Hydraulic turbine governor emergency stop valve power supply and monitoring system

Abstract

This application relates to a power supply and monitoring system for an emergency stop valve of a turbine governor. A plant AC power supply is connected to an isolation transformer, which in turn is connected to a first rectifier bridge and an MCU controller. A plant DC power supply is connected to a second rectifier bridge and the MCU controller. The first output terminals of the first and second rectifier bridges are directly connected to a charging protection and energy storage unit. After energy storage, these terminals are directly connected to the stop valve switching power supply. The second output terminals of the first and second rectifier bridges are respectively connected to the charging protection and energy storage unit via power relays. After energy storage, these terminals are directly connected to the stop valve switching power supply. The charging protection and energy storage unit and the stop valve switching power supply are connected to the stop valve. A valve core detection unit is installed on the valve core of the stop valve and is connected to the MCU controller. This application prevents malfunction of the emergency stop valve and provides accurate data support for modeling the turbine governor system.

Description

Technical Field

[0001] This application relates to the field of emergency shutdown valve power supply and monitoring systems, specifically to a power supply and monitoring system for an emergency shutdown valve of a water turbine governor. Background Technology

[0002] GB / T 9652.1-2019, "Technical Conditions for Hydropower Turbine Speed ​​Control Systems Part 1: Hydraulic Governors," includes requirements, performance indicators, and test methods for hydraulic speed control systems, specifically for emergency stop valves. The actuation time of the emergency stop valve in a hydropower turbine governor is a key indicator of its performance and safety, typically requiring an extremely short time (milliseconds) to ensure that in the event of a serious electrical or mechanical fault in the turbine, the pressure oil circuit can be instantly cut off and the relay pressure released, allowing the governor to shut down immediately and preventing damage to the unit equipment. While GB / T 9652.1-2019 does not directly specify the mechanical actuation time of the solenoid valve, it mandates that the "guide vane closing time" of the entire emergency stop circuit be completed within 3 seconds to ensure unit safety. Industry requirements stipulate that the emergency stop valve must maintain operation for 10-15 seconds after the hydropower turbine governor stops, placing higher demands on the power supply for the governor's emergency stop valve.

[0003] The current solution uses a switching power supply to power the emergency stop valve. In the event of a power failure in the plant, the valve is maintained for 10 seconds by the energy stored in the internal capacitor of the switching power supply. However, this solution has the following drawbacks: 1. The operating capacitor of the switching power supply is subject to losses, which poses a safety hazard to the emergency stop valve over a long period of time; 2. The valve core's position and the current and voltage during its operation are not detected, making it impossible to accurately determine the valve core's position and status; 3. The power supply to the emergency stop valve is not monitored, and its power supply status cannot be determined; 4. After the emergency stop valve closes, the remaining power in its supply cannot be released quickly, which can lead to malfunctions of the emergency stop valve in the complex and variable electromagnetic environment of a power plant. Summary of the Invention

[0004] The purpose of this application is to provide a power supply and monitoring system for the emergency stop valve of a turbine governor, which avoids the shortcomings of current solutions, monitors the action process data of the emergency stop valve and transmits it externally, overcomes the traditional data silos, and provides accurate data support for the modeling of the turbine governor system.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] This application provides a power supply and monitoring system for an emergency shutdown valve of a turbine governor, including a plant AC power supply, a plant DC power supply, a first rectifier bridge, a second rectifier bridge, an MCU controller, a charging protection and energy storage unit, a shutdown valve switching power supply, and a valve core detection unit. The plant AC power supply is connected to an isolation transformer, which is connected to the first rectifier bridge and the MCU controller. The plant DC power supply is connected to the second rectifier bridge and the MCU controller. The first output terminals of the first and second rectifier bridges are directly connected to the charging protection and energy storage unit and then to the shutdown valve. The switching power supply has its second output terminals of the first and second rectifier bridges connected to the charging protection and energy storage unit via power relays. The stored energy directly supplies power to the shutdown valve switching power supply. Based on the power supply voltages of the shutdown valve switching power supply (24V, 110V, and 220V for emergency shutdown valve power parameters), the charging protection and energy storage unit is designed to provide power to the shutdown valve switching power supply. The charging protection and energy storage unit is connected to the shutdown valve switching power supply, and then to the shutdown valve. The valve core of the shutdown valve is equipped with a valve core detection unit, which is connected to the MCU controller.

