CN107508262A - A kind of pole protection voltage acquisition circuit and transverter zero sequence over-voltage protection method - Google Patents
A kind of pole protection voltage acquisition circuit and transverter zero sequence over-voltage protection method Download PDFInfo
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- CN107508262A CN107508262A CN201710725759.XA CN201710725759A CN107508262A CN 107508262 A CN107508262 A CN 107508262A CN 201710725759 A CN201710725759 A CN 201710725759A CN 107508262 A CN107508262 A CN 107508262A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/06—Details with automatic reconnection
- H02H3/066—Reconnection being a consequence of eliminating the fault which caused disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/262—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of switching or blocking orders
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
Abstract
A kind of pole protection voltage acquisition circuit of disclosure and transverter zero sequence over-voltage protection method, methods described include：The electrical quantity of transverter is obtained by pole protection voltage acquisition circuit, the electrical quantity of the transverter includes converter valve side residual voltage, converter valve side voltage deviation and converter valve side electric voltage frequency deviation；According to the electrical quantity of the transverter, judge whether to meet parallel resonance condition；If meeting parallel resonance condition, judge whether transverter is in released state, and, judge whether zero sequence overvoltage protection puts into；If meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, sending the first protection by logic module instructs；The pole protection system instructs according to the described first protection, controls first relay normally closed contact to open, the bypass resistance is accessed in the input circuit.The application can be under converter deblocking state, and eliminating parallel resonance influences, and enables the quick discovering device failure of pole protection system.
Description
Technical field
The application is related to DC transmission system control protection technique field, more particularly to a kind of pole protection voltage acquisition circuit
And transverter zero sequence over-voltage protection method.
Background technology
To avoid DC equipment by badly damaged, DC transmission system is equipped with pole protection system.Work as HVDC
When system or equipment breaks down, pole protection system can be carried out calculating according to the protection definite value of setting and failure judgement type, and
Exported by the action definite value of setting, cut off failure fast and reliablely, to realize protection HVDC Equipments, ensure DC power transmission system
The purpose of system safe and stable operation.
Fig. 1 is mutual for end shield voltage measuring transformer loop circuit figure conventional in DC transmission engineering, including end shield voltage
Sensor and direct current pole protection screen cabinet.End shield voltage transformer includes CTH、CTL、Ceq, R1 and R2, CTLAnd CeqForm derided capacitors
Group, wherein, CTHAnd CTLIt is high-voltage capacitance and low-voltage capacitance, plays a part of partial pressure；CeqIt is the equivalent electric of some shunt capacitors
Hold, for adjusting and correcting partial pressure output, to reach defined voltage output value；R1 is discharge resistance, there is provided low-voltage capacitance
Discharge channel；R2 is piezo-resistance, limits the size of output voltage.When singlephase earth fault occurs, transverter voltage on valve side
In obvious zero-sequence component occurs, if converter valve side residual voltage exceedes definite value, piezo-resistance works long hours in zero
Under sequence overvoltage, easily cause the damage of piezo-resistance, or even damage derided capacitors, and then the safety for influenceing DC transmission system is steady
Fixed operation.Thus, in pole protection system, transverter zero sequence overvoltage protection is carried out using direct current pole protection screen cabinet, detects transverter
Earth fault on valve top-cross stream connecting line.
Voltage acquisition circuit in the protection screen cabinet of direct current pole, for gathering the voltage of converter valve side, and by converter valve
The control source of side is to measurement processing unit.Fig. 2 is the circuit diagram that voltage acquisition circuit is protected in existing pole, and pole protection voltage is adopted
Collect in loop, its input circuit is only designed with input resistance R and high-pressure side equivalent inductance L1, when system frequency and measurement voltage amplitude
When value produces change, there may be in parallel humorous between the capacity cell in the equiva lent impedance and end shield voltage transformer of input circuit
Shake, cause converter valve side electric voltage exception, and then zero sequence overvoltage occur.However, the existing relay protective scheme of pole protection system is only fitted
For the transverter of blocking, once converter deblocking, zero sequence overvoltage protection must exit, now, if input circuit etc.
