Power grid safety and stability protection device and method based on condensed state function resistor NGR

Abstract

The invention relates to the technical field of power system protection, and discloses a condensed state function resistor NGR-based power grid safety and stability protection device and method, and the device comprises a three-phase bus A, a bus B and a bus C. The bus A, the bus B and the bus C are respectively provided with a circuit breaker DL, and the two ends of the fracture of each circuit breaker DL are respectively connected with a first condensed state function resistor NGR in parallel. And the bus A, the bus B and the bus C are connected with a second condensed state functional resistor NGR and a first ampere meter in a star connection hanging manner. According to the power grid safety and stability protection device and method based on the condensed state function resistor NGR, short-circuit current and overvoltage in a power grid are suppressed through various functional characteristics of the condensed state function resistor NGR, electromagnetic resonance and system oscillation in the power grid are reduced, and operation of the power grid is stabilized; the first ampere meter and the second ampere meter are used for detecting each path of current in real time, so that the timely finding and processing capability of power grid faults can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system protection, and in particular to a power grid safety and stability protection device and method based on a condensed state functional resistor (NGR). Background Art

[0002] As the scale of power systems continues to expand, the safe and stable operation of power grids has become the focus of the power industry. Short-circuit current and overvoltage are the two main factors that threaten the safety of power grids. The damage caused by short-circuit in power systems is related to the capacity of equipment, the location of occurrence and the duration. At the outlet of the generator or main transformer, the peak value of the short-circuit current can reach 10 times the rated current. In addition to the thermal effect damage, the huge short-circuit current also causes damage due to strong mechanical stress. The voltage drop during a short circuit causes a tripping and power outage. The only way is to quickly and reliably cut off the fault current, but it is often difficult for circuit breakers to withstand the damage. Due to the excessive short-circuit breaking capacity and the inability to quickly open, the generator stator winding or the main transformer winding may burn out. Among them, the single-phase intermittent arc grounding overvoltage is the most serious. It often turns from a single-phase grounding to a multi-phase grounding, and the accident is expanded due to untimely handling, resulting in a large-scale power outage in the power system. Traditional protection equipment such as circuit breakers are insufficient in withstanding high short-circuit breaking capacity and rapid opening, which can easily lead to equipment damage and power outages. In addition, overvoltages caused by power system operation, switching, resonance and lightning strikes also pose a threat to the insulation of electrical equipment and the safe operation of the system. Summary of the invention

[0003] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides a power grid safety and stability protection device and method based on condensed state functional resistor NGR.

[0004] (II) Technical solution To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a power grid safety and stability protection device and method based on a condensed state functional resistor NGR, comprising a three-phase bus A bus, a B bus and a C bus, wherein the A bus, the B bus and the C bus are all provided with circuit breakers DL, both ends of the break of all circuit breakers DL are connected in parallel with a first condensed state functional resistor NGR, the A bus, the B bus and the C bus are connected in a star-connected manner with a second condensed state functional resistor NGR and a first ammeter, the intersection of three second condensed state functional resistors NGR connected in a star-connected manner is set as an artificial neutral point, and the grounding line of the artificial neutral point is connected in series with a third condensed state functional resistor NGR and a second ammeter.

[0005] Preferably, the condensed matter functional resistor NGR is a resistor element with special functions in the field of condensed matter physics. The condensed matter functional resistor NGR has electrical properties different from traditional resistors, and may exhibit nonlinear resistance behavior and quantum resistance effect. Its resistance value may change significantly with changes in external conditions such as temperature, magnetic field, and pressure. It has specific functions such as voltage limiting, superconductivity, damping, arc extinguishing, and detuning.

[0006] Preferably, the circuit breaker DL is installed on the busbar in the power system and close to the outlet end of the generator or the main transformer, and the opening and closing of the circuit breaker DL is used to control the on and off of the busbar.

[0007] Preferably, the second condensed state functional resistor NGR is connected behind the connection point between the first condensed state functional resistor NGR and the busbar, and the first ammeter is connected in series below the second condensed state functional resistor NGR.