[0007] The MCU controller is also connected to a communication interface for monitoring the switching power supply and the speed controller.

[0008] A power relay is installed between the plant AC power supply and the isolation transformer, and a power relay is also installed between the plant DC power supply and the second rectifier bridge. The power relays are connected to the GPIO pins of the MCU controller.

[0009] The valve core detection unit includes a power control relay K1 and resistors R2 and R3 connected in series with the valve core coil. Resistors R2 and R3 are connected to an operational amplifier, which samples the voltage signal. The voltage signal is then input to the PC0 pin of the MCU controller after passing through the operational amplifier. The PC0 pin of the GD32F470 references the 3.0V voltage output by the RS5030XK voltage reference to complete the emergency stop valve current acquisition. A diode FR307 is connected in parallel with the valve core to realize the inductive load current storage of the valve core for the three types of emergency stop valves, protecting the power supply from the induced voltage impact when the valve core is opened and closed. A 1N4007 is connected in series at the upper end of the valve core, and resistors R10 and R11 are connected in series after the 1N4007. The valve core voltage is monitored by the optocoupler.

[0010] Compared with the prior art, the beneficial effects of this invention are as follows: In AC / DC power coupling, the AC power supply is isolated from the emergency stop valve power supply by the power isolation transformer JBK5-250. The AC power supply is rectified into pulsed DC by the rectifier bridge GBPC3510, and the DC power supply is rectified by the GBPC3510 to achieve AC / DC power coupling. The coupled power supply stores energy in the capacitor through the charging protection circuit to supply power to the emergency stop valve switching power supply. The GD32F470 series MCU is used as the monitoring unit to detect the current, voltage, valve core position, and energy release of the emergency stop valve power supply system during the operation of the 24V, 110V, and 220V emergency stop valves, preventing malfunction of the emergency stop valve. The GD32F470 Ethernet mode in the system realizes data transmission during the operation of the emergency stop valve, providing data support for establishing an accurate mathematical model of the turbine governor system. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a system block diagram of this application;

[0013] Figure 2 This is a block diagram of the power supply system of this application;

[0014] Figure 3 This is a circuit diagram of the charging protection and energy storage unit of this application;

[0015] Figure 4 This is a circuit diagram for voltage and current monitoring and valve core position detection in this application;

[0016] Figure 5 This is a circuit diagram of the switching power supply energy release circuit of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0018] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0019] The terms “first”, “second”, etc., are used only to distinguish one entity or operation from another, and should not be construed as indicating or implying relative importance, nor as requiring or implying any such actual relationship or order between these entities or operations.

[0020] This application provides a power supply and monitoring system for an emergency shutdown valve of a turbine governor, including a plant AC power supply 1, a plant DC power supply 2, a first rectifier bridge 9, a second rectifier bridge 8, an MCU controller 5, a charging stop protection and energy storage unit 10, a shutdown valve switching power supply 11, and a valve core detection unit 12. The plant AC power supply 1 is connected to an isolation transformer 4, which is connected to the first rectifier bridge 9 and the MCU controller 5. The plant DC power supply 2 is connected to the second rectifier bridge 8 and the MCU controller 5. The first output terminal of the first rectifier bridge 9 and the first output terminal of the second rectifier bridge 8 are directly connected to the shutdown valve switching power supply 11. The second output terminal of the first rectifier bridge 9 and the second output terminal of the second rectifier bridge 8 are respectively connected to the charging protection and energy storage unit 10 through a power relay 3. The charging protection and energy storage unit is connected to the shutdown valve switching power supply. The shutdown valve switching power supply 11 is connected to the shutdown valve. The valve core of the shutdown valve is provided with a valve core detection unit 12, which is connected to the MCU controller 5.

[0021] The MCU controller is also connected to a communication interface for monitoring the switching power supply and the speed controller.

[0022] A power relay is installed between the plant AC power supply and the isolation transformer, and a power relay is also installed between the plant DC power supply and the second rectifier bridge. The power relays are connected to the GPIO pins of the MCU controller.

