Locking device applied to synchronizing device

Abstract

The utility model relates to the field of synchronizing devices, in particular to a locking device applied to a synchronizing device, which comprises a coil end and a contact end. The coil end is connected to a joint between the microcomputer multifunctional synchronization meter and the line selector, and is respectively connected with the system side three-phase line and the to-be-merged side three-phase line through the line selector; the contact end is connected with a contact of the closing relay and is connected with a line selector through the contact of the closing relay; and two ends of a contact of the synchronous blocking relay are connected with a contact of the single-side non-voltage relay and a contact of the double-side non-voltage relay, so that the situation of non-synchronous closing is reduced, the operation stability and safety of a power generation system are improved, and the accuracy of single-side non-voltage closing and double-side non-voltage closing is not influenced.

Description

Technical Field

[0001] The utility model relates to the field of synchronization devices, in particular to a locking device applied to a synchronization device. Background Art

[0002] With the growth of power demand, the existing power generation system is difficult to continue to support. Therefore, it is necessary to add new power generation equipment to the existing power generation system to increase the power supply capacity. When adding new power generation equipment (i.e., equipment to be grid-connected), in order to reduce the impact on the stability of the power generation system, the prior art usually adopts the method of synchronous paralleling to connect the equipment to be grid-connected with the existing power generation system. Among them, synchronous paralleling means that two AC power supplies are connected when the voltage amplitude, frequency, and phase are the same or similar. In the prior art, a synchronization device is used to detect the grid frequency, voltage amplitude, and voltage phase on both sides of the connection point. When the frequency difference, phase difference, and voltage difference on both sides of the connection point are all within the preset threshold range, it indicates that both sides of the connection point are in synchronization and grid connection can be performed. Otherwise, both sides of the connection point are asynchronous. Therefore, the prior art uses a synchronization device to assist manual closing and grid connection or achieve automatic closing and grid connection.

[0003] However, in on-site operation, when the closing relay of the existing synchronization device malfunctions and closes by mistake, it may lead to the situation of asynchronous closing and grid connection, bringing risks to the stability and safety of the operation of the power generation system. Therefore, the existing synchronization device is difficult to avoid the situation of asynchronous closing, reducing the operation stability of the power generation system. Summary of the Utility Model

[0004] An embodiment of the utility model discloses a locking device applied to a synchronization device, which is used to reduce the situation of asynchronous closing in the synchronization device.

[0005] An embodiment of the utility model provides a locking device applied to a synchronization device. The synchronization device includes an automatic quasi-synchronization device, a line selector, and a microcomputer multi-functional synchroscope. The automatic quasi-synchronization device is connected to the line selector, the line selector is connected to the microcomputer multi-functional synchroscope. The automatic quasi-synchronization device, the line selector, and the microcomputer multi-functional synchroscope are respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be paralleled. Both ends of the line selector are connected to the coil of the closing relay and are respectively connected to the DC power supply. The line selector is connected to the change-over switch and the contact of the closing relay. The line selector and the microcomputer multi-functional synchroscope are both connected to the contacts of the single-side no-voltage relay and the double-side no-voltage relay. It is characterized in that the locking device includes: a synchronization locking relay.

[0006] The synchronization locking relay includes a coil end and a contact end.

[0007] The coil end is connected to the connection point between the microcomputer multi-functional synchroscope and the line selector, and is respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be paralleled through the line selector;

[0008] The contact end is connected to the contact of the closing relay and is connected to the line selector through the contact of the closing relay;

[0009] Both ends of the contact of the synchronization blocking relay are connected to the contact of the single-sided no-voltage relay and the contact of the double-sided no-voltage relay.

[0010] Optionally, the coil end includes a first coil end and a second coil end;

[0011] The first coil end is connected to the three-phase lines on the system side through the line selector;

[0012] The second coil end is connected to the three-phase lines on the side to be paralleled through the line selector.

[0013] Optionally, the contact of the closing relay includes a first closing contact and a second closing contact;

[0014] One end of the first closing contact is connected to the change-over switch;

[0015] The other end of the first closing contact is respectively connected to one end of the contact of the synchronization blocking relay and the contact of the double-sided no-voltage relay;

[0016] The other end of the contact of the synchronization blocking relay and the contact of the double-sided no-voltage relay are respectively connected to one end of the second closing contact; the other end of the second closing contact is connected to the change-over switch;

[0017] The contact of the single-sided no-voltage relay is connected to both ends of the contact of the synchronization blocking relay.

[0018] Optionally, the change-over switch includes a first change-over switch and a second change-over switch;

[0019] The other end of the second closing contact is connected to the first change-over switch;

[0020] The first change-over switch is connected to the second change-over switch;

[0021] The second change-over switch is connected to the line selector and is connected to one end of the first closing contact.

[0022] Optionally, the contact of the single-sided no-voltage relay includes a first single-sided contact, a second single-sided contact, a third single-sided contact, and a fourth single-sided contact;

[0023] Both ends of the first single-sided contact are respectively connected to both ends of the contact of the synchronous locking relay;

[0024] One end of the second single-sided contact is connected to the line selector, and the other end of the second single-sided contact is connected to the DC power supply;

[0025] One end of the third single-sided contact is connected to the microcomputer multi-functional synchroscope; the other end of the third single-sided contact is connected to the DC power supply.

[0026] Optionally, the contacts of the double-sided no-voltage relay include a first double-sided contact, a second double-sided contact, and a third double-sided contact;

[0027] Both ends of the first double-sided contact are respectively connected to both ends of the first closing contact;

[0028] One end of the second double-sided contact is connected to the line selector, and the other end of the second double-sided contact is connected to the DC power supply;

[0029] One end of the third double-sided contact is connected to the microcomputer multi-functional synchroscope; the other end of the third double-sided contact is connected to the DC power supply.

