CN105914692A - Full-bridge MMC direct-current ice melting device and control method thereof - Google Patents

Abstract

The invention belongs to the technical field of power system control, and particularly relates to a full-bridge MMC direct-current ice melting device and a control method thereof. The device comprises a circuit breaker, a disconnecting switch, a connecting reactor, a full-bridge MMC based on a resonant filter, four ice melting disconnecting switches and an alternating current line to be ice-melted which are sequentially connected. The method comprises the following steps: dq decoupling controller, dc current controller and modulation voltage sharing. The full-bridge MMC direct-current ice melting device can meet the ice melting requirements of lines with various voltage levels; reference can be made to the design of the device. The control method provided by the invention can provide reference basis for the control of the direct-current ice melting device.

Description

A kind of bridge-type MMC DC de-icing device and control method thereof

Technical field

The invention belongs to technical field of electric power system control, particularly relate to a kind of bridge-type MMC DC ice melting Device and control method thereof.

Background technology

In the natural calamity that various power systems suffer from, ice disaster is the most serious.With other Accident is compared, and the loss that electrical network is caused by ice disaster is even more serious, the most then ice dodge, heavy then Tower line falling is broken, even electric power networks paralysis.

Currently in order to improve electrical network to resist the method and apparatus that ice disaster ability carries out deicing, ice-melt to circuit Have multiple.The de-icing method having been proposed that both at home and abroad is generally divided into four classes: thermal ice-melting, mechanical deicing, from The most passive deicing and additive method.Mechanical deicing is not easy to handle, and naturally passive deicing efficiency is the lowest, due to Conventional method all has shortcoming in various degree, the most all circuit cannot be carried out efficient deicing, ice-melt.And The advantage of thermal ice-melting be ice-melt in short-term, easy and simple to handle, easily implement.Thermal ice-melting is that electric energy is turned by one Become the clearing ice technology of heat energy, be usually be passed through in wire electric current make conductor overheating to reach ice-melt purpose, Exchange ice-melt and DC ice melting can be divided into.

Traditional DC de-icing device is by simple deciliter operation of outside disconnecting switch, it is possible to achieve idle benefit Repaying and the conversion of DC ice melting pattern, but it is relatively big to produce harmonic wave when running, response speed is slightly slow, needs peace The wave filter of dress larger capacity；When Traditional DC deicing device SVC runs, voltage stress, valve loss are the most greatly, And DC ice melting is held concurrently, the reactive power compensator overwhelming majority time runs on reactive-load compensation pattern, causes it comprehensive On-road efficiency is substantially reduced.These features greatly limit the range of application of Traditional DC deicing device.

Summary of the invention

In order to solve the problems referred to above, the invention provides a kind of bridge-type MMC DC de-icing device and control thereof Method processed.Device includes: linked reactor L_T, bridge-type MMC, ice-melt disconnecting link S1, S2, S3, S4,

Wherein, linked reactor L_TOne end by disconnecting switch K and circuit breaker Q F be connected on 35kV or On 10kV ac bus, linked reactor L_TThe other end be connected with the AC of bridge-type MMC；

One end of ice-melt disconnecting link S1, S2 is connected with the positive pole of the DC side of bridge-type MMC, ice-melt disconnecting link S3, One end of S4 is connected with the negative pole of the DC side of bridge-type MMC；

The other end of ice-melt disconnecting link S1 is connected with the one end treating ice-melt alternating current circuit a phase, ice-melt disconnecting link S2, S3 The other end be connected with the one end treating ice-melt alternating current circuit b phase, the other end of ice-melt disconnecting link S4 with treat that ice-melt is handed over One end of Flow Line c phase is connected, and treats that ice-melt alternating current circuit a phase, b phase, the other end of c phase are shorted together.

