High reliability combined electrical variable transmitting output device and method

Abstract

The application discloses a high-reliability combined electric quantity transmitting output device and method, a sampling module of the device is used for sampling input AC signals, and the present measurement data is calculated through an AC sampling algorithm, and the present measurement data is broadcast to other functional modules connected with the bus through an RS485 bus. An output module is used for receiving the measurement data broadcast by the sampling module, and after the measurement data is verified to be correct, the corresponding measurement data is buffered according to the type of each output channel in the module; a communication module is used for receiving the measurement data broadcast by the sampling module, and after the measurement data is verified to be correct and buffered, the measurement data is sent to a control console through the RS485 bus or Ethernet. The device is independently designed with the sampling module, the output module, the power module and the communication module, the modules are connected through the RS485 bus, the number of the modules is increased or decreased according to actual requirements, the waste of output ports is avoided, and the design of the secondary circuit is simplified.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric quantity transmitting output, in particular to a high-reliability combined electric quantity transmitting output device. BACKGROUND

[0002] The transmitter is an instrument which can convert the output voltage and current signal into a direct current signal proportional to the input signal after isolation, and it can reflect the operation state of the generator set and can be operated continuously for a long time, so it is widely used in the electric quantity measurement of the generator set. The transmitter is an important electric measuring instrument in the thermal power plant, and with the improvement of the automation level, the conventional analog electric quantity transmitter is gradually replaced by the intelligent transmitter.

[0003] In the field of steam turbine power generation, the transmitter is usually installed in the transmitter screen cabinet, and the electric quantity transmitters of the generator, the main transformer, the auxiliary transformer, the excitation transformer and the high auxiliary transformer of the same unit are all connected to the same transmitter screen cabinet, and the same screen cabinet contains active, reactive, voltage, current, frequency, power factor and other electric quantity transmitters with different functions.

[0004] The time division multiplier is used to calculate the effective value and power of the alternating current, and it is extremely susceptible to interference. When the line has a transient fault, the power output of the transmitter will produce irregular distorted signals such as distortion, amplification and reverse, which do not conform to the actual power curve, resulting in the imbalance of the steam turbine power load, the misoperation of the protection or the disorder of the valve action, causing the power of the unit to fluctuate sharply or even to trip, causing the primary frequency modulation, AGC abnormal exit and other events, which is not conducive to the stable operation of the generator set.

[0005] In order to overcome the poor anti-interference performance of the traditional analog transmitter, some manufacturers have developed digital transmitters. The specific principle is that the signals of the small CT and PT are discretized into a fixed number of instantaneous sampling values by a high-performance AD converter, and the AC sampling algorithm based on the discrete Fourier transform is used to calculate various electric quantities in the power system, which greatly improves the reliability of the transmitter.

[0006] Although the digital transmitter greatly improves the reliability of the transmitter, the number of analog direct current outputs remains the same as the original design of the traditional transmitter, which generally does not exceed 3. However, using the digital sampling principle can calculate almost all the electric quantities in the electric circuit, and due to the limitation of the maximum number of analog direct current output ports of the transmitter, other specifications of the transmitter need to be repeatedly designed and installed; for example, the active power transmitter can measure all the electric quantities in the electric circuit, but its output port has only 3 at most, in order to output other electric quantities, other specifications of the transmitter need to be redesigned and installed. This will cause design redundancy, the AC circuit wiring is interlaced, the connection wiring between the transmitters is complex, and the application cost is also increased to some extent.

[0007] In view of the problem of insufficient analog DC output ports of digital transmitters, some manufacturers have developed multifunctional intelligent transducer devices. The device usually contains two measurement circuits for measuring two different electrical circuits, and the output port of the intelligent transducer device is generally not less than 20, which fully guarantees the demand of field measurement output. The main advantage is that the secondary circuit design is simple and clear, and the construction difficulty is reduced due to the reduction of intermediate current signal series and voltage signal parallel links.

[0008] Problem one: the multifunctional intelligent transducer device adopts plug-in design, so when a plug-in function fails, it needs to be replaced accordingly.

