JP3237719U - Servo controller to control the servo valve of the steam turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a servo controller for controlling a servo valve of a steam turbine capable of satisfying the control needs of a servo valve of different units. A servo controller for controlling a servo valve of a steam turbine, including a dual slot IO base, a servo control master module and a servo control slave module, and an FPGA and a master module MCU of the servo control master module are SPI buses. The servo control master module is connected to the external connection terminal by FPGA, the master module MCU is connected to the system bus, and the valve position sensor input and servo control output channels are installed between the FPGA and the external connection terminal. , The slave module MCU is connected between the external connection terminal and the system bus, and analog quantity input and output and switching input and output channels are installed between the slave module MCU and the external connection terminal. [Selection diagram] Fig. 3

Description

The present invention belongs to the control field of a steam turbine, and specifically relates to a servo controller for controlling a servo valve of a steam turbine.

Currently commonly used in digital electro-hydraulic control systems (DEH) are DCS-based systems. DCS is an English abbreviation for distributed control system (Distributed Control System), also called a distributed control system, and is a newer type of computer control system than a centralized control system.

In a digital electro-hydraulic system (DEH) of a steam turbine, the servo control device mainly realizes closed-loop control of the valve opening of the hydraulic servomotor. The valve position command signal of the hydraulic servomotor generated by the DEH controller forms a hydraulic adjustment signal on the hydraulic servomotor by the servo amplification module and the electro-hydraulic servo valve. The stroke of the hydraulic servomotor is detected by the displacement sensor and then fed back to the servo amplification module to maintain it in line with the valve position execution of the hydraulic servomotor, thereby completing the command to the valve position of the servo device throughout the DEH. And complete the closed loop control. Since the conventional servo control device cannot be flexibly arranged, it cannot effectively meet the needs of different units.

An object of the present invention is to provide a servo controller for controlling a servo valve of a steam turbine in response to the above-mentioned problems of the prior art, and it is arranged according to an actual application situation to meet the control needs of different units. be able to.

In order to achieve the above object, the present invention has the following technical solutions.

A servo controller for controlling a servo valve of a steam turbine, which is equipped with a dual slot IO base, a servo control master module and a servo control slave module are installed on the dual slot IO base, and the servo control master module is a master module. The MCU and the FPGA are provided, the FPGA and the master module MCU are connected via the SPI bus, the servo control master module is connected to the external connection terminal to the servo control master module by the FPGA, and the master module MCU is connected to the system bus. A 2-pass valve position sensor input channel and a 2-pass servo control output channel are installed between the FPGA and the external connection terminal, the servo control slave module includes a slave module MCU, and the slave module MCU has an external connection terminal. 2pass analog amount input channel, 2pass analog amount output channel, 4pass DC48V switching input channel and 2pass DC24V switching between the slave module MCU and the external connection terminal. An output channel is installed, and the master module MCU and the slave module MCU are connected to a master-slave interconnection signal line for exchanging data via the UART port.

As a preferred solution of the servo controller according to the present invention, the 2-pass valve position sensor input channel between the FPGA and the external connection terminal supports a 3-wire or 6-wire LVDT signal.

As a preferred solution for the servo controller according to the present invention, the effective source side excitation voltage range of the 2-pass valve position sensor input channel between the FPGA and the external connection terminal is 1V to 7V, and the source side excitation frequency. The range is 1 KHz to 4 KHz, and the valve position input accuracy is ± 0.1%.

As a preferred solution for the servo controller according to the present invention, the 2-pass servo control output channel between the FPGA and the external connection terminal can be set as an output current or voltage, and the current output range is -40 mA to 40 mA. The voltage output range is −10V to 10V, and the servo control output accuracy is ± 0.2%.

As a suitable solution for the servo controller according to the present invention, the input type of the 2-pass analog amount input channel is a current of 0 to 20 mA or 4 to 20 mA, and the accuracy is 0.1% or more.

As a preferred solution of the servo controller according to the present invention, the output type of the 2-pass analog amount output channel includes a current output type and a voltage output type, and the current range of the current output type is 0 to 20 mA or 4 It is about 20 mA, the voltage range of the voltage output type is 0 to 10 V or 0 to 5 V, and the accuracy of the current of the current output type and the accuracy of the voltage of the voltage output type are 0.1% or more.

As a preferred solution of the servo controller according to the present invention, the signal type of the 4-pass DC48V switching input channel is a dry contact, and each pass supports the SOE function.

As a preferred solution of the servo controller according to the present invention, the signal type of the 2-pass DC24V switching output channel is a level signal, and the drive capacity is DC24V 0.5A per pass.

As a preferred solution for the servo controller according to the present invention, the master module MCU is connected to an onboard temperature sensor chip and a 16MB SPI NOR FLASH memory.

