A turbine unit braking system and method thereof

Abstract

The present invention discloses a turbine unit braking system and method thereof, wherein a turbine controller and a main gas regulating valve are electrically connected to control the switch state of the main gas regulating valve; a generator controller is electrically connected to a generator to control the rotation speed and power generation of the generator; an electromagnetic bearing controller is electrically connected to electromagnetic bearings I and II to control the suspension or de-suspension of the electromagnetic bearings to achieve the fixation of the axial and radial positions of the turbine generator rotor; an adjustable resistor is electrically connected to the generator controller, and the on and off control of the current is achieved through a DC circuit breaker; the turbine controller is electrically connected to the electromagnetic bearing controller, the turbine controller is electrically connected to the generator controller, the electromagnetic bearing controller is electrically connected to the generator controller, and the turbine controller is electrically connected to the adjustable resistor, and signal communication is achieved during the braking process. The present invention is an important guarantee for the reliability of the operation of the bearing protection under extreme working conditions and the safety of the operation of the turbine unit.

Description

Technical Field

[0001] The present invention belongs to the field of renewable energy power generation, and in particular relates to a turbine unit braking system and a method thereof. Background Art

[0002] The economy of turbine units has always been the focus of the industry, and increasing the design speed of the unit generally has a higher economic improvement. At present, sliding bearings are commonly used in turbine units, which are oil-lubricated, but they are subject to greater linear speed restrictions. Generally, the linear speed of the journal of sliding bearings does not exceed 50m / s. For units of the same power level, if electromagnetic bearings are used, the design speed of the unit can be increased by about 3 times, and the economy of the unit will be greatly improved. Compared with traditional sliding bearings or rolling bearings, it has multiple advantages such as low vibration, low noise, no need for lubrication, and low power consumption. The protective bearing is a key component to ensure the safety of the electromagnetic bearing. Generally, rolling bearings are selected. The protective bearing is in a relatively static state when the electromagnetic bearing is operating normally, and only plays a role in supporting the unit rotor when the bearing fails and falls or the unit is shut down. The protective bearing of a high-speed electromagnetic bearing generally has a limit on the number of drops. It bears a huge impact force in the short time when the rotor falls, and absorbs most of the rotor kinetic energy during the fall. Therefore, in many cases, when a heavy-loaded rotor falls, the protective bearing will be greatly deformed, and the rotor axis trajectory exceeds the flow clearance value inside the turbine unit, causing a huge risk of dynamic and static friction of the turbine unit. In order to ensure the reliability of the protective bearing operation under extreme working conditions and the safety of the turbine unit operation, it is necessary to design a turbine unit braking system that absorbs most of the rotor kinetic energy when the turbine rotor falls. Summary of the invention

[0003] The purpose of the present invention is to solve the above technical problems and provide a turbine unit braking system and method thereof, which is an important guarantee for protecting the reliability of bearing operation under extreme working conditions and the safety of turbine unit operation.

[0004] The technical scheme for realizing the present invention is: a turbine unit braking system, characterized in that it includes an electromagnetic bearing I, a turbine, a generator, an electromagnetic bearing II, a DC circuit breaker, a generator controller, an electromagnetic bearing controller, a turbine controller, an adjustable resistor, and a main gas regulating valve; the electromagnetic bearing I and the electromagnetic bearing II support the rotor of the turbine generator; the turbine controller and the main gas regulating valve are electrically connected to control the switching state of the main gas regulating valve; the main gas regulating valve is arranged at the air inlet of the turbine cylinder; the generator controller is electrically connected to the generator to control the rotation speed and power generation of the generator; the electromagnetic bearing controller is electrically connected to the electromagnetic bearings I and II to control the suspension or de-suspension of the electromagnetic bearings to achieve the fixing of the axial and radial positions of the turbine generator rotor; the adjustable resistor is electrically connected to the generator controller, and the on and off control of the current is achieved through the DC circuit breaker; the turbine controller is electrically connected to the electromagnetic bearing controller, the turbine controller is electrically connected to the generator controller, the electromagnetic bearing controller is electrically connected to the generator controller, and the turbine controller is electrically connected to the adjustable resistor, and the signal communication during the braking process is achieved.

[0005] The turbine controller is electrically connected to the emergency stop button.

