CN104316788A - Method for judging tripping of outgoing line of double-feed wind turbine generator - Google Patents
Method for judging tripping of outgoing line of double-feed wind turbine generator Download PDFInfo
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Abstract
The invention relates to a method for judging tripping of an outgoing line of a double-feed wind turbine generator. The method is characterized by comprising the following steps of: 1, firstly detecting current and active power of the outgoing line of a wind power plant, judging whether meeting current variation starting condition or active power variation starting condition, and if yes, judging that the outgoing line of the wind power plant is disturbed, entering a step 2 for judgment, recording a starting moment, and storing several generator operation state information, such as voltage, current and active power of the outgoing line of the wind power plant before starting, otherwise, judging that the outgoing line of the wind power plant is not disturbed, and ending continuous judgment; 2, judging whether the active power before starting is more than a set value PS1. According to the method provided by the invention, the problem that tripping criterion of the outgoing line of the wind power plant may cause misjudgment when Crowbar protection movement of the generator exists under some operation modes of the wind power plant is overcome, and electrical capacity disturbance processes, such as tripping of the outgoing line, Crowbar protection movement and the like, can be quickly identified.
Description
Technical field
The present invention relates to a kind of double-fed fan motor unit wind energy turbine set and send line tripping determination methods.
Background technology
In recent years, wind-power electricity generation is greatly developed at home, in northwest, North, Northeast China area, defined the wind power base that several large-scale wind power concentrates access.These wind power base net capacities are less, and structure comparison is weak, and due to the characteristic of Wind turbines self complicated, the safety and stability outstanding problem of system, can not meet the relevant criterion requirement of " guiding rules of power system safety and stability ".Especially, when system generation disturbance, the protection system of Wind turbines self often causes large-scale wind power unit off-grid, if now can not identify in time and take effective security and stability control measurement, easily causes mains breakdown.Therefore, to send the trip criteria of circuit very necessary for double-fed fan motor unit wind energy turbine set.
Along with greatly developing of the regional stability control as electrical network second defence line, be able to abundant grasp for the change procedure of electric parameters in transmission line of electricity tripping operation process, as shown in Figure 1,9.1s moment wind energy turbine set is sent circuit and be there occurs fault-free trip.Corresponding trip criteria comparative maturity, the trip criteria based on local electrical quantities also has more research, and the criterion at present for line tripping is: 1, Sudden Changing Rate starts; 2, power before accident | P_|>Ps1 (definite value); 3, current changing rate in accident process | Δ I|> Δ Is (definite value); 4, power after accident | Pt|≤Ps2 (definite value); 5, trip signal (selecting) is had; 6, biphase current effective value I≤Is1 (definite value) is had after accident; Device starts rear and after meeting above condition Ts1 (definite value) time delay, is namely judged to line tripping simultaneously.
But because the Crowbar protection act of double-fed fan motor unit affects, there is the possibility of erroneous judgement in such trip criteria when double-fed fan motor unit wind energy turbine set sends circuit being applied to.Theoretical analysis and on-the-spot practical operation situation all prove; when wind energy turbine set Wind turbines Crowbar protection act; Crowbar protection circuit is by the rotor windings of short circuit generator; and generator unit is still connected with electrical network; now double-fed fan motor unit runs by mouse cage asynchronous mode, and before the exchange power of wind energy turbine set and electrical network and Crowbar protection act, the revolutional slip of unit is relevant.The Crowbar protection act when double-fed fan motor unit operation is in wind rating, then after action, wind energy turbine set sends circuit active power and reactive power is 0, neither to electrical network transmission power, also not from electrical network absorbed power.Send circuit disturbance after-current accordingly less, each condition of above-mentioned line tripping criterion is all met, and causes stability control device may be mistaken for line tripping and take control measure.As shown in Figure 2, wherein the 9.2-9.36s time period is disturbance recovery but unit Crowbar protects the non-rejuvenation of still action to electric parameters feature.
On-the-spot ruuning situation shows; because wiring is too complicated or do not meet relevant operational management regulation; the tripping operation that safety stabilization control system sends circuit for wind energy turbine set judges often cannot access protection act signal and position signalling, can only carry out the tripping operation judgement sending circuit by electric parameters.
