阅读说明：本技术 一种对带合闸电阻的开关设备的容性关合性能进行评价的方法及系统 (Method and system for evaluating capacitive closing performance of switch equipment with closing resistor ) 是由 崔博源 刘泽洪 吴昱怡 王绍武 王承玉 陈允 张进 刘焱 于 2020-04-20 设计创作，主要内容包括：本发明公开了一种对带合闸电阻的开关设备的容性关合性能进行评价的方法及系统,其中方法包括：对开关设备的考核断口按照标准C2级断路器电容器组电流关合试验进行电流关合试验；计算所述开关设备在一次标准C2级电容器组电流关合试验预击穿过程中的电弧能量与实际运行工况中单次关合的平均电弧能量的比值M；对所述开关设备进行多次标准C2级断路器电容器组电流关合试验,记录所述开关设备通过电流关合试验的次数为A；确定所述开关设备在实际运行工况下的可靠开合次数为A*M次。(The invention discloses a method and a system for evaluating the capacitive closing performance of a switching device with a closing resistor, wherein the method comprises the following steps: carrying out a current closing test on the examination fracture of the switch equipment according to a standard C2-level circuit breaker capacitor bank current closing test; calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-grade capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition; carrying out multiple standard C2-level breaker capacitor bank current closing tests on the switch equipment, and recording the times of the switch equipment passing the current closing tests as A; and determining the reliable opening and closing times of the switch equipment under the actual operation working condition as A x M times.)

1. A method of evaluating capacitive turn-on performance of a switching device having a closing resistor, the method comprising:

carrying out a current closing test on the examination fracture of the switch equipment according to a standard C2-level circuit breaker capacitor bank current closing test;

calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-grade capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition;

carrying out multiple standard C2-level breaker capacitor bank current closing tests on the switch equipment, and recording the times of the switch equipment passing the current closing tests as A;

and determining the reliable opening and closing times of the switch equipment under the actual operation working condition as A x M times.

2. The method of claim 1, the switching device comprising:

the main fracture S1 and the resistor fracture S2 are in series connection with each other, and the main fracture S1 and the resistor fracture S2 are in series connection;

the examination fracture is the resistor fracture S2.

3. The method of claim 1, the switching device comprising:

a main fracture S1, a resistor fracture S2, and a parallel connection between the main fracture S1 and the resistor fracture S2;

the examination fracture is the main fracture S1.

4. The method of claim 1, comprising:

in a standard C2-level circuit breaker capacitor bank current closing test, the checking fracture of the switch equipment is concentrated phase closing at a voltage peak, and the closing inrush current value of the checking fracture is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2-level breaker capacitor bank current closing test at each time is as follows:

α is a constant, 1.8, I^α _CMtIs the α th power value of the closing inrush current.

5. The method of claim 1, comprising:

before the check fracture is closed, the resistor, the inductor and the capacitor on the branch are connected in series to divide voltage, because

wherein, ω L is the inductive reactance of the loop in the equivalent circuit; omega C is the capacitive reactance of a loop in the equivalent circuit; u shape_mIs the peak value of the supply voltage; u shape_RVoltage division is carried out on the resistor; r is resistance;

the maximum value of the turn-off inrush current of the switch equipment under the actual operation working condition is I_CMyIn the operation, the random phase closing is performed, and the relation between the closing inrush current value 1/4 and the closing phase angle in a period is expressed as follows:

i_c＝I_CMy×sinθ

wherein i_CThe switching inrush current is switched off when the phase angle of the power supply voltage is theta;

the maximum pre-breakdown time of the switching equipment without a closing resistor is T_maxWhen taking closing resistor, considering the influence of resistance partial pressure, the maximum pre-breakdown time of the switching equipment is as follows:

the relationship between the arcing time and the closing phase angle in the 1/4 cycle is expressed as:

wherein t is_aThe arc time is closed when the phase angle of the power supply voltage is theta;

the switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching equipment in the pre-breakdown process of a one-time standard C2-level breaker capacitor bank current closing test to the average arc energy of one-time closing in the actual operation working condition is as follows:

M＝Qs/Qa。

6. a system for evaluating capacitive closing performance of a switching device having a closing resistor, the system comprising:

the execution unit is used for carrying out a current closing test on the examination fracture of the switch equipment according to a standard C2-level circuit breaker capacitor bank current closing test;

the calculation unit is used for calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-level capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition;

the recording unit is used for carrying out multiple times of standard C2-level breaker capacitor bank current closing tests on the switch equipment and recording the times of the switch equipment passing the current closing tests as A;

and the determining unit is used for determining the reliable opening and closing times of the switch equipment under the actual operating condition as A x M times.

