Hydraulic turbine generator with a starting and stopping circuit
By using an excitation start-stop circuit based on the static action of thyristors and employing a long-term pulse sealing method, the mechanical damage caused by frequent tripping of the DC field circuit breaker in the pumped storage excitation system is solved, thus achieving safe isolation of the excitation system during normal shutdown and standby.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGDIAN NEW ENERGY CO LTD
- Filing Date
- 2024-01-29
- Publication Date
- 2026-06-02
AI Technical Summary
During frequent start-ups and shutdowns, the pumped storage excitation system experiences frequent tripping of the DC field circuit breaker, leading to mechanical damage and affecting the normal start-up and shutdown of the unit.
Design an excitation start-stop circuit based on the static action of thyristors. By using a long-term blocking pulse, the DC field circuit breaker is prevented from tripping during normal shutdown. The blocking state of the thyristor is used as an isolation device to realize the normal shutdown logic of the excitation system.
This effectively avoids mechanical damage to the DC magnetic field circuit breaker caused by frequent start-ups and shutdowns, ensuring that the excitation system does not affect the emergency shutdown process when in standby mode.
Smart Images
Figure CN117997180B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pumped storage power generation technology, specifically to a pumped storage excitation start-stop circuit based on the static action of thyristors. Background Technology
[0002] Whether it is a conventional synchronous generator or a pumped-storage synchronous electric generator, the excitation system is an indispensable and important auxiliary control device.
[0003] Conventional hydroelectric generating units primarily employ a self-excited excitation system, with the excitation transformer connected to the generator side of the generator outlet circuit breaker. Pumped-storage units also typically use a self-excited excitation system during normal operation, except for a short period during startup when a separately excited system is used, where the excitation transformer is connected to the main transformer side of the generator outlet circuit breaker. Figure 1 As shown.
[0004] A self-excited excitation system mainly consists of an excitation transformer (ET), an excitation AC circuit breaker (ACB), an excitation rectifier bridge (SCR), and a DC field circuit breaker (FCB). In a conventional hydroelectric excitation system, during normal shutdown, the excitation transformer (GCB) is first disconnected, followed by inverter de-excitation until the generator voltage is zero. At this point, the high-voltage side of the excitation transformer and the entire excitation main circuit are de-energized, and unless maintenance is required, there is no need to trip the AC or DC circuit breaker. In a pumped-storage excitation system, during normal shutdown, disconnecting the GCB also involves inverter de-excitation until the generator voltage is zero. However, because the high-voltage side of the excitation transformer is connected to the low-voltage side of the main transformer, it remains energized after the GCB is disconnected. Therefore, the entire excitation main circuit remains energized. For isolation and safety reasons, the excitation AC circuit breaker (ACB) or the DC field circuit breaker (FCB) is often disconnected in this situation. Since disconnecting the excitation AC circuit breaker (ACB) while it is energized may generate operational overvoltage, the DC field circuit breaker (FCB) is often disconnected instead. In this case, the excitation rectifier bridge (SCR) is in a blocked state due to the lack of trigger pulses.
[0005] The normal shutdown logic of the pumped-storage excitation system mainly includes a normal shutdown command that starts the excitation regulator inverter, briefly cuts off the thyristor pulse power supply (i.e., briefly blocks the pulse), and finally trips the DC field circuit breaker (FCB), putting the entire excitation system into standby mode until the next startup. Figure 2 As shown. Due to the frequent start-up and shutdown of pumped-storage units, frequent tripping of the DC field circuit breaker often causes mechanical damage to the circuit breaker, ultimately leading to abnormal start-up and shutdown. Therefore, a new logic for tripping the DC field circuit breaker during normal shutdown needs to be designed.
[0006] Given that thyristors are inherently excellent static switches and their blocking state provides effective isolation, a new normal shutdown logic for pumped-storage excitation systems is designed, leveraging the thyristor's blocking state. This logic involves a normal shutdown command that activates the excitation regulator inverter and permanently disconnects the excitation rectifier bridge pulse power supply (i.e., prolonged pulse blocking), preventing the DC field circuit breaker from tripping and putting the entire excitation system into standby mode until the next startup. Figure 2 As shown. Summary of the Invention
[0007] The technical problem to be solved by the present invention is to provide a pumped storage excitation start-stop circuit based on the static action of thyristors to control the start-stop of the pumped storage excitation system and achieve a new logic for normal excitation shutdown, that is, without affecting the emergency shutdown process of the excitation system. The key points of the emergency shutdown process are: the emergency command starts the excitation regulator inverter, immediately puts the demagnetizing resistor on, still briefly blocks the pulse, and quickly trips the DC field circuit breaker.
