CN105356436A - Multi-functional integrated circuit protection device - Google Patents

Abstract

The invention provides a multifunctional integrated circuit protection device applied to a 6-66kv power grid system, which includes a compound composed of nonlinear damping devices Rk1, Rk2 and a nonlinear damping resistor RG3 with ultra-low impedance characteristics and super large capacity circuit. The multi-functional comprehensive circuit protection device provided by the invention can effectively damp and suppress the rise rate and amplitude of the transient recovery voltage of the vacuum circuit breaker, and prevent the generation of cut-off overvoltage. During the breaking process of the circuit breaker, damping and restraining the operating overvoltage due to the mutual conversion of electric energy and magnetic energy, and realizing the breaking of high short-circuit capacity of the vacuum circuit breaker. The combined application of non-linear damping resistance and the circuit design of artificial neutral point O have super lightning protection, damping and suppression of phase-phase, phase-ground resonance and operating overvoltage, especially for single-phase intermittent arc grounding The overvoltage has a good inhibitory effect and can eliminate the arc overvoltage.

Description

Multifunctional integrated circuit protection device

technical field

The invention belongs to the technical field of electrical engineering, and in particular relates to a multifunctional comprehensive circuit protection device applied to a 6-66kv power grid system. It can prevent the generation of cut-off overvoltage, effectively damp and suppress the rising rate and amplitude of the transient recovery voltage of the vacuum circuit breaker. Realize breaking with high short-circuit capacity. It has super lightning protection, damping and suppression of phase-phase, phase-ground resonance overvoltage and operating overvoltage, and can strongly inhibit single-phase intermittent arc grounding overvoltage.

Background technique

Circuit breaker is a switchgear that is widely used in high-voltage electrical appliances, and it plays a very important role in maintaining the safe, economical and reliable operation of the power system. According to the arc extinguishing medium used, it can be divided into oil circuit breaker, air circuit breaker and vacuum circuit breaker. Among them, the vacuum circuit breaker is widely used in the 6-66kV power system department due to its special structure and good performance.

Due to the high insulation strength of vacuum circuit breakers, the arc extinguishing ability is extremely strong. The circuit breaker will extinguish the arc and cut off the current before the power frequency current naturally crosses zero. There is a high cut-off value of the current, and the overvoltage caused by the cut-off is very It is easy to break down electrical equipment with weak dielectric strength. In addition, the vacuum circuit breaker has a high transient recovery voltage rise rate and amplitude at both ends of the contact when it is broken, and the success of the arc extinguishing of the vacuum circuit breaker mainly depends on the rise rate of the transient recovery voltage Ldi/dt and magnitude.

At present, the main methods and products to solve the resonance and overvoltage of the 6-66KV power grid system in the domestic and foreign markets include: metal oxide arresters, resistance-capacity absorption protection devices, overvoltage devices such as arc suppression coils and TBP arc suppression cabinets, etc., and their effects Neither was great.

Contents of the invention

The purpose of the patent of this invention is to provide a multifunctional comprehensive protection device that can be widely used in electrical equipment such as generators, vacuum circuit breakers, transformers, transmission lines, and high-voltage motors in 6-66KV power grids. The non-linear damping device Rk1 , Rk2 and a composite circuit composed of a non-linear damping resistor RG3 with ultra-low impedance characteristics and large capacity.

The invention provides a multifunctional integrated circuit protection device applied to a 6-66kv power grid system.

The specific technical solutions are:

A multi-functional integrated circuit protection device applied to 6-66kv power grid system, including two first nonlinear damping resistors RK1, connected in series with each other, across the two ends of each phase vacuum circuit breaker; when the circuit breaker is closed, each phase two Only the first nonlinear damping resistor RK1 is connected in parallel, and connected in series with the second nonlinear damping resistor RK2 connected in parallel, each phase RK2 is connected to form an artificial neutral point at point O; at the artificial neutral point O Between the ground and G, there are two parallel high-power nonlinear damping resistors RG3 with ultra-low impedance characteristics and large capacity.

By adopting this way:

Two nonlinear damping resistors RK1 per phase are connected in series and connected to both ends of the vacuum circuit breaker. Using its ultra-low high-energy leakage voltage limiting characteristics, it can prevent the generation of cut-off overvoltage. And the effect of demagnetization and energy dissipation.

When the circuit breaker is closed, the A phase becomes two Rk1s connected in parallel and then connected in series with the Rk2 phases connected in parallel, and then combined with the corresponding B phase and C phase to form a star connection, forming an artificial neutral point at O point, The insulation between the phase and the neutral point can be considered according to the phase voltage standard, and the ultra-low high-energy leakage voltage limiting characteristics of the non-linear damping device can also achieve effective damping and suppression of phase-to-phase resonant overvoltage and The effect of operating overvoltage.

