CN1822491A - Power conversion device for secondary excitation - Google Patents

Abstract

This power conversion device for secondary excitation includes a diode rectifier configured by connecting DC sides of a power converter for excitation and a power converter for linkage with each other, connecting the AC side of the power converter for excitation with a secondary winding for the secondary excitation type generator through a first impedance, connecting DC connection sections of the power converter for excitation and the power converter for linkage with DC sides in parallel, and connecting the secondary winding of the secondary excitation type generator with AC side through a second impedance smaller than the first impedance. Thus, it secured the operation continuity of a power conversion device for exciting a secondary excitation type generator by protecting the power converter from overcurrent.

Description

Power conversion device for secondary excitation

Technical field:

The present invention relates to a kind of AC excitation with power conversion device with utilize the Blast Furnace Top Gas Recovery Turbine Unit (TRT) of this device; The AC excitation of being somebody's turn to do suppresses the overcurrent that the upset by electric power system takes place with power conversion device and flows to circuit conversion device on secondary excitation generator.

Background technology:

The secondary excitation generator that is utilized on the Blast Furnace Top Gas Recovery Turbine Unit (TRT) (coil shape induction generator), by on the power converter with gyrator coil excitation under slip frequency, can on the stator side, will export, the capacity of power converter can be compared the advantage that diminishes with generator capacity when having the rotation number of making variable with the alternating voltage of system frequency same frequency.

Reduce if by the ground fault of electric power system etc. voltage takes place, secondary excitation generator is to move to the accident point supplying electric current.At this moment, the excessive electric current of induction on secondary side coil, because with the power converter upper reaches excessive electric current is arranged, the element volume of power converter is become greater to generator specification equal extent or more than it to withstand this super-high-current in the excitation that is connected with primary side; Or utilize the method that the AC reactor that opens circuit is provided with etc.In addition, in patent documentation 1, disclosed and flow into electric energy according to moment and will connect the example that power conversion device under (ON) state and columns change.

[patent documentation 1] spy opens flat 11-18486 communique (record of (0004) paragraph)

Carrying out under the situation of short circuit on the AC reactor because in a single day power converter stops, so in order to restart once more supplying electric current need spended time.In addition, the capacity change of power converter is big, and then the expense of system rises, and diminishes the feature of the system that utilizes secondary excitation generator.Have again,, needing spended time on the supply capability once more because in a single day power converter stops and removing super-high-current, be used to disconnect short circuit current and restart under the situation that will carry out short circuit on the AC reactor.

Summary of the invention:

The object of the present invention is to provide a kind of power conversion device for secondary excitation, protect continuous running the compatible overcurrent of excitation of this power conversion device for secondary excitation energy with power converter with power converter generation from upsetting by systematic failures or system with secondary excitation shape generator.

The present invention, the overcurrent that produces in order to upset in system so that on secondary excitation generator does not flow to power converter, with the power converter parallel connection under by reactor rectifying device is set; To shunt at rectifying device from the overcurrent that flows into, will be little to the quantitative change that power converter flows into.

Power conversion device of the present invention, the overcurrent that produces in order to upset in system so that on secondary excitation generator does not flow to power converter, the current capacity of power converter can be diminished.

In the present invention, for the excitation of secondary excitation shape generator is protected from the overcurrent that is produced by systematic failures with power converter, and and then realize continuous running, reduced the impedance of the rectifying device of overcurrent processing unit.Below, present invention will be described in detail with reference to the accompanying on the limit.

Description of drawings

Fig. 1 is the key diagram that the circuit of the Blast Furnace Top Gas Recovery Turbine Unit (TRT) of embodiment 1 constitutes.

Fig. 2 is the control block diagram of control device of the Blast Furnace Top Gas Recovery Turbine Unit (TRT) of embodiment 1.

Among the figure: 101-windmill, 102-encoder, 201-integrator, Gen-level excitation generator, CTT1, CTT2-electromagnetic contactor, INV, CNV-power converter, REC-rectifying device, LOD-energy consumption mechanism, BR-circuit breaker, CTR1-control device.