Described bridge-type MMC is three-phase six bridge arm structure, and each brachium pontis is by filter reactor L_f, valve reactance Device L_sBe composed in series with N number of bridge-type submodule SM, in a, b, c three-phase any one phase upper brachium pontis or Filter reactor L in lower brachium pontis_fOne end and linked reactor L_TIt is connected, filter reactor L_fThe other end With valve reactor L_sOne end be connected, valve reactor L_sThe other end and the N number of bridge-type submodule being in series One end of block SM is connected, two filter reactor L on upper brachium pontis and lower brachium pontis_fBetween parallel resonance filtering Device C_f；The other end of the N number of bridge-type submodule SM on the upper brachium pontis of a, b, c three-phase links together Constitute the positive pole of bridge-type MMC DC de-icing device, the N number of bridge-type on the lower brachium pontis of a, b, c three-phase The other end of submodule SM links together and constitutes the negative pole of bridge-type MMC DC de-icing device.

Described bridge-type submodule SM includes four all-controlling power electronics devices T1, T2, T3, T4, four Individual diode D1, D2, D3, D4, an electric capacity C, a high-speed switch K_s；Full-control type power electronic The colelctor electrode of device T1, T2, T3, T4 negative pole with diode D1, D2, D3, D4 respectively is connected, The emitter stage of all-controlling power electronics device T1, T2, T3, T4 respectively with diode D1, D2, D3, The positive pole of D4 is connected；The emitter stage of all-controlling power electronics device T1 is with all-controlling power electronics device T3's Colelctor electrode be connected constitute bridge-type submodule SM positive pole, the emitter stage of all-controlling power electronics device T2 with The colelctor electrode of all-controlling power electronics device T4 is connected and constitutes the negative pole of bridge-type submodule, full-control type electric power electricity The colelctor electrode of sub-device T1 is connected and in the positive pole of electric capacity C with the colelctor electrode of all-controlling power electronics device T2 It is connected, the emitter stage phase of the emitter stage of all-controlling power electronics device T3 and all-controlling power electronics device T4 Connect and in the negative company of electric capacity C, high-speed switch K_sTwo ends respectively with the positive pole of bridge-type submodule SM and Negative pole is connected.

N number of bridge-type submodule that in described bridge-type MMC, the upper brachium pontis of a, b, c three-phase is in series The both positive and negative polarity of the N number of submodule in SM is sequentially connected in series, and the negative pole of n-th bridge-type submodule SM passes through Valve reactor L_sWith filter reactor L_fIt is connected；N number of full-bridge that the lower brachium pontis of a, b, c three-phase is in series The both positive and negative polarity of the N number of submodule in type submodule SM is sequentially connected, the 1st bridge-type submodule SM's Positive pole passes through valve reactor L_sWith filter reactor L_fIt is connected.

A kind of control method based on bridge-type MMC DC de-icing device, comprises the following steps:

1) by modularization multi-level converter MMC submodule capacitor voltage command value U_{C_rate}Deduct submodule The mean value U of the measured value of capacitance voltage_{C_avg}, obtain error, after error is carried out signal transacting, obtain module Change multilevel converter MMC ac-side current to gain merit axle component reference value i_dref, described signal processing method is Proportional integral regulates；

2) by modularization multi-level converter MMC reactive power command value Q_refDeduct wattless power measurement value Q, obtains error, obtains modularization multi-level converter MMC AC electricity after error is carried out signal transacting Meritorious axle component reference value i of stream_qref；

3) by modularization multi-level converter MMC ac-side current i_a、i_bAnd i_cCarry out Park Transformation to obtain Ac-side current is gained merit axle component measured value i_dWith idle axle component measured value i_q, by modularization multi-level converter MMC nets side three-phase voltage u_a、u_bAnd u_cCarry out Park Transformation to obtain voltage on line side and gain merit axle component measured value u_sdWith idle axle component measured value u_sq,

4) modularization multi-level converter MMC ac-side current is gained merit axle component reference value i_drefDeduct reality Measured value i_dObtain electric current to gain merit axle component error value, after error amount is carried out signal transacting, deduct feedforward amount ω₀Li_q, Deduct voltage on line side again to gain merit axle component measured value u_sd, obtain modularization multi-level converter MMC AC Voltage is gained merit axle component u_cd；

By modularization multi-level converter MMC ac-side current idle axle component reference value i_qrefDeduct measured value i_qObtain electric current idle axle component error value, after error amount is carried out signal transacting, add feedforward amount ω₀Li_d, then Plus voltage power-less axle component measured value u_sq, obtain modularization multi-level converter MMC AC voltage without Merit axle component u_cq；L is the side reactance of equivalent AC net, ω₀For electrical network fundamental frequency；