[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0009] The pumped storage excitation start-stop circuit based on the static effect of thyristors is characterized in that the circuit consists of a DC magnetic field closing circuit, an abnormal shutdown excitation system operation circuit, and a normal shutdown excitation operation circuit.
[0010] The excitation closing and de-excitation switch signal, the monitoring closing and de-excitation switch signal, and the local closing signal are connected in parallel and then connected to the closing contactor coil J1 and the closing control coil J2 in the DC magnetic field circuit breaker FCB through the DC magnetic field closing circuit to realize the closing control of the DC magnetic field circuit breaker FCB.
[0011] The monitoring circuit breaker signal, the relay protection circuit breaker signal, and the local trip signal are connected in parallel and then connected to the trip control coil J3, the abnormal shutdown sealing pulse relay J4, the time-delay sealing pulse relay J5, the demagnetizing jumper relay J6, and the sealing pulse relay J7 / J8 in the DC field circuit breaker FCB through the abnormal shutdown excitation system operation circuit. This enables the demagnetizing jumper of the excitation system to be engaged. The sealing pulse relay J7 / J8 controls the opening and closing of the normally closed contact K7 / K8 of the sealing pulse relay to control the pulse signal of the thyristor of the excitation rectifier bridge SCR.
[0012] The excitation demagnetization switch signal is connected to the normal shutdown energizing operation circuit and the normal shutdown energizing pulse relay J9 to realize the shutdown of the excitation circuit when the demagnetizing jumper is not engaged and the DC field circuit breaker FCB is not turned off.
[0013] The aforementioned pulse relay coils J7 and J8 are connected in parallel, and control the parallel circuit of normally closed contacts K7 and K8 of the pulse relay. One end of the normally closed contacts K7 and K8 of the pulse relay is connected to the positive terminal of the DC24V pulse power supply, and the other end is connected to the pulse amplification unit. The other end of the pulse amplification unit is connected to the pulse transformer in the excitation rectifier bridge SCR and the negative terminal of the DC24V pulse power supply.
[0014] The structure of the DC magnetic field closing circuit described above is as follows:
[0015] One end of the excitation and demagnetization switch signal, the monitoring and demagnetization switch signal, and the local closing signal are connected in parallel to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected in parallel to point A. The normally closed contact K3 of the tripping control coil, the normally closed auxiliary contact C1 of the DC field circuit breaker, and the closing contactor coil J1 are connected in series, and their two ends are connected to point A and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively. The two ends of the normally open contact K11 of the closing contactor and the closing control coil J2 are connected in series, and their two ends are connected to point A and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0016] The above-mentioned abnormal shutdown excitation system operation circuit structure is as follows:
[0017] One end of the monitoring circuit breaker demagnetization switch signal, the relay protection circuit breaker demagnetization switch signal, and the local trip signal are connected in parallel to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected in parallel to point B. The two ends of the auxiliary normally open contact C2 of the DC field circuit breaker and the trip control coil J3 connected in series are respectively connected to point B and the negative terminal of the DC220V DC power supply of the DC field circuit breaker.
[0018] The upper end of the normally closed contact K5 of the time-delayed sealing pulse relay is connected to point B. The lower end of the normally closed contact K5 of the time-delayed sealing pulse relay is connected in series with the parallel circuit of the abnormal shutdown sealing pulse relay coil J4 and the time-delayed sealing pulse relay coil J5. The lower end of the parallel circuit of the abnormal shutdown sealing pulse relay coil J4 and the time-delayed sealing pulse relay coil J5 is connected to the negative terminal of the DC 220V DC power supply of the DC field circuit breaker.
[0019] The two ends of the relay coil J6 of the demagnetizing jumper are connected to point B and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0020] The activation of the demagnetizing jumper and the control of the thyristor pulse signal of the excitation rectifier bridge SCR are controlled by the abnormal shutdown activation pulse relay coil J4, the delayed activation pulse relay coil J5, and the activation demagnetizing jumper relay coil J6.
[0021] The aforementioned abnormal shutdown sealing pulse relay coil J4 controls the opening and closing of the normally open contacts K41 / K42 of the abnormal shutdown sealing pulse relay, and the demagnetizing jumper relay coil J6 controls the opening and closing of the normally open contact K6 of the demagnetizing jumper relay.