Embodiment

Embodiment 1

Fig. 1 is the single line tie lines figure of the device formation of expression present embodiment.At this,, also be applicable to the situation of utilizing windmill 101 power source in addition though under the situation of wind power generation plant, describe.

At first, electric distribution and the device to the output output of a generator describes.The generator Gen that wind-force is used is secondary excitation generator (a coil shape induction generator), and the output of the three-phase alternating current of the stator side (primary side) of this generator Gen is connected with primary side by external signal electromagnetic contactor CTT1 to be opened/closed.The primary side of this external electromagnetic contactor CTT1 is connected in the primary side of electromagnetic contactor CTT2 and the primary side of circuit breaker BR.The primary side of circuit breaker BR is connected in the not shown electric power system.

Circuit breaker BR for example, possesses when electric current is excessive circuit breaker is disconnected and the function of breaking current; If circuit breaker BR is come into operation, supply power on the control device CTRL of wind power generation plant then.Even when systematic failures, also use the cell apparatus of uninterruptible power supply etc. for supply capability on control device CTRL.

In addition, the primary side of electromagnetic contactor CTT2, capacitor Cn by triangle (delta) tie lines and reactor Ln connect with the ac output end of the power converter CNV that is connected usefulness.On the other hand, connect the dc output end of the power converter CNV of (contact) usefulness, the smmothing capacitor Cd by direct current is connected with the dc output end of exciting power converter INV is sub.

Connect the power converter CNV and the exciting power converter INV of usefulness, its formation is: utilize for example semi-conductive electrical power switching element (gate semiconductor stream device, GTO, IGBT, power MOSFET); Possess separately: interchange is converted to direct current or direct current is converted to the function of interchange.

Ac output end of exciting power converter INV is connected with the secondary side coil terminal of generator Gen by reactor Lr and capacitor Cr.

In addition, with described excitation with power conversion device in parallel, rectifying device REC is connected with the secondary side coil terminal of generator Gen by reactor Lx.This rectifying device REC with its direct current component with the direct current component of described power converter INV, for example on smmothing capacitor Cd, be connected; And, also be connected with the LOD of energy consumption mechanism with power semiconductor switch and resistance.Though the situation that rectifying device REC has been possessed diode rectifier is narrated in the following description, also is not limited to diode rectifier, also can utilize semi-conductive electrical power switching element (gate semiconductor stream device, GTO, IGBT, power MOSFET).Have, in the present embodiment, the gyrator of generator Gen is connected with windmill 101 by direct or gear etc. again; Rotate though attend by the rotation of windmill, also with the waterwheel of the generating of pumping up water etc. or, the power of the internal combustion engine of gas driven generator etc., flywheel etc. down the situation of rotation be the same.

Secondly, distribution and the device that is used to control output of a generator described.The three-phase voltage of the primary side of circuit breaker BR and three-phase current, voltage sensor PTs, the current sensor CTs by separately is converted to signal Vs, the Is of low-voltage with its value, makes the signal of described low-voltage be input into control device CTRL.

Having, the primary side of electromagnetic contactor CTT1, is the voltage between electromagnetic contactor CTT1 and the generator stator again, is input into the control device CTRL that its value is converted to the signal Vg of low-voltage by voltage sensor PTg.Having, the primary side of electromagnetic contactor CTT2, is the three-phase current between electromagnetic contactor CTT2 and the power converter CNV again, its value is converted to the signal In of low-voltage by voltage sensor CTn; The signal of described low-voltage is input into control device CTRL.

Have again, with rotation number and the position of generator Gen, detect by position detector (for example encoder 102); Position phase signals PLr (spike train) is input into control device CTRL.

Have, the voltage of the smmothing capacitor Cd that is connected with the direct current portion of described power converter CNV, INV by not shown voltage sensor, is converted to the signal Edc of low-voltage again; Edc is input into control device CTRL with this signal.

Below, utilize Fig. 2 that the function of control device CTRL is described.Control device CTRL controls electromagnetic contactor CTT1, CTT2 or power converter INV, CNV, the LOD of energy consumption mechanism under signal Sg1, Sg2, Pulse_inv, Pulse_cnv, Pulse_LOD.