5) gain merit axle component u by modularization multi-level converter MMC AC voltage_cdDivide with voltage power-less axle Amount u_cqCarry out Parker inverse transformation and obtain modularization multi-level converter MMC AC three-phase voltage reference value v_m, wherein m=a, b, c；

6) by modularization multi-level converter MMC DC current command value I_dcrefDeduct DC current measures I_dc, obtain error, after error is carried out signal transacting, obtain modularization multi-level converter MMC DC voltage Reference value U_dcref；

7) with modularization multi-level converter MMC direct voltage reference value U_dcref1/2 to deduct modularization many Level converter MMC AC voltage a phase reference value va, obtains the reference value of bridge arm voltage in a phase Vpa_ref, uses direct voltage reference value U_dcref1/2 deduct modularization multi-level converter MMC AC Voltage b phase reference value vb, obtains reference value vpb_ref of bridge arm voltage in b phase, uses direct voltage reference value U_dcref1/2 deduct modularization multi-level converter MMC AC voltage c phase reference value vc, obtain c Go up reference value vpc_ref of bridge arm voltage mutually,

With modularization multi-level converter MMC direct voltage reference value U_dcref1/2 plus modularization how electric Flat transverter MMC AC voltage a phase reference value va, obtains reference value vna_ref of bridge arm voltage under a phase, Use direct voltage reference value U_dcref1/2 plus modularization multi-level converter MMC AC voltage b phase Reference value vb, obtains reference value vnb_ref of bridge arm voltage under b phase, uses direct voltage reference value U_dcref's 1/2 adds modularization multi-level converter MMC AC voltage c phase reference value vc, obtains brachium pontis under c phase Reference value vnc_ref of voltage；

8) by reference value vpm_ref of bridge arm voltage on abc three-phase, divided by submodule capacitor voltage reference value UC_rate, rounds and obtains upper brachium pontis conducting number, by reference value vnm_ref of bridge arm voltage under abc three-phase, Divided by submodule capacitor voltage reference value UC_rate, round and obtain lower brachium pontis conducting number, upper and lower bridge arm is led Logical number is sent to grading ring joint respectively, generates and triggers pulse, controls turning on and off of full-controlled device, it is achieved Control to each bridge arm voltage.

Described signal processing method is proportional integral regulation.

The transformation matrix P used in described Park Transformation_abc/dqFor:

$P_{abc/dq}=\frac{2}{3}\left[\begin{array}{ccc}cos\mathrm{\α}& cos(\mathrm{\α}-2\mathrm{\π}/3)& cos(\mathrm{\α}+2\mathrm{\π}/3)\\ sin\mathrm{\α}& sin(\mathrm{\α}-2\mathrm{\π}/3)& sin(\mathrm{\α}+2\mathrm{\π}/3)\end{array}\right]$

Wherein α=ω₀T, ω₀For electrical network fundamental frequency, t is the time.

Described equivalent AC net side reactance L is that the 1/2 of brachium pontis reactance adds connection reactance, i.e.

$L=L_T+\frac{L_s+L_f}{2}.$

The transformation matrix P used in described Parker inverse transformation_dq/abc ^-1For:

${P_{dq/abc}}^{-1}=\left[\begin{array}{cc}cos\mathrm{\α}& sin\mathrm{\α}\\ cos(\mathrm{\α}-2\mathrm{\π}/3)& sin(\mathrm{\α}-2\mathrm{\π}/3)\\ cos(\mathrm{\α}+2\mathrm{\π}/3)& sin(\mathrm{\α}+2\mathrm{\π}/3)\end{array}\right]$

Wherein α=ω₀T, ω₀For electrical network fundamental frequency, t is the time.

The beneficial effects of the present invention is:

Each submodule of bridge-type MMC is constituted by controlling flexibility ratio higher bridge-type submodule, according to Certain control and modulation rule just exporting, zero, negative module voltage so that Converter DC-side is electric The enough continuously adjustabe between rated value and zero of pressure energy, can circuit for different length be carried out within the specific limits Ice-melt, operates fairly simple.Simultaneously when transverter exports relatively low dc voltage and DC current, it is also possible to Ensure transverter AC output voltage, the quality of electric current.Therefore, modularization based on bridge-type submodule Multilevel converter has DC voltage and DC current way traffic ability, can meet DC ice melting to the change of current The requirement of device operating condition.The control method of the present invention mainly includes dq decoupling controller, and DC current controls Three parts are all pressed in device and modulation, it is possible to the design to device provides reference frame.