[0023] The power plant's load is primarily inductive, resulting in frequently high AC power supply voltages, numerous glitches, and large voltage spikes. The power plant's DC power supply batteries are grounded at their neutral point. The DC power supply monitoring system detects AC power composition and triggers DC power supply protection, posing a safety hazard to the power plant's power supply. Considering these characteristics of the power supply, a combination of hardware and software is used for power supply fault isolation. A JBK5-250 isolation transformer is connected to the AC power supply, with a -5% contact selected at the output. The output voltage is stepped down and rectified by a GBPC3510 full-wave rectifier. The DC power supply output is also rectified by a GBPC3510 full-wave rectifier. The AC and DC power supplies are coupled, and through charging protection and an energy storage unit, redundant power is supplied to the emergency stop valve. The output of the AC / DC rectifier bridge is connected to a power relay. The relay coil voltage is controlled by the GPIO pins of the monitoring system, enabling power supply to the emergency stop valve and energy release after activation.

[0024] The turbine governor's emergency stop valve is supplied with voltages of 24V, 110V, and 220V; its power is 40-50W. Based on the law of conservation of energy, the emergency stop valve's power is 60W, maintaining its output energy for 10 seconds. =600J; Energy released by the capacitor: ΔE= Capacitor calculation , To reserve a margin of 1.1 times, Assuming a switching power supply efficiency of 0.85, neglecting capacitor losses, and assuming the capacitor's discharge fully supplies the emergency stop valve's switching power supply, with the plant's AC power having a peak-to-peak value of 311V after rectification, calculate the energy storage capacitor for these three types of emergency stop valves:

[0025] The emergency stop valve is 220V DC, and the capacitor capacity is: ;

[0026] Emergency stop valve 110V DC, capacitor capacity: ;

[0027] Emergency stop valve 24V DC, capacitor capacity: ;

[0028] When the power is 60W, the energy storage capacitor parameters for the three different emergency stop valve power supply voltages (24V, 110V, and 220V) are as follows: The factory power supply has large voltage spikes and glitches; 18 units with a capacity of 1000 are selected. Parallel connection. The capacitors are connected in series with the PTC (B59950C0120A070). When the power supply is powered on, the PTC controls the charging current of each capacitor to prevent power supply short circuits from causing plant power failures. 1000 A parallel 2MR / 3W power resistor clamps the bridge arm voltage protection capacitor of the rectifier bridge, and a rectifier bridge anti-reverse connection and switching power supply voltage reverse discharge protection capacitor is connected in series at the front end of the switching power supply.

[0029] When the emergency stop valve power control relay K1 is closed, the voltage signal across the sampling resistors R2 and R3 in series with the valve core coil is isolated and amplified by the voltage signal isolation amplifier AMC1301DWVR. The 3.0V output from the reference voltage RS5030XK on the PC0 pin of the GD32F470 completes the current acquisition of the emergency stop valve. A diode FR307 connected in parallel with the valve core enables current storage for the inductive load of the emergency stop valve core, protecting the power supply from the induced voltage impact when the valve core is opened and closed. A 1N4007 (to block the reverse voltage of the emergency stop valve core and protect the optocoupler from reverse voltage breakdown), two resistors, and the optocoupler are connected in series at the upper end of the valve core to monitor the valve core voltage, realizing the monitoring of the 24V, 110V, and 220V voltages of the emergency stop valve core.

[0030] The emergency stop valve coil is equivalent to a resistor. and inductor When connected in series, the coil voltage is: , This is the real-time current of the coil. Inductance parameters during operation, inductance Depends on the air gap of the magnetic circuit and the position of the valve core The relevant, ideal model is equivalent to: , The number of coil turns. Permeability, The magnetic circuit area is... This is the initial position of the valve core. The valve core position is calculated in real time based on the detected voltage and current signals, combined with an equivalent model. The status of the electromagnetic coil circuit and whether the valve core is actuated are monitored to determine whether the coil is open-circuited, short-circuited, or whether the valve core is stuck in the initial or intermediate position.

[0031] The AC / DC power supply for the emergency stop valve is monitored using an optocoupler ORPC-817SB-TP-F. The PB1 and PB2 pins of the GD32F470 monitor the plant's AC and AC / DC power supplies, respectively. The GPIO pins PB3 and PB4 control the on / off state of the AC and DC power inputs, influencing the impact of power cut-off on the emergency stop valve. The GD32F470 calculates, analyzes, and processes the measured data. Once the stop valve is closed and the valve core reaches the designated position, the PB3 and PB4 pins of the GD32F470 output a high level, cutting off the AC and DC power inputs. Then, the PB5 pin outputs a high level to connect the energy release resistors R11 and R12, releasing residual energy from the emergency stop valve's power supply and improving the stability of the power supply system.

