CN104319738B - Protection setting calculation model for high-voltage variable-frequency motor - Google Patents

Abstract

The invention discloses a protection setting calculation model for a high-voltage variable-frequency motor. The protection setting calculation model for the high-voltage variable-frequency motor comprises a protection setting calculation model for the high-voltage variable-frequency motor with a phase-shifting transformer and a protection setting calculation model for the high-voltage variable-frequency motor without the phase-shifting transformer, and each of the two protection setting calculation models comprises a long start protection setting calculation model, a current quick-breaking protection setting calculation model, an overcurrent protection setting calculation model, a negative-sequence current protection setting calculation model, an overheat protection setting calculation model, a ground protection setting calculation model and a low-voltage protection setting calculation model; the protection setting calculation model for the high-voltage variable-frequency motor without the phase-shifting transform further comprises a locked-rotor protection setting calculation model. The protection setting calculation model for the high-voltage variable-frequency motor provides reference basis for the protection setting calculation of the high-voltage variable-frequency motor, and therefore, the protection functions are more complete, the protection set value is more reasonable, and the high-voltage frequency converter and the high-voltage motor can be protected to the utmost extent.

Description

A kind of high-pressure frequency-conversion motor protection adaptive setting model

Technical field

The present invention relates to a kind of high-pressure frequency-conversion motor protection adaptive setting model, belongs to technical field of relay protection.

Background technology

In recent years, due to being affected by load configuration change, the peak-valley difference of electrical network is increasing.For this many electromotor Group, or even the unit of Large Copacity, high parameter will participate in peaking operation.Frequently peak regulation task causes high pressure auxiliary motor Open, stop number of times increase, motor causes the situation cumulative year after year of insulation damages because being hit；On the other hand, using regulating fender, The method of valve opening carries out output regulation, causes subsidiary engine longtime running in inefficient working area, causes energy waste serious. In order to improve the running environment of motor, while in order to reduce station service power consumption rate,《Ten big emphasis energy conservation project reality in Eleventh-Five Year Plan Apply suggestion》Propose to promote variable-frequency control technique, emphasis carries out speed governing transformation to big-and-middle-sized variable working condition electric system.At present, it is most The Important Auxiliary equipment of power plant such as blower fan, water pump etc., are generally individually dragged using converter.After converter, conventional motors protection Needs can not be met and so that the safety of motor is on the hazard.The protection problem of motor in frequency conversion system is carried out research and Analysis, targetedly carries out adaptive setting optimization then, proposes more perfect, more rational synchronizing calculation method, is to work as Important topic urgently to be resolved hurrily during front Medium Voltage Variable Frequency Speed Regulation Technology is practical.

The article of the Energy Saving Benefit Analysis for bringing for high voltage converter both at home and abroad at present is a lot, but for high-voltage electric Protective strategy of adjusting after machine frequency conversion is relatively fewer, and many articles simply propose general setting method, but for true Just can in practice apply and the adaptive setting of solving practical problems discusses little.After motor attached with frequency converters, to motor Traditional protection mode generate very big impact.High-pressure frequency-conversion motor protection configuration at present is not enough, needs to study new being adapted to The relaying configuration scheme of wide scope frequency modulation high-tension motor.

The content of the invention

It is an object of the invention to provide a kind of high-pressure frequency-conversion motor protection adaptive setting model, can give high-pressure frequency-conversion Motor protection adaptive setting provides reference frame.

To reach above-mentioned purpose, the technical solution adopted in the present invention is：A kind of high-pressure frequency-conversion motor protection is adjusted meter Model is calculated, including with phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model and without phase-shifting transformer high-pressure frequency-conversion Motor protection adaptive setting model, it is described with phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model and without shifting Phase transformer high-pressure frequency-conversion motor protection adaptive setting model is included：Long starting protection adaptive setting model, electric current speed Disconnected protection seting computation model, overcurrent protection adaptive setting model, unbalanced fault protection adaptive setting model, overtemperature protection are whole Determine computation model, ground protection adaptive setting model and under-voltage protection adaptive setting model, it is described high without phase-shifting transformer Buckling frequency motor protection adaptive setting model also includes rotation-clogging protection adaptive setting model.

The long starting protection adaptive setting model is：

The specified starting current I of (a) motor_st

I_st=K_stI_e

In formula, for band phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, I_eFor phase-shifting transformer two Secondary rated current, K_stFor safety factor；For without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, I_eFor The secondary rated current of motor, K_stFor drop-off to pick-up radio；K_stTake 1.2；

(b) motor under converting operation mode, starting time proper extension, it is considered to leave nargin, if starting time is t_op

t_op=(1.2-1.3) t_qd

In formula, t_qdFor the motor start-up time of power frequency actual measurement.