[0009] As shown in Figure 1 , the AC plug-in is responsible for measuring electrical quantities in the power circuit, the CPU plug-in transmits the electrical quantities measured by the AC plug-in to the AO plug-in, and the AO plug-in outputs the measurement results of the AC plug-in. The AO plug-in usually contains power pulse output and analog DC signal output, and when any one output fails, the AO plug-in needs to be replaced as a whole. Although the power plug-in contains a dual power design, when one of the power supplies fails, the power plug-in needs to be replaced as a whole. This approach increases maintenance costs.

[0010] Problem two: the CPU plug-in and the AC plug-in of the multifunctional intelligent transducer device have no redundancy design.

[0011] Each traditional transducer in the measurement screen has an independent power supply and sampling circuit, so when one of the transducers fails, it will not affect the output of other electrical parameters of the transducer. The introduction of multifunctional intelligent transducer devices simplifies the secondary circuit design, but when the CPU plug-in and the AC plug-in fail, it will be fatal, causing all output ports to be abnormal, and all electrical parameters of the DCS to display bad points.

[0012] Therefore, when participating in DEH thermal control regulation, three independent intelligent transducer devices are still used, and only one output port of each transducer device is used, resulting in waste of other output ports of the intelligent transducer device, loss of the advantage of multiple output functions, difficulty in wiring, and greatly increased use cost.

[0013] Problem three: the AO output plug-in of the multifunctional intelligent transducer device has no clear function for each output port.

[0014] As shown in Figure 2As shown, the conventional transmitter identifies the function of each transmitter in the measurement screen cabinet, the function is single, but specific and simple. The output port of the existing multifunctional intelligent transmission device is identified by numbers, and the specific function of the output port can be pre-set by the manufacturer or set by the user on site. When the specific output line channel function needs to be determined, the corresponding drawings or other information need to be consulted, and the simple and concise function of the traditional transmitter is lost. SUMMARY

[0015] The present application provides a high-reliability combined electrical quantity transmission output device, which can solve the problems in the background art. In addition, the present application also provides a high-reliability combined electrical quantity transmission output method.

[0016] Technical scheme: On one hand, the present application provides a high-reliability combined electrical quantity transmission output device, which comprises: a sampling module, an output module, and a communication module; the sampling module, the output module, and the communication module are connected through an RS485 bus,

[0017] The sampling module is used for sampling the input AC signal and calculating the measurement data of this time through an AC sampling algorithm, and broadcasting the measurement data of this time to other functional modules connected to the bus through the RS485 bus. The measurement data represents all electrical quantity parameters obtained by measurement.

[0018] The output module is used for receiving the measurement data broadcasted by the sampling module, and after verification, the corresponding measurement data is cached according to the type of each output channel in the module, and is converted into an analog DC signal for isolation output.

[0019] The communication module is used for receiving the measurement data broadcasted by the sampling module, and after verification, the measurement data is cached and sent to the control console through the RS485 bus or Ethernet.

[0020] Further, it comprises:

[0021] Further, it comprises a power module, which is used for powering other modules, adopts a dual-channel auxiliary power input for backup, converts an AC or DC power supply into a +24V DC voltage power supply, and connects with other modules in parallel to power other modules.

[0022] Further, it comprises:

[0023] The sampling module comprises a sampling unit, a first master control unit, a first communication unit, a first display unit and a first power supply unit, the sampling unit is used for sampling a one-cycle voltage and current signal of a PT transformer and a CT transformer at a fixed time interval, and sending the AD converted result in the form of DMA to the master control unit;

[0024] The first master control unit is used for buffering the sampling data received by the DMA, calculating the measurement result by using an AC sampling algorithm, and broadcasting the measurement result to other modules on the bus in the form of broadcast through the communication unit;

[0025] The first communication unit is used for converting the USART level signal of the first master control unit into the level signal of the RS485 protocol;

[0026] The first display unit is used for displaying the measurement result, and the configuration parameters can be set by key operation;

[0027] The first power supply unit is used for converting the input +24V power supply into a +3.3V control power supply.

