Static alternating current output control rod driving mechanism power supply system

Abstract

The invention belongs to the electric technical field of nuclear power station reactors, and particularly relates to a static alternating current output control rod driving mechanism power supply system. The system comprises a first bus, a second bus, a super capacitor and a transformer assembly, the super capacitor comprises a static switch, a bidirectional AC / DC, a super capacitor and an inductor, and the transformer assembly comprises a transformer and a circuit breaker; one end of the first bus and one end of the second bus are connected with auxiliary power, the other end of the first bus and the other end of the second bus are connected with the super capacitor, the super capacitor is connected with the transformer assembly, when input power voltage fluctuation is small, the auxiliary power provides alternating current power, and finally the load is powered through the parallel redundant transformer assembly; at the moment of short-time power loss of the input power supply, the super capacitor in the system provides an alternating current power supply, and finally supplies power to the load through the parallel redundant transformer assembly. According to the invention, the reliability, the stability, the power factor and the maintainability of power supply are effectively improved, and harmonic waves are filtered out.

Description

Technical Field

[0001] The present invention belongs to the technical field of nuclear power plant reactor electrical technology, and particularly relates to a power supply system for a control rod drive mechanism with static AC output. Background Art

[0002] In the prior art, in the nuclear power plants that have been built and are under construction in China, basically a power supply system composed of 2 motor-generator sets with flywheels, 3 control cabinets and 3 breaker panels is adopted to supply power to the coils (CRDM) of the reactor control rod drive mechanism. After half-wave rectification by the rod control system, 220VAC power is provided to the CRDM. This solution mainly has problems such as relatively large noise and vibration, low efficiency, complex protection, large maintenance workload, large volume, and high price. Although the modular static rod power supply system based on SiC-MOSFET has optimized the above problems, the system output is DC, and there are also problems such as complex system. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a power supply system for a control rod drive mechanism with static AC output, which can provide a power supply system with a simple structure for the coils of the control rod drive mechanism, and has the advantages of reliability, stability, power factor, maintainability, and can filter out harmonics and reduce noise.

[0004] The technical solution adopted by the present invention:

[0005] A power supply system for a control rod drive mechanism with static AC output includes a first bus, a second bus, a super capacitor and a transformer assembly. The super capacitor includes a static switch, a bidirectional AC / DC, a super capacitor, and an inductor. The transformer assembly includes a transformer and a circuit breaker. One end of the first bus and the second bus is connected to the plant power supply, and the other end is connected to the super capacitor. The super capacitor is connected to the transformer assembly. When the input power supply voltage fluctuates slightly, the plant power supply provides AC power, and finally supplies power to the load through the parallel redundant transformer assembly. When the input power supply is short-term power-off instantaneously, the super capacitor in the system provides AC power, and finally supplies power to the load through the parallel redundant transformer assembly.

[0006] The transformer assembly is in a zigzag star structure.

[0007] The super capacitor includes a first bypass switch and a second maintenance switch. One end of the first bus is connected to the 380VAC plant power supply, and one end of the second bus is connected to the 380VAC plant power supply. The other end of the first bus is connected with a first power supply switch, and the other end of the second bus is connected with a second power supply switch. The circuit after the parallel connection of the first power supply switch and the second power supply switch is connected to one end of the first bypass switch, and the other end of the first bypass switch is connected with a second maintenance switch.

[0008] The super capacitor includes a first maintenance switch, a first static switch, a second static switch, a third static switch, and a fourth static switch. The circuit after the parallel connection of the first power supply switch and the second power supply switch is connected to one end of the first maintenance switch, and the other end of the first maintenance switch is connected to the first static switch, the second static switch, the third static switch, and the fourth static switch.

[0009] The super capacitor includes a bidirectional AC / DC, a super capacitor, and an inductor. The first static switch and the second static switch are connected in parallel and then in series with the inductor. The third static switch and the fourth static switch are connected in parallel with the above series circuit to form a parallel circuit. The other end of the parallel circuit is connected to a second maintenance switch; a parallel circuit composed of multiple bidirectional AC / DCs is connected to the circuit between the parallel circuit and the second maintenance switch, and the other end of the parallel circuit composed of multiple bidirectional AC / DCs is connected to multiple super capacitors.