Accompanying drawing explanation

Fig. 1 is the structure chart of bridge-type MMC DC de-icing device of the present invention.

Fig. 2 is bridge-type MMC structure chart.

Fig. 3 is bridge-type sub modular structure figure.

Fig. 4 is the control structure figure of bridge-type MMC DC de-icing device.

Fig. 5 is the modulation of the control method of bridge-type MMC DC de-icing device and equal laminate section.

Detailed description of the invention

Below in conjunction with the accompanying drawings, embodiment is described in detail.

The structure chart of a kind of bridge-type MMC DC de-icing device of the present invention is as it is shown in figure 1, include: even Meet reactor L_T, bridge-type MMC, ice-melt disconnecting link S1, S2, S3, S4；Wherein, linked reactor L_T One end be connected on 35kV or 10kV ac bus by disconnecting switch K and circuit breaker Q F, connect electricity Anti-device L_TThe other end be connected with the AC of bridge-type MMC；One end of ice-melt disconnecting link S1, S2 is with complete The positive pole of the DC side of bridge type MMC is connected, and one end of ice-melt disconnecting link S3, S4 is straight with bridge-type MMC's The negative pole of stream side is connected；The other end of ice-melt disconnecting link S1 is connected with the one end treating ice-melt alternating current circuit a phase, melts The other end of skates lock S2, S3 is connected with the one end treating ice-melt alternating current circuit b phase, and ice-melt disconnecting link S4's is another One end is connected with the one end treating ice-melt alternating current circuit c phase, treat ice-melt alternating current circuit a phase, b phase, c phase another Shorted on one end is together.

Bridge-type MMC topological structure as in figure 2 it is shown, its structure is three-phase six bridge arm structure, each brachium pontis By filter reactor L_f, valve reactor L_sIt is composed in series with N number of bridge-type submodule SM, a, b, c tri- Filter reactor L in the upper brachium pontis of any one phase or lower brachium pontis in mutually_fOne end and linked reactor L_TPhase Even, filter reactor L_fThe other end and valve reactor L_sOne end be connected, valve reactor L_sThe other end with The one end of the N number of bridge-type submodule SM being in series is connected, two filtering on upper brachium pontis and lower brachium pontis Reactor L_fBetween parallel resonance filter C_f；N number of bridge-type submodule on the upper brachium pontis of a, b, c three-phase The other end of block SM links together and constitutes the positive pole of bridge-type MMC DC de-icing device, a, b, c tri- The other end of the N number of bridge-type submodule SM on the lower brachium pontis of phase links together and constitutes bridge-type MMC The negative pole of DC de-icing device.

The topological structure of bridge-type submodule SM is as it is shown on figure 3, include four all-controlling power electronics devices T1, T2, T3, T4, four diodes D1, D2, D3, D4, an electric capacity C, a high-speed switch K_s；The colelctor electrode of all-controlling power electronics device T1, T2, T3, T4 respectively with diode D1, D2, D3, The negative pole of D4 be connected, the emitter stage of all-controlling power electronics device T1, T2, T3, T4 respectively with diode The positive pole of D1, D2, D3, D4 is connected；The emitter stage of all-controlling power electronics device T1 and full-control type electric power The colelctor electrode of electronic device T3 is connected and constitutes the positive pole of bridge-type submodule SM, all-controlling power electronics device The emitter stage of T2 is connected with the colelctor electrode of all-controlling power electronics device T4 and constitutes the negative pole of bridge-type submodule, The colelctor electrode of all-controlling power electronics device T1 be connected with the colelctor electrode of all-controlling power electronics device T2 and in The positive pole of electric capacity C is connected, the emitter stage of all-controlling power electronics device T3 and all-controlling power electronics device The emitter stage of T4 is connected and in the negative company of electric capacity C, high-speed switch K_sTwo ends respectively with bridge-type submodule The positive pole of SM is connected with negative pole.