The current quick adaptive setting with phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model Model includes：Vacuum circuit breaker current quick adaptive setting model and FC loop current fast tripping protection adaptive setting models, FC loop current fast tripping protection adaptive setting models include again：Without high current locking trip outlet function adaptive setting model and There is the adaptive setting model of high current locking tripping operation outlet function：

A, vacuum circuit breaker current quick adaptive setting model

(1) action current：Excitation surge current by phase-shifting transformer is escaped is adjusted, i.e.,

I_oph=KI_e

In formula：K is multiple, and depending on transformer capacity, the concrete span of K is as follows：

6300kVA and following：7~12；

6300kVA~31500kVA：4.5~7.0；

40000kVA~120000kVA：3.0~6.0；

120000kVA and more than：2.0~5.0；

(2) sensitivity check

In formula：n_TATo protect the high-voltage switch gear inlet wire no-load voltage ratio for using；

On high-tension side electric current is flowed through for line to line fault in the protection zone of high-pressure side；

I_ophFor current quick action current；

(3) action delay：By the way of vacuum circuit breaker, 0.05s is taken for all；

B, FC loop current fast tripping protection adaptive setting model：

The adaptive setting model of a, the outlet function that trips without high current locking, it is as follows：

(1) action current：It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e.,：I_oph=KI_e；

(2) action delay：t_opThe maximum duration of fuse fuse failure is taken, span is：0.3~1s.

B, the adaptive setting model for having high current locking tripping operation outlet function, it is as follows：

(1) action current：It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e.,：I_oph=KI_e；

(2) latching current definite value I_art

In formula：I_artFor high current locking definite value；

I_brkTurn-off current is allowed for vacuum contactor；

K_relFor safety factor, 1.3~1.5 are taken；

(3) action delay

t_op=0.05~1s

(4) sensitivity check

The current quick without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model is adjusted meter Calculating model also includes：Vacuum circuit breaker current quick adaptive setting model and FC loop current fast tripping protection adaptive setting moulds Type, FC loop current fast tripping protection adaptive setting models include again：The adaptive setting mould of the outlet function that trips without high current locking Type and the adaptive setting model for having high current locking tripping operation outlet function：C, vacuum circuit breaker current quick adaptive setting mould Type is as follows：

(2) action current：Principle by motor maximum starting current is escaped is adjusted, i.e.,

I_oph=K_relK_st·I_e

In formula：K_rel1.5 are taken for safety factor；

K_stFor motor starting current multiple, calculate by measured value, span is 6~8；

(2) sensitivity check

In formula：n_TAFor high-voltage switch gear inlet wire no-load voltage ratio；

For the sub-value of motor entrance minimum line to line fault electric current one；

I_ophFor current quick action current；

(3) action delay：For all, by the way of vacuum circuit breaker, movement time takes 0.05s.

D, FC loop current fast tripping protection adaptive setting model, it is as follows：

(1) adaptive setting of the outlet function that trips without high current locking：

(a) action current：

It is identical with vacuum circuit breaker current quick-breaking action current synchronizing calculation method, i.e. I_oph=K_relK_st·I_e；

(b) action delay：t_opThe maximum duration of fuse fuse failure is taken, span is：0.3~1s；

(2) there is the adaptive setting model of high current locking tripping operation outlet function, it is as follows：

(a) action current：

It is identical with vacuum circuit breaker current quick-breaking action current synchronizing calculation method, i.e. I_oph=K_relK_st·I_e；

(b) latching current setting valve I_artCalculate

In formula：I_artFor high current locking definite value；I_brkTurn-off current is allowed for vacuum contactor；K_relFor safety factor, take 1.3~1.5；

(3) action delay：

t_op=0.05~1s；

(4) sensitivity check：

The overcurrent protection adaptive setting model is：

(a) action current

For band phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, action current I_opBecome by phase shift is escaped The secondary rated current of depressor is adjusted；For without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, action electricity Stream I_opAdjust by the secondary rated current of motor is escaped；

In formula：K_relFor safety factor, 1.05~1.2 are taken；

K_rFor drop-off to pick-up radio, 0.85~0.95 is taken；

(b) action delay

t_op=(1-1.1) t_qd

In formula：t_opFor overcurrent protection action delay；

t_qdFor the motor start-up time.

The unbalanced fault protection adaptive setting model includes：Negative phase-sequence I section protection seting computation model and negative phase-sequence II section are protected Shield protection seting computation model：

(a) negative phase-sequence I section protection seting computation model：

By when motor negative phase-sequence feedback current when escaping unsymmetrical short-circuit outside area and motor start-up due to current transformer The negative-sequence current that error and transient characterisitics occur, and ensure motor in larger load two-phase operation and motor interior not There are enough sensitivity synthesis to consider to calculate during symmetrical short-circuit：

Action current I_2.1dz：

I_2.1dz=(0.6~1.4) I_e

Action delay t_2.1dz：

If 1) device provides negative phase-sequence reverse blocking function, t_2.1dz=(0.5~1) s；

If 2) device does not provide negative phase-sequence reverse blocking function, t_2.1dz=(5~6) s is biphase short to escape motor outside The misoperation that the negative-sequence current that road failure is produced causes；

(b) negative phase-sequence II section protection seting computation model：

By escaping when motor normally runs possible maximum negative-sequence current and motor when compared with Smaller load two-phase operation There is enough sensitivity to consider, use as sensitive unbalance protection, alarm may be selected：

Action current I_2.2dz：

I_2.2dz=(0.2~0.35) I_e

Action delay t_2.2dz：Take the starting time more than motor.