[0010] A switching control module is provided between the first power supply switch and the second power supply switch to ensure that after one of the busbars fails, it can be switched to the other busbar.

[0011] The transformer assembly includes a first transformer, a second transformer, a first circuit breaker, and a second circuit breaker. One end of the first transformer is connected to the second maintenance switch, and the other end is connected to a first circuit breaker; one end of the first circuit breaker is connected to the first transformer, and the other end is the system output port; one end of the second transformer is connected to the second maintenance switch, and the other end is connected to a second circuit breaker; one end of the first circuit breaker is connected to the first transformer, and the other end is the system output port.

[0012] Before the bidirectional AC / DC is started, the first bypass switch is in the closed state, and the plant power supply directly provides 220VAC / 50Hz power for the rod control system power cabinet through the parallel redundant zigzag star transformer assembly.

[0013] Close the second maintenance switch to charge the super capacitor energy storage cabinet with 380VAC.

[0014] After charging is completed, the dynamic voltage compensation circuit is put into operation by closing the first maintenance switch, the first static switch and the first static switch, and disconnecting the first bypass switch.

[0015] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0016] (1) A power supply system for a control rod drive mechanism with a static AC output provided by the present invention effectively improves the reliability, stability, power factor, maintainability of power supply, and filters out harmonics.

[0017] (2) The power supply system for the control rod drive mechanism with static AC output provided by the present invention has no rotating components, reducing the noise of the system.

[0018] (3) The power supply system for the control rod drive mechanism with static AC output provided by the present invention is designed as a standardized cabinet, with a small floor area, light equipment weight, and no special requirements for installation and maintenance.

[0019] (4) The power supply system for the control rod drive mechanism with static AC output provided by the present invention has a modular design for supercapacitors, and is simple to operate and maintain.

[0020] (5) The power supply system for the control rod drive mechanism with static AC output provided by the present invention has a fully digital monitoring, and high fault location accuracy.

[0021] (6) The power supply system for the control rod drive mechanism with static AC output provided by the present invention can meet the power supply requirements of control rod drive mechanisms for various types of nuclear power plants such as small reactors and large reactors. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of the power supply system for the control rod drive mechanism with static AC output provided by the present invention.

[0024] In the figure: 1 - First busbar, 2 - Second busbar, 3 - First power supply switch, 4 - Second power supply switch, 5 - First bypass switch, 6 - First maintenance switch, 7 - Second maintenance switch, 8 - First static switch, 9 - Second static switch, 10 - Third static switch, 11 - Fourth static switch, 12 - First transformer, 13 - Second transformer, 14 - First circuit breaker, 15 - Second circuit breaker, 16 - Bidirectional AC / DC, 17 - Supercapacitor, 18 - Inductor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. These terms are only used for the convenience of describing the present invention 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. Therefore, they should not be construed as limiting the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" 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 or an electrical connection; it can be directly connected or indirectly connected 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 invention can be understood according to specific situations.

[0028] As Figure 1 shown, a power supply system for a control rod drive mechanism with static AC output provided by the present invention includes a first bus 1, a second bus 2, a super capacitor, and a transformer assembly. The super capacitor includes a static switch, a bidirectional AC / DC 16, a super capacitor 17, and an inductor 18. The transformer assembly includes a transformer and a circuit breaker. One end of the first bus 1 and the second bus 2 is connected to the plant power supply, and the other end is connected to the super capacitor. The super capacitor is connected to the transformer assembly. When the input power supply voltage fluctuates slightly, the plant power supply provides AC power, and finally supplies power to the load through the parallel redundant transformer assembly. When the input power supply is short-term power-off instantaneously, the super capacitor in the system provides AC power, and finally supplies power to the load through the parallel redundant transformer assembly.

[0029] The transformer assembly is of a zigzag star structure;

[0030] Specifically, the super capacitor includes a first bypass switch 5, a first maintenance switch 6, a second maintenance switch 7, a first static switch 8, a second static switch 9, a third static switch 10, a fourth static switch 11, a bidirectional AC / DC 16, a super capacitor 17, and an inductor 18.

[0031] One end of the first bus 1 is connected to the 380VAC plant power supply, and one end of the second bus 2 is connected to the 380VAC plant power supply. The other end of the first bus 1 is connected with a first power supply switch 3, and the other end of the second bus 2 is connected with a second power supply switch 4.