7. The system of claim 6, the switching device comprising:

the main fracture S1 and the resistor fracture S2 are in series connection with each other, and the main fracture S1 and the resistor fracture S2 are in series connection;

the examination fracture is the resistor fracture S2.

8. The system of claim 6, the switching device comprising:

a main fracture S1, a resistor fracture S2, and a parallel connection between the main fracture S1 and the resistor fracture S2;

the examination fracture is the main fracture S1.

9. The system of claim 6, configured to:

in a standard C2-level circuit breaker capacitor bank current closing test, the checking fracture of the switch equipment is concentrated phase closing at a voltage peak, and the closing inrush current value of the checking fracture is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2-level breaker capacitor bank current closing test at each time is as follows:

α is a constant, 1.8, I^α _CMtIs the α th power value of the closing inrush current.

10. The system of claim 6, configured to:

before the check fracture is closed, the resistor, the inductor and the capacitor on the branch are connected in series to divide voltageDue to the fact thatCan simplify to resistance and electric capacity series connection partial pressure, and the partial pressure is on the resistance:

wherein, ω L is the inductive reactance of the equivalent circuit; omega C is the capacitive reactance of the equivalent circuit; u shape_mIs the peak value of the supply voltage; u shape_RVoltage division is carried out on the resistor; r is resistance;

the maximum value of the turn-off inrush current of the switch equipment under the actual operation working condition is I_CMyIn the operation, the random phase closing is performed, and the relation between the closing inrush current value 1/4 and the closing phase angle in a period is expressed as follows:

i_c＝I_CMy×sinθ；

wherein i_CThe switching inrush current is switched off when the phase angle of the power supply voltage is theta;

the maximum pre-breakdown time of the switching equipment without a closing resistor is T_maxWhen taking closing resistor, considering the influence of resistance partial pressure, the maximum pre-breakdown time of the switching equipment is as follows:

the relationship between the arcing time and the closing phase angle in 1/4 cycles can be expressed as:

wherein t is_aThe arc time is closed when the phase angle of the power supply voltage is theta;

the switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching equipment in the pre-breakdown process of a one-time standard C2-level breaker capacitor bank current closing test to the average arc energy of one-time closing in the actual operation working condition is as follows:

M＝Qs/Qa。

Technical Field

The invention relates to the technical field of electrical equipment tests, in particular to a method and a system for evaluating capacitive closing performance of switching equipment with a closing resistor.

Background

The ultra-high voltage power grid has large power adjustment amplitude, the capacity of an alternating current filter bank or a reactive compensation capacitor bank is large, switching is frequent, and the requirement on the electrical service life of switch equipment is high. Note: since the ac filter is mainly formed by capacitors, it is subsequently considered uniformly by capacitor banks.

In the process of developing a circuit breaker and other switching equipment, the capacitive current switching capacity is an important factor influencing the structure of an arc extinguish chamber and the switching-on/switching-off speed. The switch equipment can generate high-frequency inrush current when closing a capacitor bank or an alternating current filter bank, the back-to-back capacitor bank is particularly serious when closing the capacitor bank, because the installation position between the capacitor banks is close, the inductance is very small, the capacitor bank which is put into the capacitor bank can charge the capacitor bank to be put into the capacitor bank, the inrush current with very high amplitude and frequency is generated, the inrush current amplitude is several times to dozens of times larger than the normal working current, the frequency can reach thousands of hertz, and the contact fusion welding and burning loss, the part damage, the insulation damage and the like are easily caused.