[0030] Optionally, the synchronization device further includes a third change-over switch;

[0031] One side of the third change-over switch is connected to the DC power supply;

[0032] The other side of the third change-over switch is connected to the distributed control system, the coil of the single-sided no-voltage relay, the coil of the double-sided no-voltage relay, and the DC power supply;

[0033] The distributed control system is respectively connected to the coil of the single-sided no-voltage relay and the coil of the double-sided no-voltage relay.

[0034] Optionally, the model of the synchronous locking relay includes SID-2SJ.

[0035] Optionally, the model of the closing relay includes ZJY-220.

[0036] Optionally, the single-sided no-voltage relay and the double-sided no-voltage relay are intermediate relays.

[0037] It can be seen from the above technical solutions that the embodiments of the present utility model have the following advantages:

[0038] An embodiment of the present utility model provides a locking device applied to a synchronization device. The synchronization device includes an automatic quasi-synchronization device, a line selector, and a microcomputer multi-functional synchroscope. The automatic quasi-synchronization device is connected to the line selector, the line selector is connected to the microcomputer multi-functional synchroscope, the automatic quasi-synchronization device, the line selector, and the microcomputer multi-functional synchroscope are respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be paralleled. The two ends of the line selector are connected to the coil of the closing relay and are respectively connected to the DC power supply. The line selector is connected to the change-over switch and the contact of the closing relay. The line selector and the microcomputer multi-functional synchroscope are both connected to the contacts of the single-side no-voltage relay and the double-side no-voltage relay. The locking device includes: a synchronization locking relay. The synchronization locking relay includes a coil end and a contact end. The coil end is connected to the connection point between the microcomputer multi-functional synchroscope and the line selector, and is respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be paralleled through the line selector. The coil end is connected to the contact of the closing relay and is connected to the line selector through the contact of the closing relay. The two ends of the contact of the synchronization locking relay are connected to the contacts of the single-side no-voltage relay and the double-side no-voltage relay.

[0039] In the present utility model, the coil end of the synchronization locking relay is connected to the connection point between the line selector and the microcomputer multi-functional synchroscope, for monitoring the voltage, phase angle, and frequency of the three-phase lines on the system side and the three-phase lines on the side to be paralleled. The contact end of the synchronization locking relay is connected to the contact of the closing relay and is connected to the line selector through the contact of the closing relay, so that the contact of the synchronization locking relay is connected into the closing circuit of the existing synchronization device. Thus, when the system side and the side to be paralleled meet the synchronization conditions, the contact of the synchronization locking relay closes, enabling the circuit between the contact of the closing relay and the line selector to be normally conducted, and thus normal synchronization closing can be achieved. When the system side and the side to be paralleled do not meet the synchronization conditions (i.e., non-synchronization), the contact of the synchronization locking relay does not act and remains in the normally open state, so that the circuit between the contact of the closing relay and the line selector is in the open state. In this case, even if the closing relay malfunctions and closes, since the circuit between the contact of the closing relay and the line selector is in the open state, the two sides of the connection point cannot be normally paralleled, thus avoiding the situation of non-synchronization closing and paralleling. Moreover, in the present utility model, the contacts of the single-side no-voltage relay and the double-side no-voltage relay are connected in parallel at both ends of the contact of the synchronization locking relay, so that when there is a single-side no-voltage situation or a double-side no-voltage situation on the system side and the paralleling side, the closing circuit can be normally conducted, realizing single-side no-voltage closing and paralleling or double-side no-voltage closing and paralleling, and avoiding the interference of the new connection structure between the synchronization locking relay and the closing coil on the normal closing operations of single-side no-voltage closing and double-side no-voltage closing, further enhancing the stability of the operation of the power generation system.

[0040] Therefore, the present utility model constructs a connection structure among a synchronization locking relay, a line selector, a closing relay, a single-side no-voltage relay, and a double-side no-voltage relay, which can reduce the situation of out-of-synchronization closing, improve the operation stability and safety of the power generation system, and maintain the accuracy of single-side no-voltage closing and double-side no-voltage closing. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Figure 1 FIG. 1 is one of the schematic structural diagrams of a locking device applied to a synchronization device provided in an embodiment of the present utility model;

[0043] Figure 2 FIG. 2 is another schematic structural diagram of a locking device applied to a synchronization device provided in an embodiment of the present utility model;

[0044] Figure 3 FIG. 3 is one of the schematic principle diagrams of a locking device applied to a synchronization device provided in an embodiment of the present utility model;

[0045] Figure 4 FIG. 4 is another schematic principle diagram of a locking device applied to a synchronization device provided in an embodiment of the present utility model;

[0046] Figure 5 FIG. 5 is one of the schematic principle diagrams of a synchronization device provided in an embodiment of the present utility model;

[0047] Figure 6 FIG. 6 is another schematic principle diagram of a synchronization device provided in an embodiment of the present utility model;

[0048] Figure 7 FIG. 7 is a third schematic principle diagram of a synchronization device provided in an embodiment of the present utility model;

[0049] Figure 8 FIG. 8 is the schematic structural diagram of a closing relay provided in an embodiment of the present utility model;

[0050] Figure 9 FIG. 9 is the schematic structural diagram of a synchronization locking relay provided in an embodiment of the present utility model;

[0051] Figure 10 FIG. 10 is the schematic structural diagram of a single-side no-voltage relay provided in an embodiment of the present utility model;

[0052] Figure 11 It is a schematic structural diagram of a bilateral non-pressure relay provided in an embodiment of the present utility model;

[0053] Figure 12 It is a schematic structural diagram of a locking device applied to a synchronization device provided in another embodiment of the present utility model;

[0054] Figure 13 It is a schematic structural diagram of a locking device applied to a synchronization device provided in still another embodiment of the present utility model. Specific embodiments

[0055] The present utility model provides a locking device applied to a synchronization device, which is used to reduce the situation of non-synchronous closing in the synchronization device.

[0056] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0057] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "front", "rear", "upper", "lower", "two ends", "center", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. The relational terms such as "first" and "second" are only used to distinguish one entity from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities.