[0006] A braking method for a turbine unit braking system comprises the following steps:

[0007] 1) During normal operation, the turbine generator rotor is supported on electromagnetic bearings I and II, and the turbine controller, electromagnetic bearing controller, and generator controller monitor the working status of the turbine, generator, electromagnetic bearing I, and electromagnetic bearing II respectively;

[0008] 2) When the emergency stop button is pressed or the turbine, generator, electromagnetic bearing I, or electromagnetic bearing II fails, the protective shutdown signal will be transmitted to the turbine controller. After receiving the above signal, the turbine controller first sends a command to disconnect the external load to the external system, and at the same time sends a valve quick closing signal to the main gas regulating valve, and sends a command to switch to the voltage stabilization control mode to the generator controller after a delay of 0.5S; at the same time, the turbine controller sends a braking resistor input command to the adjustable resistor. After receiving the input command, the adjustable resistor immediately sends a closing command to the DC circuit breaker. In this way, after the conversion of the generator controller, a closed-loop DC current is formed at its outlet, and the kinetic energy of the motor rotor is converted into electrical energy transmitted to the adjustable resistor by the generator controller;

[0009] 3) During braking, the turbine controller will send a real-time adjustment command of the braking resistor value to the adjustable resistor according to the deceleration slope curve set in the control logic to prevent damage to the turbine generator rotor caused by excessive torque at high power and low speed;

[0010] 4) When the speed drops to 100 rpm, the turbine controller sends a command to disconnect the braking resistor to the adjustable resistor, and the adjustable resistor then sends a disconnect command to the DC circuit breaker, and the braking process ends.

[0011] The generator control system mainly composed of the generator controller, the magnetic bearing control system mainly composed of the electromagnetic bearing controller, and the turbine control system mainly composed of the turbine controller are integrated in design. All braking commands are ultimately sent through the turbine controller, which simultaneously controls the action of the main steam regulating valve and the adjustable resistor, covering the entire fault range of the unit.

[0012] The beneficial effects of the present invention are:

[0013] 1. The present invention is provided with two braking control modes: manual emergency stop button and logic automatic protection, which greatly ensures the safety of unit operation.

[0014] 2. The generator control system, magnetic bearing control system and turbine control system of the present invention are integratedly designed. All braking commands are ultimately sent through the turbine controller, which simultaneously controls the action of the main steam regulating valve and the adjustable resistor, covering the entire fault range of the unit with high control accuracy and good operability.

[0015] 3. The braking system of the present invention adopts a non-contact form and utilizes the principle of converting kinetic energy into electrical energy dissipation. It has good repeatability and adjustable braking power, and can meet various braking requirements such as fast and slow. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a simplified schematic diagram of a turbine unit braking system according to an embodiment of the present invention.

[0017] Numbers in the figure: 1—electromagnetic bearing I, 2—turbine, 3—generator, 4—electromagnetic bearing II, 5—DC circuit breaker, 6—generator controller, 7—emergency stop button, 8—electromagnetic bearing controller, 9—turbine controller, 10—adjustable resistor, 11—main gas regulating valve. DETAILED DESCRIPTION

[0018] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0019] like Figure 1As shown, a turbine unit braking system includes an electromagnetic bearing Ⅰ1, a turbine 2, a generator 3, an electromagnetic bearing Ⅱ4, a DC circuit breaker 5, a generator controller 6, an emergency stop button 7, an electromagnetic bearing controller 8, a turbine controller 9, an adjustable resistor 10, and a main gas regulating valve 11. The electromagnetic bearing I1 and the electromagnetic bearing II4 are arranged at both ends of the turbine unit to support the rotating turbine generator rotor when the turbine unit is running; the main gas regulating valve 11 is arranged at the air inlet of the turbine 2 cylinder, the turbine controller 9 is connected to the main gas regulating valve 11 through a cable, and controls the switch state of the main gas regulating valve 11 by sending a signal; the generator controller 6 is connected to the generator 3 through a cable, and controls the speed and power generation of the generator 3; the electromagnetic bearing controller 8 is connected to the electromagnetic bearing I1 and the electromagnetic bearing II4 through a cable, controls the suspension or de-suspension of the electromagnetic bearing I1 and the electromagnetic bearing II4, and realizes the fixing of the axial and radial positions of the turbine generator rotor; the adjustable resistor 10 is connected to the generator controller 6 through a cable, and realizes the on-off control of the current through the DC circuit breaker 5, and dissipates the electric energy of the generator 3 during braking. The turbine controller 9 and the electromagnetic bearing controller 8, the turbine controller 9 and the generator controller 6, the electromagnetic bearing controller 8 and the generator controller 6, the turbine controller 9 and the emergency stop button 7 are all connected through cables, and realize mutual communication of signals during the braking process.

[0020] A braking method for a turbine unit braking system comprises the following steps:

[0021] 1) When the unit is operating normally, the turbine generator rotor is supported on electromagnetic bearings Ⅰ1 and Ⅱ4, and the turbine controller 9, electromagnetic bearing controller 8, and generator controller 6 monitor the working status of turbine 2, generator 3, electromagnetic bearing Ⅰ1, and electromagnetic bearing Ⅱ4 respectively;