[0008] Preferably, the third condensed state functional resistor NGR is connected in series to the upper end of the grounding wire close to the artificial neutral point, and the second ammeter is connected in series to the lower end of the grounding wire close to the grounding point.

[0009] Preferably, when a short-circuit current occurs in the power grid, the first condensed functional resistor NGR can effectively suppress the rising rate and amplitude of the transient recovery voltage of the circuit breaker DL by utilizing its ultra-large high-energy characteristic voltage limiting, ensuring that the circuit breaker DL can quickly and effectively interrupt the fault current and protect the generator or main transformer from damage.

[0010] Preferably, the second condensed state functional resistor NGR adopts a large-diameter valve plate with three characteristic functions: high voltage and large energy capacity, low voltage and large current, and strong damping. It can achieve no overvoltage in the power grid without considering the charge rate. The second condensed state functional resistor NGR can reduce the electromagnetic resonance and system oscillation in the power grid through its strong damping characteristics to stabilize the operation of the power grid, achieve arc elimination and detuning, damp the occurrence of resonant overvoltage, and avoid the occurrence of fire.

[0011] Preferably, the third condensed state functional resistor NGR is connected across the artificial neutral point and the ground G to extinguish the single-phase grounding arc and damp the resonant overvoltage, prevent the accident from expanding, and ensure the safety of the power grid. It has a strong energy dissipation and demagnetization capability, and completely eliminates the occurrence of intermittent arc grounding overvoltage and resonant overvoltage caused by line breakage, non-full-phase operation of the circuit breaker, or a different phase.

[0012] Preferably, the first ammeter and the second ammeter are both connected to a high-voltage online monitoring unit, which collects digital current signals with high-voltage characteristics in real time through encoding, and combines radio transmission, reception and computer technology to achieve sensitive, accurate and reliable monitoring of each current. The intelligent control unit analyzes and judges based on the monitoring data, and issues alarms and prompts once an abnormality is found, thereby realizing intelligent early warning management.

[0013] Compared with the prior art, the present invention provides a power grid safety and stability protection device and method based on condensed state functional resistor NGR, which has the following beneficial effects: 1. The power grid safety and stability protection device and method based on the condensed state functional resistor NGR can effectively suppress the short-circuit current and overvoltage in the power grid through the ultra-large high-energy characteristic voltage limiting performance of the first condensed state functional resistor NGR, enhance the self-protection capability of the power grid, ensure the safe and stable operation of the power grid, and significantly improve the safety of the power grid.

[0014] 2. The power grid safety and stability protection device and method based on the condensed state functional resistor NGR can achieve zero overvoltage in the power grid regardless of the charge rate through the functional characteristics of the second condensed state functional resistor NGR, such as large energy capacity, low voltage, large current, and strong damping. The strong damping characteristics can reduce electromagnetic resonance and system oscillation in the power grid to stabilize the operation of the power grid.

[0015] 3. The power grid safety and stability protection device and method based on the condensed functional resistor NGR can detect the current of each line in real time through the first ammeter and the second ammeter, and can issue alarms and prompts for abnormalities in the circuit, thereby improving the ability to timely discover and handle power grid faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the wiring principle diagram of the present invention.