[0058] Unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", "fixation", "setting" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0059] Please refer to Figure 1, an embodiment of a blocking device applied to a synchronization device provided in an embodiment of the present utility model. The present utility model is an improvement based on the structure of the existing synchronization device. To clearly illustrate the improvement of this embodiment, this embodiment first introduces the existing synchronization device. In the actual operation process, the conventional working process of the existing synchronization device is as follows: after the synchronization device enters the synchronization working state, it first performs self-check on the device. If the self-check fails, the device alarms and enters the blocking state. After the self-check passes, the device checks the input quantity. If the input quantity or the TV voltage does not meet the conditions, the device alarms and enters the blocking state; if the input quantity is normal, the device outputs a "ready" signal. At this time, if the "start synchronization work" signal is valid, the device outputs a "start synchronization" output signal and determines the synchronization mode. The possible synchronization modes include single-side no-voltage closing, double-side no-voltage closing, same-frequency grid connection, and different-frequency grid connection; after determining the synchronization mode, it enters the synchronization process. During the synchronization process, if an abnormal situation occurs (such as when not closing the grid with no-voltage, the system side or the side to be connected has no voltage, synchronization timeout, etc.), the device alarms and enters the blocking state; when the synchronization closing condition is met, the device issues a closing command to complete the synchronization operation; when synchronizing the generator, if the frequency difference or the voltage difference exceeds the set value and frequency modulation and voltage regulation are allowed, the device issues a frequency modulation or voltage regulation control command to quickly meet the synchronization conditions.

[0060] Among them, the existing synchronization device includes: an automatic quasi-synchronization device 1, a line selector 2, and a microcomputer multi-functional synchroscope 3; the automatic quasi-synchronization device 1 is connected to the line selector 2, the line selector 2 is connected to the microcomputer multi-functional synchroscope 3, the automatic quasi-synchronization device 1, the line selector 2, and the microcomputer multi-functional synchroscope 3 are respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be connected, the two ends of the line selector 2 are connected to the coil of the closing relay 4 and are respectively connected to the DC power supply 5; the line selector 2 is connected to the change-over switch 6 and the contacts of the closing relay 4; the line selector 2 and the microcomputer multi-functional synchroscope 3 are both connected to the contacts of the single-side no-voltage relay 7 and the contacts of the double-side no-voltage relay 8.

[0061] Among them, the automatic synchronization device 1 uses the existing synchronization device SID-2FY of Guoli Intelligent, which has the function of automatically identifying the parallel connection point for grid connection, that is, automatically identifying whether it is differential frequency grid connection or same frequency grid connection (loop closing) currently. During differential frequency grid connection, it can accurately determine the grid connection timing and complete shock-free grid connection when the phase angle difference is zero. The microcomputer multi-functional synchroscope 3 uses SID-2SL-A of Guoli Intelligent, which can be used to receive single-side no-voltage confirmation signal, double-side no-voltage confirmation signal, parallel connection point signal input, AC sampling signal input of the three-phase line on the system side, and AC sampling signal input of the three-phase line on the side to be paralleled. And the microcomputer multi-functional synchroscope 3 can also be used to indicate the current phase difference during differential frequency grid connection, and indicate the current power angle during same frequency grid connection, and also has the function of selecting single-side no-voltage closing or double-side no-voltage closing. The line selector 2 uses the existing line selector 2SID-2X-B-8 of Guoli Intelligent, which can realize automatic line selection for 8 synchronization point signals and support remote control line selection or manual line selection. The change-over switch 6 is used to provide test function and working function, and provide manual control, automatic control and switching function.

[0062] The synchronization device composed of the automatic synchronization device 1, the line selector 2, and the microcomputer multi-functional synchroscope 3 is respectively connected to the three-phase line on the system side and the three-phase line on the side to be paralleled, and is used to detect the voltage, phase, and frequency at both ends of the system side and the side to be paralleled (that is, both ends of the parallel connection point) to monitor whether the parallel connection point at both ends meets the synchronization conditions. After the synchronization device enters the synchronization working state, the automatic synchronization device 1 judges whether there are synchronization modes such as single-side no-voltage, double-side no-voltage, same frequency grid connection, and differential grid connection at the parallel connection point currently, and performs corresponding actions according to the synchronization mode. Among them, the line selector 2, the closing relay 4, and the change-over switch 6 constitute the closing loop of the synchronization device. When the parallel connection point at both sides meets the synchronization conditions of differential frequency grid connection or same frequency grid connection, the contacts of the closing relay 4 close, the closing loop conducts, and the automatic synchronization device performs the grid connection operation. When the parallel connection point at both sides meets the single-side no-voltage condition or the double-side condition, the single-side no-voltage relay 7 is energized and conducts or the double-side no-voltage relay 8 is energized and conducts, and the contacts of the closing relay 4 close, realizing single-side no-voltage closing and double-side no-voltage closing.

[0063] Based on the above existing system structure, the blocking device provided in this embodiment includes: a synchronization blocking relay 9; the synchronization blocking relay 9 includes a coil end and a contact end; the coil end is connected to the connection between the microcomputer multi-functional synchroscope 3 and the line selector 2, and is respectively connected to the three-phase line on the system side and the three-phase line on the side to be paralleled through the line selector 2; the contact end is connected to the contact of the closing relay 4 and is connected to the line selector 2 through the contact of the closing relay 4; both ends of the contact of the synchronization blocking relay 9 are connected to the contact of the single-side no-voltage relay 7 and the contact of the double-side no-voltage relay 8.