The power converter CNV that connects usefulness, the front and back that in service and generator Gen is connected with electric power system by electromagnetic contactor CTT1 at wind power generation plant implement that direct voltage that the direct voltage Edc with smmothing capacitor Cd controls is consistently controlled and system's nonsignificant zero power (power factor) is controlled.Thus, if it is that direct voltage reduces that exciting power converter INV uses the result of direct current power, the power converter CNV that then connects usefulness from electric power system take out electric power and so that direct voltage charge in smmothing capacitor Cd and keep consistently and move; Exciting on the contrary power converter INV is with smmothing capacitor Cd charging and under the situation of the DC voltage rising at smmothing capacitor Cd two ends, the power converter CNV of connection usefulness is converted to alternating electromotive force with direct current power and discharges, so that direct voltage keeps consistently and moves.

At first, the control to power converter CNV is described in detail.Described alternating voltage detected value Vs is input into three-phase two phase converter 32trs.In addition, output V α and the V β of described three-phase two phase converter 32trs are input into phase rotation indicator THDET.Described phase rotation indicator THDET, with following the position phase signals THs of the voltage of system, for example carrying out computing, the rheme phase signals THs of institute is output in three-phase two-phase coordinate converter 32dqtrs and described two-phase three-phase coordinate converter dq23trs with position synchronised circulation (PLL:phaselocked loop) mode.Described direct voltage command value Eref and described dc voltage detection value Edc are input into the DC voltage regulator DCAVR that for example is made of pi controller.DC voltage regulator DCAVR so that the deviation of the command value of input and detected value is zero, adjusts d shaft current command value (effectively the dividing current instruction value) Idnstr of output, is output in current regulator 1-ACR.

Three-phase two-phase coordinate converter 32dqtrs utilizes the change type shown in (several 1) formula from the electric current I n of input, computing d shaft current detected value Idn (effectively dividing electric current) and q shaft current detected value Iqn (invalid minute electric current) are output in d shaft current detected value Idn current regulator 1-ACR, q shaft current detected value Iqn are output in current regulator 2-ACR.

[several 1]

$\left[\begin{array}{c}\mathrm{Idn}\\ \mathrm{Iqn}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{THs}\right)& \sin \left(\mathrm{THs}\right)\\ -\sin \left(\mathrm{THs}\right)& \cos \left(\mathrm{THs}\right)\end{array}\right]\left[\begin{array}{c}\mathrm{Iu}\·\cos \left(0\right)+\mathrm{Iv}\·\cos (2\mathrm{\π}/3)+\mathrm{Iw}\·\cos (4\mathrm{\π}/3)\\ \mathrm{Iu}\·\sin \left(0\right)+\mathrm{Iv}\·\sin (2\mathrm{\π}/3)+\mathrm{Iw}\·\sin (4\mathrm{\π}/3)\end{array}\right]$

Described current regulator 1-ACR so that the deviation of described d shaft current command value Idnstr and described d shaft current detected value Idn is zero and the d shaft voltage command value Vdn0 of output is adjusted, is output in adder 301.Similarly, described current regulator 2-ACR so that the deviation of described q shaft current command value (command value during power factor 1=0) and described q shaft current detected value Iqn is zero and the q shaft voltage command value Vqn0 of output is adjusted, is output in adder 302.At this, described current regulator 1-ACR, 2-ACR for example can be made of pi controller.

Voltage coordinate transducer dqtrs utilizes the change type shown in (several 2) formula from α composition V α and the β composition V β of the described voltage Vs of input, computing d shaft voltage detected value (the position phase constituent consistent with the system voltage vector) Vds and q shaft voltage detected value (with the perpendicular composition of described d shaft voltage detected value Vds) Vqs will be output in described adder 301,302 separately.

Described adder 301 is carried out described d shaft voltage command value Vdn0 and described d shaft voltage detected value Vds addition and is output in two-phase three-phase coordinate converter dq23trs.Similarly, described adder 302 is carried out described q shaft voltage command value Vqn0 and described q shaft voltage detected value Vqs addition and is output in two-phase three-phase coordinate converter dq23trs.