[0022] Point B is connected to one end of the normally open contact K41 of the abnormal shutdown sealing pulse relay and the normally open contact K6 of the demagnetizing jumper relay in parallel. The other end of the normally open contact K41 of the abnormal shutdown sealing pulse relay and the normally open contact K6 of the demagnetizing jumper relay in parallel is point D.
[0023] The two ends of the demagnetizing jumper are connected to point D and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0024] The upper end of the normally open contact K42 of the abnormal shutdown sealing pulse relay is connected to point D. The lower end of the normally open contact K42 of the abnormal shutdown sealing pulse relay is connected to one end of the sealing pulse relay coils J7 and J8 connected in parallel. The other end of the sealing pulse relay coils J7 and J8 connected in parallel is connected to the negative terminal of the DC220V DC power supply of the DC field circuit breaker.
[0025] The above-mentioned normal shutdown excitation operation circuit structure is as follows:
[0026] The excitation demagnetization switch signal is connected in parallel with the normally open contact K91 of the normal shutdown sealing pulse relay. The two ends of the parallel connection are respectively connected to the positive terminal of the DC220V DC power supply of the DC field circuit breaker and point C.
[0027] The normally open contact K92 of the normal shutdown sealing pulse relay is connected at both ends to point C and the upper ends of the normally closed contacts K7 and K8 of the sealing pulse relay, respectively.
[0028] The normally closed contact K12 of the closing contactor is connected in series with the coil J9 of the normal shutdown sealing pulse relay. The two ends are connected to point C and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0029] The aforementioned pumped storage excitation start-stop circuit operates on the pumped storage excitation system, which consists of an excitation transformer ET, an excitation AC circuit breaker ACB, an excitation rectifier bridge SCR, and a DC field circuit breaker FCB connected in series. The high-voltage side of the excitation transformer ET is connected to the upper end of the generator outlet circuit breaker GCB.
[0030] This invention provides a pumped storage excitation start-stop circuit based on the static action of thyristors. By using a method of prolonged interruption of the thyristor pulse power supply (i.e., prolonged pulse blocking), it can effectively solve the problem of mechanical damage to the circuit breaker caused by frequent tripping of the DC field circuit breaker due to excessively frequent start-stop of the pumped storage unit. Since the thyristor itself is a very good static switch and its blocking state is a very good isolation device, a new normal shutdown logic for pumped storage excitation is designed by taking advantage of the thyristor blocking state. That is, the normal shutdown command starts the excitation regulator inverter and disconnects the excitation rectifier bridge pulse power supply for a long time, i.e., prolonged pulse blocking, without tripping the DC field circuit breaker, so that the entire excitation system enters a standby state until the next start-up. Attached Figure Description
[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0032] Figure 1 This is a schematic diagram of the main circuit of the excitation system in this invention;
[0033] Figure 2 This is the logic diagram of the DC field circuit breaker tripping function in this invention.
[0034] Figure 3 This is a circuit diagram of the start-stop control circuit for the excitation system of the present invention.
[0035] The components include: DC 220V DC power supply for the DC magnetic field circuit breaker, DC magnetic field circuit breaker FCB, auxiliary normally closed / normally open contacts C1 / C2 for the DC magnetic field circuit breaker, closing contactor coil J1, normally open contact K11 for the closing contactor, normally closed contact K12 for the closing contactor, closing control coil J2, opening control coil J3, normally closed contact K3 for the opening control coil, abnormal shutdown activation pulse relay coil J4, normally open contact K41 / K42 for the abnormal shutdown activation pulse relay, delayed activation pulse relay coil J5, normally closed contact K5 for the delayed activation pulse relay, activation demagnetizing jumper relay coil J6, normally open contact K6 for the activation demagnetizing jumper relay, activation pulse relay J7 / J8, normally closed contact K7 / K8 for the activation pulse relay, normal shutdown activation pulse relay coil J9, normally open contact K91 / K92 for the normal shutdown activation pulse relay, and DC 24V pulse power supply. Detailed Implementation
[0036] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.
[0037] like Figures 1-3 As shown in the figure, the pumped storage excitation start-stop circuit based on the static effect of thyristors is characterized in that the circuit consists of a DC magnetic field closing circuit, an abnormal shutdown excitation system operation circuit, and a normal shutdown excitation operation circuit.