Summary of the invention
The object of this invention is to provide a kind of double-fed fan motor unit wind energy turbine set and send line tripping determination methods, contact point signal can not be utilized, local electrical quantities is only relied on to judge that double-fed fan motor unit wind energy turbine set sends line tripping, the line tripping no matter under which kind of method of operation, which kind of reason causes, all can accurately identify; When wind energy turbine set Wind turbines Crowbar protection act, send the reliable not malfunction of trip criteria of circuit; After system is subject to other disturbance, send the reliable not malfunction of trip criteria of circuit.
A kind of double-fed fan motor unit wind energy turbine set sends line tripping determination methods, and its special feature is, comprises the steps:
(1) electric current and the active power that wind energy turbine set sends circuit is first detected, judge whether that meeting current change quantity starts or active power variable quantity entry condition, if satisfy condition, then judge that wind energy turbine set is sent circuit and is disturbed, enter step (2) to judge, and record Startup time, preserve wind energy turbine set before starting and send the voltage of circuit, electric current and active power these several operating states of the units information; Otherwise judge that wind energy turbine set is sent circuit and is not disturbed, no longer continue to judge;
(2) judge whether start front active power is greater than setting value PS1;
(3) judge in perturbation process, whether current effective value occurs the process that declines rapidly, namely every cycle current effective value slippage meets or exceeds setting value Δ Is;
(4) judge in perturbation process, whether voltage occurs uphill process and meet or exceed setting value Uups;
(5) after judging disturbance, whether active power absolute value is less than or equal to setting value PS2;
(6) judge that whether disturbance after-current effective value is lower, namely have at least biphase current effective value to be less than or equal to setting value IS2;
(7) after starting, if meet the condition of step (2) to step (6) simultaneously, be then judged as that wind energy turbine set sends line tripping after time delay Ts1, otherwise think that sending circuit does not occur tripping operation.
The determination methods that in step (1), whether active power variable quantity starts is: detect the active-power P that current wind energy turbine set sends circuit in real time
twith active-power P before 200ms
t-200msdifference, if the absolute value of this difference is continuous be greater than setting value Δ PS for 3-6 time, then start wind energy turbine set send line tripping judge;
The determination methods that in described step (1), whether current change quantity starts is: detect current any phase current instantaneous value i in real time
twith current i before 20ms
t-20msdifference, if the absolute value of this difference is continuous be greater than setting value Δ Is for 3-6 time, then start wind energy turbine set send line tripping judge.
The condition of described step (3) and the decline of step (4) electric current and voltage rise, needs to satisfy condition for 3-6 time.
Active power and the required conditional request continuously effective met of electric current after disturbance in step (5) and step (6).
The inventive method solves existing wind energy turbine set and sends the mistake problem that line tripping criterion exists during unit Crowbar protection act under some method of operation of wind energy turbine set, can identify fast and send the electric parameters perturbation process such as line tripping, Crowbar protection act; Criterion strong adaptability, reliability is high, can realize protecting perfect cooperation with relating to net; Greatly save human and material resources and financial resources, improve automaticity and efficiency.
Accompanying drawing explanation
Fig. 1 is that in background technology, wind energy turbine set sends critical electrical amount variation diagram in line tripping process;
Fig. 2 is that in background technology, wind energy turbine set sends critical electrical amount variation diagram in line tripping process;
Fig. 3 is that in background technology, wind energy turbine set sends critical electrical amount variation diagram in line tripping process;
Fig. 4 is that in background technology, wind energy turbine set sends critical electrical amount variation diagram in circuit Crowbar protection act process;
Fig. 5 is that in background technology, wind energy turbine set sends critical electrical amount variation diagram in circuit Crowbar protection act process;
Fig. 6 is that in background technology, wind energy turbine set sends critical electrical amount variation diagram in circuit Crowbar protection act process;
Fig. 7 is that wind energy turbine set of the present invention sends line tripping decision logic block diagram.
Embodiment
The present invention relates to a kind of double-fed fan motor unit wind energy turbine set and send line tripping determination methods.Belong to power system automatic field, comprise the following steps: to gather three-phase current and the voltage that wind energy turbine set sends circuit, the effective value of calculating voltage electric current and power, by detecting current break and the startup of chugging judgment means; If power is higher than setting definite value before starting; In perturbation process, every cycle electric current slippage is higher than setting definite value; Voltage raises and reaches setting definite value; Active power after disturbance and active current are all lower than setting value; Through setting time delay after satisfying condition, be then judged as that wind energy turbine set is sent line tripping and taked corresponding control measure.Adopt method of the present invention, solve existing method exists erroneous judgement under some method of operation of wind energy turbine set problem after Crowbar protection act.