[0064] In this embodiment, the synchronization blocking relay 9 uses the existing digital synchronization checking relay SID-2SJ product of Guoli Intelligence. It has the functions of monitoring the voltages, phase angles, and frequencies of the three-phase lines on the system side and the three-phase lines on the incoming side, can monitor whether the two sides of the connection point meet the synchronization conditions, and has the function of setting the setting values of the allowable voltage difference, allowable frequency difference, and allowable phase angle difference. When the voltage difference (i.e., the voltage difference value) between the system side and the incoming side exceeds the allowable voltage difference setting value, the frequency difference (frequency difference value) exceeds the allowable frequency difference setting value, and the phase angle difference (phase angle difference value) exceeds the allowable frequency difference setting value, the contacts of the synchronization blocking relay 9 will automatically conduct, indicating that the two sides of the connection point meet the synchronization conditions and differential grid connection or same-frequency grid connection can be carried out. Therefore, the synchronization blocking relay 9 in this embodiment has the function of monitoring whether the two sides of the connection point meet the synchronization conditions. The structure of the synchronization blocking relay 9 is as Figure 9 shown.

[0065] In this embodiment, the coil of the synchronization blocking relay 9 is connected to the connection points between the line selector 2 and the microcomputer multifunction meter. Among them, the terminals in the line selector 2 for connecting the three-phase lines on the system side and the three-phase lines on the incoming side are connected to the terminals in the microcomputer multifunction meter for connecting the three-phase lines on the system side and the three-phase lines on the incoming side, and the coil of the synchronization blocking relay 9 is specifically connected to the connection point between these two terminals for receiving the voltages, frequencies, and phase angles of the system side and the incoming side.

[0066] In this embodiment, the contact end of the synchronization blocking relay 9 is connected to the contacts of the closing relay 4 and is connected to the line selector 2 through the contacts of the closing relay 4, so that the contacts of the synchronization blocking relay 9 are connected in series to the closing circuit of the existing synchronization device. Thus, when the system side and the incoming side meet the synchronization and paralleling conditions, the contacts of the synchronization blocking relay 9 and the contacts of the closing relay 4 are closed simultaneously, enabling the circuit between the contacts of the closing relay 4 and the line selector 2 to be normally conducted, and normal synchronization closing can be achieved. When the two sides of the connection point do not meet the synchronization conditions (i.e., non-synchronization), the contacts of the synchronization blocking relay 9 are in the normally open state, so that the circuit between the contacts of the closing relay 4 and the line selector 2 is in the open state. In this case, even if the closing relay 4 malfunctions and closes, since the circuit between the contacts of the closing relay 4 and the line selector 2 is in the open state, the two sides of the connection point cannot be normally grid-connected, thus avoiding the occurrence of non-synchronization closing and grid connection.

[0067] Moreover, in this embodiment, the contacts of the single-sided no-voltage relay 7 and the contacts of the double-sided no-voltage relay 8 are connected in parallel across the contacts of the synchronization locking relay 9, so that when single-sided no-voltage or double-sided no-voltage occurs in the system, normal closing can be achieved, avoiding interference with single-sided no-voltage closing and double-sided no-voltage closing. Therefore, by constructing the connection structure between the synchronization locking relay 9 and the line selector 2, closing relay 4, single-sided no-voltage relay 7, and double-sided no-voltage relay 8, the present utility model can reduce the situation of non-synchronous closing, improve the stability and safety of the power generation system operation, and does not affect the accuracy of single-sided no-voltage closing and double-sided no-voltage closing.

[0068] In a specific embodiment, the coil ends include a first coil end and a second coil end;

[0069] The first coil end is connected to the three-phase lines on the system side through the line selector;

[0070] The second coil end is connected to the three-phase lines on the side to be paralleled through the line selector.

[0071] It should be noted that as Figure 4 shown, Q1 is the line selector, TBB is the microcomputer multi-functional synchroscope, SYS-UA is the A-phase line on the system side, SYS-UB is the B-phase line or N-phase line on the system side, GEN-UA is the A-phase line on the side to be paralleled, GEN-UB is the B-phase line or N-phase line on the side to be paralleled, TJJ is the synchronization locking relay. 1KJ is the single-sided no-voltage relay, 2KJ is the double-sided no-voltage relay. JK1-1 to JK1-14, JK3-1 to JK3-18, etc. all represent the terminals of the microcomputer multi-functional synchroscope. JK1-1 to JK1-14, JK3-1 to JK3-18, etc. all represent the terminals of the microcomputer multi-functional synchroscope. JK6-1 to JK6-8, JK7B-1 to JK7B-4, etc. all represent the terminals of the line selector.

[0072] For the existing line selector, JK7B-1 and JK7B-2 are respectively used to connect to SYS-UA and SYS-UB; JK7B-3 and JK7B-4 of the line selector are respectively used to connect to GEN-UA and GEN-UB. Among them, JK1-1 and JK1-2 in the microcomputer multi-functional synchroscope are respectively connected to JK7B-1 and JK7B-2 to receive the voltage, frequency, and phase angle of the system side, and JK1-3 and JK1-4 in the microcomputer multi-functional synchroscope are respectively connected to JK7B-3 and JK7B-4 to receive the voltage, frequency, and phase angle of the side to be paralleled.

[0073] The 2-terminal and 4-terminal of the first coil of the synchro-blocking relay in this embodiment are respectively connected to the connection points between JK7B-3, JK7B-4 and JK1-3, JK1-4, and the 6-terminal and 8-terminal of the second coil of the synchro-blocking relay are respectively connected to the connection points between JK1-1, JK1-2 and JK7B-1, JK7B-2.

[0074] In a specific embodiment, the contacts of the closing relay include a first closing contact and a second closing contact;

[0075] One end of the first closing contact is connected to the transfer switch;

[0076] The other end of the first closing contact is respectively connected to one end of the contact of the synchro-blocking relay and the contact of the double-sided no-voltage relay;

[0077] The other end of the contact of the synchro-blocking relay and the contact of the double-sided no-voltage relay are respectively connected to one end of the second closing contact; the other end of the second closing contact is connected to the transfer switch;

[0078] The contact of the single-sided no-voltage relay is connected to both ends of the contact of the synchro-blocking relay.