Occurs parallel resonance between capacity cell in effect impedance and end shield voltage transformer, pole protection system will be unable to rapidly find
And exclude equipment fault.
The content of the invention
The application provides a kind of pole protection voltage acquisition circuit and transverter zero sequence over-voltage protection method, to solve transverter
During unblock, if there is parallel resonance, pole protection system can not rapidly removing faults the problem of.
In a first aspect, the embodiment of the present application provides a kind of pole protection voltage acquisition circuit, system is protected for pole, including it is defeated
Entry loop, output loop and measurement processing unit, wherein, input circuit includes input resistance and connected with the input resistance
High-pressure side equivalent inductance, output loop include low-pressure side equivalent inductance, the low-pressure side equivalent inductance and the measurement processing list
Member connection, the input circuit also include the first relay normally closed contact, the second relay normally closed contact and bypass resistance；It is described
First relay normally closed contact is connected with the input resistance；Second relay normally closed contact and first relay are normal
Closed contact is connected；The bypass resistance is in parallel with first relay normally closed contact.
Alternatively, the resistance of the bypass resistance is 1-2 times of the input resistance.
Second aspect, the embodiment of the present application also provide a kind of transverter zero sequence over-voltage protection method, and system is protected for pole,
The pole protection voltage acquisition circuit of the pole protection system includes input circuit, output loop and measurement processing unit, wherein, institute
Stating input circuit includes bypass resistance and the first relay normally closed contact being sequentially connected in series, the second relay normally closed contact, defeated
Enter resistance, high-pressure side equivalent inductance, the bypass resistance is in parallel with first relay normally closed contact, and methods described includes：
The electrical quantity of transverter is obtained by pole protection voltage acquisition circuit, the electrical quantity of the transverter includes the change of current
Device valve side residual voltage, converter valve side voltage deviation and converter valve side electric voltage frequency deviation；
According to the electrical quantity of the transverter, judge whether to meet parallel resonance condition；
If meeting parallel resonance condition, judge whether transverter is in released state, and, judge zero sequence overvoltage protection
Whether put into；
If meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, the is sent by logic module
One protection instruction；The pole protection system instructs according to the described first protection, controls first relay normally closed contact to open,
The bypass resistance is set to access in the input circuit.
Further, the pole protection system instructs according to the described first protection, controls first relay is normally closed to touch
After the step of point is opened, methods described also includes：
After the T that is delayed, judge whether to meet parallel resonance condition；
If meeting parallel resonance condition, judge whether transverter is in released state, and, judge zero sequence overvoltage protection
Whether put into；
If meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, sent out by the logic module
The second protection is sent to instruct；The pole protection system instructs according to the described second protection, controls second relay normally closed contact
Open, disconnect the input circuit.
Further, according to the electrical quantity of the transverter, judge whether to meet parallel resonance condition as steps described below：
Judge whether converter valve side residual voltage is more than definite value；
Judge whether converter valve side voltage deviation is more than definite value；And
Judge whether converter valve side electric voltage frequency deviation is more than definite value；
If meet simultaneously converter valve side residual voltage be more than definite value, converter valve side voltage deviation be more than definite value and
Converter valve side electric voltage frequency deviation is more than definite value, then meets parallel resonance condition；
If converter valve side residual voltage is more than definite value, converter valve side voltage deviation is more than definite value and converter valve
Side electric voltage frequency deviation is more than in definite value, and at least one is invalid, then is unsatisfactory for parallel resonance condition.
Further, methods described also includes：If meet that parallel resonance condition, transverter are in released state and zero
In sequence overvoltage protection input, at least one is invalid, and the pole protects system not perform protection act.