Between the artificial neutral point O and the ground G, there is a high-power nonlinear damping resistor RG3 with a zero-sequence current channel. Using its ultra-low impedance characteristics and large capacity, it can play the role of super lightning protection, and Effectively suppress the operating overvoltage generated by the inductance-capacitance energy conversion between phase and ground.

The invention also provides another multifunctional integrated circuit protection device applied to a 6-66kv power grid system.

The specific technical solution is: a multifunctional integrated circuit protection device applied to a 6-66kv power grid system, using the first nonlinear damping resistor RK1 in series with the second nonlinear damping resistor RK2; The RK2 connection forms an artificial neutral point at point O, and is grounded through the high-power nonlinear damping resistor RG3 with ultra-low impedance characteristics and large capacity.

The device made of this single group of composite circuits can be installed in various parts of power plants, substations and lines, and can also achieve super lightning protection, harmonic elimination, damping and suppression of resonance overvoltage, operating overvoltage and single-phase intermittent arc grounding effect of overvoltage.

The present invention also provides a circuit protection device applied to a 6-66kv power grid system, the first non-linear damping resistor RK1 connected across the two ends of the contact of the vacuum circuit breaker.

Utilizing its ultra-low high-energy leakage voltage limiting characteristics, it can prevent the generation of cut-off overvoltage, and can play the role of commutation and demagnetization and energy dissipation during high cut-off breaking.

Compared with the prior art, the multifunctional integrated circuit protection device provided by the present invention adopts nonlinear damping resistance to protect electrical equipment such as generators, transformers, transmission lines, high-voltage motors, etc.; it has the advantages of eliminating ferromagnetic resonance and suppressing surge current Good damping and arc suppression can effectively limit the overvoltage between the phase-to-ground and phase-to-phase of the neutral point non-directly grounded system grid to a lower voltage level.

Description of drawings

Fig. 1 is the schematic diagram of the circuit structure of the first technical solution of the present invention;

Fig. 2 is the schematic diagram of the circuit structure of the second technical solution of the present invention;

Fig. 3 is the circuit wiring diagram of the third technical solution of the present invention;

Fig. 4 is the test wiring diagram of embodiment 1 of the present invention;

Fig. 5 is a test wave chart when a single-phase intermittent arc-light grounding occurs in a circuit that does not use a multifunctional integrated circuit protection device in Example 2 of the present invention;

Fig. 6 is a test wave chart when a single-phase intermittent arc is grounded in a circuit using a multifunctional integrated circuit protection device in Example 2 of the present invention;

Fig. 7 is a wave recording diagram of the addition of a multi-functional comprehensive protection device for power grids in Embodiment 3 of the present invention.

detailed description

The present invention will be further described below in conjunction with the drawings and embodiments.

As shown in Figure 1:

A multi-functional integrated circuit protection device applied to 6-66kv power grid system, including two first nonlinear damping resistors RK1, connected in series with each other, across the two ends of each phase vacuum circuit breaker; when the circuit breaker is closed, each phase two Only the first nonlinear damping resistor RK1 is connected in parallel, and connected in series with the second nonlinear damping resistor RK2 connected in parallel, each phase RK2 is connected to form an artificial neutral point at point O; at the artificial neutral point O Between the ground and G, there are two parallel high-power nonlinear damping resistors RG3 with ultra-low impedance characteristics and large capacity.

as shown in picture 2:

A multifunctional integrated circuit protection device applied to a 6-66kv power grid system, using a first nonlinear damping resistor RK1 in series with a second nonlinear damping resistor RK2; connecting with the RK1 and RK2 of the other two phases, in the Point O forms an artificial neutral point, which is grounded through the high-power nonlinear damping resistor RG3 with ultra-low impedance characteristics and large capacity.

As shown in Figure 3:

A circuit protection device applied to a 6-66kv power grid system, a first nonlinear damping resistor RK1 connected across the two ends of a vacuum circuit breaker contact.

Embodiment 1: cut off the no-load transformer to prevent cut-off overvoltage test;

When the vacuum circuit breaker cuts off the no-load transformer, it may generate a cut-off overvoltage as high as 200kV at both ends of the fracture. The multi-functional integrated circuit protection device provided by the present invention passes the no-load transformer cut-off test.

As shown in Figure 4, it is the wiring diagram of the no-load transformer removal test.