[0079] As Figure 2 shown, HJ represents the closing relay, TJJ represents the synchro-blocking relay, 1KJ represents the single-sided no-voltage relay, and 2KJ represents the double-sided no-voltage relay. Among them, the 2-terminal and 10-terminal of the first closing contact of the closing relay are connected to the 1-terminal and 3-terminal of the contact of the synchro-blocking relay, the 3-terminal of the contact of the synchro-blocking relay is connected to the 9-terminal of the second closing contact, the 11-terminal and 14-terminal of the contact of the single-sided no-voltage relay are respectively connected to the 1-terminal and 3-terminal of the contact of the synchro-blocking relay, the 11-terminal of the contact of the double-sided no-voltage relay is connected to the 10-terminal of the first closing contact and is connected to the 1-terminal of the contact of the synchro-blocking relay, and the 14-terminal of the contact of the double-sided no-voltage relay is connected to the 9-terminal of the second closing contact and is connected to the 3-terminal of the contact of the synchro-blocking relay. Therefore, the contacts of the single-sided no-voltage relay and the double-sided no-voltage relay are connected in parallel to the contact of the synchro-blocking relay.

[0080] In a specific embodiment, the transfer switch includes a first transfer switch 62 and a second transfer switch 61;

[0081] The other end of the second closing contact is connected to the first transfer switch 62;

[0082] The first transfer switch 62 is connected to the second transfer switch 61;

[0083] The second transfer switch 61 is connected to the line selector and is connected to one end of the first closing contact.

[0084] It should be noted that, as Figure 2 shown, the line selector 2 is connected to the second change-over switch 61, the first change-over switch 62 is connected to the second closing contact, and the second change-over switch 61 is connected to the first closing contact.

[0085] The second change-over switch 61 is a change-over switch of Siemens model LW39-16B-6KC-6909 / 6, which provides the switching functions of automatic closing, manual closing, and withdrawal from closing. When it is switched to automatic closing, the line selector can trigger the closing of the contact of the closing relay according to the received closing instruction to achieve closing. When it is switched to manual closing, if the manual closing button is pressed, the line selector will trigger the closing of the contact of the closing relay to achieve manual closing. The first change-over switch 62 provides the working function and the testing function. When in the working function, it indicates that the system is in the working state. When in the testing function, the synchronization device can be tested.

[0086] In an application example, the schematic diagram of the line selector is as Figure 3 shown, Figure 3 where Q1 is the line selector, D TK is the second change-over switch, G TK is the first change-over switch, KM+ and KM- are respectively the positive and negative poles of the DC power supply. 1ZK is the DC air switch. WY is the third change-over switch, DCS is the distributed control system, and 1AN to 8AN represent the paralleling points 1 to 8 selected by the DCS. JK1B, JK3, JK4, JK7B, etc. respectively represent the terminals of the line selector. The rectangular frames indicated by 1KJ, 2KJ, and HJ respectively represent the coils of the single-side no-voltage relay, the double-side no-voltage relay, and the closing relay.

[0087] As Figure 3As shown, terminals 1 to 4, 7, 9, and 12 to 20 of the second transfer switch are connected to the line selector. Terminal 2 of the first closing contact of the closing relay is connected to terminal 8 of the second transfer switch. Terminal 10 of the first closing contact is connected to terminal 1 of the contact of the synchronization blocking relay. Terminal 3 of the synchronization blocking relay is connected to terminal 9 of the second closing contact. Terminal 1 of the second closing contact is connected to terminal 4 of the first transfer switch. Terminal 3 of the first transfer switch is connected to terminal 10 of the second transfer switch. Therefore, the contact of the synchronization blocking relay is connected in series to the closing circuit of the first closing contact, the second closing contact, the first transfer switch, the second transfer switch, and the line selector. Based on this structure, when the contacts of the synchronization blocking relay, the first closing contact, and the second closing contact are all conducting, the closing circuit can conduct normally for synchronization and grid connection. When the synchronization relay detects non-synchronization on both sides of the connection point, the contact of the synchronization relay does not operate and remains normally open. At this time, even if the closing relay performs a non-synchronization closing, since the contact of the synchronization relay is in an open state, the closing circuit cannot conduct normally, thus avoiding the situation of non-synchronization closing in the existing synchronization device and improving the stability and safety of the operation of the power generation system.

[0088] In a specific embodiment, the contacts of the single-sided no-voltage relay include a first single-sided contact, a second single-sided contact, a third single-sided contact, and a fourth single-sided contact;

[0089] Both ends of the first single-sided contact are respectively connected to both ends of the contact of the synchronization blocking relay;

[0090] One end of the second single-sided contact is connected to the line selector, and the other end of the second single-sided contact is connected to the DC power supply;

[0091] One end of the third single-sided contact is connected to the microcomputer multi-functional synchroscope; the other end of the third single-sided contact is connected to the DC power supply.

[0092] In a specific embodiment, the contacts of the double-sided no-voltage relay include a first double-sided contact, a second double-sided contact, and a third double-sided contact;

[0093] Both ends of the first double-sided contact are respectively connected to both ends of the first closing contact;

[0094] One end of the second double-sided contact is connected to the line selector, and the other end of the second double-sided contact is connected to the DC power supply;

[0095] One end of the third double-sided contact is connected to the microcomputer multi-functional synchroscope; the other end of the third double-sided contact is connected to the DC power supply.

[0096] It should be noted that in this embodiment, the first single-sided contact that is idle in the existing single-sided no-voltage relay is connected in parallel at both ends of the contact of the synchronization locking relay, and both ends of the idle first double-sided contact of the existing double-sided no-voltage relay are connected in parallel at both ends of the contact of the synchronization locking relay. Thus, when a single-sided no-voltage or double-sided no-voltage situation occurs, the closing circuit can be normally conducted for grid connection operation, avoiding the problem that the newly added synchronization locking relay interferes with single-sided no-voltage closing or double-sided no-voltage closing, and further improving the stability and safety of the operation of the power generation system.