From above technical scheme, the application provides a kind of pole protection voltage acquisition circuit and the overvoltage of transverter zero sequence is protected
Maintaining method, protected in pole in the input circuit in voltage acquisition circuit, it is normal to add the first relay normally closed contact, the second relay
Closed contact and bypass resistance；When carrying out transverter zero sequence overvoltage protection, first, the change of current is obtained by pole protection voltage acquisition circuit
The electrical quantity of device, judge whether to meet parallel resonance condition, that is, judge the equiva lent impedance and end shield voltage transformer of input circuit
In capacity cell between whether produce parallel resonance, when meeting parallel resonance condition, and transverter is in released state, zero sequence
Overvoltage protection is put into, then protection system in pole controls the first relay normally closed contact to open, and bypass resistance is accessed input circuit, this
When, the equiva lent impedance of input circuit changes, and then eliminates parallel resonance state, transverter voltage on valve side is recovered normal, realizes
Transverter zero sequence overvoltage protection；If after the T that is delayed, parallel resonance does not eliminate yet, and pole protection system controls the second relay
Normally-closed contact is opened, and disconnects input circuit.The application under converter deblocking state, can eliminate the shadow of parallel resonance state
Ring, rapidly find in time and abatement apparatus failure, enable pole protection voltage acquisition circuit quick-recovery normal work soon, avoid pressing
Quick resistance and derided capacitors damage under overvoltage, so as to ensure the safe and stable operation of DC transmission system.
Brief description of the drawings
Fig. 1 is the end shield voltage measuring transformer loop circuit figure commonly used in DC transmission engineering；
Fig. 2 is the circuit diagram that voltage acquisition circuit is protected in existing pole；
Fig. 3 is the circuit diagram that voltage acquisition circuit is protected in a kind of pole that the application one implements to exemplify；
Fig. 4 is a kind of flow chart of another transverter zero sequence over-voltage protection method for implementing to exemplify of the application；
Fig. 5 is a kind of flow chart of the another transverter zero sequence over-voltage protection method for implementing to exemplify of the application；
Fig. 6 is a kind of logic chart of the another transverter zero sequence over-voltage protection method for implementing to exemplify of the application.
Embodiment
In order that those skilled in the art more fully understand the technical scheme in the application, it is right below in conjunction with accompanying drawing
Technical scheme in the embodiment of the present application is clearly and completely described.
The embodiment of the application one provides a kind of pole protection voltage acquisition circuit, as shown in figure 3, pole protection voltage acquisition returns
Road is used for pole protection system, including input circuit, output loop and measurement processing unit, wherein, input circuit includes input electricity
Resistance R and the high-pressure side equivalent inductance L1 to be connected with input resistance R, output loop include low-pressure side equivalent inductance L2, low-pressure side etc.
Effect inductance L2 is connected with measurement processing unit, and it is normally closed that input circuit also includes the first relay normally closed contact K1, the second relay
Contact K2 and bypass resistance r；First relay normally closed contact K1 connects R with input resistance；Second relay normally closed contact K2 with
First relay normally closed contact K1 connects；Bypass resistance r is in parallel with the first relay normally closed contact K1.
Pole protection voltage acquisition circuit is used for the voltage on valve side data for gathering transverter, high-pressure side equivalent inductance L1 and low pressure
Side equivalent inductance L2 forms secondary PT (Potential Transformer, voltage transformer), and the voltage on valve side of transverter is through two
After secondary PT conversions, input to measurement processing unit.Before the action of transverter zero sequence overvoltage protection is performed, the first relay is normally closed to be touched
Point K1 and the second relay normally closed contact K2 is original state, i.e. normally off, and now, bypass resistance r is by the first relay
Normally-closed contact K1 short circuits, bypass resistance r are not accessed in input circuit, and input circuit is also kept closed.
When the first relay normally closed contact K1 disconnects from original state, bypass resistance r by access input circuit, this
When, bypass resistance r connects with input resistance R, high-pressure side equivalent inductance L1 respectively, and then changes input circuit equiva lent impedance
Become, caused parallel connection is humorous between being advantageous to eliminate the capacity cell in the equiva lent impedance and end shield voltage transformer of input circuit
Shake；If being delayed in T, parallel resonance state is not eliminated, and the second relay normally closed contact K2 disconnects from original state, is made whole defeated
Entry loop is switched off, and then thoroughly eliminates parallel resonance, in time rapidly find and abatement apparatus failure, make pole protection voltage adopt
Collection loop can recover normal work, avoid piezo-resistance and derided capacitors from being damaged under overvoltage, so as to ensure DC power transmission system
The safe and stable operation of system.