Due to the above characteristics brought by the operating conditions, the contacts of the switching devices for switching the filter banks or the capacitor banks must have a higher electrical life. The frequent opening and closing performance of the switch equipment for opening and closing the capacitive current of the capacitor bank of the C2-level circuit breaker is difficult to guarantee by the times of the current opening and closing tests of the capacitor bank of the C2-level circuit breaker, so that the opening and closing capacitive current performance of the switch equipment passing the standard C2-level test is accurately evaluated on the basis of the standard C2-level test, and the test checking times are properly increased according to the requirements of running conditions so as to verify the frequent opening and closing performance of the capacitive current of the circuit breaker.

The high-voltage-class circuit breaker generates overvoltage during switching-on operation, which is harmful to a power grid system, and a switching-on resistor is put into the high-voltage-class circuit breaker at a certain moment to convert part of electric energy into heat energy, so that the aims of weakening electromagnetic oscillation and limiting overvoltage can be fulfilled. The engineering closing resistor is mainly put into two modes as shown in fig. 1:

closing resistor mode 1: when closing, the main fracture is closed first to connect the closing resistor in series into the loop, and the closing inrush current is very small and the frequency is very low; the break of the rear closing resistor short-circuits the closing resistor to a bypass, bears large inrush current and has high frequency. When the resistor is disconnected, the main fracture is completed, and the resistor fracture does not participate in the disconnection process.

Closing resistor mode 2: when closing, firstly closing the resistor fracture to connect the closing resistor in series into the loop, and the closing inrush current is very small and the frequency is very low; the rear closing main fracture is used for short-circuiting the closing resistor to a bypass, and the short-circuiting bypass bears large inrush current and has high frequency. When the resistor is disconnected, the main fracture is completed, and the resistor fracture does not participate in the disconnection process.

After the switching-on resistor is added, the participation of a resistor fracture is increased in the switching-off process, the circuit structure is changed, when the existing C2-level circuit breaker capacitor bank current switching-off test is used for examining the switching equipment with the switching-on resistor, the influence of the switching-on resistor input on the capacitive switching-off capability of the switching equipment is not fully considered, the examined object is not clear in the test, and the evaluation on the capacitive switching-off performance of the switching equipment is not accurate enough.

Therefore, a technique for evaluating the capacitive closing performance of a switching device having a closing resistor is required.

Disclosure of Invention

The technical scheme of the invention provides a method and a system for evaluating the capacitive closing performance of a switching device with a closing resistor, which aim to solve the problem of how to evaluate the capacitive closing performance of the switching device with the closing resistor.

In order to solve the above problems, the present invention provides a method for evaluating capacitive switching performance of a switching device having a switching-on resistance, the method including:

carrying out a current closing test on the examination fracture of the switch equipment according to a standard C2-level circuit breaker capacitor bank current closing test;

calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-grade capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition;

carrying out multiple standard C2-level breaker capacitor bank current closing tests on the switch equipment, and recording the times of the switch equipment passing the current closing tests as A;

and determining the reliable opening and closing times of the switch equipment under the actual operation working condition as A x M times.

Preferably, the switching device comprises:

the main fracture S1 and the resistor fracture S2 are in series connection with each other, and the main fracture S1 and the resistor fracture S2 are in series connection;

the examination fracture is the resistor fracture S2.

Preferably, the switching device comprises:

a main fracture S1, a resistor fracture S2, and a parallel connection between the main fracture S1 and the resistor fracture S2;

the examination fracture is the main fracture S1.

Preferably, the method comprises the following steps:

in a standard C2-level circuit breaker capacitor bank current closing test, the checking fracture of the switch equipment is concentrated phase closing at a voltage peak, and the closing inrush current value of the checking fracture is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2-level breaker capacitor bank current closing test at each time is as follows:

α is a constant, 1.8, I^α _CMtTo the power of α of the closing inrush currentThe value is obtained.