[0097] Specifically, as Figure 3 shown, 1L5~21 represents the line nodes from 1L5 to 1L21, and 1L23~24 and 1L51~56 are the same as 1L5~21.

[0098] The 11-end and 14-end of the first single-sided contact are respectively connected to the 1-end and 3-end of the contact of the synchronization locking relay. The 24-end of the second single-sided contact is connected to the JK3-1 end of the line selector. The 21-end of the second single-sided contact is connected to the DC air switch 1ZK through the line node 1L21, and is connected to the positive pole KM+ of the DC power supply through the DC control switch 1ZK. The 44-end of the third single-sided contact is connected to the JK3-13 end of the microcomputer multi-functional synchroscope, and the 41-end of the third single-sided contact is connected to the DC air switch 1ZK through the line node 1L6, and is connected to the positive pole KM+ of the DC power supply through the DC control switch 1ZK.

[0099] The 11-end and 14-end of the first double-sided contact are respectively connected to the 10-end and 9-end of the first closing contact, and are connected in parallel at the 1-end and 3-end of the contact of the synchronization locking relay. The 24-end of the second double-sided contact is connected to the JK3-2 end of the line selector. The 21-end of the second double-sided contact is connected to the DC air switch 1ZK through the line node 1L21, and is connected to the positive pole KM+ of the DC power supply through the DC control switch 1ZK. The 44-end of the third double-sided contact is connected to the JK3-14 end of the microcomputer multi-functional synchroscope, and the 41-end of the third double-sided contact is connected to the DC air switch 1ZK through the line node 1L7, and is connected to the positive pole KM+ of the DC power supply through the DC control switch 1ZK.

[0100] In a specific embodiment, the synchronization device further includes a third change-over switch;

[0101] One side of the third change-over switch is connected to the DC power supply;

[0102] The other side of the third change-over switch is connected to the distributed control system, the coil of the single-sided no-voltage relay, the coil of the double-sided no-voltage relay, and the DC power supply;

[0103] The distributed control system is respectively connected to the coil of the single-sided no-voltage relay and the coil of the double-sided no-voltage relay.

[0104] It should be noted that the third change-over switch WY can adopt the change-over switch of Siemens model LW39-16B-6KC-121J / 2. The distributed control system DCS is a part of the existing power generation system.

[0105] Specifically, as Figure 3 shown, the contact 2, contact 4, and contact 6 of the third change-over switch are connected to the line node 1L7, and are connected to the DC air switch 1ZK through the line node 1L7, and are connected to the positive pole KM+ of the DC power supply through the DC control switch 1ZK. The terminal 1 of the third change-over switch is connected to the A1 terminal of the coil of the single-sided no-voltage relay through the line node 1L25. The A2 terminal of the coil of the single-sided no-voltage relay is connected to the line node 1L52, and is connected to the DC air switch 1ZK through the line node 1L52, and is connected to the negative pole KM- of the DC power supply through the DC control switch 1ZK. The contact 5 of the third change-over switch is connected to the line node 1L23, and is respectively connected to the single-sided no-voltage confirmation control switch and the double-sided no-voltage confirmation control switch of the distributed control system DCS through the line node 1L23. Among them, the single-sided no-voltage confirmation control switch is connected to the A1 terminal of the coil of the single-sided no-voltage relay, and the double-sided no-voltage confirmation control switch is connected to the line nodes 1L27-28, and is connected to the A1 terminal of the coil of the double-sided no-voltage relay through the line nodes 1L27-28. The contact 3 of the third change-over switch is connected to the A1 terminal of the coil of the double-sided no-voltage relay, and the A2 terminal 1L52 of the coil of the double-sided no-voltage relay is connected to the DC air switch 1ZK, and is connected to the negative pole KM- of the DC power supply through the DC control switch 1ZK.

[0106] Among them, the third change-over switch is used to switch the monitoring mode, and the conduction conditions of its respective contacts are shown in Table 1.

[0107] Table 1

[0108]

[0109] As shown in Table 1, × indicates conduction, and the arrow indicates the rotation direction of the switch. The monitoring modes include the single-sided no-voltage monitoring mode, the synchronization monitoring mode, and the double-sided no-voltage monitoring mode. Among them, the synchronization monitoring includes differential grid connection monitoring and same-frequency grid connection monitoring. When switching to the single-sided no-voltage monitoring mode, the contacts 1-2 of the third change-over switch are conducted. When switching to the double-sided no-voltage monitoring mode, the contacts 3-4 of the third change-over switch are conducted. When switching to the synchronization monitoring mode, the contacts 5-6 and contacts 7-8 of the third change-over switch are conducted.

[0110] The single-sided no-voltage confirmation control switch and the double-sided no-voltage confirmation control switch are controlled by a distributed control system. When it is determined that there is no voltage on one side, the distributed control system closes the single-sided no-voltage confirmation control switch, making the circuit between the coil of the single-sided no-voltage relay and the DC power supply conducting, causing the coil of the single-sided no-voltage relay to be energized, triggering the contacts of the single-sided no-voltage relay to close. At the same time, the automatic synchronization device sends a synchronization closing signal to the line selector, and the line selector closes the control switch connected to the closing coil HJ, making the coil of the closing relay energized and the contacts of the closing relay conducting. And because the closing contacts in the closing circuit are conducting and the contacts of the single-sided no-voltage relay connected in parallel with the contacts of the synchronization blocking relay are conducting, the entire closing circuit is conducting, so that grid connection can be carried out normally. The double-sided no-voltage is the same as the single-sided no-voltage, which will not be elaborated here. Among them, the connection relationship between the automatic synchronization device 1 and the line selector 2 can be referred to Figure 5 。 Figure 5 In which, Z1 represents the automatic synchronization device 1, and Q1 represents the line selector. The connection relationship between the line selector and the distributed control system can be referred to Figure 6 , and the connection relationship between the automatic synchronization device and the distributed control system can be referred to Figure 7 , the connection relationships among the automatic synchronization device, the line selector, the distributed control system, and the microcomputer multi-functional synchroscope are all prior arts. Therefore, it will not be elaborated here.