Alternatively, bypass resistance r resistance is 1-2 times of input resistance R, and this design will not make pole protect voltage acquisition
Loop produces excessive loss, at the same time it can also preferably change the impedance operator of input circuit, destroys the condition of parallel resonance,
So as to quickly eliminate parallel resonance, discovery and abatement apparatus failure, enable pole protection voltage acquisition circuit to recover normal work in time
Make, avoid piezo-resistance and derided capacitors from being damaged under overvoltage, so as to ensure the safe and stable operation of DC transmission system.
Another embodiment of the application provides a kind of transverter zero sequence over-voltage protection method, as shown in figure 4, for pole protection system
System, the pole protection voltage acquisition circuit of pole protection system include input circuit, output loop and measurement processing unit, wherein, it is defeated
Entry loop includes bypass resistance r and the first relay normally closed contact K1 being sequentially connected in series, the second relay normally closed contact K2, defeated
It is in parallel with the first relay normally closed contact K1 to enter resistance R, high-pressure side equivalent inductance L1, bypass resistance r, methods described includes：
Step S101, by the pole protection voltage acquisition circuit obtain transverter electrical quantity, the transverter it is electric
Amount includes converter valve side residual voltage, converter valve side voltage deviation and converter valve side electric voltage frequency deviation.Wherein, the change of current
Device valve side residual voltage includes YY valves side residual voltage and YD valves side residual voltage；Converter valve side voltage deviation includes YY valves side
The voltage deviation of any phase of voltage deviation and YD valves side of any phase；Converter valve side electric voltage frequency deviation is any phase in valve side
Electric voltage frequency deviation.
Step S102, according to the electrical quantity of the transverter, judge whether to meet parallel resonance condition.Judge to input back
Whether parallel resonance occurs between capacity cell in the equiva lent impedance and end shield voltage transformer on road.
Step S103, if meeting parallel resonance condition, judge whether transverter is in released state, and, judge zero
Whether sequence overvoltage protection puts into.
Step S104, if meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, by logic
Module sends the first protection instruction.Transverter is under released state, the equiva lent impedance and end shield voltage transformer of input circuit
In capacity cell between occur parallel resonance, and zero sequence overvoltage protection is put into, and now, transverter zero sequence overvoltage protection condition is complete
Portion meets that sending the first protection by logic module instructs.In the embodiment of the present application, logic module is applied not only to send the first guarantor
Finger shield makes, it may also be used for the judgement to transverter zero sequence overvoltage protection condition.
Step S105, the pole protection system instruct according to the described first protection, control first relay is normally closed to touch
Point is opened, and the bypass resistance is accessed in the input circuit.Now, bypass resistance r respectively with input resistance R, high-pressure side
Equivalent inductance L1 connects, and then input circuit equiva lent impedance is changed, be advantageous to eliminate input circuit equiva lent impedance and
Caused parallel resonance between capacity cell in end shield voltage transformer, pole is set to protect voltage acquisition circuit normal work,
Timely rapidly discovering device failure, avoids piezo-resistance and derided capacitors from being damaged under overvoltage, so as to ensure direct current transportation
The safe and stable operation of system.
Further, methods described also includes：
Step S106, if meeting that parallel resonance condition, transverter are in released state and zero sequence overvoltage protection input
In, at least one is invalid, and the pole protects system not perform protection act.I.e. and if only if meets parallel resonance condition, changes
When stream device is in released state and zero sequence overvoltage protection input while set up, pole protection system can just perform protection act, control
The first relay normally closed contact K1 openings are made, are made in bypass resistance r access input circuits, otherwise, logic module does not send any
Protection instruction, pole protects system also just not perform protection act.