[0017] In the figure: 1. bus A; 2. bus B; 3. bus C; 4. circuit breaker DL; 5. first condensed state functional resistor NGR; 6. second condensed state functional resistor NGR; 7. first ammeter; 8. artificial neutral point; 9. third condensed state functional resistor NGR; 10. second ammeter. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example See also Figure 1The present invention provides a technical solution: the power grid safety and stability protection device based on the condensed state functional resistor NGR is installed on the three-phase busbar at the outlet of the generator or main transformer of the power system, the busbar is divided into A busbar 1, B busbar 2 and C busbar 3, and the A busbar 1, B busbar 2 and C busbar 3 are all provided with circuit breakers DL4, and both ends of the break of all circuit breakers DL4 are connected in parallel with the first condensed state functional resistor NGR5, the A busbar 1, the B busbar 2 and the C busbar 3 are connected in a star connection manner with the second condensed state functional resistor NGR6 and the first ammeter 7, and the three second condensed The intersection of the state function resistor NGR6 connected in star connection is set as the artificial neutral point 8. The grounding line of the artificial neutral point 8 is connected in series with the third condensed state function resistor NGR9 and the second ammeter 10, which can prevent all electrical equipment hung on the power grid bus from being damaged by overvoltage and overcurrent (including short-circuit current). The circuit breaker DL4 at the generator or main transformer outlet needs to have a large capacity, not only high reliability, maintenance-free, and long life, but also a large rated current and high short-circuit capacity opening and closing capability. To solve the heating problem under long-term full-load operation, it is also necessary to It can withstand the strong impact of huge short-circuit electric force when opening and closing large capacity. In addition, these high-performance circuit breakers have strong arc extinguishing ability, high dielectric recovery strength, and small arc extinguishing chamber contact distance. However, due to the extremely high dielectric recovery strength, the arc is extinguished and the current is cut off before the power frequency current naturally crosses zero. There is a high current cutoff value. The overvoltage caused by the cutoff can easily break down electrical equipment with weak insulation dielectric strength. At the same time, a transient recovery voltage and amplitude with a very high rise rate will be generated at the DL4 fracture of the circuit breaker. These fatal weaknesses can easily cause the DL4 arc to reignite. The burnt contact may cause the contact to melt and stick and fail to open, causing an explosion. The first condensed state functional resistor NGR5 has the functions of commutation and freewheeling demagnetization. With its ultra-large high-energy characteristic and voltage-limiting characteristic, it can effectively suppress the rising rate and amplitude of the transient recovery voltage of the circuit breaker. When the high current is cut off, it can actively play the role of commutation demagnetization and energy dissipation. The circuit breaker DL4 can quickly and effectively break the fault current to ensure that the generator or main transformer is not burned due to the circuit breaker tripping and failure to open. The three second condensed state functional resistors NGR6 are each connected in series with a first ammeter 7, and are connected to the power sources A, B, On the C three-phase bus, an artificial neutral point 8 of the power supply is formed at the intersection of the star connection. To solve the overvoltage of the power grid, the metal oxide arrester MOA has been widely used in the power system. Its core component is the metal oxide resistor (MOR). During the operation of the power grid voltage, it has been subjected to overvoltage surge shocks for a long time, which makes the nonlinear characteristics of the MOR deteriorate, the active current increases, and the valve plate heat increases. Because the MOR has the negative resistance characteristic of NTC, the resistance value R decreases, and the strong positive feedback makes the leakage current become larger and larger, and finally leads to thermal collapse. In order to reduce the aging degree of the MOA valve plate and extend its service life, it can only rely on sacrificing residual pressure in exchange for a lower charge rate, thereby reducing the protection performance.The second condensed state function resistor NGR6 adopts a large-diameter valve plate with three characteristics of high voltage and large energy capacity, low voltage and large current, and strong damping. It can make the power grid free of overvoltage (no partial discharge of the cable) without considering the charge rate, realize arc extinguishing and detuning, damping resonance overvoltage, and avoid fire. A third condensed state function resistor NGR9 is connected to a second ammeter 10 between the artificial neutral point 8 and the ground G, which is used for the extinguishing of arc and the occurrence of damping resonance in single-phase circuit. It has a strong energy dissipation and demagnetization ability, and completely eliminates the occurrence of intermittent arc light grounding overvoltage and the resonance overvoltage caused by line breakage, non-full-phase action of circuit breakers or a different phase. The ultra-high-new online high-voltage DC leakage real-time detection circuit uses the encoding method to continuously collect digital current signals with high voltage characteristics, combined with radio transmission, reception and computer technology, to sensitively, accurately and reliably detect the currents of each line in real time and implement intelligent early warning management. It can issue alarms and prompts for abnormalities in the circuit. ,

[0020] In summary, the power grid safety and stability protection device and method based on the condensed state functional resistor NGR suppresses short-circuit current and overvoltage in the power grid through the various functional characteristics of the condensed state functional resistor NGR, reduces electromagnetic resonance and system oscillation in the power grid to stabilize the operation of the power grid, and performs real-time detection of currents through the first ammeter 7 and the second ammeter 10, which can issue alarms and prompts for abnormalities in the circuit, thereby improving the ability to promptly detect and handle power grid faults.