[0038] The excitation closing and de-excitation switch signal, the monitoring closing and de-excitation switch signal, and the local closing signal are connected in parallel and then connected to the closing contactor coil J1 and the closing control coil J2 in the DC magnetic field circuit breaker FCB through the DC magnetic field closing circuit to realize the closing control of the DC magnetic field circuit breaker FCB.
[0039] The monitoring circuit breaker signal, the relay protection circuit breaker signal, and the local trip signal are connected in parallel and then connected to the trip control coil J3, the abnormal shutdown sealing pulse relay J4, the time-delay sealing pulse relay J5, the demagnetizing jumper relay J6, and the sealing pulse relay J7 / J8 in the DC field circuit breaker FCB through the abnormal shutdown excitation system operation circuit. This enables the demagnetizing jumper of the excitation system to be engaged. The sealing pulse relay J7 / J8 controls the opening and closing of the normally closed contact K7 / K8 of the sealing pulse relay to control the pulse signal of the thyristor of the excitation rectifier bridge SCR.
[0040] The excitation demagnetization switch signal is connected to the normal shutdown energizing operation circuit and the normal shutdown energizing pulse relay J9 to realize the shutdown of the excitation circuit when the demagnetizing jumper is not engaged and the DC field circuit breaker FCB is not turned off.
[0041] The aforementioned pulse relay coils J7 and J8 are connected in parallel, and control the parallel circuit of normally closed contacts K7 and K8 of the pulse relay. One end of the normally closed contacts K7 and K8 of the pulse relay is connected to the positive terminal of the DC24V pulse power supply, and the other end is connected to the pulse amplification unit. The other end of the pulse amplification unit is connected to the pulse transformer in the excitation rectifier bridge SCR and the negative terminal of the DC24V pulse power supply.
[0042] The structure of the DC magnetic field closing circuit described above is as follows:
[0043] One end of the excitation and demagnetization switch signal, the monitoring and demagnetization switch signal, and the local closing signal are connected in parallel to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected in parallel to point A. The normally closed contact K3 of the tripping control coil, the normally closed auxiliary contact C1 of the DC field circuit breaker, and the closing contactor coil J1 are connected in series, and their two ends are connected to point A and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively. The two ends of the normally open contact K11 of the closing contactor and the closing control coil J2 are connected in series, and their two ends are connected to point A and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0044] The above-mentioned abnormal shutdown excitation system operation circuit structure is as follows:
[0045] One end of the monitoring circuit breaker demagnetization switch signal, the relay protection circuit breaker demagnetization switch signal, and the local trip signal are connected in parallel to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected in parallel to point B. The two ends of the auxiliary normally open contact C2 of the DC field circuit breaker and the trip control coil J3 connected in series are respectively connected to point B and the negative terminal of the DC220V DC power supply of the DC field circuit breaker.
[0046] The upper end of the normally closed contact K5 of the time-delayed sealing pulse relay is connected to point B. The lower end of the normally closed contact K5 of the time-delayed sealing pulse relay is connected in series with the parallel circuit of the abnormal shutdown sealing pulse relay coil J4 and the time-delayed sealing pulse relay coil J5. The lower end of the parallel circuit of the abnormal shutdown sealing pulse relay coil J4 and the time-delayed sealing pulse relay coil J5 is connected to the negative terminal of the DC 220V DC power supply of the DC field circuit breaker.
[0047] The two ends of the relay coil J6 of the demagnetizing jumper are connected to point B and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0048] The activation of the demagnetizing jumper and the control of the thyristor pulse signal of the excitation rectifier bridge SCR are controlled by the abnormal shutdown activation pulse relay coil J4, the delayed activation pulse relay coil J5, and the activation demagnetizing jumper relay coil J6.
[0049] The aforementioned abnormal shutdown sealing pulse relay coil J4 controls the opening and closing of the normally open contacts K41 / K42 of the abnormal shutdown sealing pulse relay, and the demagnetizing jumper relay coil J6 controls the opening and closing of the normally open contact K6 of the demagnetizing jumper relay.
[0050] Point B is connected to one end of the normally open contact K41 of the abnormal shutdown sealing pulse relay and the normally open contact K6 of the demagnetizing jumper relay in parallel. The other end of the normally open contact K41 of the abnormal shutdown sealing pulse relay and the normally open contact K6 of the demagnetizing jumper relay in parallel is point D.