In the embodiment of the present application, judge whether to meet parallel resonance condition, judge whether transverter is in released state, with
And judging whether zero sequence overvoltage protection puts into, these three judgment steps can be carried out by different sequencings, in the application
State to use in exemplary embodiment and first judge whether to meet that parallel resonance condition, or these three judgment steps can also be entered simultaneously
OK, in the application, it is what is together decided on by the result of these three judgment steps that whether logic module, which sends the first protection instruction,.
The another embodiment of the application provides a kind of transverter zero sequence over-voltage protection method, as shown in figure 5, above-mentioned steps S104
Afterwards, methods described also includes：
Step S201, after the T that is delayed, judge whether to meet parallel resonance condition.In pole, protection system disconnects the first relay
After device normally-closed contact K1, because the impedance operator of input circuit changes, parallel resonance condition is caused to be destroyed, parallel resonance
It can gradually be eliminated, in default delay T time, if parallel resonance state does not eliminate thoroughly, pole can still be protected
The work of system has an impact, and therefore, whether meets parallel resonance condition, it is necessary to rejudge after the T that is delayed.At this time, it may be necessary to
Again the electrical quantity of transverter is obtained in real time, whether is eliminated with accurate judgement parallel resonance.
Step S202, if meeting parallel resonance condition, judge whether transverter is in released state, and, judge zero
Whether sequence overvoltage protection puts into.After the T that is delayed, judge pole protection system whether continue executing with protection act, still to judge be
It is no to meet transverter zero sequence overvoltage protection condition.If being unsatisfactory for parallel resonance condition, step S206 is performed.
Step S203, if meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, by described
Logic module sends the second protection instruction.Transverter is under released state, and the equiva lent impedance and end shield voltage of input circuit are mutual
Parallel resonance occurs between capacity cell in sensor, and zero sequence overvoltage protection is put into, now, transverter zero sequence overvoltage protection bar
Part all meets that sending the second protection by logic module instructs.In the embodiment of the present application, logic module is applied not only to transmission
Two protection instructions, it may also be used for the judgement to transverter zero sequence overvoltage protection condition.
Step S204, the pole protection system instruct according to the described second protection, control second relay is normally closed to touch
Point is opened, and disconnects the input circuit.Now, input circuit is in off state, and the equiva lent impedance of input circuit can not be with
Parallel resonance occurs for capacity cell in end shield voltage transformer, and then parallel resonance is thoroughly eliminated, avoid piezo-resistance and
Derided capacitors damage under zero sequence overvoltage, so as to ensure the safe and stable operation of DC transmission system.
Step S205, if transverter is in non-released state, and/or, zero sequence overvoltage protection is not put into, then performs step
S206。
Step S206, the pole protect system not perform protection act.If meet that parallel resonance condition, transverter are in
In released state and zero sequence overvoltage protection input, at least one is invalid, and pole protects system not perform protection act.I.e. when and
Only when meeting that parallel resonance condition, transverter be in released state and zero sequence overvoltage protection input while when setting up, pole is protected
System can just perform protection act, and the second relay normally closed contact K2 of control is opened, and disconnects input circuit, otherwise, logic mould
Block does not send any protection instruction, and pole protects system also just not perform protection act.
In the embodiment of the present application, judge whether to meet parallel resonance condition, judge whether transverter is in released state, with
And judging whether zero sequence overvoltage protection puts into, these three judgment steps can be carried out by different sequencings, in the application
State to use in exemplary embodiment and first judge whether to meet that parallel resonance condition, or these three judgment steps can also be entered simultaneously
OK, in the application, it is what is together decided on by the result of these three judgment steps that whether logic module, which sends the second protection instruction,.
The another embodiment of the application provides a kind of relay protective scheme of transverter zero sequence over-voltage protection method, as shown in fig. 6, bag
Electrical quantity criterion area, quantity of state criterion area and pole protection system are included, wherein, pole protection system includes logic module.Electrical quantity
Criterion area meets parallel resonance condition for judging whether, quantity of state criterion area is used to judge whether transverter is in released state
And judge whether zero sequence overvoltage protection puts into.In quantity of state criterion area, the actual motion shape of transverter is obtained by pole control system
State, judges whether transverter is in released state, and the released state information of transverter is sent to the logic of pole protection system
Module.