Preferably, the method comprises the following steps:

before the check fracture is closed, the resistor, the inductor and the capacitor on the branch are connected in series to divide voltage, because

Can simplify to resistance and electric capacity series connection partial pressure, and the partial pressure is on the resistance:

wherein, ω L is the inductive reactance of the equivalent circuit; omega C is the capacitive reactance of the equivalent circuit; um is the peak value of the power supply voltage; u shape_RVoltage division is carried out on the resistor; r is resistance;

the maximum value of the turn-off inrush current of the switch equipment under the actual operation working condition is I_CMyIn the operation, the random phase closing is performed, and the relation between the closing inrush current value 1/4 and the closing phase angle in a period is expressed as follows:

i_c＝I_CMy×sinθ

wherein i_CThe switching inrush current is switched off when the phase angle of the power supply voltage is theta;

the maximum pre-breakdown time of the switching equipment without a closing resistor is T_maxWhen taking closing resistor, considering the influence of resistance partial pressure, the maximum pre-breakdown time of the switching equipment is as follows:

the relationship between the arcing time and the closing phase angle in 1/4 cycles can be expressed as:

wherein t is_aThe arc time is closed when the phase angle of the power supply voltage is theta;

the switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching equipment in the pre-breakdown process of a one-time standard C2-level breaker capacitor bank current closing test to the average arc energy of one-time closing in the actual operation working condition is as follows:

M＝Qs/Qa。

based on another aspect of the present invention, the present invention provides a system for evaluating capacitive closing performance of a switching device with a closing resistor, the system comprising:

the execution unit is used for carrying out a current closing test on the examination fracture of the switch equipment according to a standard C2-level circuit breaker capacitor bank current closing test;

the calculation unit is used for calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-level capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition;

the recording unit is used for carrying out multiple times of standard C2-level breaker capacitor bank current closing tests on the switch equipment and recording the times of the switch equipment passing the current closing tests as A;

and the determining unit is used for determining the reliable opening and closing times of the switch equipment under the actual operating condition as A x M times.

Preferably, the switching device comprises:

the main fracture S1 and the resistor fracture S2 are in series connection with each other, and the main fracture S1 and the resistor fracture S2 are in series connection;

the examination fracture is the resistor fracture S2.

Preferably, the switching device comprises:

a main fracture S1, a resistor fracture S2, and a parallel connection between the main fracture S1 and the resistor fracture S2;

the examination fracture is the main fracture S1.

Preferably, for:

in a standard C2 class breaker capacitor bank current closing test, the switchThe examination fracture of the equipment is concentrated phase closure at the voltage peak, and the closure inrush current value of the examination fracture is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2-level breaker capacitor bank current closing test at each time is as follows:

α is a constant, 1.8, I^α _CMtIs the α th power value of the closing inrush current.

Preferably, for:

before the check fracture is closed, the resistor, the inductor and the capacitor on the branch are connected in series to divide voltage, because

Can simplify to resistance and electric capacity series connection partial pressure, and the partial pressure is on the resistance:

wherein, ω L is the inductive reactance of the equivalent circuit; omega C is the capacitive reactance of the equivalent circuit; um is the peak value of the power supply voltage; u shape_RVoltage division is carried out on the resistor; r is resistance;

the maximum value of the turn-off inrush current of the switch equipment under the actual operation working condition is I_CMyIn operation, the random phase closing, closing inrush current value 1/4 can be expressed as the following relation to the closing phase angle:

i_c＝I_CMy×sinθ；

wherein i_CThe switching inrush current is switched off when the phase angle of the power supply voltage is theta;

the maximum pre-breakdown time of the switching equipment without a closing resistor is T_maxWhen taking closing resistor, considering the influence of resistance partial pressure, the maximum pre-breakdown time of the switching equipment is as follows:

the relationship between the arcing time and the closing phase angle in 1/4 cycles can be expressed as:

wherein t is_aThe arc time is closed when the phase angle of the power supply voltage is theta;

the switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching equipment in the pre-breakdown process of a one-time standard C2-level breaker capacitor bank current closing test to the average arc energy of one-time closing in the actual operation working condition is as follows:

