Multi-trigger control type field suppression device of excitation system

Abstract

The utility model discloses a multi-trigger control type field suppression device of an excitation system. The multi-trigger control type field suppression device is composed of a field suppression switch, a switch trigger module, a high-voltage trigger module, a transition diode (BOD) trigger module, a pulse selection module, a voltage acquisition module, a silicon controlled rectifier, a field suppression resistor and a generator rotor winding. According to the utility model, the problem that the rotor is overheated and burnt due to the fact that the de-excitation resistor cannot be put into the de-excitation device of the excitation system of a high-capacity generator and a short-circuit impact generator due to the damage of the rotor diode (BOD) module is solved, the reliable putting of the de-excitation device of the excitation system under various working conditions and fault conditions is ensured, and the reliability of the excitation system is improved. The method is of great significance to safe and reliable operation of a high-capacity generator and a short-circuit impact generator.

Description

Technical Field

[0001] The utility model belongs to the field of static excitation of large-capacity generators and short-circuit generators, and in particular relates to a multi-trigger control type demagnetization device for a generator excitation system. Background Art

[0002] The excitation system is an important component of the synchronous generator. In order to protect the insulation of the generator rotor when it is shut down or fails, a demagnetization device is usually installed in the excitation system to reduce the rotor voltage and quickly release the energy in the rotor. Due to the high rotor voltage of the generator, a turn-on diode (BOD) triggered demagnetization device is often used. The turn-on voltage characteristic of the turn-on diode is used to form a pulse to trigger the thyristor. When the rotor reverse voltage exceeds the turn-on voltage, the demagnetization resistor is put into operation to absorb the energy in the rotor. This demagnetization device is controlled by a turn-on diode. When the turn-on diode fails, the thyristor is turned off and the demagnetization resistor cannot be put into operation, causing the rotor to overheat and burn. The multi-trigger control type demagnetization device of the excitation system of the present application detects the demagnetization switch state and the rotor voltage to form multiple pulses to trigger the thyristor, thereby putting the demagnetization resistor into operation, releasing the rotor energy and improving the safety of the system. Summary of the invention

[0003] The utility model aims to disclose a multi-trigger control type demagnetization device of an excitation system with high redundancy, safety and reliability.

[0004] The technical solution adopted by the utility model is: it is composed of a demagnetization switch, a switch trigger module, a high-voltage trigger module, a breakover diode (BOD) trigger module, a pulse selection module, a voltage acquisition module, a thyristor, a demagnetization resistor and a generator rotor winding. The DC output of the excitation system enters the generator rotor winding through the demagnetization switch, the state of the demagnetization switch is connected to the switch trigger module, the rotor voltage is connected to the high-voltage trigger module and the breakover diode (BOD) trigger module through the voltage acquisition module, the outputs of the switch trigger module, the high-voltage trigger module and the breakover diode (BOD) trigger module all enter the pulse selection module, the pulse selection module output pulse enters the control pole of the thyristor, and the thyristor is connected in series with the demagnetization resistor and then connected in parallel at both ends of the generator rotor winding to form a whole.

[0005] In the multi-trigger controlled demagnetization device of the above-mentioned excitation system, the switch trigger module is composed of a switch detection trigger unit, a double D pulse generating unit, and a pulse transformer. The state of the demagnetization switch enters the switch detection trigger unit, the output of the switch detection trigger unit is connected to the double D pulse generating unit, the output of the double D pulse generating unit is connected to the pulse transformer, and the output of the pulse transformer is the output of the switch trigger module.

[0006] In the multi-trigger control demagnetization device of the above-mentioned excitation system, the high-voltage trigger module is composed of a high-voltage detection voltage divider unit, a voltage conditioning and comparison unit, a voltage trigger unit, and a pulse amplification unit. The rotor voltage enters the high-voltage detection voltage divider unit through the voltage acquisition module, and the output of the high-voltage detection voltage divider unit is connected to the voltage conditioning and comparison unit. The output of the voltage conditioning and comparison unit is connected to the voltage trigger unit. The output of the voltage trigger unit is connected to the pulse amplification unit, and the output of the pulse amplification unit is the output of the high-voltage trigger module.

[0007] In the multi-trigger control demagnetization device of the above-mentioned excitation system, the pulse selection module is composed of a pulse receiving unit and a pulse interlocking unit. The outputs of the switch trigger module, the high-voltage trigger module, and the breakover diode (BOD) trigger module respectively enter the pulse receiving unit, and the output of the pulse receiving unit enters the pulse interlocking unit. The output of the pulse interlocking unit is the output of the pulse selection module.

[0008] The beneficial effects of the utility model are:

[0009] 1. The utility model has a simple structure and strong versatility.