[0022] 2) When the on-site personnel find an emergency and press the emergency stop button 7, or the turbine 2, generator 3, electromagnetic bearing Ⅰ1, and electromagnetic bearing Ⅱ4 fail, the protective shutdown signal will be transmitted to the turbine controller 9. After the turbine controller 9 receives the emergency shutdown signal from various devices including the manual shutdown, it will first send an instruction to disconnect the external load to the external system, and at the same time send a valve quick closing signal to the main gas regulating valve 11, and send a command to switch to the voltage stabilization control mode to the generator controller 6 after a delay of 0.5S. At the same time, the turbine controller 9 sends a braking resistor input command to the adjustable resistor 10. After receiving the input command, the adjustable resistor 10 immediately sends a closing command to the DC circuit breaker 5. In this way, after the conversion of the generator controller 6, its outlet forms a closed-loop DC current, and the kinetic energy of the turbine generator rotor is converted into electrical energy transmitted to the adjustable resistor 10 by the generator controller;

[0023] 3) During the braking process, the turbine controller 9 will send a real-time adjustment command of the braking resistor value to the adjustable resistor 10 according to the deceleration slope curve set in the control logic to prevent damage to the turbine generator rotor caused by excessive torque at high power and low speed.

[0024] 4) When the speed drops to 100 rpm, the turbine controller 9 sends a command to disconnect the braking resistor to the adjustable resistor 10, and the adjustable resistor 10 then sends a disconnection command to the DC circuit breaker 5, and the braking process ends.

[0025] The generator control system mainly composed of the generator controller 6, the magnetic bearing control system mainly composed of the electromagnetic bearing controller 8 and the turbine control system mainly composed of the turbine controller 9 are integratedly designed. All braking commands are ultimately sent through the turbine controller, which simultaneously controls the actions of the main steam regulating valve and the adjustable resistor, covering the entire fault range of the unit.

Claims

1. A turbine unit braking system, characterized in that: The invention comprises an electromagnetic bearing I, a turbine, a generator, an electromagnetic bearing II, a DC circuit breaker, a generator controller, an electromagnetic bearing controller, a turbine controller, an adjustable resistor, and a main gas regulating valve; the electromagnetic bearing I and the electromagnetic bearing II support the rotors of the turbine and the generator; the turbine controller and the main gas regulating valve are electrically connected to control the switching state of the main gas regulating valve; the main gas regulating valve is arranged at the air inlet of the turbine cylinder; the generator controller is electrically connected to the generator to control the rotation speed and power generation of the generator; the electromagnetic bearing controller is electrically connected to the electromagnetic bearing I and the electromagnetic bearing II to control the suspension or de-suspension of the electromagnetic bearing I and the electromagnetic bearing II to fix the axial and radial positions of the rotors of the turbine and the generator; the adjustable resistor is electrically connected to the generator controller and realizes the on / off control of the current through the DC circuit breaker; the turbine controller is electrically connected to the electromagnetic bearing controller, the turbine controller is electrically connected to the generator controller, the electromagnetic bearing controller is electrically connected to the generator controller, and the turbine controller is electrically connected to the adjustable resistor to realize signal communication during the braking process.

2. The turbine unit braking system according to claim 1, characterized in that: The turbine controller is electrically connected to the emergency stop button.

3. The braking method of the turbine unit braking system according to claim 2, characterized in that: The steps include: 1) During normal operation, the rotors of the turbine and generator are supported on electromagnetic bearings I and II, and the turbine controller, generator controller and electromagnetic bearing controller monitor the working status of the turbine, generator, electromagnetic bearing I and electromagnetic bearing II respectively; 2) When the emergency stop button is pressed or the turbine, generator, electromagnetic bearing I, or electromagnetic bearing II fails, the protective shutdown signal will be transmitted to the turbine controller. After receiving the above signal, the turbine controller first sends a command to disconnect the external load to the external system, and at the same time sends a valve quick closing signal to the main gas regulating valve, and sends a command to switch to the voltage stabilization control mode to the generator controller after a delay of 0.5S; at the same time, the turbine controller sends a braking resistor input command to the adjustable resistor. After receiving the input command, the adjustable resistor immediately sends a closing command to the DC circuit breaker. In this way, after the conversion of the generator controller, its outlet forms a closed-loop DC current, and the kinetic energy of the motor rotor is converted into electrical energy transmitted to the adjustable resistor by the generator controller; 3) During braking, the turbine controller will send a real-time adjustment command of the braking resistor value to the adjustable resistor according to the deceleration slope curve set in the control logic to prevent damage to the rotor of the turbine and generator caused by excessive torque at high power and low speed; 4) When the speed drops to 100 rpm, the turbine controller sends a command to disconnect the braking resistor to the adjustable resistor, and the adjustable resistor then sends a disconnect command to the DC circuit breaker, and the braking process ends.

4. The braking method of the turbine unit braking system according to claim 3, characterized in that: The generator control system mainly composed of the generator controller, the magnetic bearing control system mainly composed of the electromagnetic bearing controller, and the turbine control system mainly composed of the turbine controller are integrated in design. All braking commands are ultimately sent through the turbine controller, which simultaneously controls the action of the main steam regulating valve and the adjustable resistor, covering the entire fault range of the unit.

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