A, b, c three-phase is referred to for the N number of bridge-type submodule SM cascaded structure in bridge-type MMC N number of bridge-type submodule SM of being in series of upper brachium pontis in the both positive and negative polarity of N number of submodule be sequentially connected, The negative pole of i.e. SM1 is connected with the positive pole of SM2, and the negative pole of SM2 is connected with the positive pole of SM3, by that analogy, The positive pole of last SM1 is connected with bridge-type MMC, the negative pole of SMN and L_fIt is connected；A, b, c three-phase The both positive and negative polarity of the N number of submodule in N number of bridge-type submodule SM that lower brachium pontis is in series is sequentially connected, The negative pole of i.e. SM1 is connected with the positive pole of SM2, and the negative pole of SM2 is connected with the positive pole of SM3, by that analogy, The positive pole of last SM1 and L_fBeing connected, the negative pole of SMN is connected with bridge-type MMC

In the present invention, the control method of bridge-type MMC DC de-icing device comprises the following steps, such as Fig. 4 Shown in:

1) by modularization multi-level converter MMC submodule capacitor voltage command value U_{C_rate}Deduct submodule The mean value U of the measured value of block capacitance voltage_{C_avg}, obtain error, after it is carried out signal transacting, obtain mould Block multilevel converter MMC ac-side current is gained merit axle component reference value i_dref, described signal transacting side Method is proportional integral regulation；

2) by modularization multi-level converter MMC reactive power command value Q_refDeduct wattless power measurement Value Q, obtains error, obtains modularization multi-level converter MMC AC after it is carried out signal transacting Electric current is gained merit axle component reference value i_qref, described signal processing method is proportional integral regulation；

3) by modularization multi-level converter MMC ac-side current i_a、i_bAnd i_cCarry out Parker (Park) to become Change, be i.e. multiplied by transformation matrix P_abc/dq, obtain ac-side current and gain merit axle component measured value i_dDivide with idle axle Amount measured value i_q, modularization multi-level converter MMC is netted side three-phase voltage u_a、u_bAnd u_cCarry out Parker (Park) conversion, is i.e. multiplied by transformation matrix P_abc/dq, obtain voltage on line side and gain merit axle component measured value u_sdAnd nothing Merit axle component measured value u_sq, wherein transformation matrix P_abc/dqFor:

$P_{abc/dq}=\frac{2}{3}\left[\begin{array}{ccc}cos\mathrm{\α}& cos(\mathrm{\α}-2\mathrm{\π}/3)& cos(\mathrm{\α}+2\mathrm{\π}/3)\\ sin\mathrm{\α}& sin(\mathrm{\α}-2\mathrm{\π}/3)& sin(\mathrm{\α}+2\mathrm{\π}/3)\end{array}\right]$

Wherein α=ω₀T, ω₀For electrical network fundamental frequency, t is the time；

4) modularization multi-level converter MMC ac-side current is gained merit axle component reference value i_drefDeduct Measured value i_dObtain electric current to gain merit axle component error value, after it is carried out signal transacting, deduct feedforward amount ω₀Li_q, Deduct voltage on line side again to gain merit axle component measured value u_sd, obtain modularization multi-level converter MMC exchange Side voltage is gained merit axle component u_cd；Described signal processing method is proportional integral regulation,

By modularization multi-level converter MMC ac-side current idle axle component reference value i_qrefDeduct actual measurement Value i_qObtain electric current idle axle component error value, after it is carried out signal transacting, add feedforward amount ω₀Li_d, then Plus voltage power-less axle component measured value u_sq, obtain modularization multi-level converter MMC AC voltage Idle axle component u_cq；Described signal processing method is proportional integral regulation；

Described L is the side reactance of equivalent AC net, for brachium pontis reactance L_s+L_f1/2 plus connect reactance L_T, I.e.