[0051] The two ends of the demagnetizing jumper are connected to point D and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0052] The upper end of the normally open contact K42 of the abnormal shutdown sealing pulse relay is connected to point D. The lower end of the normally open contact K42 of the abnormal shutdown sealing pulse relay is connected to one end of the sealing pulse relay coils J7 and J8 connected in parallel. The other end of the sealing pulse relay coils J7 and J8 connected in parallel is connected to the negative terminal of the DC220V DC power supply of the DC field circuit breaker.
[0053] The above-mentioned normal shutdown excitation operation circuit structure is as follows:
[0054] The excitation demagnetization switch signal is connected in parallel with the normally open contact K91 of the normal shutdown sealing pulse relay. The two ends of the parallel connection are respectively connected to the positive terminal of the DC220V DC power supply of the DC field circuit breaker and point C.
[0055] The normally open contact K92 of the normal shutdown sealing pulse relay is connected at both ends to point C and the upper ends of the normally closed contacts K7 and K8 of the sealing pulse relay, respectively.
[0056] The normally closed contact K12 of the closing contactor is connected in series with the coil J9 of the normal shutdown sealing pulse relay. The two ends are connected to point C and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively.
[0057] The aforementioned pumped storage excitation start-stop circuit operates on the pumped storage excitation system, which consists of an excitation transformer ET, an excitation AC circuit breaker ACB, an excitation rectifier bridge SCR, and a DC field circuit breaker FCB connected in series. The high-voltage side of the excitation transformer ET is connected to the upper end of the generator outlet circuit breaker GCB.
[0058] Example:
[0059] A novel logic and circuit for normal shutdown of pumped storage excitation based on the static effect of thyristors, such as... Figure 2 , Figure 3 This includes: DC 220V DC power supply for the DC magnetic field circuit breaker, DC magnetic field circuit breaker FCB, auxiliary normally closed / normally open contacts C1 / C2 for the DC magnetic field circuit breaker, closing contactor J1, normally open contact K11 for the closing contactor, normally closed contact K12 for the closing contactor, closing control coil J2, opening control coil J3, normally closed contact K3 for the opening coil, abnormal shutdown activation pulse relay J4, normally open contact K41 / K42 for the abnormal shutdown activation pulse relay, time-delayed pulse relay J5, and normally closed contact of the time-delayed pulse relay. The circuit breaker consists of contact K5, a demagnetizing jumper relay J6, a normally open contact of the demagnetizing jumper relay K6, a blocking pulse relay J7 / J8, a normally closed contact of the blocking pulse relay K7 / K8, a normal shutdown blocking pulse relay J9, a normally open contact of the normal shutdown blocking pulse relay K91 / K92, and a pulse power supply of DC24V. The DC field circuit breaker FCB is composed of auxiliary contacts C1 / C2 of the DC field circuit breaker, a closing contactor J1, a normally open contact of the closing contactor K11, a closing control coil J2, and a tripping control coil J3.
[0060] When the excitation and demagnetization switch, the monitoring and demagnetization switch, or the local closing switch are activated, one end of the normally closed contact K3 of the trip coil is connected to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected to the auxiliary normally closed contact C1 of the DC field circuit breaker. The other end of the auxiliary normally closed contact C1 of the DC field circuit breaker is connected to the negative terminal of the DC220V DC power supply of the DC field circuit breaker. One end of the normally open contact K11 of the closing contactor is connected to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected to the closing control coil J2. The other end of the closing control coil J2 is connected to the negative terminal of the DC220V DC power supply of the DC field circuit breaker.