[0028] Further, comprising:

[0029] The sampling unit comprises a PT transformer, a CT transformer and an AD converter, the generator terminal voltage and current are connected to the internal PT transformer and CT transformer through the wiring terminal, the PT transformer and the CT transformer are connected to the sampling circuit and the AD converter after transmitting the AC small signal, and the AD converter is connected to the first master control unit in the form of a parallel port; the first communication unit is an RS485 driver, and the first master control unit is connected to the RS485 driver in the form of USART protocol port.

[0030] Further, comprising:

[0031] The output module comprises a second master control unit, an output unit, a second communication unit, a second display unit and a second power supply unit;

[0032] The second master control unit is used for receiving the measurement result broadcast by the sampling module, selecting the valid measurement result according to the output type and buffering, converting the measurement result into a PWM signal with a duty cycle in proportional change, and connecting to the output unit to convert the corresponding measurement result into a 4-20mA signal for output;

[0033] The output unit is used for isolating the PWM signal of the master control unit, and converting and outputting the PWM signal into a 4-20mA signal by using a current loop chip;

[0034] The second communication unit is used for converting the USART level signal of the second master control unit into the level signal of the RS485 protocol.

[0035] The second power supply unit is used for converting the input +24V power supply into +3.3V control power supply, and the input +24V power supply is isolated to supply power to the output unit;

[0036] The second display unit is used for displaying the real-time output current of each channel, and setting the range and output type of each channel through the key operation.

[0037] Further comprising:

[0038] The second communication unit comprises two RS485 communication bus interfaces, an RS485 driver, the RS485 communication bus interfaces A and B are connected with the RS485 driver respectively, the second master control unit is connected with the RS485 driver through the USART protocol port, the second master control unit contains the MODBUS-RTU protocol internally, and is used for receiving the measurement data broadcasted by the sampling module; when one communication bus interface is abnormal, the correct output of the output module is not affected.

[0039] The second power supply unit is composed of a BUCK circuit and an isolation power supply module, the BUCK circuit is responsible for converting the input +24V power supply into +3.3V voltage for the control circuit, and the isolation power supply module is used for isolating the input +24V power supply into +24V for supplying power to the current loop output unit.

[0040] Further comprising:

[0041] The communication module comprises a third master control unit, an RS485 communication unit, an Ethernet communication unit, a third display unit and a third power supply unit; wherein,

[0042] The third master control unit is used for receiving the measurement results broadcasted by the preceding sampling module and buffering, exchanging messages with the control console through the RS485 bus or the Ethernet, and sending data to the control console according to the message command of the control console;

[0043] The RS485 communication unit comprises two RS485 communication bus interfaces C and D, the RS485 communication bus interfaces C and D are mutually backed-up communication interfaces, and are respectively used for transmitting data to the control console, and when one communication bus interface is abnormal, the transmission of data to the control console is not affected;

[0044] The Ethernet communication unit comprises two Ethernet interfaces E and F, the Ethernet interfaces E and F are mutually backed-up communication interfaces, and adopt the MODBUS-TCP protocol, and are used for sending measurement data to the control console;

[0045] The third power supply unit is used for converting the input +24V power supply into +3.3V control power supply;

[0046] The third display unit is used for displaying the information of address, port and rate of each communication port, and setting the address, port and rate of each communication port through key operation.

[0047] In another aspect, the application also provides a high-reliability combined electrical quantity transmission output method, which specifically comprises the following steps:

[0048] After the power supply module is powered on, the sampling module, the output module and the communication module are initialized and configured to work normally.

[0049] The first main control unit of the sampling module controls the AD converter to sample the one-cycle voltage and current signals of the internal PT transformer and CT transformer at a fixed time interval, and the first main control unit buffers the continuous sampling point data, calculates the electrical quantity parameters by using the discrete Fourier algorithm, and detects the PT disconnection, CT disconnection and overcurrent state.