Compared with the prior art, the present invention has the following beneficial effects. By installing the servo control master module and the servo control slave module on the dual slot IO base, it is possible to flexibly set whether or not the servo control slave module is required according to the actual application situation. The servo control master module of the present invention completes the most major valve position sampling, circuit adjustment and control output, and the servo control slave module completes additional functional I / O and signal processing. The master module MCU and the slave module MCU can communicate with each other via the master-slave interconnection signal line to exchange data, facilitate integrated arrangement, and have a simple structure. The present invention can realize servo valve control in one-to-one mode and is applied to servo valves with more input and output points to meet the control needs of different steam turbine units as much as possible.

It is a structural schematic diagram of the system formed by assembling the servo controller which concerns on this invention. It is a schematic diagram of the external structure of a single servo controller which concerns on this invention. It is a circuit structure diagram of the servo control master module which concerns on this invention. It is a circuit structure diagram of the servo control slave module which concerns on this invention.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

The present invention provides a servo controller for controlling a servo valve of a steam turbine, the dual slot IO base is provided, and a servo control master module and a servo control slave module are installed on the dual slot IO base, which is shown in FIG. ..

The servo control master module includes a master module MCU and an FPGA, the FPGA and the master module MCU are connected via the SPI bus, and the servo control master module is connected to the external connection terminal to the servo control master module by the FPGA to be a master. The module MCU is connected to the system bus, and a 2-pass valve position sensor input channel and a 2-pass servo control output channel are installed between the FPGA and the external connection terminal, and are shown in FIG. The master module MCU is connected to the onboard temperature sensor chip and 16MB of SPI NOR FLASH memory. The servo master module in FIG. 3 outputs a sine wave signal of 1 to 7 V, 1 KHz to 4 KHz by the IO port of the instruction FPGA transmitted from the host computer, and sine 24 voltage output points by the internal logic lookup table of the FPGA. Fitting to the wave, the FPGA converts the voltage amplitude output value corresponding to the code value to the voltage output by the DAC, passes through the comparator built by the arithmetic amplifier, and then inputs it to the push-pull circuit to improve the voltage drive capability. Then, the voltage is input to the exciting coil of the LVDT by the external connection terminal, the servo master module is accessed by the external connection terminal via the secondary coil in the LVDT, and the voltage induced by the LVDT secondary coil by the position recollection ADC. The amplitude signal is recollected and the ADC chip is connected to the FPGA. The servo current output command signal is first transmitted by the FPGA with the code value corresponding to the output command, converted into a specific voltage amplitude by the DAC chip, passed through the comparator constructed by the arithmetic amplifier, and then passed through the push-pull circuit. The output drive capability is improved, and after passing through the V / I conversion circuit, the current signal is output by the external connection terminal, the current signal is output and recollected, and the output command signal matches the collected one. Secure to do. If not, report the servo current output failure instruction.

The FPGA 2-pass valve position sensor input channel supports 3-wire or 6-wire LVDT signals. The source side excitation voltage effective value range is 1V to 7V, the source side excitation frequency range is 1KHz to 4KHz, and the valve position input accuracy is ± 0.1%.

The FPGA 2-pass servo control output channel can be set as an output current or voltage, with a current output range of -40mA to 40mA, a voltage output range of -10V to 10V, and a servo control output accuracy of ± 0. .2%.

The servo control master module supports hot swap and has a closed loop control cycle of 4 ms.

The servo control slave module is equipped with a slave module MCU, the slave module MCU is connected between the external connection terminal and the system bus, and a 2-pass analog amount input channel and 2-pass analog quantity input channel between the slave module MCU and the external connection terminal. An analog quantity output channel, a 4-pass DC48V switching input channel and a 2-pass DC24V switching output channel are installed and are shown in FIG. All connections to the outside of the circuit are connected by a hard wiring method via an external connection terminal, and for the analog amount output circuit, the instruction signal is first output to the DAC chip by the SPI communication method using the IO pin of the MCU, and then. The command signal is converted into a specific voltage amplitude by the DAC chip, the voltage amplitude is converted into the corresponding current signal by the V / I drive circuit, and after passing through the EMC protection circuit, it is connected to the field device by the external connection terminal. .. For the analog amount input circuit, the current signal input from the outside of the external connection terminal passes through the EMC protection circuit, and then the current signal input from the outside is converted into a voltage signal of the corresponding amplitude by the I / V conversion circuit. The input terminal corresponding to the ADC samples the voltage amplitude signal, converts it into the corresponding code value, communicates with the MCU via the SPI bus, and reads the corresponding code value input from the ADC chip. Regarding the switching output circuit, the IO pin of the MCU outputs the switching command corresponding to the high and low levels, and when outputting the high level signal, it corresponds to the on command, drives the MOS switch to the optical coupling type relay, and optical coupling. The optical coupling type relay is turned on after receiving the ON command of the MOS switch, outputs the 24VDC level after passing through the EMC protection circuit, and is connected to the external device by the external connection terminal. For the digital amount input circuit, after accessing the dry contact signal through the external connection terminal and passing through the EMC protection circuit, the optical coupler is turned on when the dry contact is turned on, and the optical coupler is turned on when the dry contact is turned off. Is turned off and the signal is transmitted to the MCU.