The Over Heat Protection Setting Calculation model includes：Motor occur it is overheated when Over Heat Protection Setting Calculation model and Based on the overheated Over Heat Protection Setting Calculation models risen with real index curve of IEC60255-8；

When () motor occurs overheated a, temperature is raised always with actual exponential curve starting climbing speed, and its model is

In formula：I_eFor the secondary rated current of motor；

I_eqTo cause the equivalent current of heating；

τ is electric motor overheating time constant；

I₁、I₂For the positive and negative sequence electric current of motor；

K₁、K₂For positive and negative sequence heating effect of current coefficient, K in starting process of motor₁Take 0.5~1, K₂Take 3~10；

B () is as follows based on the overheated Over Heat Protection Setting Calculation models with the rising of real index curve of IEC60255-8：

In formula：I_[0]For overheated front motor current；

ξ is a coefficient for considering to radiate under motor normal operation, takes 50%；

I_∞For overtemperature protection starting current, span is (1.05~1.15) I_e。

The ground protection adaptive setting model includes：Isolated neutral system one-phase ground protection adaptive setting model With Neutral Point Through Low Resistance system one-phase ground protection adaptive setting model：

A, isolated neutral system one-phase ground protection adaptive setting model are as follows：

(1) action current

Earth current by protection installation place is flow through when escaping single-phase earthing outside area is calculated, i.e.,：

In formula：I_op.0For single-phase earthing zero sequence excess current protection act electric current；

K_relFor safety factor, 2.5~3s is taken when protection act also trips, protection act takes 2~2.5s when signal；

To supply the earth current of short dot by protection equipment during single-phase earthing outside dorsal zone,I_eFor the back of the body By protection equipment positive direction capacitance current sum during single-phase earthing outside lateral areas；

(2) movement time

When 3~10kV earth currents are not less than 10A, 0.5~1s is taken；

When 3~10kV earth currents are less than 10A, to 300MW and above unit, if meeting selectivity and sensitivity requirement When, take 0.5~1s；

It is actionable in letter when can not such as meet sensitivity and selectively require when 3~10kV earth currents are less than 10A Number, take 0.5s；

(3) sensitivity test

In formula：When being that single-phase earthing occurs by protection equipment, the total sub-value of earthing capacitance current two in trouble point；

B, Neutral Point Through Low Resistance system one-phase ground protection adaptive setting model are as follows：

(1) action current：Take the greater in both following (a) and (b)；

A () calculates by single-phase earthing outside area is escaped

In formula：K_relFor safety factor, 1.1~1.15 are taken；

B () calculates by busy hour out-of-balance current is escaped

I_op.0=K_relI_umb

In formula：K_relFor safety factor, 1.3 are taken；

I_umbFor busy hour out-of-balance current；

I_umb≤ (0.1~0.15) × I_N, I_NFor feeder line rated current；

(2) action delay：0~0.05s；

(3) sensitivity check

In formula：For single-phase earthing of small current earthing system electric current.

The under-voltage protection adaptive setting model includes as follows：

(1) for the motor with intermediate system, the operation voltage of low-voltage variation：

U_dz=(0.6~0.7) U_N

Action delay：0.5~1.5s；

(2) for the motor for automatically engaging stand-by machine, the operation voltage of under-voltage protection：

U_dz=(0.4~0.5) U_N

Action delay：5~10s.

The rotation-clogging protection adaptive setting model is as follows：

(1) below 600MW units：

Action current：I_dz=(1.3~1.5) I_e；

Action delay：t_op.set=15~20s；

(2) the fan-type units of more than 600MW：

Calculate by sort time overcurrent is escaped

Action current：I_dz=(1.8~2.0) I_e；

Action delay：t_op.set=15~20s；

Or

Adjust as action current setting valve：I_dz=1.5I_e；

Action delay：t_op.set=25~30s；

(3) 600MW is with charging pump class unit：

Action current：I_dz=(1.3~1.5) I_e；

Action delay：t_op.set=15~20s.

Compared with prior art, the beneficial effect that reached of the present invention is：There is provided a kind of guarantor of high-pressure frequency-conversion motor Shield adaptive setting model, to high-pressure frequency-conversion motor protection adaptive setting reference frame is provided, and makes defencive function more perfect, Protection definite value is more reasonable, and high voltage converter and high-tension motor are protected to greatest extent, significantly reduces the operation dimension of thermal power plant Shield cost.

Specific embodiment

High-pressure frequency-conversion motor protection adaptive setting model, including adjust with phase-shifting transformer high-pressure frequency-conversion motor protection Computation model and without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model.

With phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model and without phase-shifting transformer high-pressure frequency-conversion electricity Motivation protection seting computation model is included：Long starting protection adaptive setting model, current quick adaptive setting model, Overcurrent protection adaptive setting model, unbalanced fault protection adaptive setting model, Over Heat Protection Setting Calculation model, ground protection Adaptive setting model and under-voltage protection adaptive setting model.

Each protection seting computation model in the present invention is further described below, for clearly illustrating the present invention Technical scheme, and can not be limited the scope of the invention with this.