[0032] GD32F470 measures release time Monitor capacitor capacitance decay. Power supply energy release: , For energy storage capacitor capacity, Energy storage voltage; energy release time: , The energy release ratio refers to the energy released by the emergency stop valve. It reaches 100%, and the energy is completely released.

[0033] The AC / DC power supply for the emergency stop valve is monitored using an optically isolated ORPC-817SB-TP-F. When the GPIO pins of the GD32F470 detect no power input, GPIO pins PB3 and PB4 control the switching on and off of the AC / DC power input, cutting off the power supply's impact on the emergency stop valve. The GD32F470 calculates, analyzes, and processes the measured data. After determining that the stop valve is closed and the valve core is in the designated position, pins PB3 and PB4 of the GD32F470 output a high level, first cutting off the AC / DC power input. Then, pin PB5 outputs a high level to connect the energy release resistors R11 and R12, completing the release of residual energy in the emergency stop valve's power supply and improving the stability of the stop valve's power supply system.

[0034] GD32F470 measures release time Monitor capacitor capacitance decay. Power supply energy release: , For energy storage capacitor capacity, Energy storage voltage; energy release time: , The energy release ratio refers to the energy released by the emergency stop valve. It reaches 100%, and the energy is completely released.

[0035] The GD32F470 extends the CH390 via SPI bus to achieve data transmission via Ethernet. During the operation of the emergency stop valve spool, voltage, current, valve spool position calculation, and plant power data monitoring data are transmitted externally using the standard MODBUS communication protocol. This overcomes the data silos in the emergency stop valve control method of traditional governor control methods and provides accurate data support for the modeling of the turbine governor system.

[0036] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A power supply and monitoring system for an emergency stop valve of a water turbine governor, characterized in that, The system includes a plant AC power supply, a plant DC power supply, a first rectifier bridge, a second rectifier bridge, an MCU controller, a charging protection and energy storage unit, a shutdown valve switching power supply, and a valve core detection unit. The plant AC power supply is connected to an isolation transformer, which is connected to the first rectifier bridge and the MCU controller. The plant DC power supply is connected to the second rectifier bridge and the MCU controller. The first output terminals of the first and second rectifier bridges are directly connected to the charging protection and energy storage unit and then to the shutdown valve switching power supply. The charging protection and energy storage unit provides power to the shutdown valve switching power supply. The second output terminals of the first and second rectifier bridges are respectively connected to the charging protection and energy storage unit through power relays. The shutdown valve switching power supply is connected to the shutdown valve. A valve core detection unit is provided on the valve core of the shutdown valve and is connected to the MCU controller.

2. The power supply and monitoring system for the emergency stop valve of a water turbine governor according to claim 1, characterized in that, The MCU controller is also connected to a communication interface for monitoring the switching power supply and the speed controller.

3. The power supply and monitoring system for the emergency stop valve of a turbine governor according to claim 1, characterized in that, A power relay is installed between the plant AC power supply and the isolation transformer, and a power relay is also installed between the plant DC power supply and the second rectifier bridge. The power relays are connected to the GPIO pins of the MCU controller.

4. The power supply and monitoring system for the emergency stop valve of a turbine governor according to claim 1, characterized in that, The valve core detection unit includes a power control relay K1. The valve core detection unit also includes resistors R2 and R3 connected in series with the valve core coil. Resistors R2 and R3 are connected to an operational amplifier. Resistors R2 and R3 sample voltage signals, which are then input to the PC0 pin of the MCU controller after passing through the operational amplifier. The MCU controller completes the acquisition of the emergency stop valve current. A diode FR307 is connected in parallel with the valve core to achieve inductive load current storage in the emergency stop valve core, protecting the power supply from induced voltage surges when the valve core is opened and closed. A 1N4007 is connected in series at the upper end of the valve core, followed by resistors R10 and R11. Valve core voltage monitoring is achieved through the valve core and an optocoupler.

5. The power supply and monitoring system for the emergency stop valve of a water turbine governor according to claim 4, characterized in that, The optocoupler is connected to the GPIO pins of the MCU controller. The PB1 and PB2 pins of the MCU controller monitor the plant AC and plant AC / DC power supplies, respectively. The PB3 and PB4 pins control the input AC and DC power supplies. The GPIO pins of the MCU controller work together to cut off the power supply's influence on the emergency stop valve.

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