The input type of the 2-pass analog amount input channel between the slave module MCU and the external connection terminal is a current of 0 to 20 mA or 4 to 20 mA, and the current accuracy is 0.1% or more. The analog amount input supports 2-wire and 4-wire connection methods.

The output type of the 2-pass analog amount output channel includes a current output type and a voltage output type, and the current range of the current output type is 0 to 20 mA or 4 to 20 mA, and the voltage range of the voltage output type. Is 0 to 10V or 0 to 5V, and the accuracy of the current of the current output type and the accuracy of the voltage of the voltage output type are 0.1% or more.

The signal type of the 4-pass DC48V switching input channel is dry contact, and each pass supports SOE function.

The signal type of the 2-pass DC24V switching output channel is a level signal and the drive capability is DC24V 0.5A per pass.

The servo control slave module supports hot swap.

The master module MCU and the slave module MCU are connected to the master-slave interconnection signal line for exchanging data via the UART port.

The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention, and as can be understood by those skilled in the art, the technical solution without departing from the spirit and principle of the present invention. The means can further make various simple modifications and substitutions, all of which fall within the scope of the claims.

Claims (10)

It is a servo controller for controlling the servo valve of the steam turbine.
A dual slot IO base is provided, a servo control master module and a servo control slave module are installed on the dual slot IO base, and the servo control master module is equipped with a master module MCU (Microcontroller Unit) and an FPGA (Field Programmable Gate Array). The FPGA and the master module MCU are connected via an SPI (Serial Peripheral interface) bus, the servo control master module is connected to an external connection terminal to the servo control master module by the FPGA, and the master module MCU is a system bus. A 2-pass valve position sensor input channel and a 2-pass servo control output channel are installed between the FPGA and the external connection terminal, and the servo control slave module includes a slave module MCU and the slave module. The MCU is connected between the external connection terminal and the system bus, and has a 2-pass analog amount input channel, a 2-pass analog amount output channel, and a 4-pass DC48V between the slave module MCU and the external connection terminal. A switching input channel and a 2-pass DC24V switching output channel are installed, and the master module MCU and the slave module MCU are connected to a master-slave interconnection signal line for exchanging data via a UART port. A servo controller for controlling the servo valve of the steam turbine. The first aspect of claim 1, wherein the two-pass valve position sensor input channel between the FPGA and the external connection terminal supports a 3-wire or 6-wire LVDT (Linear Variable Differential Transformer) signal. Servo controller for controlling the servo valve of the steam turbine. The source-side excitation voltage effective value range of the two-pass valve position sensor input channel between the FPGA and the external connection terminal is 1V to 7V, and the source-side excitation frequency range is 1KHz to 4KHz. The servo controller for controlling the servo valve of the steam turbine according to claim 1. The servo valve of the steam turbine according to claim 3, wherein the valve position input accuracy of the two-pass valve position sensor between the FPGA and the external connection terminal is ± 0.1%. Servo controller for. The two-pass servo control output channel between the FPGA and the external connection terminal can be set as an output current or an output voltage, and the output range of the output current is −40 mA to 40 mA of the output voltage. The servo for controlling the servo valve of the steam turbine according to claim 1, wherein the output range is -10V to 10V, and the servo control output accuracy of the servo control master module is ± 0.2%. controller. The servo valve of the steam turbine according to claim 1, wherein the input type of the two-pass analog amount input channel is a current of 0 to 20 mA or 4 to 20 mA, and the current accuracy is 0.1% or more. Servo controller for controlling. The output type of the two-pass analog amount output channel includes a current output type and a voltage output type, and the current range of the current output type is 0 to 20 mA or 4 to 20 mA, and the voltage range of the voltage output type. The steam turbine according to claim 1, wherein is 0 to 10 V or 0 to 5 V, and the accuracy of the current of the current output type and the accuracy of the voltage of the voltage output type are 0.1% or more. Servo controller for controlling the servo valve. The servo for controlling the servo valve of the steam turbine according to claim 1, wherein the signal type of the 4-pass DC48V switching input channel is a dry contact and supports an SOE (Sequence of event) function. controller. The steam turbine servo valve according to claim 1, wherein the signal type of the two-pass DC24V switching output channel is a level signal and the drive capacity is DC24V 0.5A per pass. Servo controller. The servo controller for controlling a steam turbine servo valve according to claim 1, wherein the master module MCU is connected to an onboard temperature sensor chip and a 16 MB SPI NOR FLASH memory.

Images