1.1. long starting protection adaptive setting model

(1) the specified starting current I of motor_st

I_st=K_stI_e

In formula, for band phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, I_eFor phase-shifting transformer two Secondary rated current, K_stFor safety factor；For without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, I_eFor The secondary rated current of motor, K_stFor drop-off to pick-up radio；K_stTypically take 1.2.

(2) motor is under converting operation mode, starting time proper extension, it is considered to leave nargin, if starting time is t_op

t_op=(1.2-1.3) t_qd

In formula, t_qdFor power frequency actual measurement the motor start-up time, i.e., motor start-up to rotating speed reach rated speed when Between.When not surveying, can use：Water circulating pump is 20s, and electrically driven feed pump is 20s, and pressure fan is 20s, and induced-draught fan is 20s, coal-grinding Machine is 20s, and exhaust blower is 15s, and faster motor can use 10s for some other startup.

1.2. current quick adaptive setting model

Current quick adaptive setting model includes that vacuum circuit breaker current quick adaptive setting model and FC are returned Road current quick adaptive setting model, and FC loop current fast tripping protection adaptive setting models include：Close without high current The adaptive setting model and the adaptive setting model for having high current locking tripping operation outlet function of lock tripping operation outlet function.For band is moved Phase transformer high-pressure frequency-conversion motor protection adaptive setting model, meter of adjusting without phase-shifting transformer high-pressure frequency-conversion motor protection Model is calculated, respective current quick adaptive setting model is established respectively.

Current quick adaptive setting model in band phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model Detailed content is as follows：

1.2.1. vacuum circuit breaker current quick adaptive setting model

(1) action current

Excitation surge current by escaping phase shift transformation and suppressing device is adjusted, i.e.,

I_oph=KI_e

In formula：K is multiple, and depending on transformer capacity, the span of K is as follows：

6300kVA and following：7~12；

6300kVA~31500kVA：4.5~7.0；

40000kVA~120000kVA：3.0~6.0；

120000kVA and more than：2.0~5.0.

(2) sensitivity check

In formula：n_TATo protect (high-voltage switch gear inlet wire) the CT no-load voltage ratios for using；

On high-tension side electric current is flowed through for line to line fault in the protection zone of high-pressure side；

I_ophFor current quick action current.

(3) action delay

For all, by the way of vacuum circuit breaker, movement time takes 0.05s.

1.2.2.FC loop current fast tripping protection adaptive setting model

The adaptive setting model of the outlet function that 1.2.2.1 trips without high current locking：

(1) action current

It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e. I_oph=KI_e。

(2) action delay

t_opThe maximum duration of fuse fuse failure is taken, recommends 0.3s~1s.

1.2.2.2 there is the adaptive setting model of high current locking tripping operation outlet function：

(1) action current

It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e. I_oph=KI_e。

(2) latching current definite value I_art

In formula：I_artFor high current locking definite value；

I_brkTurn-off current is allowed for vacuum contactor；

K_relFor safety factor, 1.3~1.5 are taken；

(3) action delay

t_op=0.05~1s；

(4) sensitivity check

Without current quick adaptive setting mould in phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model The detailed content of type is as follows：

2.3.1 vacuum circuit breaker current quick adaptive setting model

(1) action current

Principle by motor maximum starting current is escaped is adjusted, i.e.,

I_oph=K_relK_st·I_e

In formula：K_rel1.5 are taken for safety factor.K_stFor motor starting current multiple, typically between 6~8, should be by reality Measured value is calculated, and as without actual measurement K is taken_st=7.

(2) sensitivity check

In formula：n_TAFor CT no-load voltage ratios；For the sub-value of motor entrance minimum line to line fault electric current one；

I_ophFor current quick action current.

(3) action delay

For all, by the way of vacuum circuit breaker, movement time takes 0.05s.

2.3.2FC loop current fast tripping protection adaptive setting model

(1) adaptive setting of the outlet function that trips without high current locking：

(a) action current

It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e. I_oph=K_relK_st·I_e。

(b) action delay

t_opThe maximum duration of fuse fuse failure is taken, span is 0.3~1s.

(2) there is the adaptive setting of high current locking tripping operation outlet function：

(a) action current

It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e. I_oph=K_relK_st·I_e。

(b) latching current setting valve I_artCalculate

In formula：I_artFor high current locking definite value；I_brkTurn-off current is allowed for vacuum contactor；K_relFor safety factor, take 1.3~1.5.

(c) action delay：

t_op=0.05~1s；

(d) sensitivity check：

1.3. overcurrent protection adaptive setting model

(1) action current

Adjust by the secondary rated current of phase shift change pressure is escaped

In formula：K_relFor safety factor, 1.05~1.2 are taken；

K_rFor drop-off to pick-up radio, 0.85~0.95 is taken.

(2) action delay

t_op=(1-1.1) t_qd

In formula：t_opFor overcurrent protection action delay；t_qdFor the motor start-up time.