[0050] The sampling module broadcasts the measurement data to all modules on the bus through the RS485 communication interface by using the MODBUS-RTU protocol.

[0051] All output modules and communication modules receive the broadcast message conforming to the MODBUS-RTU protocol through the A port and the B port of the RS485 communication interface, and buffer the measurement data on the two buses from the A port and the B port respectively.

[0052] When the output module is in the normal mode, the measurement data of the A port is preferentially used, and the measurement data of the B port is used when the A port communication is wrong.

[0053] When the output module is in the high-reliability mode, if there is no disconnection and overcurrent fault state in the two groups of measurement data, the measurement data of the A port is preferentially used, when there is PT and CT disconnection state in any one group of data, the group of data without PT and CT disconnection state is used, and when the measurement data of the B port has overcurrent state, the measurement data of the B port is used.

[0054] The output module converts the electrical quantity data into the PWM signal with linearly changing duty cycle according to the finally used measurement data, and controls the current loop chip to output the 4-20mA signal after isolation.

[0055] The C port and the D port of the RS485 communication interface of the communication module, and the A port and the B port of the Ethernet monitor the console message information in real time, and send the measurement data to the console when receiving the data request message.

[0056] Beneficial effects: (1) the device of the application independently designs the sampling module, the output module, the power module and the communication module, connects the modules through the RS485 bus, increases or decreases the number of corresponding modules according to actual needs, avoids the waste of the output port, and simplifies the design of the secondary circuit; (2) the device of the application expands the function module through the bus mode, meets the system redundant design, and greatly improves the reliability of the system; (3) the device of the application adopts a combined design method, the function of each module is clear, compared with the traditional transmitter, it has the advantages of clear function, compared with the intelligent transmitter, it has the advantages of simple secondary circuit wiring and rich output port; (4) the device of the application realizes the final overall function through the combination of function modules, when a certain function module fails, only the corresponding module needs to be replaced, effectively reducing the maintenance difficulty and cost; (5) the application miniaturizes, modularizes and intensifies the sampling module, the output module, the power module and the communication module, which is convenient for engineering design and installation; BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 It is a plug-in installation schematic diagram of the multifunctional intelligent transmitter in the prior art;

[0058] Figure 2 It is a traditional transmitter measuring screen in the prior art;

[0059] Figure 3 It is a high-reliability combined electric quantity transmitter output device structure diagram according to the embodiment of the application;

[0060] Figure 4 It is an extended combined function structure schematic diagram according to the embodiment of the application;

[0061] Figure 5 It is a sampling module structure schematic diagram according to the embodiment of the application;

[0062] Figure 6 It is an output module structure schematic diagram according to the embodiment of the application;

[0063] Figure 7 It is a communication module structure schematic diagram according to the embodiment of the application;

[0064] Figure 8 It is a high-reliability combined electric quantity transmitter output method flow chart according to the embodiment of the application. DETAILED DESCRIPTION

[0065] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of the present application.

[0066] As shown in Figure 3 The present application discloses a high-reliability combined electrical quantity transmitting output device, which is used for transmitting and outputting electrical parameters at a generator end of a generator set. The device comprises a sampling module, an output module, a power module and a communication module. In order to facilitate free and rapid combination, all the modules are installed in an embedded standard guide rail (35mm) mode.

[0067] The sampling module, the output module and the communication module are connected through an RS485 bus mode.

[0068] The sampling module is used for sampling an input AC signal, calculating the current measurement data through an AC sampling algorithm, and broadcasting the current measurement data to other functional modules connected to the bus through the RS485 bus. The measurement data represent all the measured electrical quantity parameters.

[0069] The output module is used for receiving the measurement data broadcasted by the sampling module, buffering the corresponding measurement data according to the type of each output channel in the module after verification, and converting the measurement data into analog DC signals for isolation output, respectively.

[0070] The communication module is used for receiving the measurement data broadcasted by the sampling module, buffering the measurement data after verification, and sending the measurement data to a remote control console through the RS485 bus or Ethernet.