[0010] 2. Adopt demagnetization switch and rotor voltage multi-trigger mode, and each trigger module is put into operation according to different working conditions to improve the service life of the device.

[0011] 3. The demagnetization device is put into use in multiple modes to improve the redundancy of the demagnetization device and ensure the insulation of the generator rotor winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the structural diagram of the multi-trigger control demagnetization device of the excitation system.

[0013] Figure 2 Detailed diagram of the switch trigger module.

[0014] Figure 3 Detailed diagram of the high voltage trigger module.

[0015] Figure 4 Detailed diagram of the pulse selection module.

[0016] Explanation of the marks in the figure: 1-demagnetization switch; 2-switch trigger module; 3-high voltage trigger module; 4-breakover diode (BOD) trigger module; 5-pulse selection module; 6-voltage acquisition module; 7-thyristor; 8-demagnetization resistor; 9-generator rotor winding; 10-switch detection trigger unit; 11-double D pulse generation unit; 12-pulse transformer; 13-high voltage detection voltage divider unit; 14-voltage conditioning comparison unit; 15-voltage trigger unit; 16-pulse amplification unit; 17-pulse receiving unit; 18-pulse interlocking unit. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the examples of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present application.

[0018] like Figure 1 As shown, a multi-trigger control type demagnetization device of an excitation system is composed of a demagnetization switch 1, a switch trigger module 2, a high-voltage trigger module 3, a breakover diode (BOD) trigger module 4, a pulse selection module 5, a voltage acquisition module 6, a thyristor 7, a demagnetization resistor 8 and a generator rotor winding 9. The DC output of the excitation system enters the generator rotor winding 9 through the demagnetization switch 1, the state of the demagnetization switch 1 is connected to the switch trigger module 2, the rotor voltage is connected to the high-voltage trigger module 3 and the breakover diode (BOD) trigger module 4 through the voltage acquisition module 6, the outputs of the switch trigger module 2, the high-voltage trigger module 3 and the breakover diode (BOD) trigger module 4 all enter the pulse selection module 5, the pulse selection module 5 outputs the pulse and enters the control electrode of the thyristor 7, the thyristor 7 is connected in series with the demagnetization resistor 8 and then connected in parallel at both ends of the generator rotor winding 9 to form a whole. The working steps of the demagnetization device of the excitation system are as follows: the switch trigger module 2 generates a trigger pulse when the demagnetization switch 1 is disconnected, the voltage acquisition module 6 samples the rotor voltage and sends it to the high-voltage trigger module 3 and the breakover diode (BOD) trigger module 4, the high-voltage trigger module 3 compares the rotor voltage with the set safety value, and sends a trigger pulse when the rotor voltage is higher than the safety set value. The breakover diode (BOD) trigger module 4 sends a pulse when the rotor voltage reaches the breakover voltage. The pulses of the above three modules are output through the pulse selection module 5 to trigger the thyristor 7, so that the demagnetization resistor 8 and the rotor winding 9 form a closed loop, releasing the energy of the generator rotor winding 9.

[0019] like Figure 2 As shown, the switch trigger module 2 is composed of a switch detection trigger unit 10, a double D pulse generating unit 11, and a pulse transformer 12. The state of the demagnetization switch 1 enters the switch detection trigger unit 10, the output of the switch detection trigger unit 10 is connected to the double D pulse generating unit 11, the output of the double D pulse generating unit 11 is connected to the pulse transformer 12, and the output of the pulse transformer 12 is the output of the switch trigger module 2. When the demagnetization switch 1 is disconnected, the switch detection trigger unit 10 sends a trigger signal, the double D pulse generating unit 11 forms a high-speed pulse train signal, which is amplified and output by the pulse transformer 12, and the output of the pulse selection module 5 triggers the thyristor 7, and the demagnetization resistor 8 is put into use to release the energy of the generator rotor winding 9.

[0020] like Figure 3As shown, the high-voltage trigger module 3 is composed of a high-voltage detection voltage-dividing unit 13, a voltage conditioning and comparison unit 14, a voltage trigger unit 15, and a pulse amplifying unit 16. The rotor voltage enters the high-voltage detection voltage-dividing unit 13 through the voltage acquisition module 6. The output of the high-voltage detection voltage-dividing unit 13 is connected to the voltage conditioning and comparison unit 14. The output of the voltage conditioning and comparison unit 14 is connected to the voltage trigger unit 15. The output of the voltage trigger unit 15 is connected to the pulse amplifying unit 16. The output of the pulse amplifying unit 16 is the output of the high-voltage trigger module 3. The rotor voltage enters the high-voltage detection voltage-dividing unit 13 through the voltage acquisition module 6, and enters the voltage conditioning and comparison unit 14 after being processed by the high-voltage detection voltage-dividing unit 13. When the voltage is higher than the safety threshold set in the voltage conditioning and comparison unit 14, the voltage conditioning and comparison unit 14 outputs a command signal to the voltage trigger unit 15. The voltage trigger unit 15 generates a pulse, which is amplified and output by the pulse amplifying unit 16. The pulse selection module 5 outputs the trigger thyristor 7, which is turned on to the demagnetizing resistor 8 to release the energy of the generator rotor winding 9.