[0021] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A power grid safety and stability protection device and method based on condensed state functional resistor (NGR), comprising three-phase busbars A busbar (1), B busbar (2) and C busbar (3), characterized in that: The A busbar (1), the B busbar (2) and the C busbar (3) are all provided with circuit breakers DL (4), both ends of the break points of all the circuit breakers DL (4) are connected in parallel with first condensed state functional resistors NGR (5), the A busbar (1), the B busbar (2) and the C busbar (3) are connected in a star-connected manner with second condensed state functional resistors NGR (6) and a first ammeter (7), the intersection of the three second condensed state functional resistors NGR (6) connected in a star-connected manner is set as an artificial neutral point (8), and the grounding line of the artificial neutral point (8) is connected in series with a third condensed state functional resistor NGR (9) and a second ammeter (10).

2. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: Condensed matter functional resistor NGR is a resistor element with special functions in the field of condensed matter physics. Condensed matter functional resistor NGR has electrical properties different from traditional resistors, and may exhibit nonlinear resistance behavior and quantum resistance effect. Its resistance value may change significantly with changes in external conditions such as temperature, magnetic field, and pressure. It has specific functions such as voltage limiting, superconductivity, damping, arc extinguishing, and detuning.

3. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: The circuit breaker DL (4) is installed on a busbar in the power system and is close to an outlet of a generator or a main transformer. The opening and closing of the circuit breaker DL (4) is used to control the on and off of the busbar.

4. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: The second condensed state functional resistor NGR (6) is connected behind the connection point between the first condensed state functional resistor NGR (5) and the busbar, and the first ammeter (7) is connected in series below the second condensed state functional resistor NGR (6).

5. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: The third condensed state functional resistor NGR (9) is connected in series to the upper end of the grounding wire close to the artificial neutral point (8), and the second ammeter (10) is connected in series to the lower end of the grounding wire close to the grounding point.

6. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: When a short-circuit current occurs in the power grid, the first condensed functional resistor NGR (5) can effectively suppress the rising rate and amplitude of the transient recovery voltage of the circuit breaker DL (4) by utilizing its ultra-large high-energy characteristic voltage limiting, thereby ensuring that the circuit breaker DL (4) can quickly and effectively interrupt the fault current and protect the generator or main transformer from damage.

7. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: The second condensed state functional resistor NGR (6) adopts a large-diameter valve plate with three characteristics: high voltage and large energy capacity, low voltage and large current, and strong damping. It can achieve no overvoltage in the power grid regardless of the charge rate. The second condensed state functional resistor NGR (6) can reduce the electromagnetic resonance and system oscillation in the power grid through its strong damping characteristics to stabilize the operation of the power grid, achieve arc elimination and detuning, damp the occurrence of resonant overvoltage, and avoid the occurrence of fire.

8. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: The third condensed state functional resistor NGR (9) is connected across the artificial neutral point (8) and the ground G to extinguish the single-phase grounding arc and damp the resonant overvoltage, prevent the accident from expanding, and ensure the safety of the power grid. It has a strong energy dissipation and demagnetization capability, and completely eliminates the occurrence of intermittent arc grounding overvoltage and the resonant overvoltage caused by line breakage, non-full-phase operation of the circuit breaker or a different phase.

9. The power grid safety and stability protection device and method based on condensed state functional resistor NGR according to claim 1 is characterized in that: The first ammeter (7) and the second ammeter (10) are both connected to a high-voltage online monitoring unit. The high-voltage online monitoring unit collects digital current signals with high voltage characteristics in real time through coding, and combines radio transmission, reception and computer technology to achieve sensitive, accurate and reliable monitoring of each current. The intelligent control unit analyzes and judges based on the monitoring data, and issues an alarm and prompt once an abnormality is found, thereby achieving intelligent early warning management.

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