1.4. negative phase-sequence overcurrent protection adaptive setting model

Motor turn-to-turn short circuit, disconnected phase, phase sequence error, the larger unbalanced protection of supply voltage are made in negative phase-sequence overcurrent protection, Play back-up protection effect to motor asymmetry short circuit fault.Unbalanced fault protection adaptive setting model includes：Negative phase-sequence I section is protected Adaptive setting model and negative phase-sequence II section protection protection seting computation model.

(1) negative phase-sequence I section protection seting computation model

By when motor negative phase-sequence feedback current when escaping unsymmetrical short-circuit outside area and motor start-up due to current transformer The negative-sequence current that error and transient characterisitics occur, and ensure motor in larger load two-phase operation and motor interior not There are enough sensitivity synthesis to consider to calculate during symmetrical short-circuit.

Action current I_2.1dz：

I_2.1dz=(0.6~1.4) I_e

Action delay t_2.1dz：

If 1) device provides negative phase-sequence reverse blocking function, t_2.1dz=(0.5~1) s；

If 2) device does not provide negative phase-sequence reverse blocking function, t_2.1dz=(5~6) s is biphase short to escape motor outside The misoperation that the negative-sequence current that road failure is produced causes；

(2) negative phase-sequence II section protection seting computation model

By escaping when motor normally runs possible maximum negative-sequence current and motor when compared with Smaller load two-phase operation There is enough sensitivity to consider, use as sensitive unbalance protection, alarm may be selected.

Action current I_2.2dz：

I_2.2dz=(0.2~0.35) I_e

Action delay t_2.2dz：Typically take the starting time more than motor.

1.5. Over Heat Protection Setting Calculation model

Over Heat Protection Setting Calculation model includes：Motor occur it is overheated when Over Heat Protection Setting Calculation model and be based on The overheated Over Heat Protection Setting Calculation models risen with real index curve of IEC60255-8.

Over Heat Protection Setting Calculation model when () motor occurs overheated a：Motor occur it is overheated when, temperature always with Actual exponential curve starting climbing speed is raised, and its model is

In formula：I_eFor the secondary rated current of motor；

I_eqTo cause the equivalent current of heating；

τ is electric motor overheating time constant；Should be provided by motor maker, such as producer does not provide, can be according to producer The capability of overload data of offer, locked rotor current and allow stator temperature rise, the motor start-up electricity under stall time, starting current Flow multiple and starting time to calculate.

I₁、I₂For the positive and negative sequence electric current of motor；

K₁、K₂For positive and negative sequence heating effect of current coefficient, K in starting process of motor₁0.5~1 is taken, negative-sequence current heat effect COEFFICIENT K₂3~10 are taken, 6 are typically can use；

B () is as follows based on the overheated Over Heat Protection Setting Calculation models with the rising of real index curve of IEC60255-8：

In formula：I_[0]For overheated front motor current, generally equivalent to rated current, if motor overload is in cold standby State, then equal to zero；

ξ is a coefficient for considering to radiate under motor normal operation, takes 50%；

I_∞For overtemperature protection starting current, span is (1.05~1.15) I_e, typically can use 1.1I_e。

Adaptive setting

(4) radiate time constant, can use 32~36min, for high power motor, generally takes 4 τ.

1.6. ground protection adaptive setting model

Ground protection adaptive setting model includes：Isolated neutral system one-phase ground protection adaptive setting model is with Property point Jing small resistance grounding system one-phase ground protection adaptive setting models.

1.6.1 isolated neutral system one-phase ground protection adaptive setting model

(1) action current

Earth current by protection installation place is flow through when escaping single-phase earthing outside area is calculated, i.e.,：

In formula：I_op.0For single-phase earthing zero sequence excess current protection act electric current；

K_relFor safety factor, 2.5~3s is taken when protection act also trips, protection act takes 2~2.5s when signal.

To supply the earth current of short dot by protection equipment during single-phase earthing outside dorsal zone,I_eFor the back of the body By protection equipment positive direction capacitance current sum during single-phase earthing outside lateral areas.

(2) movement time

When 3~10kV earth currents are not less than 10A, 0.5~1s is taken.

When 3~10kV earth currents are less than 10A, to 300MW and above unit, if meeting selectivity and sensitivity requirement When, it is proposed that tripping operation is selected, 0.5~1s is taken movement time.

It is actionable in letter when can not such as meet sensitivity and selectively require when 3~10kV earth currents are less than 10A Number, movement time takes 0.5s.

(3) sensitivity test

In formula：When being that single-phase earthing occurs by protection equipment, the total sub-value of earthing capacitance current two in trouble point；

1.6.2 Neutral Point Through Low Resistance system one-phase ground protection adaptive setting

(1) action current：Take both (a) and (b) the greater.

A () calculates by single-phase earthing outside area is escaped

In formula：K_relFor safety factor, 1.1~1.15 are taken.

B () calculates (only just consider this principle when special zero sequence CT is not used) by busy hour out-of-balance current is escaped

I_op.0=K_relI_umb

In formula：K_relFor safety factor, 1.3 are taken；

I_umbFor busy hour out-of-balance current；

Generally：I_umb≤ (0.1~0.15) × I_N, I_NFor feeder line rated current.

(2) action delay：0~0.05s.

