a power supply interface, a signal acquisition interface and a network communication interface are fixed on the side edge of the electromagnetic shielding box; the acquisition circuit board comprises a signal sampling module and a signal processing module, the signal sampling module comprises an FPGA chip and an A/D conversion chip connected with the FPGA chip, and a sampling end of the A/D conversion chip is connected with a signal conditioning circuit; the signal processing module comprises a DSP chip, and an SDRAM (synchronous dynamic random access memory) memory, a FLASH memory and an Ethernet interface module which are connected with the DSP chip; the DSP chip comprises an EMIFA interface, the DSP chip is connected with the FPGA through the EMIFA interface, and sampling data acquired by the FPGA are transmitted to the DSP chip through the EMIFA interface; the input end of the signal conditioning circuit is connected with the signal acquisition interface through a cable; the Ethernet interface is connected with the network communication interface through a cable; the acquisition circuit board is connected with an external power supply through a power interface.

4. The thermal power generating unit excitation coil voltage comprehensive monitoring system according to claim 3, characterized in that: the signal acquisition interface is connected with a divider resistance sensor, the divider resistance sensor comprises divider resistances R1 and R2 which are connected IN series, two ends of R1 and R2 are respectively connected with a voltage acquisition input end IN and a ground, and a connection point OUT of R1 and R2 is connected with the signal acquisition interface of the voltage acquisition device; the voltage acquisition input end IN is connected with the voltage acquisition point of the excitation coil.

5. The thermal power generating unit excitation coil voltage comprehensive monitoring system according to claim 3, characterized in that: the signal conditioning circuit comprises an attenuation circuit, an impedance conversion circuit, an amplification circuit and an ADC (analog-to-digital converter) driving circuit which are sequentially connected; the input end of the attenuation circuit is connected with an external voltage sensor; and the output end of the ADC driving circuit is connected with the sampling input end of the A/D conversion chip.

6. The thermal power generating unit excitation coil voltage integrated monitoring system according to claim 5, characterized in that: the attenuation circuit is passive attenuation and comprises voltage division resistors R10 and R13; and the voltage dividing resistors R10 and R13 are respectively connected with a capacitor and a resistor in parallel for high-frequency compensation.

7. The thermal power generating unit excitation coil voltage integrated monitoring system according to claim 5, characterized in that: the impedance transformation circuit comprises a voltage follower circuit comprising a transport amplifier OPA656, a forward input of the transport amplifier OPA656 being connected to an output of the attenuation network, a reverse input of the transport amplifier OPA656 being directly connected to the output.

8. The thermal power generating unit excitation coil voltage integrated monitoring system according to claim 5, characterized in that: the amplifying circuit comprises an operational amplifier AD8009, and the positive input end of the operational amplifier AD8009 is connected with the output end of the impedance conversion circuit; the inverting input is connected to the output through a resistor R32.

9. The thermal power generating unit excitation coil voltage integrated monitoring system according to claim 5, characterized in that: the ADC driving circuit comprises a high-speed differential amplifier AD8138, wherein a positive input end of the high-speed differential amplifier AD8138 is connected with an output end of the amplifying circuit and is simultaneously connected with a differential signal reverse output end, and the reverse input end of the high-speed differential amplifier AD8138 is respectively connected with a zero potential point and the differential signal positive output end through a resistor; the level reference end of the high-speed differential amplifier AD8138 is connected with the level reference end of the A/D conversion chip; and the differential signal output end of the high-speed differential amplifier AD8138 is connected with the input end of the A/D conversion chip.