M＝Qs/Qa。

the technical scheme of the invention provides a method and a system for evaluating the capacitive closing performance of a switching device with a closing resistor, wherein the method comprises the following steps: carrying out a current closing test on the examination fracture of the switch equipment according to a standard C2-level circuit breaker capacitor bank current closing test; calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-level capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition; carrying out multiple standard C2-level breaker capacitor bank current closing tests on the switch equipment, and recording the times of the switch equipment passing the current closing tests as A; and determining the reliable opening and closing times of the switch equipment under the actual operation working condition as A x M times. The technical scheme of the invention provides a method for evaluating the capacitive closing performance of switching equipment with a closing resistor, which comprises the steps of providing test and examination objects of two different closing resistor schemes, and providing an equivalent calculation method of a laboratory concentrated phase closing capacitive current test and a field operation random phase closing capacitive current working condition from the energy equivalent angle. The technical scheme of the invention solves the problem that the capacitive current switching performance of the switching equipment with a switching-on resistor cannot be accurately evaluated in the current switching test of the capacitor bank of the existing C2-level circuit breaker.

Drawings

A more complete understanding of exemplary embodiments of the present invention may be had by reference to the following drawings in which:

fig. 1 is a schematic diagram of a main fracture and a resistor fracture connected in series according to a closing resistor scheme in the prior art;

fig. 2 is a schematic diagram of a main fracture and a resistor fracture connected in parallel according to a closing resistor scheme in the prior art;

fig. 3 is a flowchart of a method for evaluating capacitive closing performance of a switching device with a closing resistor according to a preferred embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a switching-on resistance switching mode 1 in the engineering according to the preferred embodiment of the invention;

fig. 5 is a schematic circuit diagram of a switching-on resistance switching mode 2 in the engineering according to the preferred embodiment of the invention;

FIG. 6 is an equivalent circuit diagram before closure of the fracture according to the preferred embodiment of the present invention; and

fig. 7 is a system configuration diagram for evaluating capacitive switching performance of a switching device having a switching-on resistor according to a preferred embodiment of the present invention.

Detailed Description

The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.

Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

Fig. 3 is a flowchart of a method for evaluating capacitive switching performance of a switching device with a switching-on resistor according to a preferred embodiment of the present invention. Fig. 4 shows a circuit schematic diagram of a switching-on resistor switching mode 1 in engineering according to an embodiment of the present invention, wherein C1, C2, and … … Cn are parallel capacitor banks connected to a bus through a switching device, S1 and S2 are fractures of a last group of capacitor switching devices, the switching device is provided with a switching-on resistor, the switching-on resistor is the switching-on mode 1, S1 is a main fracture, S2 is a resistor fracture, and the main fracture and the resistor fracture are closed in series. In this connection mode, the on-off capacitive current performance of the resistor fracture needs to be checked, and the checking object of the switch device capacitive current on-off test is the S2 fracture.

Fig. 5 shows a circuit schematic diagram of a switching-on resistor switching mode 2 in engineering, wherein C1, C2 and … … Cn are parallel capacitor banks and are connected to a bus through switching equipment, and S1 and S2 are fractures of the last capacitor switching equipment. The switching equipment is provided with a closing resistor, the closing resistor is in a switching mode 2, S1 is a main fracture, S2 is a resistor fracture, and the main fracture and the resistor fracture are in parallel closing. In this connection mode, the on-off capacitive current performance of the main fracture is checked, and the checked object of the switch device capacitive current on-off test is the S1 fracture.

As shown in fig. 3, the present invention provides a method for evaluating capacitive switching performance of a switching device with a switching resistor, the method including:

preferably, in step 101: and carrying out a current closing test on the checking fracture of the switch equipment according to a standard C2-level breaker capacitor bank current closing test. The invention carries out current switching-on and switching-off tests on the examination fracture of the switching equipment according to the current switching-on and switching-off tests of the standard C2-level breaker capacitor bank.

Preferably, at step 102: and calculating the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-grade capacitor bank current closing test to the average arc energy of single closing in the actual operation condition. The method calculates the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-grade capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition.

Preferably, in step 103: and performing multiple current closing tests on the switch equipment of the standard C2-level breaker capacitor bank, and recording the times of the switch equipment passing the current closing tests as A.

Preferably, at step 104: and determining the reliable opening and closing times of the switch equipment under the actual operation working condition as A x M times. In the invention, if the switch equipment passes A (A is a positive integer) times of standard C2 level closing tests, the reliable opening and closing times of the switch equipment under the actual operation working condition is judged to be A x M times.