[0071] The power module is used for powering other modules, adopts a dual-channel auxiliary power input for backup, converts an AC or DC power supply into a +24V DC voltage power supply, and connects with other modules in a parallel mode to power other modules.

[0072] As an improvement of the above device, the sampling module comprises a sampling unit, a first master control unit, a first communication unit, a first display unit and a first power supply unit.

[0073] The sampling unit is used for sampling the internal small PT and small CT secondary one-cycle voltage and current signals at a fixed time interval, and sending the AD converted results to the master control unit in the form of DMA.

[0074] The first master control unit is used for buffering the sampling data received by the DMA, calculating the effective value, power and other measurement results by using the AC sampling algorithm, and broadcasting the measurement results to other modules on the bus in the form of broadcast through the communication unit.

[0075] The first communication unit is used for converting the USART level signal of the MCU into the level signal of the RS485 protocol.

[0076] The first display unit is used for displaying the measurement results and can set the configuration parameters through the key operation.

[0077] The first power supply unit is used for converting the input +24V power supply into a +3.3V control power supply.

[0078] Specifically, the sampling module includes a PT transformer, a CT transformer, a microcontroller (MCU), an AD converter, an RS485 driver and a power supply unit. Figure 5 As shown in the figure, three-phase current and voltage output interfaces, two RS485 communication bus interfaces and one power supply interface are provided; the generator terminal voltage and current are connected with the internal PT and CT transformers through the wiring terminals, the PT and CT transformers connect the converted AC small signals with the sampling circuit and the AD converter, and the AD converter is connected with the MCU controller in the form of a parallel port. The MCU controller internally contains an AC sampling algorithm, and the electrical quantity parameters are calculated according to the sampling sequence obtained by the AD converter; the MCU controller is connected with the RS485 driver by using the USART protocol port, and the MCU controller internally contains the MODBUS-RTU protocol, which is used for broadcasting the measurement data to other modules connected to the bus. The power supply unit converts the input +24V power supply into a +3.3V voltage by using a BUCK circuit, which is used for supplying power to other circuits of the sampling module.

[0079] As an improvement of the above device, the output module includes a second master control unit, an output unit, a second communication unit, a second display unit and a second power supply unit; wherein,

[0080] The second master control unit is used for receiving the measurement results broadcast by the sampling module, selecting the valid measurement results according to the output type and buffering, converting the measurement results into the PWM signal with the duty cycle changing in proportion, and connecting to the output unit to convert the corresponding measurement results into the 4-20mA signal for output.

[0081] The output unit is used for isolating the PWM signal of the master control unit and converting the PWM signal into the 4-20mA signal by using a current loop chip.

[0082] The second communication unit is used for converting the USART level signal of the MCU into the level signal of the RS485 protocol.

[0083] Second power supply unit for converting the input +24V power supply to +3.3V control power supply, after isolation of the input +24V power supply to the output unit.

[0084] Second display unit for displaying the real-time output current of each channel, and the range and output type of each channel can be set through key operation.

[0085] Specifically, the output module includes a microcontroller (MCU), an RS485 driver, a current loop output unit, and a power supply unit. Figure 6 As shown, it is equipped with 1 power interface, 2 RS485 communication bus interfaces, and 3 analog output interfaces; RS485 communication bus interfaces A and B are connected with the RS485 driver, the MCU controller is connected with the RS485 driver through the USART protocol port, the MCU controller contains the MODBUS-RTU protocol inside, which is used to receive the measurement data broadcast by the two different sampling modules, and when one communication bus interface is abnormal, it does not affect the correct output of the output module. The MCU controller converts the corresponding measurement data into PWM signals with proportional duty cycle according to the output type of the three different output channels, and the current loop output unit drives the current loop chip to output 4-20mA direct current signal after isolation of the PWM signal of the MCU controller. The power supply unit is mainly composed of a BUCK circuit and an isolation power module, the BUCK circuit is responsible for converting the input +24V power supply to +3.3V voltage for the control circuit, and the isolation power module is used to isolate the input +24V power supply to +24V for the power supply of the current loop output unit.