[0061] When a monitoring command for the demagnetizing switch, a relay protection command for the demagnetizing switch, or a local tripping command is issued, one end of the normally open auxiliary contact C2 of the DC magnetic field circuit breaker is connected to the positive DC220V terminal of the DC power supply of the DC magnetic field circuit breaker, and the other end is connected to the tripping control coil J3. The other end of the tripping control coil J3 is connected to the negative DC220V terminal of the DC power supply of the DC magnetic field circuit breaker. One end of the normally closed contact K5 of the time-delayed sealing pulse relay is connected to the positive DC220V terminal of the DC power supply of the DC magnetic field circuit breaker, and the other end is connected to the abnormal shutdown sealing pulse relay J4 and the time-delayed sealing pulse relay J5. The abnormal shutdown sealing pulse relay J4 and the time-delayed sealing pulse relay J5 are connected in parallel. Both the abnormal shutdown sealing pulse relay J4 and the time-delayed sealing pulse relay J5 are connected to the negative terminal of the DC power supply of the DC magnetic field circuit breaker. One end of the demagnetizing jumper relay J6 is connected to the positive DC power supply of the DC magnetic field circuit breaker, and the other end... The abnormal shutdown locking pulse relay normally open contact K41 is connected to the negative terminal of the DC power supply of the DC field circuit breaker. One end of K41 is connected to the positive terminal of the DC power supply of the DC field circuit breaker, and the other end is connected to the demagnetizing jumper and the normally open contact K6 of the demagnetizing jumper relay. The normally open contact K41 and the normally open contact K6 of the demagnetizing jumper relay are connected in parallel. The other end of the demagnetizing jumper is connected to the negative terminal of the DC power supply of the DC field circuit breaker. The abnormal shutdown locking pulse relay normally open contact K42 is connected to the normally open contact K41 and the normally open contact K6 of the demagnetizing jumper relay, and the other end is connected to two locking pulse relays J7 / J8 and the normally open contact K92 of the normal shutdown locking pulse relay. The two locking pulse relays J7 / J8 are connected in parallel. The other end of the two locking pulse relays J7 / J8 is connected to the negative terminal of the DC power supply of the DC field circuit breaker.
[0062] When the excitation demagnetization switch is activated, one end of the normally closed contact K12 of the closing contactor is connected to the positive terminal of the DC power supply of the DC field circuit breaker and the normally open contact K91 / K92 of the normal shutdown sealing pulse relay. The normally open contacts K91 and K92 of the normal shutdown sealing pulse relay are connected in series. The other end of the normally closed contact K12 of the closing contactor is connected to the normal shutdown sealing pulse relay J9. The other end of the normal shutdown sealing pulse relay J9 is connected to the negative terminal of the DC power supply of the DC field circuit breaker.
[0063] One end of the normally open contact K91 of the normal shutdown sealing pulse relay is connected to the positive terminal of the DC power supply of the DC field circuit breaker, and the other end is connected to the normally open contact K92 of the normal shutdown sealing pulse relay. The other end of the normally open contact K92 of the normal shutdown sealing pulse relay is connected to the normally open contact K42 of the abnormal shutdown sealing pulse relay and two sealing pulse relays J7 / J8. The other end of the two sealing pulse relays J7 / J8 is connected to the negative terminal of the DC power supply of the DC field circuit breaker.
[0064] The two normally closed contacts K7 / K8 of the pulse relay are connected in parallel. One end is connected to the positive terminal of the pulse power supply DC24V, and the other end is connected to the pulse amplification unit. The other end of the pulse amplification unit is connected to the pulse transformer and the negative terminal of the pulse power supply DC24V.
[0065] The following describes the working principle of the new logic and circuit for normal shutdown of pumped storage excitation based on the static effect of thyristors provided in the embodiments of the present invention:
[0066] In this circuit, the DC 220V DC power supply of the DC magnetic field circuit breaker, the auxiliary normally closed contact C1 of the DC magnetic field circuit breaker, the closing contactor J1, the normally open contact K11 of the closing contactor, the closing control coil J2, and the normally closed contact K3 of the opening coil constitute the DC magnetic field closing circuit. When the excitation closing command, the monitoring closing command, or the local closing command is given, the closing circuit is activated, the closing contactor J1 operates, the normally open contact K11 of the closing contactor closes, the closing control coil J2 is energized, and the DC magnetic field circuit breaker FCB closes. At this time, the auxiliary normally closed contact C1 of the DC magnetic field circuit breaker opens, the auxiliary normally open contact C2 of the DC magnetic field circuit breaker closes, and the normally closed contact K12 of the closing contactor in the opening circuit is turned off, so that the opening circuit can be locked out when the DC magnetic field circuit breaker FCB is in the closed state, to ensure the normal operation of the excitation system.