The present invention takes following technical scheme to realize:
(1) electric current and the active power that wind energy turbine set sends circuit is first detected, judge whether that meeting current change quantity starts or active power variable quantity entry condition, if satisfy condition, then judge that wind energy turbine set is sent circuit and is disturbed, enter step (2) to judge, and record Startup time, preserve wind energy turbine set before starting and send the circuit running state information such as voltage, electric current, power of circuit;
(2) according to the quantity of information that step (1) is preserved, before judging disturbance, whether active power absolute value is more than or equal to setting value PS1 (this value generally sets for this reason under Line Flow, the value that can impact the stabilization of power grids when sending line tripping); If active power reaches setting value, continue step (3), if do not reached, then sentence and do not occur sending line tripping.
(3) according to the quantity of information that step (1) is preserved, judge in perturbation process, whether current effective value occurs the process that declines rapidly, whether every cycle electric current slippage reaches setting value Δ Is, and (this value sets according to electrical network actual conditions, usually can be set to 5% ~ 10% of rated current; If electric current slippage reaches definite value, continue step (4), if do not reached, then sentence and do not occur sending line tripping.
(4) according to the quantity of information that step (1) is preserved, judge whether send line voltage distribution in perturbation process occurs progressively elevation process, and whether every cycle ascending amount reaches definite value Uups (usually can be set to 115% ~ 120% of rated voltage); If voltage progressively raises reach definite value, continue step (5), if do not reached, then sentence and do not occur sending line tripping.
(5) judge disturbance terminate rear active power absolute value whether be less than or equal to setting value PS2 (this value generally get wind energy turbine set run minimum technology go out force value, usually can be set to 10% of rated power); If active power reaches setting value, continue step (6), if do not reached, then sentence and do not occur sending line tripping.
(6) judge disturbance terminate after-current absolute value whether have at least two-phase be less than or equal to setting value IS2 (this value generally get wind energy turbine set run minimum current go out force value, usually can be set to 10% of rated current); If electric current reaches setting value, continue step (7), if do not reached, then sentence and do not occur sending line tripping.
(7) if meet above condition in steps; then device time delay Ts1 (this value is the bigger the better within the time that system can bear, but should be noted to relate to wind energy turbine set net protection match usually be set as 20 ~ 100ms) after be judged as that wind energy turbine set sends line tripping.
In the present invention, step (1) power variation starts determination methods and is: detect current active-power P in real time
twith active-power P before 200ms
t-200msdifference, if its absolute value is continuous be greater than definite value Δ PS for 3-6 time, then start wind energy turbine set send line tripping judgment means; Current change quantity starts determination methods: detect current any phase current instantaneous value i in real time
twith current i before 20ms
t-20msdifference, if its absolute value is for several times greater than definite value Δ Is continuously, then starts wind energy turbine set and send line tripping judgment means.The setting of definite value Δ PS, Δ Is is suitably less under then should ensureing to escape the prerequisite of normal power swing and power adjustments, to ensure sensitivity.Sending circuit Δ PS and can be set as 50MW usually for 500kV and above, sending circuit Δ PS and can establish 10MW for 220/330kV electric pressure; Δ Is is then set as 10% of rated current usually.
Step (2) reflects the flow situations before sending line accident, and line tripping only occurs when trend is heavier and just can impact the stabilization of power grids, the setting of PS1 definite value can provide according to stability Calculation.
Step (3) (4) reflect the variation characteristic sending electric parameters in line tripping process, and the current disturbing setting △ Is that can be able to bear according to system, can be set to 5% ~ 10% of rated current usually; The setting of Uups then needs voltage fluctuation when escaping normal operation, is usually not less than the ratings of 1.1 times, and can matches with relating to net protection.
Step (5) (6) reflect and send line tripping after stable state electric parameters, theoretical value is 0, only need escape the measuring error of device, the minimum technology that definite value PS2 generally gets wind energy turbine set operation goes out force value, can be set as 10% of rated power, corresponding definite value IS2 also can be set as 10% of rated current accordingly.
Step (7) ensure that device wind energy turbine set send the non-tripping operation of circuit and power zero passage and measurements interference time reliable not malfunction; TSI definite value is the bigger the better within the time that system can bear; but should be noted that relating to net protection with wind energy turbine set matches, and is set as 20 ~ 100ms usually.