[0086] As an improvement of the above device, the communication module comprises a third master control unit, an RS485 communication unit, an Ethernet communication unit, a third display unit, and a third power supply unit; wherein,

[0087] The third master control unit is used to receive the measurement results broadcast by the sampling module and buffer, exchange messages with the control console through the RS485 bus or Ethernet, and send data to the control console according to the message command of the control console.

[0088] The RS485 communication unit includes two RS485 communication bus interfaces C and D, which are backup communication interfaces, and are used to transmit data to the control console, and when one communication bus interface is abnormal, it does not affect the transmission of data to the control console;

[0089] The Ethernet communication unit includes two Ethernet interfaces E and F, which are backup communication interfaces and use the MODBUS-TCP protocol to send measurement data to the control console.

[0090] The third power supply unit is used to convert the input +24V power supply into a +3.3V control power supply.

[0091] The third display unit is used to display the address, port, and speed information of each communication port, and the address, port, and speed of each communication port can be set by button operation.

[0092] Specifically, the communication module includes a microcontroller (MCU), an RS485 driver, an Ethernet module, and a power supply unit. For example... Figure 7 As shown, it is equipped with one power interface, four RS485 communication bus interfaces, and two Ethernet interfaces. RS485 communication bus interfaces A and B are connected to the RS485 driver, and the MCU controller connects to the RS485 driver via a USART protocol port. The MCU controller internally includes the MODBUS-RTU protocol to receive measurement data broadcast by the two different sampling modules, ensuring data transmission reliability even if one communication bus interface fails. RS485 communication bus interfaces C and D are mutually redundant communication interfaces used to transmit data to the control console; failure of one communication bus interface does not affect data transmission to the control console. Ethernet interfaces E and F are mutually redundant communication interfaces using the MODBUS-TCP protocol, used to send measurement data to the control console.

[0093] The power module uses dual independent power supplies, so the output of the power module will not be affected when one external power supply fails. The external power output adopts a universal AC form, providing +24V power to power other modules.

[0094] like Figure 4 As shown, the present invention uses various module combinations to form a device that meets the final functional requirements, and connects them through an RS485 bus to achieve the function of the extended device.

[0095] The device of this invention has the function of expanding DC output circuits. Since one output module supports three DC outputs, this invention expands the DC output circuits in multiples of three. Unlike existing multi-functional intelligent transmitters, each output module of this invention can be defined as having a fixed output function. For example, the output module responsible for three-phase current output has each output channel fixed to output the effective values ​​of the three-phase currents A, B, and C at the factory, maintaining the advantage of the simplicity of traditional transmitters. Compared to multi-functional intelligent transmitters, the "on-demand allocation" combination of output circuits effectively avoids waste of output circuits.

[0096] The device has the function of sampling module redundancy, since the output module and the communication module both have double RS485 ports, the broadcast measurement data of two sampling modules can be received simultaneously, and when one communication port fails, the data reception of the output module and the communication module is not affected.

[0097] As Figure 8 shown, based on the above system, embodiment 2 of the present application proposes a high-reliability combined electrical quantity transmission output method, which specifically includes the following steps:

[0098] Step 1) After the power module of the device is powered on, each module is initialized and configured to work normally.

[0099] Step 2) The MCU controller of the AC sampling module controls the AD converter to sample the one-cycle voltage and current signals of the internal small PT and small CT secondary at a fixed time interval, the MCU controller buffers the continuous sampling point data, calculates the electrical quantity parameters using the discrete Fourier algorithm, and detects the PT disconnection, CT disconnection and overcurrent state.

[0100] Step 3) The AC sampling module uses the MODBUS-RTU protocol to broadcast measurement data to all modules on the bus through the RS485 communication interface.

[0101] Step 4) All output modules and communication modules receive broadcast messages conforming to the MODBUS-RTU protocol through the A port and the B port of the RS485 communication interface, and buffer 2 sets of measurement data from the A port and the B port respectively.