(3) sensitivity check

In formula：For single-phase earthing of small current earthing system electric current.

1.7. under-voltage protection adaptive setting model

When supply network voltage is reduced, the rotating speed of asynchronous motor will decline, and work as the recovery of power supply buses voltage When, a large amount of motor self-startings are absorbed compared with the big several-fold starting current of its rated current, cause voltage recovery time to be spun out. To prevent from making the serious reduction of line voltage long-time during motor self-starting, low-voltage guarantor is generally installed on secondary motor Shield, when power supply buses voltage is reduced to certain value, time delay cuts off on secondary motor, makes power supply buses have enough voltage, To ensure important motor self-starting.Under-voltage protection is divided into two-stage：

(1) it is low for the motor of the coal pulverizer and ash pump, slurry pump, coal breaker for having middle coal bunker pulverized coal preparation system etc. The operation voltage of voltage protection：

U_dz=(0.6~0.7) U_N

Action delay：0.5~1.5s.

(2) feed pump and condensate pump of stand-by machine and the motor of water circulating pump are automatically engaged, is sent for having The motor of blower fan and blow-through stove pulverized coal preparation system coal pulverizer, the operation voltage of under-voltage protection：

U_dz=(0.4~0.5) U_N

Action delay：5~10s.

1.8. rotation-clogging protection adaptive setting model

Also include rotation-clogging protection adaptive setting mould without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model Type, it is specific as follows：

(1) below 600MW units：

Action current：I_dz=(1.3~1.5) I_e；

Action delay：t_op.set=15~20s；

(2) the fan-type units of more than 600MW：

Calculate by sort time overcurrent is escaped

Action current：I_dz=(1.8~2.0) I_e；

Action delay：t_op.set=15~20s；

Or

Adjust as action current setting valve：I_dz=1.5I_e；

Action delay：t_op.set=25~30s；

(3) 600MW is with charging pump class unit：

Action current：I_dz=(1.3~1.5) I_e；

Action delay：t_op.set=15~20s.

The above is only the preferred embodiment of the present invention, it is noted that for the ordinary skill people of the art For member, on the premise of without departing from the technology of the present invention principle, some improvement and deformation can also be made, these improve and deform Also should be regarded as protection scope of the present invention.

Claims (9)

1. a kind of high-pressure frequency-conversion motor protection adaptive setting model, it is characterised in that include band phase-shifting transformer high-pressure frequency-conversion Motor protection adaptive setting model and without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, the band is moved Phase transformer high-pressure frequency-conversion motor protection adaptive setting model and adjust without phase-shifting transformer high-pressure frequency-conversion motor protection Computation model is included：Long starting protection adaptive setting model, current quick adaptive setting model, overcurrent protection are whole Determine computation model, unbalanced fault protection adaptive setting model, Over Heat Protection Setting Calculation model, ground protection adaptive setting model With under-voltage protection adaptive setting model, it is described also to wrap without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model Include rotation-clogging protection adaptive setting model；

The long starting protection adaptive setting model is：

The specified starting current I of (a) motor_st

I_st=K_stI_e

In formula, for band phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, I_eIt is secondary specified for phase-shifting transformer Electric current, K_stFor safety factor；For without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, I_eFor motor Secondary rated current, K_stFor drop-off to pick-up radio；K_stTake 1.2；

(b) motor under converting operation mode, starting time proper extension, it is considered to leave nargin, if starting time be t_op

t_op=(1.2-1.3) t_qd

In formula, t_qdFor the motor start-up time of power frequency actual measurement.

2. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that band phase shift The current quick adaptive setting model of transformer high-voltage adjustable frequency motor protection seting computation model includes：Vacuum circuit breaker Current quick adaptive setting model and FC loop current fast tripping protection adaptive setting models, FC loop current fast tripping protections are whole Determine computation model includes again：Trip without high current locking and export the adaptive setting model of function and have high current locking tripping operation outlet The adaptive setting model of function：

A, vacuum circuit breaker current quick adaptive setting model

(1) action current：Excitation surge current by phase-shifting transformer is escaped is adjusted, i.e.,

I_oph=KI_e

In formula：K is multiple, and depending on transformer capacity, the concrete span of K is as follows：

6300kVA and following：7~12；

6300kVA~31500kVA：4.5~7.0；

40000kVA~120000kVA：3.0~6.0；

120000kVA and more than：2.0~5.0；

(2) sensitivity check

$K_{sen}=\frac{I_{k.min}^{\left(2\right)}}{I_{oph}{n}_{TA}}\≥2$

In formula：n_TATo protect the CT no-load voltage ratios for using；

On high-tension side electric current is flowed through for line to line fault in the protection zone of high-pressure side；

I_ophFor current quick action current；

(3) action delay：By the way of vacuum circuit breaker, 0.05s is taken for all；

B, FC loop current fast tripping protection adaptive setting model：

The adaptive setting model of a, the outlet function that trips without high current locking, it is as follows：

(1) action current：It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e.,：I_oph=KI_e；

(2) action delay：t_opThe maximum duration of fuse fuse failure is taken, span is：0.3~1s；