After testing, the maximum value of the cut-off overvoltage on the power supply side appears in phase C with an amplitude of 7880V, and the maximum value of the cut-off overvoltage on the load side appears in phase A with an amplitude of only 8487V. Using the multifunctional comprehensive circuit protection device provided by the invention can play a good protective role in preventing cut-off overvoltage.

Example 2: Single-phase intermittent arc grounding test

Single-phase grounding is the main fault form of the power system. Intermittent arcing grounding causes electromagnetic oscillation between inductors and capacitors, forming arcing grounding overvoltage throughout the entire system.

In a distribution network where the cable-based capacitive current reaches more than 100A, the test wave chart of A-phase single-phase intermittent arc grounding occurs:

Fig. 5 is a test wave chart of single-phase intermittent arc grounding without installing a multi-functional integrated circuit protection device;

Fig. 6 is a test wave chart of a single-phase intermittent arc grounding when a multi-functional integrated circuit protection device is installed;

After testing, there is no multifunctional integrated circuit protection device installed in the circuit, the maximum peak voltage of phase A of the normal phase reaches 23KV, the maximum peak voltage of phase B reaches 38KV, and the maximum peak voltage of phase C reaches 36KV;

And when the multi-functional integrated circuit protection device is installed in the circuit, the maximum peak voltage of phase A is 12KV, the maximum peak voltage of phase B is 17.5KV, and the maximum peak voltage of phase C is 17KV.

The multifunctional integrated circuit protection device provided by the invention can destroy and damp the electromagnetic oscillation between the inductance and the capacitance, and can quickly discharge the free oscillation charge to the ground, effectively suppressing the generation of normal phase arc light grounding overvoltage. The arc suppressing coil can be canceled; the requirements for safe operation of electrical equipment in the system can be met.

Embodiment 3: Rapid breaking test of fault short-circuit current

As the transmission capacity of the power system continues to expand, the short-circuit current level of the power grid continues to increase, and there will be accidents where the maximum short-circuit current exceeds the rated short-circuit breaking current of the circuit breaker, and the arc extinguishing failure of the circuit breaker cannot break the short-circuit fault. damage electrical equipment.

The multi-functional comprehensive protection device for the power grid can effectively damp and suppress the rising rate and amplitude of the transient recovery voltage of the vacuum circuit breaker, and it has the function of commutation, energy dissipation, magnetic arc extinguishing.

Use the same vacuum circuit breaker to carry out 50KA three-phase short-circuit current breaking test respectively.

Figure 7 is the direct test wiring diagram of the three-phase circuit;

After testing, the three-phase fault short-circuit current can be broken smoothly after the multi-functional integrated circuit protection device is installed. Effectively suppress the maximum amplitude of the transient recovery voltage at both ends of the vacuum circuit breaker fracture 26KV, so that the arc of the vacuum circuit breaker will not re-ignite, which can ensure the breaking of the fault short-circuit current and prevent the occurrence of hazardous accidents. In the absence of a composite power grid protection circuit, the test results of the wave recording of the three-phase short-circuit fault current on the same vacuum circuit breaker show that neither phase A nor phase C can be effectively broken, resulting in A\ C The two-phase vacuum tube is burned out.

The above are only some embodiments of the present invention, and the present invention is not limited to the above-mentioned embodiments. All similar modifications, changes and replacements made to the above-mentioned embodiments according to the technical essence of the present invention still belong to the present invention. within the scope of the technical program. The protection scope of the present invention is defined only by the claims.

Claims (3)

1. A multifunctional integrated circuit protection device applied to a 6-66kv power grid system, characterized in that: it includes two first nonlinear damping resistors RK1, which are connected in series with each other and connected across the two ends of each phase vacuum circuit breaker; the circuit breaker When closed, two first nonlinear damping resistors RK1 of each phase are connected in parallel, connected in series with two second nonlinear damping resistors RK2 connected in parallel, and each phase RK2 is connected to form an artificial neutral point at point O; Between the artificial neutral point O and the ground G, there are two parallel high-power nonlinear damping resistors RG3 with ultra-low impedance characteristics and large capacity. 2. A multifunctional integrated circuit protection device applied to a 6-66kv grid system, characterized in that: the first nonlinear damping resistor RK1 is connected in series with the second nonlinear damping resistor RK2; the other two phases of the RK1 Connect with RK2 to form an artificial neutral point at point O, and ground through the high-power nonlinear damping resistor RG3 with ultra-low impedance characteristics and large capacity. 3. A circuit protection device applied to a 6-66kv power grid system, characterized in that: a first non-linear damping resistor RK1 connected across the two ends of the contact of the vacuum circuit breaker.