Described two-phase three-phase coordinate converter dq23trs, the input rheme phase signals Ths of institute and, Vdn as a result, the Vqn of described each adder, by the change type shown in (several 3) formula and (several 4) formula output voltage command value Vun, Vvn, the Vwn of described transducer carried out computing, be output in PWM arithmetic unit PWMn.

[several 2]

$\left[\begin{array}{c}\mathrm{Vds}\\ \mathrm{Vqs}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{THs}\right)& \sin \left(\mathrm{THs}\right)\\ -\sin \left(\mathrm{THs}\right)& \cos \left(\mathrm{THs}\right)\end{array}\right]\left[\begin{array}{c}\mathrm{V\α}\\ \mathrm{V\β}\end{array}\right]$

[several 3]

$\left[\begin{array}{c}\mathrm{Va}\\ \mathrm{Vb}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{THs}\right)& -\sin \left(\mathrm{THs}\right)\\ \sin \left(\mathrm{THs}\right)& \cos \left(\mathrm{THs}\right)\end{array}\right]\left[\begin{array}{c}\mathrm{Vdn}\\ \mathrm{Vqn}\end{array}\right]$

[several 4]

$\left[\begin{array}{c}\mathrm{Vun}\\ \mathrm{Vvn}\\ \mathrm{Vwn}\end{array}\right]=\left[\begin{array}{cc}\cos \left(0\right)& \sin \left(0\right)\\ \cos (2\mathrm{\π}/3)& \sin (2\mathrm{\π}/3)\\ \cos (4\mathrm{\π}/3)& \sin (4\mathrm{\π}/3)\end{array}\right]\left[\begin{array}{c}\mathrm{Va}\\ \mathrm{Vb}\end{array}\right]$

Described PWM arithmetic unit PWMn, door (gate) signal Pulse_cnv that will constitute n the power semiconductor enforcement ONOFF of described power converter CNV from voltage instruction Vun, Vvn, the Vwn that imports by pulse width modulation carries out computing, is output in described power converter CNV.

Secondly, the control to power converter INV describes.The rotation number of expression generator and the position phase signals PLr of position are input into rotation phase rotation indicator ROTDET.Rotation phase rotation indicator ROTDET, the pulse PLr of meter digital phase signals and when being scaled phase signals is reset to the position phase signals 0, will overflow from 0 to the 360 position phase signals RTH that spends and be output in adder 303 by a pulse (for example Z phase pulse in the coding of ABZ mode) in rotation once.

The carry-out bit phase signals LTH of position phase signals RTH and isochronous controller SYNC carries out add operation and becomes a phase signals TH on adder 303, position phase signals TH and the rheme phase signals THs of institute import and excitation position arithmetic unit SLDET mutually together.

Described excitation position phase arithmetic unit SLDET carries out subtraction with rheme phase signals TH of institute and THs, and the number of pole-pairs of implementing generator doubly and the position phase signals THr of the electrical angle frequency of the gyrator of output generator.

Power arithmetic device PQCAL, input: d shaft current Ids, its be equidirectional with the U phasor1 of system power Is by the system voltage of the change type shown in described (several 1) formula detection; Q shaft current Iqs, the U phasor1 of itself and system voltage is straight-through; Described d shaft voltage detected value Vds; With q shaft voltage detected value Vqs; And by (several 5) formula, the effective power Ps of arithmetic system and reactance capacity Qs.

[several 5]

Ps＝3(Vds×Ids+Vqs×Iqs)

Qs＝3(-Vds×Iqs+Vqs×Ids)

Effective power adjuster APR, the power output instruction Pref of input effective power Ps and wind power generation plant, the torque current command value Iq0 of output output is so that the deviation of described power command value Pref and described power detection value Ps is zero.

Have again, reactance capacity adjuster AQR, the power output instruction Qref of input reactance capacity Qs and wind power generation plant, and output excitation current instruction value Id0 are so that the deviation of described power command value Qref and described power detection value Qs is zero.At this, described power regulator APR, reactance capacity adjuster AQR for example can be made of the proportional integral device.