Logic module uses meets that transverter is in released state, zero sequence overvoltage protection simultaneously with door, only its input
Put into and meet parallel resonance condition, its output end can just send the first protection instruction, and system is protected according to the first protection in pole
Instruction, act the first relay normally closed contact K1, i.e., protection system in pole controls the first relay normally closed contact K1 to open, and makes side
In road resistance r access input circuits.Similarly, meet that transverter is in unblock shape simultaneously by the T that is delayed, only its input
State, zero sequence overvoltage protection put into and met parallel resonance condition, and its output end can just send the second protection instruction, pole protection system
System instructs according to the second protection, acts the second relay normally closed contact K2, i.e., protection system in pole controls the second relay normally closed
Contact K2 is opened, and disconnects input circuit.
In electrical quantity criterion area, according to the electrical quantity of the transverter, judge whether to meet that parallel connection is humorous as steps described below
Shake condition：
Judge whether converter valve side residual voltage is more than definite value；
Judge whether converter valve side voltage deviation is more than definite value；And
Judge whether converter valve side electric voltage frequency deviation is more than definite value；
If meet simultaneously converter valve side residual voltage be more than definite value, converter valve side voltage deviation be more than definite value and
Converter valve side electric voltage frequency deviation is more than definite value, then meets parallel resonance condition；
If converter valve side residual voltage is more than definite value, converter valve side voltage deviation is more than definite value and converter valve
Side electric voltage frequency deviation is more than in definite value, and at least one is invalid, then is unsatisfactory for parallel resonance condition.
Converter valve side residual voltage is more than definite value, including YY valves side residual voltage is more than definite value, is with formula expression
UVY_a+UVY_b+UVY_c ﹥ Δs；It is UVD_a+UVD_b+ with formula expression and YD valves side residual voltage is more than definite value
UVD_c ﹥ Δs.
In formula：UVY_a+UVY_b+UVY_c is YY valves side residual voltage, and UVD_a+UVD_b+UVD_c is YD valves side zero sequence
Voltage, Δ are the definite value of residual voltage.Whether converter valve side residual voltage judged more than definite value using OR gate, i.e. UVY_
In a+UVY_b+UVY_c ﹥ Δs and UVD_a+UVD_b+UVD_c ﹥ Δs, at least one establishment, then result of determination is converter valve
Side residual voltage is more than definite value.
Converter valve side voltage deviation is more than definite value, including the voltage deviation of any phase in YY valves side is more than definite value, uses formula
Expression is Δ UY ﹥ Δs U；It is Δ UD ﹥ Δs U with formula expression and the voltage deviation of any phase in YD valves side is more than definite value.
In formula：Δ UY is the voltage deviation of any phase in YY valves side, and Δ UD is the voltage deviation of any phase in YD valves side, and Δ U is
The definite value of voltage deviation.Whether converter valve side voltage deviation judged more than definite value using OR gate, i.e. Δ UY ﹥ Δs U and Δ
In UD ﹥ Δs U, at least one establishment, then result of determination is that converter valve side voltage deviation is more than definite value.
Converter valve side electric voltage frequency deviation is more than definite value, i.e. the electric voltage frequency deviation of any phase in valve side is more than definite value, uses
Formula expression is Δ Uf ﹥ Δs f.In formula, Δ Uf is the electric voltage frequency deviation of any phase in valve side, and Δ f is electric voltage frequency deviation
Definite value.
Whether it is more than whether definite value, converter valve side voltage deviation are more than definite value and change to converter valve side residual voltage
Whether stream device voltage on valve side frequency departure is judged more than definite value, the result of determination of this three is carried out into AND operation, by this
Operation result can determine whether to meet parallel resonance condition.