B, the adaptive setting model for having high current locking tripping operation outlet function, it is as follows：

(1) action current：It is identical with vacuum circuit breaker current quick-breaking action current adaptive setting model, i.e.,：I_oph=KI_e；

(2) latching current setting valve I_art

$20I_{TA.n}\≥I_{art}=\frac{I_{brk}}{K_{rel}{n}_{TA}}$

In formula：I_TA.nFor rated current of vacuum circuit breaker；

I_artFor high current locking definite value；

I_brkTurn-off current is allowed for vacuum contactor；

K_relFor safety factor, 1.3~1.5 are taken；

(3) action delay

t_op=0.05~1s；

(4) sensitivity check

$K_{sen}=\frac{I_{art}}{I_{oph}}\≥2.$

3. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that

The current quick adaptive setting mould without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model Type also includes：Vacuum circuit breaker current quick adaptive setting model and FC loop current fast tripping protection adaptive setting models, FC loop current fast tripping protection adaptive setting models include again：Without high current locking trip outlet function adaptive setting model and There is the adaptive setting model of high current locking tripping operation outlet function：

C, vacuum circuit breaker current quick adaptive setting model, it is as follows：

(1) action current：Principle by motor maximum starting current is escaped is adjusted, i.e.,

I_oph=K_relK_st·I_e

In formula：K_rel1.5 are taken for safety factor；

K_stFor motor starting current multiple, calculate by measured value, span is 6~8；

(2) sensitivity check

$K_{sen}=\frac{I_{k.\min }^{\left(2\right)}}{I_{oph}{n}_{TA}}\≥2$

In formula：n_TATo protect the CT no-load voltage ratios for using；

For the sub-value of motor entrance minimum line to line fault electric current one；

I_ophFor current quick action current；

(3) action delay：For all, by the way of vacuum circuit breaker, movement time takes 0.05s；

D, FC loop current fast tripping protection adaptive setting model, it is as follows：

(1) adaptive setting of the outlet function that trips without high current locking：

(a) action current：

It is identical with vacuum circuit breaker current quick-breaking action current synchronizing calculation method, i.e. I_oph=K_relK_st·I_e；

(b) action delay：t_opThe maximum duration of fuse fuse failure is taken, span is：0.3~1s；

(2) there is the adaptive setting model of high current locking tripping operation outlet function, it is as follows：

(a) action current：

It is identical with vacuum circuit breaker current quick-breaking action current synchronizing calculation method, i.e. I_oph=K_relK_st·I_e；

(b) latching current setting valve I_artCalculate

$20I_{TA.n}\≥I_{art}=\frac{I_{brk}}{K_{rel}{n}_{TA}}$

In formula：I_TA.nFor rated current of vacuum circuit breaker；I_artFor high current locking definite value；I_brkAllow for vacuum contactor disconnected Open electric current；K_relFor safety factor, 1.3~1.5 are taken；

(3) action delay：

t_op=0.05~1s；

(4) sensitivity check：

$K_{sen}=\frac{I_{art}}{I_{oph}}\≥2.$

4. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that the overcurrent Protection seting computation model is：

(a) action current

For band phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, action current I_opBy escaping phase-shifting transformer Secondary rated current is adjusted；For without phase-shifting transformer high-pressure frequency-conversion motor protection adaptive setting model, action current I_op Adjust by the secondary rated current of motor is escaped；

$I_{op}=\frac{K_{rel}}{K_r}{I}_e$

In formula：K_relFor safety factor, 1.05~1.2 are taken；

K_rFor drop-off to pick-up radio, 0.85~0.95 is taken；

(b) action delay

t_op=(1-1.1) t_qd

In formula：t_opFor overcurrent protection action delay；

t_qdFor the motor start-up time.

5. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that the negative phase-sequence electricity Stream protection seting computation model includes：Negative phase-sequence I section protection seting computation model and negative phase-sequence II section protection protection seting computation model：

(a) negative phase-sequence I section protection seting computation model：

By when motor negative phase-sequence feedback current when escaping unsymmetrical short-circuit outside area and motor start-up due to current transformer error And the negative-sequence current that transient characterisitics occur, and ensure that motor is asymmetric in larger load two-phase operation and motor interior There are enough sensitivity synthesis to consider to calculate when short-circuit：

Action current I_2.1dz：

I_2.1dz=(0.6~1.4) I_e

Action delay t_2.1dz：

If 1) device provides negative phase-sequence reverse blocking function, t_2.1dz=(0.5~1) s；

If 2) device does not provide negative phase-sequence reverse blocking function, t_2.1dz=(5~6) s, to escape the line to line fault event of motor outside The misoperation that the negative-sequence current that barrier is produced causes；

(b) negative phase-sequence II section protection seting computation model：

There is foot when compared with Smaller load two-phase operation by possible maximum negative-sequence current and motor when motor normally runs is escaped Enough sensitivity considers, uses as sensitive unbalance protection, may be selected to alert：

Action current I_2.2dz：

I_2.2dz=(0.2~0.35) I_e

Action delay t_2.2dz：Take the starting time more than motor.

6. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that the overheated guarantor Shield adaptive setting model includes：Over Heat Protection Setting Calculation model and overheated based on IEC60255-8 when motor occurs overheated With the Over Heat Protection Setting Calculation model that real index curve rises；

When () motor occurs overheated a, temperature is raised always with actual exponential curve starting climbing speed, and its model is

${\∫}_0^t\[{\left(\frac{I_{eq}}{I_e}\right)}^2-{1.05}^2\]dt\≥\mathrm{\τ}$

$I_{eq}^2=K_1{I}_1^2+K_2{I}_2^2$

In formula：I_eFor the secondary rated current of motor；

I_eqTo cause the equivalent current of heating；

τ is electric motor overheating time constant；

I₁、I₂For the positive and negative sequence electric current of motor；

K₁、K₂For positive and negative sequence heating effect of current coefficient, K in starting process of motor₁Take 0.5~1, K₂Take 3~10；

B () is as follows based on the overheated Over Heat Protection Setting Calculation models with the rising of real index curve of IEC60255-8：

${\∫}_0^t\frac{1}{\ln \left(\frac{I_{eq}^2-{\mathrm{\ξI}}_{\[0\]}^2}{I_{eq}^2-I_{\mathrm{\∞}}^2}\right)}dt\≥\mathrm{\τ}$

In formula：I_[0]For overheated front motor current；

ξ is a coefficient for considering to radiate under motor normal operation, takes 50%；

I_∞For overtemperature protection starting current, span is (1.05~1.15) I_e。

7. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that the ground connection is protected Shield adaptive setting model includes：Isolated neutral system one-phase ground protection adaptive setting model and neutral point Jing small resistor connect Ground system one-phase ground protection adaptive setting model：

A, isolated neutral system one-phase ground protection adaptive setting model are as follows：

(1) action current

Earth current by protection installation place is flow through when escaping single-phase earthing outside area is calculated, i.e.,：

$I_{op.0}=K_{rel}{I}_k^{\left(1\right)}$

In formula：I_op.0For single-phase earthing zero sequence excess current protection act electric current；

K_relFor safety factor, 2.5~3s is taken when protection act also trips, protection act takes 2~2.5s when signal；

To supply the earth current of short dot by protection equipment during single-phase earthing outside dorsal zone,I_eOutside for dorsal zone By protection equipment positive direction capacitance current sum during single-phase earthing；

(2) movement time

When 3~10kV earth currents are not less than 10A, 0.5~1s is taken；

When 3~10kV earth currents are less than 10A, to 300MW and above unit, if meet selectivity and sensitivity requirement, Take 0.5~1s；

It is actionable in signal when can not such as meet sensitivity and selectively require when 3~10kV earth currents are less than 10A, take 0.5s；

(3) sensitivity test

$K_{sen}^{\left(1\right)}=\frac{I_{k\mathrm{\Σ}}^{\left(1\right)}-I_k^{\left(1\right)}}{I_{op.0}}\≥1.5$

In formula：When being that single-phase earthing occurs by protection equipment, the total sub-value of earthing capacitance current two in trouble point；

B, Neutral Point Through Low Resistance system one-phase ground protection adaptive setting model are as follows：

(1) action current：Take the greater in both following (a) and (b)；

A () calculates by single-phase earthing outside area is escaped

$I_{op.0}=K_{rel}{I}_k^{\left(1\right)}$

In formula：K_relFor safety factor, 1.1~1.15 are taken；

B () calculates by busy hour out-of-balance current is escaped

I_op.0=K_relI_umb

In formula：K_relFor safety factor, 1.3 are taken；

I_umbFor busy hour out-of-balance current；

I_umb≤ (0.1~0.15) × I_N, I_NFor feeder line rated current；

(2) action delay：0~0.05s；

(3) sensitivity check

$K_{sen}^{\left(1\right)}=\frac{I_{k\mathrm{\Σ}}^{\left(1\right)}}{I_{op.0}}\≥2$

In formula：For single-phase earthing of small current earthing system electric current.

8. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that the low-voltage Protection seting computation model includes as follows：

(1) for the motor with intermediate system, the operation voltage of low-voltage variation：

U_dz=(0.6~0.7) U_N

Action delay：0.5~1.5s；

(2) for the motor for automatically engaging stand-by machine, the operation voltage of under-voltage protection：

U_dz=(0.4~0.5) U_N

Action delay：5~10s；

In formula：U_NFor busbar voltage.

9. high-pressure frequency-conversion motor protection adaptive setting model according to claim 1, it is characterised in that the stall is protected Shield adaptive setting model is as follows：

(1) below 600MW units：

Action current：I_dz=(1.3~1.5) I_e；

Action delay：t_op.set=15~20s；

(2) the fan-type units of more than 600MW：

Calculate by sort time overcurrent is escaped

Action current：I_dz=(1.8~2.0) I_e；

Action delay：t_op.set=15~20s；

Or

Adjust as action current setting valve：I_dz=1.5I_e；

Action delay：t_op.set=25~30s；

(3) 600MW is with charging pump class unit：

Action current：I_dz=(1.3~1.5) I_e；

Action delay：t_op.set=15~20s.