[0032] A switching control module is provided between the first power supply switch 3 and the second power supply switch 4 to ensure that it can be switched to the other bus after one of the buses fails;

[0033] The circuit after the first power supply switch 3 and the second power supply switch 4 are connected in parallel is connected to one end of the first bypass switch 5, and the other end of the first bypass switch 5 is connected to a second maintenance switch 7;

[0034] The circuit after the first power supply switch 3 and the second power supply switch 4 are connected in parallel is connected to one end of the first maintenance switch 6, and the other end of the first maintenance switch 6 is connected to a first static switch 8, a second static switch 9, a third static switch 10, and a fourth static switch 11; the first static switch 8 and the second static switch 9 are connected in parallel and then connected in series with an inductor 18, the third static switch 10 and the fourth static switch 11 are connected in parallel with the above series circuit to form a parallel circuit, and the other end of the parallel circuit is connected to a second maintenance switch 7; a parallel circuit composed of a plurality of bidirectional AC / DCs 16 is connected to the circuit between the parallel circuit and the second maintenance switch 7, and the other end of the parallel circuit composed of the plurality of bidirectional AC / DCs 16 is connected to a plurality of supercapacitors 17;

[0035] The transformer assembly includes a first transformer 12, a second transformer 13, a first circuit breaker 14, and a second circuit breaker 15. One end of the first transformer 12 is connected to the second maintenance switch 7, and the other end is connected to a first circuit breaker 14; one end of the first circuit breaker 14 is connected to the first transformer 12, and the other end is the system output port; one end of the second transformer 13 is connected to the second maintenance switch 7, and the other end is connected to a second circuit breaker 15; one end of the first circuit breaker 15 is connected to the first transformer 13, and the other end is the system output port.

[0036] The working principle of the present invention is as follows:

[0037] During the normal operation of the new static AC rod power supply system, to adapt to various operating states of the reactor, the 380VAC input power supply is supplied by different plant buses. When one input power supply fails, it is automatically switched to the other power supply through a switching switch. Before the bidirectional AC / DC bidirectional converter is started, the first bypass switch 5 is in the closed state, and 380VAC directly provides 220VAC / 50Hz power for the rod control system power cabinet through the parallel redundant zigzag star transformer; closing the second maintenance switch 7 can charge the modular supercapacitor energy storage cabinet through 380VAC.

[0038] After charging is completed, the dynamic voltage compensation circuit is put into operation by closing the first maintenance switch 6, the first static switch 8 and the first static switch 9, and disconnecting the first bypass switch 5. When the input power supply voltage fluctuates slightly, the static switch is controlled by detecting the harmonic components and reactive current components in the load current, and real-time voltage regulation is enabled. At the same time, reactive power, harmonics, and three-phase unbalance can be compensated in real time, thereby providing functions such as fast dynamic reactive power compensation and harmonic filtering for the power grid or electrical load, effectively improving the stability of the load voltage, compensating unbalanced loads, filtering load harmonics, and improving the load power factor.

[0039] During a short power outage of the input power supply or the transient period of the switched power supply, the modular supercapacitor in the system provides a 220VAC / 50Hz power supply for the load through the AC / DC bidirectional converter and the parallel redundant zigzag star transformer.

[0040] During the normal operation of a nuclear power plant, the static rod power supply system mainly supplies power to the coils of the reactor control rod drive mechanism (CRDM). A failure of the rod power supply system will cause the magnetic coils of the CRDM to lose power. At this time, the drive rod and the control rod fall into the reactor core by their own gravity, causing the reactor to scram, which directly affects the reliable and economic operation of the nuclear power plant. The novel static AC rod power supply system of the present invention is based on energy storage type dynamic voltage compensation technology and can meet the power supply requirements of the load when the input power supply voltage fluctuates. It effectively improves the reliability, stability, power factor, and maintainability of the power supply, filters out harmonics, reduces noise, and can meet the AC power supply requirements of the control rod drive mechanisms of various types of nuclear power plants, such as small reactors and large reactors.