[0111] Therefore, in this embodiment, by connecting the contacts of the synchronization blocking relay in series between the two contacts of the closing relay, the situation that the closing relay closes accidentally when non-synchronization occurs can be avoided. And by connecting the contacts of the single-sided no-voltage relay and the double-sided no-voltage relay in parallel at both ends of the contacts of the synchronization blocking relay, when there is no voltage on one side or both sides at the connection point, the system can still close normally, avoiding the interference of the newly added synchronization blocking relay on the single-sided no-voltage closing and the double-sided no-voltage closing.

[0112] In a specific embodiment, the model of the closing relay includes ZJY-220.

[0113] It should be noted that the structure of the closing relay and the connection relationships of each end of the closing relay can be referred to Figure 8 。

[0114] In a specific embodiment, the single-sided no-voltage relay and the double-sided no-voltage relay are intermediate relays.

[0115] It should be noted that the single-sided no-voltage relay and the double-sided no-voltage relay selected are CR-M2200C4L of ABB. The structures of the single-sided no-voltage relay and the double-sided no-voltage relay can be referred to Figures 10 - 11 。

[0116] As a further improvement, in a preferred embodiment, one end of the contact of the synchronization blocking relay is connected to the automatic synchronization device.

[0117] It should be noted that the automatic synchronization device is connected to one end of the contact of the synchronization blocking relay and is used to monitor the on-off state of the synchronization blocking relay. When the automatic synchronization device determines that both sides of the connection point meet the synchronization conditions and detects that the contact of the synchronization blocking relay is closed, the automatic synchronization device outputs a synchronization closing signal to the line selector, and the line selector triggers the contact of the closing relay to close after receiving the synchronization closing signal.

[0118] In this embodiment, by constructing the connection between the contact of the synchronization blocking relay and the automatic synchronization device, when both sides of the connection point meet the synchronization conditions, the automatic synchronization device outputs a closing signal to conduct the contact of the closing relay after detecting that the contact of the synchronization blocking relay is closed, thereby further avoiding the situation of non-synchronous closing and further improving the stability and safety of the operation of the power generation system.

[0119] Specifically, as Figure 12 shown, connect the 3 terminal of the contact of the synchronization blocking relay to the JK9-16 terminal of the automatic synchronization device. When the contact of the synchronization blocking relay is closed, the automatic synchronization device monitors the corresponding signal through the JK9-16 terminal, thereby realizing the monitoring of the state of the contact of the synchronization blocking relay.

[0120] As a further improvement, in another preferred embodiment, refer to Figure 13 , the synchronization blocking relay further includes another contact, and the distributed control system DCS is connected to both ends of the other contact of the synchronization blocking relay.

[0121] As Figure 13 shown, in this embodiment, the 5 terminal and the 7 terminal of the other contact of the synchronization blocking relay are connected to the distributed control system DCS. When the synchronization blocking relay detects that both sides of the connection point meet the synchronization conditions, it closes its own two pairs of contacts. Therefore, the distributed control system DCS is connected to the 5 terminal and the 7 terminal of the other contact of the synchronization blocking relay. When this contact is closed, the distributed control system DCS receives the corresponding electrical signal, indicating that the synchronization blocking relay detects that both sides of the connection point meet the synchronization conditions and has performed the corresponding closing action. Based on the connection relationship between the other contact of the synchronization blocking relay and the distributed control system constructed in this embodiment, the staff can use the distributed control system DCS to monitor the operating state of the synchronization blocking relay and can terminate the synchronization paralleling by using the distributed control system DCS when necessary, so as to further improve the stability and safety of the operation of the power generation system.

[0122] In an application scenario, based on the connection relationship between the distributed control system (DCS) in the prior art and the line selector and the automatic synchronization device, and combined with the connection relationship between the distributed control system (DCS) constructed in this embodiment and the synchronization blocking relay, the situation of out-of-synchronization closing can be further avoided.

[0123] As Figure 7 shown, the distributed control system (DCS) is connected to the closing signal output terminal of the automatic synchronization device and is connected to the emergency termination synchronization input terminal of the line selector.

[0124] Among them, the distributed control system (DCS) is connected to the closing signal output terminal of the automatic synchronization device for receiving the closing signal of the automatic synchronization device. The distributed control system (DCS) is connected to the emergency termination synchronization input terminal of the line selector and can be used to send an emergency termination synchronization signal to the line selector to cause the line selector to terminate the synchronization paralleling.

[0125] As Figure 7 shown, the closing signal output terminal JK9-2 of the automatic synchronization device is connected to the distributed control system (DCS). As Figure 3 shown, one end of the emergency termination synchronization switch of the distributed control system (DCS) is connected to terminal 6 of JK3 of the line selector, and the other end is connected to the positive pole KM+ of the DC power supply. Among them, the emergency termination synchronization switch is controlled by the distributed control system (DCS). When emergency termination of synchronization is required, the distributed control system (DCS) closes the emergency termination synchronization switch, so that the JK3-6 terminal of the line selector obtains a high-level signal, causing the line selector to perform the action of terminating the synchronization.

[0126] Therefore, in this application scenario, by setting the distributed control system (DCS), when the distributed control system (DCS) only receives the signals transmitted by the automatic synchronization device or the synchronization blocking relay, it outputs a synchronization inconsistency warning and outputs a termination synchronization signal to the line selector to avoid the situation of out-of-synchronization closing caused by the malfunction of the closing relay.