The torque current command value Iq0 utmost point excitation current instruction value Id0 of the current instruction value of each output of described power regulator APR, reactance capacity adjuster AQR is input into transducer SW.

Whether transducer SW decision uses the output of described effective power adjuster APR and reactance capacity adjuster AQR, or, with torque current command value Iqo zero setting, the whether output of working voltage adjuster on excitation current instruction value Id0.At this, transducer SW is before electromagnetic contactor CTT1 drops into, promptly when making generator stator voltage be synchronized with the voltage synchronous operation of system voltage, select: with torque current command value Iq0 zero setting, the output of working voltage adjuster on excitation current instruction value Id0, and from dropping into the output of using effective power adjuster APR and reactance capacity adjuster AQR behind the electromagnetic contactor CTT1.

At this, AVR describes to voltage adjuster.Voltage adjuster AVR, with the amplitude Vgpk of generator stator voltage Vg as value of feedback, on the amplitude of system voltage Vs input as adding of command value the value Vsref of filter, the excitation current instruction value Id1 that the deviation of the amplitude of generator stator voltage Vg and described command value is changed to zero output is output in described transducer SW.At this, voltage adjuster AVR for example can be made of pi controller.This voltage adjuster AVR, hold electromagnetic contactor CTT1 is moved under opening, consistent for the amplitude that makes system voltage with the amplitude of the stator voltage of generator Gen, will carry out the running of computing from the excitation current instruction value that power converter INV flow into the primary side of generator Gen.

Three-phase two-phase coordinate converter 32dqtrs utilizes the change type shown in (several 6) formula from the electric current I r of input and the position phase THr of gyrator (rotor), computing d shaft current detected value Idr (exciting current composition) and q shaft voltage detected value Iqr (moment of torsion electric current composition) are output in d shaft current detected value Idr current regulator 4-ACR, q shaft current detected value Iqr are output in current regulator 3-ACR.

[several 6]

$\left[\begin{array}{c}\mathrm{Idr}\\ \mathrm{Iqr}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{THr}\right)& \sin \left(\mathrm{THr}\right)\\ -\sin \left(\mathrm{THr}\right)& \cos \left(\mathrm{THr}\right)\end{array}\right]\left[\begin{array}{c}\mathrm{Iu}\·\cos \left(0\right)+\mathrm{Iv}\·\cos (2\mathrm{\π}/3)+\mathrm{Iw}\·\cos (4\mathrm{\π}/3)\\ \mathrm{Iu}\·\sin \left(0\right)+\mathrm{Iv}\·\sin (2\mathrm{\π}/3)+\mathrm{Iw}\·\sin (4\mathrm{\π}/3)\end{array}\right]$

Described current regulator 4-ACR is so that the deviation of described d shaft current command value Id1 or Id0 and described d shaft current detected value Idr is zero and the d shaft voltage command value Vdr of output is adjusted.Similarly, described current regulator 3-ACR is so that the deviation of described q shaft current command value Iq1 or Iq0 and described q shaft current detected value Iqr is zero and the q shaft voltage command value Vqr of output is adjusted.At this, described current regulator for example can be made of the proportional integral device.

Described d shaft voltage command value Vdr and described q shaft voltage detected value Vqr are input into two-phase three-phase coordinate converter dq23trs; Described two-phase three-phase coordinate converter dq23trs, with the rheme phase signals THr of institute, with from described each input value, by the change type shown in (several 7) formula and (several 8) formula, voltage instruction value Vur, Vvr, the Vwr of the output of described transducer dq23trs are carried out computing, and be output in PWM arithmetic unit PWMr.