In the embodiment of the present application, all to be related to each conditional logic judgement, when result of determination is true, logical value takes 1, conversely, then
Logical value goes 0.Such as when judging whether to meet transverter zero sequence overvoltage protection condition, meet parallel resonance condition, at transverter
In released state, but zero sequence overvoltage protection is not put into, then in corresponding truth table, value is respectively 1,1,0, carries out "AND" logic
During computing, result of calculation 0, then it is unsatisfactory for flowing device zero sequence overvoltage protection condition, pole protects system not perform protection act.Other
Condition distinguishing process can refer to example, will not be repeated here.
From above technical scheme, the application provides a kind of pole protection voltage acquisition circuit and the overvoltage of transverter zero sequence is protected
Maintaining method, protected in pole in the input circuit in voltage acquisition circuit, it is normal to add the first relay normally closed contact, the second relay
Closed contact and bypass resistance；When carrying out transverter zero sequence overvoltage protection, first, the change of current is obtained by pole protection voltage acquisition circuit
The electrical quantity of device, judge whether to meet parallel resonance condition, that is, judge the equiva lent impedance and end shield voltage transformer of input circuit
In capacity cell between whether produce parallel resonance, when meeting parallel resonance condition, and transverter is in released state, zero sequence
Overvoltage protection is put into, then protection system in pole controls the first relay normally closed contact to open, and bypass resistance is accessed input circuit, this
When, the equiva lent impedance of input circuit changes, and then eliminates parallel resonance state, transverter voltage on valve side is recovered normal, realizes
Transverter zero sequence overvoltage protection；If after the T that is delayed, parallel resonance does not eliminate yet, and pole protection system controls the second relay
Normally-closed contact is opened, and disconnects input circuit.The application under converter deblocking state, can eliminate the shadow of parallel resonance state
Ring, in time rapidly find and abatement apparatus failure, enable pole protection voltage acquisition circuit recover normal work, avoid pressure-sensitive electricity
Resistance and derided capacitors damage under overvoltage, so as to ensure the safe and stable operation of DC transmission system.
It should be noted that herein, the relational terms of such as " first " and " second " or the like are used merely to one
Individual entity or operation make a distinction with another entity or operation, and not necessarily require or imply these entities or operate it
Between any this actual relation or order be present.Those skilled in the art are considering specification and are putting into practice hair disclosed herein
After bright, other embodiments of the present invention will readily occur to.The application is intended to any modification of the present invention, purposes or suitable
Answering property changes, and these modifications, purposes or adaptations follow the general principle of the present invention and including of the invention undisclosed
Common knowledge or conventional techniques in the art.Description and embodiments are considered only as exemplary, the present invention
True scope and spirit pointed out by claim.
It should be appreciated that the invention is not limited in the precision architecture for being described above and being shown in the drawings, and
And various modifications and changes can be being carried out without departing from the scope.The scope of the present invention is only limited by appended claim.
Claims (6)
1. voltage acquisition circuit is protected in a kind of pole, system, including input circuit, output loop and measurement processing list are protected for pole
Member, wherein, input circuit includes input resistance and the high-pressure side equivalent inductance connected with the input resistance, and output loop includes
Low-pressure side equivalent inductance, the low-pressure side equivalent inductance are connected with the measurement processing unit, it is characterised in that described to input back
Road also includes the first relay normally closed contact, the second relay normally closed contact and bypass resistance；First relay is normally closed to be touched
Point is connected with the input resistance；Second relay normally closed contact is connected with first relay normally closed contact；It is described
Bypass resistance is in parallel with first relay normally closed contact.
2. voltage acquisition circuit is protected in pole according to claim 1, it is characterised in that the resistance of the bypass resistance is institute
State input resistance 1-2 times.