[0021] like Figure 4 As shown, the pulse selection module 5 is composed of a pulse receiving unit 17 and a pulse interlocking unit 18. The outputs of the switch trigger module 2, the high voltage trigger module 3, and the breakover diode (BOD) trigger module 4 enter the pulse receiving unit 17 respectively, and the output of the pulse receiving unit 17 enters the pulse interlocking unit 18. The output of the pulse interlocking unit 18 is the output of the pulse selection module 5. The pulses of the switch trigger module 2, the high voltage trigger module 3, and the breakover diode trigger module 4 are processed by the pulse receiving unit 17 and enter the pulse interlocking unit 18. The pulse interlocking unit 18 selects the fastest response pulse output and locks the pulses of other modules at the same time, ensuring that the output pulse triggers the thyristor 7 and connects the demagnetization resistor 8 to the rotor winding 9 circuit, thereby effectively releasing the energy of the generator rotor winding 9 and protecting the generator rotor insulation.

[0022] The utility model is suitable for the demagnetization device of the excitation system of large-capacity generators and short-circuit generators. It effectively solves the problem of single triggering of previous demagnetization devices through a multi-module triggering mode, improves the redundancy and reliability of the demagnetization device, and ensures the insulation safety of the generator rotor winding.

[0023] Although the basic principle and main features of the utility model are described above in conjunction with the accompanying drawings, technicians in this industry should understand that the above embodiments do not limit the utility model in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the utility model.

Claims

1. A multi-trigger control type demagnetization device for an excitation system, characterized in that: The invention comprises a demagnetization switch (1), a switch trigger module (2), a high-voltage trigger module (3), a breakover diode (BOD) trigger module (4), a pulse selection module (5), a voltage acquisition module (6), a thyristor (7), a demagnetization resistor (8) and a generator rotor winding (9). The DC output of the excitation system enters the generator rotor winding (9) through the demagnetization switch (1), the state of the demagnetization switch (1) is connected to the switch trigger module (2), the rotor voltage is connected to the high-voltage trigger module (3) and the breakover diode (BOD) trigger module (4) through the voltage acquisition module (6), the outputs of the switch trigger module (2), the high-voltage trigger module (3) and the breakover diode (BOD) trigger module (4) all enter the pulse selection module (5), the pulse selection module (5) outputs a pulse and enters the control electrode of the thyristor (7), the thyristor (7) and the demagnetization resistor (8) are connected in series and then connected in parallel to the two ends of the generator rotor winding (9) to form a whole.

2. The multi-trigger control type demagnetization device of the excitation system according to claim 1, characterized in that: The switch trigger module (2) is composed of a switch detection trigger unit (10), a dual D pulse generating unit (11), and a pulse transformer (12); the state of the demagnetization switch (1) enters the switch detection trigger unit (10); the output of the switch detection trigger unit (10) is connected to the dual D pulse generating unit (11); the output of the dual D pulse generating unit (11) is connected to the pulse transformer (12); and the output of the pulse transformer (12) is the output of the switch trigger module (2).

3. The multi-trigger control type demagnetization device of the excitation system according to claim 1, characterized in that: The high-voltage trigger module (3) is composed of a high-voltage detection voltage-dividing unit (13), a voltage conditioning and comparison unit (14), a voltage trigger unit (15), and a pulse amplification unit (16); the rotor voltage enters the high-voltage detection voltage-dividing unit (13) via the voltage acquisition module (6); the output of the high-voltage detection voltage-dividing unit (13) is connected to the voltage conditioning and comparison unit (14); the output of the voltage conditioning and comparison unit (14) is connected to the voltage trigger unit (15); the output of the voltage trigger unit (15) is connected to the pulse amplification unit (16); and the output of the pulse amplification unit (16) is the output of the high-voltage trigger module (3).

4. The multi-trigger control type demagnetization device of the excitation system according to claim 1, characterized in that: The pulse selection module (5) is composed of a pulse receiving unit (17) and a pulse interlocking unit (18); the outputs of the switch trigger module (2), the high voltage trigger module (3) and the breakover diode (BOD) trigger module (4) respectively enter the pulse receiving unit (17); the output of the pulse receiving unit (17) enters the pulse interlocking unit (18); and the output of the pulse interlocking unit (18) is the output of the pulse selection module (5).

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