[several 7]

$\left[\begin{array}{c}\mathrm{Va}\\ \mathrm{Vb}\end{array}\right]=\left[\begin{array}{cc}\cos \left(\mathrm{THr}\right)& -\sin \left(\mathrm{THr}\right)\\ \sin \left(\mathrm{THr}\right)& \cos \left(\mathrm{THr}\right)\end{array}\right]\left[\begin{array}{c}\mathrm{Vdr}\\ \mathrm{Vqr}\end{array}\right]$

[several 8]

$\left[\begin{array}{c}\mathrm{Vur}\\ \mathrm{Vvr}\\ \mathrm{Vwr}\end{array}\right]=\left[\begin{array}{cc}\cos \left(0\right)& \sin \left(0\right)\\ \cos (2\mathrm{\π}/3)& \sin (2\mathrm{\π}/3)\\ \cos (4\mathrm{\π}/3)& \sin (4\mathrm{\π}/3)\end{array}\right]\left[\begin{array}{c}\mathrm{Va}\\ \mathrm{Vb}\end{array}\right]$

Described PWM arithmetic unit PWMr, carry out computing from voltage instruction Vur, Vvr, the Vwr of input by the gate signal Pulse_inv that pulse width modulation will constitute m the semiconductor element enforcement connection disconnection (ONOFF) of described power converter INV, be output in described power converter INV.

Isochronous controller SYNC has two big functions.One is that the amplitude that makes stator voltage is used for being fit to the function that the voltage instruction value of the amplitude of system voltage carries out computing; Second is the function position phase, that position phase correction value LTH carries out computing that the position that makes the stator voltage before system connects is used for being fit to mutually system voltage.

At first, the amplitude to the 1st function describes synchronously.In order to make voltage amplitude synchronous, calculate the amplitude Vspk of system voltage from the quadratic sum of described V α and V β, in the amplitude of computing, remove ripple (ripple) composition and as the voltage instruction value Vsref of described voltage adjuster by time lag of first order filter etc.Similarly, stator voltage Vgpk is also become to assign to try to achieve with β by the α composition, and it is utilized in the value of feedback Vgpk of described voltage adjuster, also is used in the amplitude judgement synchronously.Amplitude is judged synchronously, and described voltage instruction value Vsref and voltage amplitude Vgpk are compared, and it is synchronous to be judged to be amplitude when being on duty in certain setting.

Secondly, the position synchronised to the 2nd function describes.Position synchronised function, for the position that makes described system voltage mutually and stator voltage consistent, its phasic difference is calculated.If this phasic difference is exported as position phase correction value LTH, then,, the output of integrator is exported as position phase correction value LTH so in phasic difference, put into the integrator of band amplitude limiter because the position of generator stator voltage changes mutually intensely.Position phase correction value LTH is rotated a phase RTH to carry out plus and minus calculation and tries to achieve rotation position phase TH.

At this, described excitation position phase THr deducts rotation position phase TH and tries to achieve from system voltage position phase THs like that as described, is called so-called slip frequency.Thus, if the position of power converter INV phase signals THr on the throne is descended excitation mutually, stator angular frequency 1 is with the angular frequency 0 consistent (ω 0=ω 1) of system voltage; The position is mutually also by position phase correction value LTH unanimity.

Isochronous controller SYNC when consistent, transmits synchronizing signal SYN in described voltage and position on system controller SYS.This system controller SYS, if accept synchronizing signal SYN, output makes signal Sg0, the Sg1 of transducer SW and electromagnetic contactor CTT1 effect.Export synchronous marker for determination SYN if phasic difference is roughly consistent, system controller SYS is when being sent to control transformation signal Sg0 on the transducer SW, and instruction is closed in output to electromagnetic contactor CTT1.

Below, the described rectifying device REC when relevant system is upset generation describes.When system voltage reduced, the voltage difference delta V by induced voltage and system voltage made electric current increase Δ I.At this moment, if the line number of secondary excitation generator is than being a, then the electric current at last Δ I/a increases.When the electric current of this Δ I/a is big, excessive electric current is arranged at the upper reaches then.