[0041] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced by the present invention. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0042] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A power supply system for a control rod drive mechanism with static AC output, characterized in that, It includes a first busbar (1), a second busbar (2), a supercapacitor, and a transformer assembly. The supercapacitor includes a static switch, a bidirectional AC / DC (16), a supercapacitor (17), and an inductor (18). The transformer assembly includes a transformer and a circuit breaker. One end of the first busbar (1) and the second busbar (2) is connected to the auxiliary power supply of the plant, and the other end is connected to the supercapacitor. The supercapacitor is connected to the transformer assembly. When the input power supply voltage fluctuates slightly, the auxiliary power supply of the plant provides AC power, and finally supplies power to the load through the parallel redundant transformer assembly. When the input power supply loses power instantaneously for a short time, the supercapacitor in the system provides AC power, and finally supplies power to the load through the parallel redundant transformer assembly.

2. The power supply system for the control rod drive mechanism with static AC output according to claim 1, characterized in that, The transformer assembly is of a zigzag star structure.

3. The power supply system for the control rod drive mechanism with static AC output according to claim 2, characterized in that, The supercapacitor includes a first bypass switch (5) and a second maintenance switch (7). One end of the first busbar (1) is connected to the 380VAC auxiliary power supply of the plant, and one end of the second busbar (2) is connected to the 380VAC auxiliary power supply of the plant. The other end of the first busbar (1) is connected with a first power supply switch (3), and the other end of the second busbar (2) is connected with a second power supply switch (4). The circuit after the parallel connection of the first power supply switch (3) and the second power supply switch (4) is connected to one end of the first bypass switch (5), and the other end of the first bypass switch (5) is connected with a second maintenance switch (7).

4. The power supply system of the control rod drive mechanism with static AC output according to claim 3, characterized in that, The supercapacitor includes a first maintenance switch (6), a first static switch (8), a second static switch (9), a third static switch (10), and a fourth static switch (11). The circuit after the parallel connection of the first power supply switch (3) and the second power supply switch (4) is connected to one end of the first maintenance switch (6), and the other end of the first maintenance switch (6) is connected with the first static switch (8), the second static switch (9), the third static switch (10), and the fourth static switch (11).

5. The power supply system for the control rod drive mechanism with static AC output according to claim 4, characterized in that, The supercapacitor includes a bidirectional AC / DC (16), a supercapacitor (17), and an inductor (18). The first static switch (8) and the second static switch (9) are connected in parallel and then in series with the inductor (18). The third static switch (10) and the fourth static switch (11) are connected in parallel with the above series circuit to form a parallel circuit. The other end of the parallel circuit is connected with a second maintenance switch (7). A parallel circuit composed of multiple bidirectional AC / DCs (16) is connected to the circuit between the parallel circuit and the second maintenance switch (7). The other end of the parallel circuit composed of multiple bidirectional AC / DCs (16) is connected with multiple supercapacitors (17).

6. The power supply system for the control rod drive mechanism with static AC output according to claim 5, characterized in that, A switching control module is provided between the first power supply switch (3) and the second power supply switch (4) to ensure that it can be switched to the other busbar after one of the busbars fails.

7. The power supply system for the control rod drive mechanism with static AC output according to claim 6, characterized in that, The transformer assembly includes a first transformer (12), a second transformer (13), a first circuit breaker (14), and a second circuit breaker (15). One end of the first transformer (12) is connected to the second maintenance switch (7), and the other end is connected to the first circuit breaker (14). One end of the first circuit breaker (14) is connected to the first transformer (12), and the other end is the system output outlet. One end of the second transformer (13) is connected to the second maintenance switch (7), and the other end is connected to the second circuit breaker (15). One end of the first circuit breaker (15) is connected to the first transformer (13), and the other end is the system output outlet.

8. The power supply system for the control rod drive mechanism with static AC output according to claim 7, characterized in that, Before the bidirectional AC / DC (16) is started, the first bypass switch (5) is in the closed state, and the plant power supply directly provides 220VAC / 50Hz power for the rod control system power cabinet through the parallel redundant zigzag star transformer assembly.

9. The power supply system for the control rod drive mechanism with static AC output according to claim 8, characterized in that, Close the second maintenance switch (7) to charge the supercapacitor energy storage cabinet with 380VAC.

10. The power supply system of the control rod drive mechanism with static AC output according to claim 9, characterized in that, After the charging is completed, the dynamic voltage compensation circuit is put into operation by closing the first maintenance switch (6), the first static switch (8), and the first static switch (9) and opening the first bypass switch (5).

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