[0102] Step 5) When the output module is configured in normal mode, the measurement data of the A port is used preferentially, and when the A port communication is wrong, the measurement data of the B port is used.

[0103] Step 6) When the output module is configured in high-reliability mode, if there is no disconnection and overcurrent fault state in the two sets of measurement data, the measurement data of the A port is used preferentially. When there is PT or CT disconnection state in any one set of data, the data set without PT or CT disconnection state is used. When the measurement data of the B port has an overcurrent state, the measurement data of the B port is used.

[0104] Step 7) The output module converts the electrical quantity data into a PWM signal with a linearly changing duty cycle according to the finally used measurement data, controls the current loop chip to output a 4-20mA signal after isolation.

[0105] Step 8) The C port and the D port of the RS485 communication interface of the communication module, and the A port and the B port of the Ethernet monitor the console message information in real time, and when a data request message is received, the measurement data is sent to the console.

[0106] While the preferred embodiments of the application have been described, additional variations and modifications can be made to these embodiments by those skilled in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, it is intended that the appended claims include all such modifications and variations as fall within the scope of the present application.

[0107] It is apparent that those skilled in the art can make various changes and modifications to the embodiments of the application without departing from the spirit and scope of the application. Thus, it is intended that the present application include all such modifications and alterations insofar as they come within the scope of the appended claims and their equivalents.

Claims

1. A high reliability combined electrical variable transmitting output device, characterized by, The device comprises a sampling module, an output module and a communication module, which are connected through an RS485 bus, The sampling module is used for sampling the input AC signal and calculating the measurement data through an AC sampling algorithm, and broadcasting the measurement data to other functional modules connected to the bus through the RS485 bus; wherein the measurement data represents all electrical quantity parameters obtained by measurement; The output module is used for receiving the measurement data broadcasted by the sampling module, and after verification, buffering the corresponding measurement data according to the type of each output channel in the module, and converting the measurement data into analog DC signals for isolation output; The communication module is used for receiving the measurement data broadcasted by the sampling module, buffering the measurement data after verification, and sending the measurement data to a control console through the RS485 bus or Ethernet; The device further comprises a power module, which is used for powering other modules, adopts a dual-channel auxiliary power input, converts AC or DC power supply into a +24V DC voltage power supply, and connects to other modules in parallel to power other modules; The sampling module comprises a sampling unit, a first master control unit, a first communication unit, a first display unit and a first power supply unit, the sampling unit is used for sampling the one-cycle voltage and current signals of the PT and CT transformers at a fixed time interval, and sending the AD converted results to the master control unit in the form of DMA; The first master control unit is used for buffering the sampling data received by DMA, calculating the measurement results by using the AC sampling algorithm, and broadcasting the measurement results to other modules on the bus through the communication unit; The first communication unit is used for converting the USART level signal of the first master control unit into an RS485 protocol level signal; The first display unit is used for displaying the measurement results, and can set configuration parameters through key operation; The first power supply unit is used for converting the input +24V power supply into a +3.3V control power supply.

2. The high reliability combined electrical variable transmitting output device of claim 1, wherein, The sampling unit comprises a PT transformer, a CT transformer and an AD converter, the generator terminal voltage and current are connected to the internal PT transformer and CT transformer through the terminal, the PT transformer and CT transformer connect the converted AC small signal to the sampling circuit and the AD converter, and the AD converter is connected to the first master control unit in the form of parallel port; the first communication unit is an RS485 driver, and the first master control unit is connected to the RS485 driver in the form of USART protocol port.

3. The high reliability combined electrical variable transmitting output device of claim 2, wherein, The output module comprises a second master control unit, an output unit, a second communication unit, a second display unit and a second power supply unit; The second master control unit is used for receiving the measurement results broadcasted by the sampling module, selecting the valid measurement results according to the output type and buffering the measurement results, converting the measurement results into PWM signals with proportional duty cycle change, and connecting the measurement results to the output unit to convert the measurement results into 4-20mA signals for output; The output unit is used for isolating the master control unit PWM signal and converting the PWM signal into a 4-20mA signal by a current loop chip; The second communication unit is used for converting the USART level signal of the second master control unit into an RS485 protocol level signal; The second power supply unit is used for converting the input +24V power supply into a +3.3V control power supply and supplying power to the output unit after isolating the input +24V power supply; The second display unit is used for displaying the real-time output current of each channel and setting the range and output type of each channel through key operation.