In primary side, because power converter and rectifying device REC are connected by reactor Lr, Lx separately, at electric current I c that flows through on the Lr and the electric current I x that on Lx, flows through, represent by (several 9) formula and (several 10) formula, and the ratio of impedance Z Lr, Zlx by reactor Lr, lx is shunted.The super-high-current that causes by at this moment upset, the flip-flop contrary composition of the fault current that results from and on primary side (stator), flow through, because become alternating current and present in coil sides, by reactor Lr, Lx, can make the impedance of the power converter of primary side and rectifying device REC different.At this, if the impedance Z Lr of the reactor Lr of the impedance Z Lx of the reactor Lx of rectifying device side and power converter side is identical or diminish than it, would be effective to the protection of overcurrent.Preferably, the electric current of shunting on the rectifying device REC side is become: the value than the output current that deducts power converter from the output specification electric current of generator Gen is big, and for below 85% of output specification electric current, more preferably, be such below 50%, the ratio of the impedance Z Lr of the impedance Z Lx of the reactor Lx of setting rectifying device side and the reactor Lr of power converter side.

[several 9]

Ic＝(Δl/a)×Zlx/(Zlr+Zlx)

[several 10]

Ix＝(Δl/a)×Zlr/(Zlr+Zlx)

Fen Liu electric current like this charges to the smmothing capacitor Cd and the capacitor Cx of direct current component, makes DC voltage rising.Because if DC voltage rising, the element or the capacitor that constitute rectifier or power converter cause insulation breakdown, so surpass setting, for example LOD of the consumption of energy mechanism action in 110% o'clock usually the time at direct voltage.

For the consumption of energy mechanism action direct voltage is controlled at below the setting, the deviation of the 2nd direct voltage command value Rref_0V and detected value Edc is detected on subtracter 304.Utilize amplitude limiter LIM, as the input of DC voltage regulator DCAVR2, wherein said amplitude limiter LIM is negative in deviation, output bias when promptly the DirectCurrent Voltage Ratio command value is big; Deviation is being for just, and promptly the DirectCurrent Voltage Ratio command value hour is changed to zero with output.

Described DC voltage regulator DCAVR2, only when the DirectCurrent Voltage Ratio command value is big, need make the described energy consumption LOD of mechanism action, the command value DUTY that will be used for the switch element of ON/OFF carries out computing, and the command pulse value Pulse_LOD that will be used for the ON/OFF switch element by described command value is output in the described energy consumption LOD of mechanism.

The described energy consumption LOD of mechanism for example, is connected resistance R and power semiconductor switch element connected in series ground and constitutes; Switch element is when ON, so that the power of direct voltage consumes on resistance R and moves.Like this, by the LOD of consumption of energy mechanism action, direct voltage is remained on below the setting.

Have again, rectifying device REC and the LOD of energy consumption mechanism are arranged on the power converter side in parallel and constitute; The direct current output of power converter for example is configured by the terminal that on smmothing capacitor the direct current component of rectifying device REC is connected; One or more, rectifying device REC and the LOD of energy consumption mechanism only can be configured under the capacity of necessity.

As more than, in the present embodiment, change the value of reactor Lx and on gyrator, connect rectifying device; Because the direct current component of rectifying device REC is connected with the direct current component of power conversion device, the major part of the overcurrent that can will produce on gyrator flows to the rectifying device side, and the electric current that can will flow on the power conversion device side diminishes.Thus, has the effect that the current capacity with power converter diminishes.Have again, in the present embodiment,, there is no need to make the gate signal of power converter to stop, the operation of power converter can be continued implement because can suppress the overcurrent of power converter.

Have again, in the present embodiment, the LOD of energy consumption mechanism is set on the DC side of rectifying device, because it is moved when the DC voltage rising that overcurrent causes, can be from the overvoltage protection utensil of direct voltage.Have again, because constituting of adopting is provided with rectifying device in parallel, the system that desired operation continues when the overcurrent of systematic failures takes place, or set up by indivedual settings and carry out correspondence the output of postrun power being implemented fast desired system, to the formation that waits correspondence flexibly is not set under the unnecessary situation.