[0067] Furthermore, in this circuit, the DC 220V DC power supply of the DC field circuit breaker, the normally open auxiliary contact C2 of the DC field circuit breaker, the tripping control coil J3, the abnormal shutdown activation pulse relay J4, the normally open contact K41 / K42 of the abnormal shutdown activation pulse relay, the time-delayed activation pulse relay J5, the normally closed contact K5 of the time-delayed activation pulse relay, the demagnetizing jumper relay J6, the normally open contact K6 of the demagnetizing jumper relay, the demagnetizing pulse relay J7 / J8, the normally closed contact K7 / K8 of the demagnetizing pulse relay, and the DC 24V pulse power supply constitute the abnormal shutdown excitation system operation circuit; the DC field circuit breaker FCB, consisting of the auxiliary contacts C1 / C2 of the DC field circuit breaker, the closing contactor J1, the normally open contact K11 of the closing contactor, the closing control coil J2, and the tripping control coil J3, constitutes the local tripping, relay protection tripping demagnetizing switch, and monitoring tripping demagnetizing switch circuit; when the monitoring tripping demagnetizing switch commands... Upon receiving a command from the demagnetizing switch or a local tripping command, the DC field circuit breaker's auxiliary normally open contact C2 closes, energizing the tripping control coil J3 and causing the DC field circuit breaker FCB to trip. At this time, the abnormal shutdown blocking pulse relay J4, the time-delay blocking pulse relay J5, and the jumper relay J6 are energized. The normally open contacts K41 / K42 of the abnormal shutdown blocking pulse relay close, the normally closed contact K5 of the time-delay blocking pulse relay opens after 60 seconds, the normally open contact K6 of the demagnetizing jumper relay closes, the blocking pulse relays J7 / J8 are energized, and the normally closed contacts K7 / K8 of the blocking pulse relay open. At this point, the excitation system engages the demagnetizing jumper and blocks the thyristor pulse signal. Meanwhile, the normally closed contact K3 of the tripping coil in the closing circuit opens, allowing the closing circuit to be locked out when the DC field circuit breaker FCB is in the tripping state, ensuring the normal operation of the excitation system.
[0068] Furthermore, in this circuit, the normal shutdown energizing pulse relay J9, the normally open contact K91 / K92 of the normal shutdown energizing pulse relay, the normally closed contact K12 of the closing contactor, the energizing pulse relay J7 / J8, the normally closed contact K7 / K8 of the energizing pulse relay, and the DC24V pulse power supply constitute the normal shutdown excitation operation circuit. When the excitation de-energizing switch commands, the normal shutdown energizing pulse relay J9 is energized, the normally open contact K91 / K92 of the normal shutdown energizing pulse relay closes, the energizing pulse relay J7 / J8 is energized, the normally closed contact K7 / K8 of the energizing pulse relay opens, and the thyristor trigger pulse signal is turned off. At this time, the excitation system does not engage the jumper and does not turn off the DC field circuit breaker FCB. Instead, it uses a long-term energizing pulse to turn off the thyristor, thereby turning off the excitation circuit.
[0069] Optionally, the DC power supply voltage of the DC field circuit breaker is 220V, and the pulse power supply is 24V.
[0070] In summary, the embodiments of the present invention provide a new logic and circuit for normal shutdown of pumped storage excitation based on the static action of thyristors. Since the thyristor itself is a very good static switch and its blocking state is a very good isolation device, the DC field circuit breaker is kept from tripping during normal shutdown by utilizing the blocking state of the thyristor. By changing the normal shutdown logic of the pumped storage excitation system, and using a method of long-term interruption of the thyristor pulse power supply (long-term pulse blocking) instead of tripping the DC field circuit breaker during normal shutdown, the mechanical damage to the circuit breaker caused by frequent tripping of the DC field circuit breaker due to the frequent start-up and shutdown of the pumped storage unit can be effectively solved.