As shown in fig. 4, the switching device includes: the main fracture S1, the resistor fracture S2, the main fracture S1 and the resistor fracture S2 are in series connection; the checking fracture is a resistance fracture S2.

As shown in fig. 5, the switching device includes: the main fracture S1, the resistor fracture S2, the main fracture S1 and the resistor fracture S2 are in parallel connection; the checking fracture is a main fracture S1.

Preferably, the method further comprises:

in a standard C2-level circuit breaker capacitor bank current closing test, an examination fracture of a switch device is concentrated phase closing at a voltage peak, and the closing inrush current value of the examination fracture is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2-level breaker capacitor bank current closing test at each time is as follows:

α is a constant, 1.8, I^α _CMtIs the α th power value of the closing inrush current.

Preferably, the method comprises:

before the fracture is checked to be closed, the resistor, the inductor and the capacitor on the branch are connected in series for voltage division, because

Can be simplified into voltage division by connecting a resistor and a capacitor in series and electricityThe upper resistance partial pressure is:

wherein, ω L is the inductive reactance of the equivalent circuit; omega C is the capacitive reactance of the equivalent circuit; um is the peak value of the power supply voltage; u shape_RVoltage division is carried out on the resistor; r is resistance;

the maximum value of the closing inrush current of the switch equipment under the actual operation working condition is I_CMyIn operation, the random phase closing, closing inrush current value 1/4 can be expressed as the following relation to the closing phase angle:

i_c＝I_CMy×sinθ；

wherein i_CThe switching inrush current is switched off when the phase angle of the power supply voltage is theta;

the maximum pre-breakdown time of the switching equipment without a closing resistor is T_maxWhen taking closing resistor, considering the influence of resistance partial pressure, the maximum pre-breakdown time of the switching equipment is as follows:

the relationship between the arcing time and the closing phase angle in 1/4 cycles can be expressed as:

wherein t is_aThe arc time is closed when the phase angle of the power supply voltage is theta;

the switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching equipment in the pre-breakdown process of a one-time standard C2-level breaker capacitor bank current closing test to the average arc energy of one-time closing in the actual operation working condition is as follows:

M＝Qs/Qa。

the invention starts from the angle of arc energy, calculates the arc energy of a standard C2-level test of the switch equipment with a closing resistance and a pre-breakdown arcing process of a field operation working condition, and analyzes the equivalent condition of the capacitive current closing capability of the C2-level test of the switch equipment with the closing resistance.

In the pre-breakdown process, the high-frequency inrush current effect is mainly used, and the inrush current provided by a power frequency power supply can be ignored during the simplified analysis, generally, the arc energy can be used as ∑ I^α·t_a(1<α<2) Characterization, where I is the off current value, t_aIs the pre-breakdown time.

In a standard C2-level test, the examination fracture of the switch equipment is concentrated phase closing at a voltage peak value, and a closing inrush current value is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2 capacitor bank current closing test each time is as follows:

where α may be 1.8.

In actual operating conditions, the closing phase is random. Because of resistance voltage division, the fracture voltage of the fracture to be checked is lower than the bus voltage, and the pre-breakdown time in the closing process is correspondingly reduced. After the closing resistor is connected in series with the branch circuit, before the checked fracture is closed, the equivalent circuit diagram is shown in fig. 6, wherein S is the checked fracture.

Before the examined fracture is closed, the resistor, the inductor and the capacitor on the branch are connected in series to divide voltage, becauseCan simplify to resistance and electric capacity series connection partial pressure, and the partial pressure is on the resistance:

switch with a switch bodyThe maximum value of the closing inrush current under the operation condition of the equipment is I_CMyWhen the phase is closed at random phase position in operation, the current is in direct proportion to the sine value of the closed phase angle theta in 1/4 power frequency period, i.e. i_c＝I_CMy×sinθ。

The maximum pre-breakdown time of the switching equipment is T without a closing resistor_max. When the switch-on resistor is arranged, the influence of resistor voltage division is considered, and the maximum pre-breakdown time of the switch equipment is