Embodiment 1:
Below in conjunction with accompanying drawing 7, the invention will be further described.Supposing a certain wind energy turbine set to send circuit, normally to send power be 100MW, and rated voltage is 110kV, and rated current is 1000A, and this sends that circuit minimum technology exerts oneself is 40MW.Analysis result is when needing to take control measure in 40ms after this line tripping, otherwise it is stable that electrical network will be caused to lose.
First tripping operation judgment means gathers the current and voltage quantities that wind energy turbine set sends circuit, and the electric parameters such as calculating voltage current effective value, active power;
If device is not activated, then start according to current change quantity or power variation judgment means, the difference of the power before current active power and 200ms is greater than definite value △ PS=10MW, or before any phase current instantaneous value and 20ms, difference between currents is greater than definite value Δ Is=100A, then thinks that device starts after continuous 5ms.
(the 5s time is kept) after entering starting state, record the active-power P-1s before startup, before judging disturbance, whether active power is greater than definite value PS1=30MW, if meet, proceeds to send line tripping and judges, otherwise startup counter is subtracted 1, jumps out this and interrupt judging.
Electric current slippage in start-up course is judged, i.e. current flow effective value I after starting
kwith electric current I before a cycle
k-20msdifference | △ I|=|I
k-I
k-20ms| does>=△ Is=100A meet? if meet, proceed to send line tripping and judge, otherwise will send line tripping delay counter and subtract 1, jump out this and interrupt judgement.
Whether following detection system voltage is increased to Uups=126kV, if do not raise, will send line tripping operation delay counter and subtract 1, and jump out this and interrupt judging.If increase, continue to send line tripping and judge.
After satisfying condition, then detect the electric parameters such as electric current, active power in perturbation process, if active power | P
k| < Ps2=10MW, two-phase active current is less than IS1=100A, then continue judgement and send line tripping, otherwise will send line tripping delay counter and subtract 1, jumps out this and interrupts judgement.After above-mentioned condition all meets, send line tripping delay counter and add 1, be judged as sending line tripping after tripping operation time delay is greater than Ts1=40ms.
Claims (4)
1. double-fed fan motor unit wind energy turbine set sends a line tripping determination methods, it is characterized in that, comprises the steps:
(1) electric current and the active power that wind energy turbine set sends circuit is first detected, judge whether that meeting current change quantity starts or active power variable quantity entry condition, if satisfy condition, then judge that wind energy turbine set is sent circuit and is disturbed, enter step (2) to judge, and record Startup time, preserve wind energy turbine set before starting and send the voltage of circuit, electric current and active power these several operating states of the units information; Otherwise judge that wind energy turbine set is sent circuit and is not disturbed, no longer continue to judge;
(2) judge whether start front active power is greater than setting value PS1;
(3) judge in perturbation process, whether current effective value occurs the process that declines rapidly, namely every cycle current effective value slippage meets or exceeds setting value Δ Is;
(4) judge in perturbation process, whether voltage occurs uphill process and meet or exceed setting value Uups;
(5) after judging disturbance, whether active power absolute value is less than or equal to setting value PS2;
(6) judge that whether disturbance after-current effective value is lower, namely have at least biphase current effective value to be less than or equal to setting value IS2;
(7) after starting, if meet the condition of step (2) to step (6) simultaneously, be then judged as that wind energy turbine set sends line tripping after time delay Ts1, otherwise think that sending circuit does not occur tripping operation.
2. a kind of double-fed fan motor unit wind energy turbine set as claimed in claim 1 sends line tripping determination methods, it is characterized in that:
The determination methods that in step (1), whether active power variable quantity starts is: detect the active-power P that current wind energy turbine set sends circuit in real time
twith active-power P before 200ms
t-200msdifference, if the absolute value of this difference is continuous be greater than setting value Δ PS for 3-6 time, then start wind energy turbine set send line tripping judge;
The determination methods that in described step (1), whether current change quantity starts is: detect current any phase current instantaneous value i in real time
twith current i before 20ms
t-20msdifference, if the absolute value of this difference is continuous be greater than setting value Δ Is for 3-6 time, then start wind energy turbine set send line tripping judge.
3. a kind of double-fed fan motor unit wind energy turbine set as claimed in claim 1 sends line tripping determination methods, it is characterized in that: the condition of described step (3) and the decline of step (4) electric current and voltage rise, needs to satisfy condition for 3-6 time.
4. a kind of double-fed fan motor unit wind energy turbine set as claimed in claim 1 sends line tripping determination methods, it is characterized in that: active power and the required conditional request continuously effective met of electric current after disturbance in step (5) and step (6).
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