Claims
1. A pumped-storage excitation start-stop circuit based on the static action of a thyristor, characterized in that, The excitation closing and de-excitation switch, the monitoring closing and de-excitation switch, and the local closing switch are connected in parallel and then connected at point A to the closing contactor coil J1 and the closing control coil J2 inside the DC field circuit breaker FCB to realize the closing control of the DC field circuit breaker FCB. The monitoring circuit breaker, relay protection circuit breaker, and local circuit breaker are connected at point B to the tripping control coil J3, abnormal shutdown blocking pulse relay coil J4, time-delay blocking pulse relay coil J5, demagnetizing jumper relay coil J6, and blocking pulse relay coil J7 / J8 in the DC field circuit breaker FCB. This enables the activation of the excitation system demagnetizing jumper. The blocking pulse relay J7 / J8 controls the opening and closing of the normally closed switch K7 / K8 to control the pulse signal of the excitation rectifier bridge SCR blocking thyristor. The excitation demagnetization switch is connected to the coil J9 of the normal shutdown sealing pulse relay at point C to achieve the shutdown of the excitation circuit when the excitation system is not engaged by the demagnetization jumper and the DC field circuit breaker FCB is not turned off. The excitation and demagnetization switches, the monitoring and demagnetization switches, and the local closing switch are connected in parallel at one end to the positive terminal of the DC220V DC power supply of the DC field circuit breaker, and the other end is connected in parallel to point A; the normally closed switch K3 of the opening control coil, the normally closed auxiliary switch C1 of the DC field circuit breaker, and the closing contactor coil J1 are connected in series at both ends to point A and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively; the normally open switch K11 of the closing contactor and the closing control coil J2 are connected in series at both ends to point A and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively. The monitoring demagnetizing switch, the relay protection demagnetizing switch and the local trip switch are connected in parallel at one end to the positive terminal of the DC 220V DC power supply of the DC field circuit breaker, and the other end is connected in parallel to point B. The two ends of the auxiliary normally open switch C2 of the DC field circuit breaker and the tripping control coil J3 connected in series are respectively connected to point B and the negative terminal of the DC220V DC power supply of the DC field circuit breaker; The upper end of the normally closed switch K5 of the time-delayed sealing pulse relay is connected to point B. The lower end of the normally closed switch K5 of the time-delayed sealing pulse relay is connected in series with the parallel circuit of the abnormal shutdown sealing pulse relay coil J4 and the time-delayed sealing pulse relay coil J5. The lower end of the parallel circuit of the abnormal shutdown sealing pulse relay coil J4 and the time-delayed sealing pulse relay coil J5 is connected to the negative terminal of the DC 220V DC power supply of the DC field circuit breaker. The two ends of the relay coil J6 of the demagnetizing jumper are connected to point B and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively. The activation of the demagnetizing jumper and the control of the thyristor pulse signal of the excitation rectifier bridge SCR are controlled by the abnormal shutdown activation pulse relay coil J4, the delayed activation pulse relay coil J5, and the activation demagnetizing jumper relay coil J6. The excitation demagnetization switch is connected in parallel with the normally open switch J91 of the normal shutdown sealing pulse relay, and the two ends of the parallel connection are respectively connected to the positive terminal of the DC220V DC power supply of the DC field circuit breaker and point C. During normal shutdown, the upper and lower ends of the normally open switch J92 of the sealing pulse relay are connected to point C and the upper ends of the sealing pulse relay coils J7 and J8 in parallel, respectively. The normally closed switch K12 of the closing contactor and the coil J9 of the normal shutdown sealing pulse relay are connected in series at point C and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively. The described pulse relay coils J7 and J8 are connected in parallel and control the parallel circuit of normally closed switches K7 and K8 of the pulse relay. One end of the normally closed switches K7 and K8 of the pulse relay is connected to the positive terminal of the pulse power supply DC24V, and the other end is connected to the pulse amplification unit. The other end of the pulse amplification unit is connected to the pulse transformer in the excitation rectifier bridge SCR and the negative terminal of the pulse power supply DC24V. The abnormal shutdown sealing pulse relay coil J4 controls the opening and closing of the normally open switch K41 / K42 of the abnormal shutdown sealing pulse relay, and the demagnetizing jumper relay coil J6 controls the opening and closing of the normally open switch K6 of the demagnetizing jumper relay. Point B is connected to one end of the normally open switch K41 of the abnormal shutdown sealing pulse relay and the normally open switch K6 of the demagnetizing jumper relay in parallel. The other end of the normally open switch K41 of the abnormal shutdown sealing pulse relay and the normally open switch K6 of the demagnetizing jumper relay in parallel is point D. The two ends of the demagnetizing jumper are connected to point D and the negative terminal of the DC220V DC power supply of the DC field circuit breaker, respectively. The upper end of the normally open switch K42 of the abnormal shutdown sealing pulse relay is connected to point D, and the lower end of the normally open switch K42 of the abnormal shutdown sealing pulse relay is connected to one end of the parallel connection of sealing pulse relay coils J7 and J8. The other end of the parallel connection of sealing pulse relay coils J7 and J8 is connected to the negative terminal of the DC220V DC power supply of the DC field circuit breaker.
2. The pumped-storage excitation start-stop circuit based on the static action of a thyristor according to claim 1, characterized in that, The pumped storage excitation start-stop circuit operates on the pumped storage excitation system, which consists of an excitation transformer ET, an excitation AC circuit breaker ACB, an excitation rectifier bridge SCR, and a DC field circuit breaker FCB connected in series. The high-voltage side of the excitation transformer ET is connected to the upper end of the generator outlet circuit breaker GCB.