[0127] In an application example, the advantages of the synchro-blocking relay further include: the synchro conditions on both sides of the paralleling point are indicated in a digital manner, with good visualization effect; moreover, the synchro-blocking relay can obtain power through the PT without an additional external power supply; also, the secondary voltage of the TV input to the synchro-blocking relay can be phase voltage or line voltage, and if there are different rated operating voltages due to gear differences, adaptive correction can be performed through parameter setting; furthermore, if there is an inherent phase angle difference between the voltages on both sides of the synchro-blocking relay, correction can be made by separately setting the rotation angle of the system-side voltage for each paralleling point; also, the synchro-blocking relay can separately set the allowable voltage difference, allowable frequency difference, and allowable angle difference. When the voltage difference, frequency difference, and phase angle difference exceed the allowable values, the contacts of the synchro-blocking relay act to automatically block the closing circuit.

[0128] Among them, the working principle of the synchro-blocking relay is as follows: The synchro-blocking relay can set condition judgments, where the conditions can include: (1) Angle difference allowed: The real-time phase angle difference between the system side and the side to be paralleled is within the parameter value of the "synchronization allowable angle" set; (2) Voltage difference allowed: The real-time voltage difference between the system side and the side to be paralleled is within the parameter value of the "allowable voltage difference", and setting the parameter value of "allowable voltage difference" to 0 means not considering the condition of allowable voltage difference; (3) Frequency difference allowed: The real-time frequency difference between the system side and the side to be paralleled is within the parameter value of the "allowable voltage difference", and setting the parameter value of "allowable frequency difference" to 0 means not considering the condition of allowable frequency difference. The synchro-blocking relay can set the conditions for the contacts to act, which can be set as (angle difference allowed) && (voltage difference allowed) && (frequency difference allowed), where "&&" means that the front and rear conditions are both satisfied. When the two sides of the paralleling point do not meet the above condition nodes, it returns, that is, the synchro-blocking relay does not act.

[0129] The above has introduced in detail a blocking device applied to a synchro device provided by the present utility model. For those of ordinary skill in the art, according to the idea of the embodiments of the present utility model, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A blocking device applied to a synchronization device, the synchronization device comprising an automatic quasi-synchronization device, a line selector, and a microcomputer multi-functional synchroscope; the automatic quasi-synchronization device is connected to the line selector, the line selector is connected to the microcomputer multi-functional synchroscope, the automatic quasi-synchronization device, the line selector, and the microcomputer multi-functional synchroscope are respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be paralleled, both ends of the line selector are connected to the coil of a closing relay and are respectively connected to a DC power supply; the line selector is connected to a changeover switch and the contacts of the closing relay; the line selector and the microcomputer multi-functional synchroscope are both connected to the contacts of a single-side no-voltage relay and the contacts of a double-side no-voltage relay, characterized in that, The latching device includes: a synchronization latching relay; The synchronization latching relay includes a coil terminal and a contact terminal; The coil terminal is connected to the connection point between the microcomputer multi-functional synchroscope and the line selector, and is respectively connected to the three-phase lines on the system side and the three-phase lines on the side to be paralleled through the line selector; The contact terminal is connected to the contact of the closing relay, and is connected to the line selector through the contact of the closing relay; Both ends of the contact of the synchronization latching relay are connected to the contact of the single-side no-voltage relay and the contact of the double-side no-voltage relay.

2. The latching device according to claim 1, characterized in that, The coil terminal includes a first coil terminal and a second coil terminal; The first coil terminal is connected to the three-phase lines on the system side through the line selector; The second coil terminal is connected to the three-phase lines on the side to be paralleled through the line selector.

3. The latching device according to claim 1, wherein, The contact of the closing relay includes a first closing contact and a second closing contact; One end of the first closing contact is connected to the change-over switch; The other end of the first closing contact is respectively connected to one end of the contact of the synchronization latching relay and the contact of the double-side no-voltage relay; The other end of the contact of the synchronization latching relay and the contact of the double-side no-voltage relay are respectively connected to one end of the second closing contact; the other end of the second closing contact is connected to the change-over switch; The contact of the single-side no-voltage relay is connected to both ends of the contact of the synchronization latching relay.

4. The latching device according to claim 3, characterized in that, The change-over switch includes a first change-over switch and a second change-over switch; The other end of the second closing contact is connected to the first change-over switch; The first change-over switch is connected to the second change-over switch; The second change-over switch is connected to the line selector and is connected to one end of the first closing contact.

5. The latching device according to claim 3, characterized in that, The contact of the single-side no-voltage relay includes a first single-side contact, a second single-side contact, a third single-side contact, and a fourth single-side contact; Both ends of the first single-side contact are respectively connected to both ends of the contact of the synchronization latching relay; One end of the second single-side contact is connected to the line selector, and the other end of the second single-side contact is connected to the DC power supply; One end of the third single-side contact is connected to the microcomputer multi-functional synchroscope; The other end of the third single-side contact is connected to the DC power supply.

6. The latching device according to claim 3, characterized in that, The contact of the double-side no-voltage relay includes a first double-side contact, a second double-side contact, and a third double-side contact; Both ends of the first double-side contact are respectively connected to both ends of the first closing contact; One end of the second double-side contact is connected to the line selector, and the other end of the second double-side contact is connected to the DC power supply; One end of the third double-side contact is connected to the microcomputer multi-functional synchroscope; The other end of the third double-side contact is connected to the DC power supply.

7. The latching device according to claim 3, characterized in that, The synchronization device further includes a third change-over switch; One side of the third change-over switch is connected to the DC power supply; The other side of the third change-over switch is connected to the distributed control system, the coil of the single-side no-voltage relay, the coil of the double-side no-voltage relay, and the DC power supply; The distributed control system is respectively connected to the coil of the single-side no-voltage relay and the coil of the double-side no-voltage relay.

8. The latching device according to claim 1, characterized in that, The model of the synchronization blocking relay includes SID-2SJ.

9. The latching device according to claim 1, characterized in that, The model of the closing relay includes ZJY-220.

10. The latching device according to claim 1, wherein, The single-sided no-voltage relay and the double-sided no-voltage relay are intermediate relays.

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