The arcing time is proportional to the sine of the closing phase angle theta in 1/4 power frequency period, i.e.The switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching device in the pre-breakdown process of a one-time standard C2-level capacitive current closing test to the average arc energy of a single closing in the actual operating condition is as follows:

M＝Qs/Qa。

the invention provides a method for evaluating the capacitive closing performance of a switching device with a closing resistor, which defines the assessment object of the capacitive current closing test of the switching device with the closing resistor, and provides the steps of the capacitive current closing test of the switching device with the closing resistor and an equivalent calculation method of the capacitive current closing test of the switching device with the closing resistor and the closing working condition in operation. The evaluation method provided by the invention can more accurately evaluate the capacitive switching performance of the switching equipment with the switching-on resistor, and on-site maintenance plans can be respectively made for the switching equipment according to the performance evaluation and the actual use condition, so that the requirement of fine management of the switching equipment in engineering is met.

The following illustrates embodiments of the invention: for example, a converter station 800kV ac filter is configured with: BP11/13 AC filter, SC high voltage shunt capacitor and HP24/36 AC filter.

In order to inhibit the switching-on inrush current, the switching equipment for switching on the capacitive current in the converter station uses a switching-on resistor, the switching-on resistor used for a BP11/13 filter bank circuit breaker is 1500 omega, the switching-on resistor used for an SC and HP24/36 filter bank circuit breaker is 600 omega, and the maximum value I of the switching-on inrush current under the working condition of field operation is_CMyThe temperature was 9.5 kA.

The switching-on resistor of the capacitor bank circuit breaker used in the station is connected in series with the main fracture and the resistor fracture. Therefore, the switch device capacitive current closing test is evaluated by a resistor fracture. Wherein, the closing inrush current value I in the standard C2 level test of the switch equipment_CMt10 kA. The switchgear model test passed 300 standard C2-level closing tests.

When the switching device is used for switching on and off alternating current filters and capacitors of different models and is matched with switching-on resistors with different resistance values, the switching device passes 300 times of standard C2-grade capacitor bank switching-on and switching-off tests, and the equivalent condition of the switching-on and switching-off working conditions in operation is as follows:

when the method is used for closing the BP11/13 alternating current filter, the random phase in equivalent operation can be closed for 1221 times;

when the method is used for closing the SC alternating current filter, the random phase in equivalent operation can be closed for 1200 times;

when used for closing an HP24/36 AC filter, the filter can be equivalently operated for 1421 times by random phase closing.

If the influence of closing resistance is considered, the circuit breaker of the model passes 300 times of standard C2 capacitor bank closing tests, and is closed only by 800 times in random phase in equivalent operation.

The performance evaluation is carried out according to the method provided by the invention, so that the overhaul period can be prolonged, different overhaul plans can be respectively formulated for circuit breakers used by filters of different types, and different overhaul periods are adopted.

The invention combines the capacitive current closing test of the switch equipment with the closing resistance and the equivalent calculation method of the closing working condition in operation, and can accurately evaluate the performance level of the closing capacitive current of the switch equipment with the opening and closing capacitive current of the closing resistance.

Fig. 7 is a system configuration diagram for evaluating capacitive switching performance of a switching device having a switching-on resistor according to a preferred embodiment of the present invention. Fig. 4 shows a circuit schematic diagram of a switching-on resistor switching mode 1 in engineering according to an embodiment of the present invention, wherein C1, C2, and … … Cn are parallel capacitor banks connected to a bus through a switching device, S1 and S2 are fractures of a last group of capacitor switching devices, the switching device is provided with a switching-on resistor, the switching-on resistor is the switching-on mode 1, S1 is a main fracture, S2 is a resistor fracture, and the main fracture and the resistor fracture are closed in series. In this connection mode, the on-off capacitive current performance of the resistor fracture needs to be checked, and the checking object of the switch device capacitive current on-off test is the S2 fracture.

Fig. 5 shows a circuit schematic diagram of a switching-on resistor switching mode 2 in engineering, wherein C1, C2 and … … Cn are parallel capacitor banks and are connected to a bus through switching equipment, and S1 and S2 are fractures of the last capacitor switching equipment. The switching equipment is provided with a closing resistor, the closing resistor is in a switching mode 2, S1 is a main fracture, S2 is a resistor fracture, and the main fracture and the resistor fracture are in parallel closing. In this connection mode, the on-off capacitive current performance of the main fracture is checked, and the checked object of the switch device capacitive current on-off test is the S1 fracture.