Claims (12)

1, a kind of power conversion device for secondary excitation possesses: AC excitation power converter, the secondary coil AC excitation of the secondary excitation generator that it will be connected with electric power system the stator side; With the control device of this AC excitation with power converter; It is characterized in that, wherein,

Described AC excitation power converter possesses exciting the 1st power converter and the 2nd power converter that is connected usefulness, and the DC side of the 1st power converter is connected with the DC side of the 2nd power converter;

The AC side of described the 1st power converter is being connected with the secondary coil of described secondary excitation generator by the 1st impedance;

And possessing rectifying device, it is connected DC side parallel ground on the direct current coupling part of described the 1st power converter and the 2nd power converter, has connected AC side by the 2nd impedance on the secondary coil of described secondary excitation generator.

2, power conversion device for secondary excitation according to claim 1 is characterized in that,

Described the 1st impedance and the 2nd impedance are reactors.

3, power conversion device for secondary excitation according to claim 1 is characterized in that,

The value of described the 1st impedance is bigger than the value of the 2nd impedance.

4, power conversion device for secondary excitation according to claim 1 is characterized in that,

Described rectifying device is the diode rectification device.

5, power conversion device for secondary excitation according to claim 1 is characterized in that,

On the DC side of described rectifying device, connected energy consumption mechanism.

6, power conversion device for secondary excitation according to claim 5 is characterized in that,

Described control device, utilize described energy consumption mechanism and with the DC voltage control of described rectifying device below setting.

7, power conversion device for secondary excitation according to claim 1 is characterized in that,

Described AC excitation power converter possesses: the terminal that by described the 2nd impedance the AC side of diode rectifier is connected on the secondary coil of described secondary excitation generator; With on the direct current component of the DC side of DC side that has been connected described the 1st power converter and the 2nd power converter, connect the terminal of the DC side of described diode rectifier.

8, a kind of power conversion device for secondary excitation possesses: secondary excitation generator, and it is connected in electric power system with the stator side; With the AC excitation power converter, the secondary coil AC excitation that it will this secondary excitation generator; With the control device of this AC excitation with power converter; It is characterized in that, wherein,

Described AC excitation power converter possesses exciting the 1st power converter and the 2nd power converter that is connected usefulness, and the DC side of the 1st power converter is connected with the DC side of the 2nd power converter;

The AC side of described the 1st power converter is being connected by the 1st reactor and described secondary excitation generator;

And possessing rectifying device, it is connected DC side in parallel on the direct current coupling part of described the 1st power converter and the 2nd power converter, connected AC side by the 2nd reactor on described secondary excitation generator;

The impedance of described the 1st reactor is bigger than the impedance of described the 2nd reactor.

9, power conversion device for secondary excitation according to claim 8 is characterized in that,

Described rectifying device is a diode rectifier.

10, power conversion device for secondary excitation according to claim 9 is characterized in that,

Described AC excitation power converter possesses: the terminal that by described the 2nd reactor the AC side of diode rectifier is connected on described secondary excitation generator; With the terminal that on the direct current component that is connected in DC side the DC side of described diode rectifier is connected with the DC side of described the 1st power converter and the 2nd power converter.

11, power conversion device for secondary excitation according to claim 8 is characterized in that,

On the DC side of described rectifying device, connected the energy consumption mechanism that possesses thyristor and resistance.

12, a kind of secondary excitation wind power generation plant possesses: secondary excitation generator, and it possesses the gyrator and the stator that is connected with electric power system that is driven by windmill; The AC excitation power converter, the AC excitation that it will this secondary excitation generator; With the control device of this AC excitation with power converter; It is characterized in that, wherein,

Described AC excitation power converter possesses exciting the 1st power converter and the 2nd power converter that is connected usefulness, and the DC side of the 1st power converter is connected with the DC side of the 2nd power converter;

The AC side of described the 1st power converter is being connected by the 1st reactor and described secondary excitation generator;

And possessing rectifying device, it is connected DC side in parallel on the direct current coupling part of described the 1st power converter and the 2nd power converter, connected AC side by the 2nd reactor on described secondary excitation generator;

On the DC side of this rectifying device, connect the energy consumption mechanism that possesses thyristor and resistance;

The impedance of described the 1st reactor is bigger than the impedance of described the 2nd reactor.

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