3. a kind of transverter zero sequence over-voltage protection method, system is protected for pole, the pole protection voltage of the pole protection system is adopted
Collection loop include input circuit, output loop and measurement processing unit, wherein, the input circuit including bypass resistance and according to
The first relay normally closed contact, the second relay normally closed contact, input resistance, the high-pressure side equivalent inductance of secondary series connection, the side
Road resistance is in parallel with first relay normally closed contact, it is characterised in that methods described includes：
The electrical quantity of transverter is obtained by pole protection voltage acquisition circuit, the electrical quantity of the transverter includes converter valve
Side residual voltage, converter valve side voltage deviation and converter valve side electric voltage frequency deviation；
According to the electrical quantity of the transverter, judge whether to meet parallel resonance condition；
If meeting parallel resonance condition, judge whether transverter is in released state, and, whether judge zero sequence overvoltage protection
Input；
If meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, sending first by logic module protects
Finger shield makes；The pole protection system instructs according to the described first protection, controls first relay normally closed contact to open, makes institute
Bypass resistance is stated to access in the input circuit.
4. according to the method for claim 3, it is characterised in that the pole protection system instructs according to the described first protection,
After the step of controlling first relay normally closed contact to open, methods described also includes：
After the T that is delayed, judge whether to meet parallel resonance condition；
If meeting parallel resonance condition, judge whether transverter is in released state, and, whether judge zero sequence overvoltage protection
Input；
If meeting that transverter is in released state and zero sequence overvoltage protection input simultaneously, the is sent by the logic module
Two protection instructions；The pole protection system instructs according to the described second protection, controls second relay normally closed contact to open,
Disconnect the input circuit.
5. according to the method for claim 3, it is characterised in that according to the electrical quantity of the transverter, as steps described below
Judge whether to meet parallel resonance condition：
Judge whether converter valve side residual voltage is more than definite value；
Judge whether converter valve side voltage deviation is more than definite value；And
Judge whether converter valve side electric voltage frequency deviation is more than definite value；
If meet that converter valve side residual voltage is more than definite value, converter valve side voltage deviation is more than definite value and the change of current simultaneously
Device voltage on valve side frequency departure is more than definite value, then meets parallel resonance condition；
If converter valve side residual voltage is more than definite value, converter valve side voltage deviation is more than definite value and converter valve side electricity
Frequency departure is pressed to be more than in definite value, at least one is invalid, then is unsatisfactory for parallel resonance condition.
6. according to the method described in claim any one of 3-5, it is characterised in that methods described also includes：
If meeting that parallel resonance condition, transverter are in released state and zero sequence overvoltage protection input, at least one is not
Set up, the pole protects system not perform protection act.
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| CN201710725759.XA CN107508262B (en) | 2017-08-22 | 2017-08-22 | A kind of pole protection voltage acquisition circuit and inverter zero sequence over-voltage protection method |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201234125Y (en) * | 2008-07-09 | 2009-05-06 | 江苏省电力公司泗洪县供电公司 | Single-phase grounding failure automatic processing equipment for low current grounding system |
| EP3148032A1 (en) * | 2015-09-28 | 2017-03-29 | GE Energy Power Conversion Technology Ltd | Power supply system of a set of loads connected in parallel to a dc power bus |
| CN206148928U (en) * | 2016-11-23 | 2017-05-03 | 高雅琦 | Power transformer's zero -sequence protection circuit |
| CN106849033A (en) * | 2017-04-14 | 2017-06-13 | 云南电网有限责任公司电力科学研究院 | A kind of optimization method of transverter zero sequence overvoltage protection logic |
-
2017
- 2017-08-22 CN CN201710725759.XA patent/CN107508262B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201234125Y (en) * | 2008-07-09 | 2009-05-06 | 江苏省电力公司泗洪县供电公司 | Single-phase grounding failure automatic processing equipment for low current grounding system |
| EP3148032A1 (en) * | 2015-09-28 | 2017-03-29 | GE Energy Power Conversion Technology Ltd | Power supply system of a set of loads connected in parallel to a dc power bus |
| CN206148928U (en) * | 2016-11-23 | 2017-05-03 | 高雅琦 | Power transformer's zero -sequence protection circuit |
| CN106849033A (en) * | 2017-04-14 | 2017-06-13 | 云南电网有限责任公司电力科学研究院 | A kind of optimization method of transverter zero sequence overvoltage protection logic |
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