4. The high reliability combined electrical variable transmitting output device of claim 3, wherein, The second communication unit comprises two RS485 communication bus interfaces and an RS485 driver, the RS485 communication bus interfaces A and B are connected with the RS485 driver, the second master control unit is connected with the RS485 driver through a USART protocol port, the second master control unit contains a MODBUS-RTU protocol inside, is used for receiving the measurement data broadcasted by the sampling module, and when one communication bus interface is abnormal, the correct output of the output module is not affected; The second power supply unit is composed of a BUCK circuit and an isolation power supply module, the BUCK circuit is responsible for converting the input +24V power supply into a +3.3V voltage for the control circuit, and the isolation power supply module is used for isolating the input +24V power supply into +24V for supplying power to the current loop output unit.

5. The high reliability combined electrical variable transmitting output device of claim 4, wherein, The communication module comprises a third master control unit, an RS485 communication unit, an Ethernet communication unit, a third display unit and a third power supply unit, wherein, The third master control unit is used for receiving the measurement results broadcasted by the foregoing sampling module and buffering, exchanging messages with the control console through the RS485 bus or the Ethernet, and sending data to the control console according to the message command of the control console; The RS485 communication unit comprises two RS485 communication bus interfaces C and D, the RS485 communication bus interfaces C and D are mutually backed-up communication interfaces and are respectively used for transmitting data to the control console, and when one communication bus interface is abnormal, the transmission of data to the control console is not affected; The Ethernet communication unit comprises two Ethernet interfaces E and F, the Ethernet interfaces E and F are mutually backed-up communication interfaces and adopt a MODBUS-TCP protocol, and are used for sending measurement data to the control console; The third power supply unit is used for converting the input +24V power supply into a +3.3V control power supply; The third display unit is used for displaying the address, port and rate information of each communication port and setting the address, port and rate of each communication port through key operation.

6. A high-reliability combined electric quantity transmitting output method realized by the high-reliability combined electric quantity transmitting output device according to claim 5, characterized in that, The method specifically comprises: S1, after the power supply module is powered on, the sampling module, the output module and the communication module are initialized and configured to work normally; S2 The first master unit of the sampling module controls the AD converter to sample the voltage and current signals of the internal PT transformer and CT transformer at a fixed time interval, the first master unit buffers the continuous sampling point data, calculates the electrical quantity parameters using the discrete Fourier algorithm, and detects the PT disconnection, CT disconnection and overcurrent state; S3 The sampling module uses the MODBUS-RTU protocol to broadcast measurement data to all modules on the bus through the RS485 communication interface; S4 All output modules and communication modules receive broadcast messages conforming to the MODBUS-RTU protocol through the A port and B port of the RS485 communication interface, and buffer the measurement data on the two buses from the A port and B port respectively; S5 When the output module is in normal mode, the measurement data of the A port is used preferentially, and the measurement data of the B port is used when the A port communication error occurs; S6 When the output module is in high reliability mode, if there is no disconnection and overcurrent fault state in the two groups of measurement data, the measurement data of the A port is used preferentially, if there is PT or CT disconnection state in any one group of data, the data without PT or CT disconnection state is used, and if the measurement data of the B port exists overcurrent state, the measurement data of the B port is used; S7 The output module converts the electrical quantity data into a PWM signal with a linear change in duty cycle according to the finally used measurement data, and controls the current loop chip to output a 4-20mA signal after isolation; S8 The C port and D port of the RS485 communication interface of the communication module, and the Ethernet A port and B port monitor the console message information in real time, and send the measurement data to the console when receiving the data request message.

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