As shown in fig. 7, the present invention provides a system for evaluating capacitive switching performance of a switching device having a switching resistor, the system including:

the execution unit 701 is used for performing a current closing test on the examination fracture of the switch device according to a standard C2-level circuit breaker capacitor bank current closing test. The invention carries out current switching-on and switching-off tests on the examination fracture of the switching equipment according to the current switching-on and switching-off tests of the standard C2-level breaker capacitor bank.

The calculating unit 702 is configured to calculate a ratio M of arc energy during a pre-breakdown process of a primary standard C2-class capacitor bank current closing test of the switching device to average arc energy of a single closing in an actual operating condition. The method calculates the ratio M of the arc energy of the switching equipment in the pre-breakdown process of the primary standard C2-grade capacitor bank current closing test to the average arc energy of single closing in the actual operation working condition.

The recording unit 703 is configured to perform multiple standard C2-class breaker capacitor bank current closing tests on the switching device, and record the number of times that the switching device passes the current closing test as a.

A determining unit 704, configured to determine that the number of reliable opening and closing times of the switchgear under the actual operating condition is a x M times. In the invention, if the switch equipment passes A (A is a positive integer) times of standard C2 level closing tests, the reliable opening and closing times of the switch equipment under the actual operation working condition is judged to be A x M times.

As shown in fig. 4, the switching device includes: the main fracture S1, the resistor fracture S2, the main fracture S1 and the resistor fracture S2 are in series connection; the checking fracture is a resistance fracture S2.

As shown in fig. 5, the switching device includes: the main fracture S1, the resistor fracture S2, the main fracture S1 and the resistor fracture S2 are in parallel connection; the checking fracture is a main fracture S1.

Preferably, the system is for:

in a standard C2-level circuit breaker capacitor bank current closing test, an examination fracture of a switch device is concentrated phase closing at a voltage peak, and the closing inrush current value of the examination fracture is I_CMtMaximum pre-breakdown time of T_maxThe arc energy Qs in the pre-breakdown process of the standard C2-level breaker capacitor bank current closing test at each time is as follows:

α is a constant, 1.8, I^α _CMtIs the α th power value of the closing inrush current.

Preferably, the system is for:

before the fracture is checked to be closed, the resistor, the inductor and the capacitor on the branch are connected in series for voltage division, becauseCan simplify to resistance and electric capacity series connection partial pressure, and the partial pressure is on the resistance:

wherein, ω L is the inductive reactance of the equivalent circuit; omega C is the capacitive reactance of the equivalent circuit; um is the peak value of the power supply voltage; u shape_RVoltage division is carried out on the resistor; r is resistance;

the maximum value of the closing inrush current of the switch equipment under the actual operation working condition is I_CMyIn operation, the random phase closing, closing inrush current value 1/4 can be expressed as the following relation to the closing phase angle:

i_c＝I_CMy×sinθ；

wherein i_CThe switching inrush current is switched off when the phase angle of the power supply voltage is theta; the maximum pre-breakdown time of the switching equipment without a closing resistor is T_maxWhen taking closing resistor, considering the influence of resistance partial pressure, the maximum pre-breakdown time of the switching equipment is as follows:

the relationship between the arcing time and the closing phase angle in 1/4 cycles can be expressed as:

wherein t is_aThe arc time is closed when the phase angle of the power supply voltage is theta;

the switching equipment is switched on at random phases in operation, and the average arc energy Qa of single switching-on is as follows:

the ratio of the arc energy of the switching equipment in the pre-breakdown process of a one-time standard C2-level breaker capacitor bank current closing test to the average arc energy of one-time closing in the actual operation working condition is as follows:

M＝Qs/Qa。

the invention has been described with reference to a few embodiments. However, other embodiments of the invention than the one disclosed above are equally possible within the scope of the invention, as would be apparent to a person skilled in the art from the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [ device, component, etc ]" are to be interpreted openly as referring to at least one instance of said device, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.