$L=L_T+\frac{L_s+L_f}{2};$

5) gain merit axle component u by modularization multi-level converter MMC AC voltage_cdWith voltage power-less axle Component u_cqCarry out Parker (Park) inverse transformation, be i.e. multiplied by transformation matrix and obtain modularization multi-level converter MMC AC three-phase voltage reference value v_m(wherein m=a, b, c, lower same),

Wherein, transformation matrix P_dq/abc ^-1Form be

${P_{dq/abc}}^{-1}=\left[\begin{array}{cc}cos\mathrm{\α}& sin\mathrm{\α}\\ cos(\mathrm{\α}-2\mathrm{\π}/3)& sin(\mathrm{\α}-2\mathrm{\π}/3)\\ cos(\mathrm{\α}+2\mathrm{\π}/3)& sin(\mathrm{\α}+2\mathrm{\π}/3)\end{array}\right];$

6) modularization multi-level converter MMC DC current command value Idcref deducts DC current survey Value Idc, obtains error, obtains modularization multi-level converter MMC straight after it is carried out signal transacting Stream voltage reference value Udcref, described signal processing method is proportional integral regulation；

7) module is deducted with the 1/2 of modularization multi-level converter MMC direct voltage reference value Udcref Change multilevel converter MMC AC voltage a phase reference value va, obtain the reference of bridge arm voltage in a phase Value vpa_ref, deducts modularization multi-level converter MMC with the 1/2 of direct voltage reference value Udcref AC voltage b phase reference value vb, obtains reference value vpb_ref of bridge arm voltage in b phase, uses direct current The 1/2 of pressure reference value Udcref deducts modularization multi-level converter MMC AC voltage c phase reference value Vc, obtains reference value vpc_ref of bridge arm voltage in c phase,

Many plus modularization with the 1/2 of modularization multi-level converter MMC direct voltage reference value Udcref Level converter MMC AC voltage a phase reference value va, obtains the reference value of bridge arm voltage under a phase Vna_ref, exchanges plus modularization multi-level converter MMC with the 1/2 of direct voltage reference value Udcref Side voltage b phase reference value vb, obtains reference value vnb_ref of bridge arm voltage under b phase, joins with DC voltage Examine value Udcref 1/2 adds modularization multi-level converter MMC AC voltage c phase reference value vc, Obtain reference value vnc_ref of bridge arm voltage under c phase；

8) the equal laminate section of modulation in the control method of the present invention is as shown in Figure 5:

By reference value vpm_ref of bridge arm voltage on abc three-phase, divided by submodule capacitor voltage reference value UC_rate, rounds and obtains upper brachium pontis conducting number, by reference value vnm_ref of bridge arm voltage under abc three-phase, Divided by submodule capacitor voltage reference value UC_rate, round and obtain lower brachium pontis conducting number, by upper and lower bridge arm Conducting number is sent to grading ring joint respectively, generates and triggers pulse, controls turning on and off of full-controlled device, real The now control to each bridge arm voltage.

This embodiment is only the present invention preferably detailed description of the invention, but protection scope of the present invention is not limited to In this, any those familiar with the art, in the technical scope that the invention discloses, can think easily The change arrived or replacement, all should contain within protection scope of the present invention.Therefore, the protection model of the present invention Enclose and be as the criterion with scope of the claims.

Claims (9)

1. a bridge-type MMC DC de-icing device, it is characterised in that including: linked reactor L_T、 Bridge-type MMC, ice-melt disconnecting link S1, S2, S3, S4,

Wherein, linked reactor L_TOne end by disconnecting switch K and circuit breaker Q F be connected on 35kV or On 10kV ac bus, linked reactor L_TThe other end be connected with the AC of bridge-type MMC；

One end of ice-melt disconnecting link S1, S2 is connected with the positive pole of the DC side of bridge-type MMC, ice-melt disconnecting link S3, One end of S4 is connected with the negative pole of the DC side of bridge-type MMC；

The other end of ice-melt disconnecting link S1 is connected with the one end treating ice-melt alternating current circuit a phase, ice-melt disconnecting link S2, S3 The other end be connected with the one end treating ice-melt alternating current circuit b phase, the other end of ice-melt disconnecting link S4 with treat that ice-melt is handed over One end of Flow Line c phase is connected, and treats that ice-melt alternating current circuit a phase, b phase, the other end of c phase are shorted together.

Device the most according to claim 1, it is characterised in that described bridge-type MMC is three-phase six bridge Arm configuration, each brachium pontis is by filter reactor L_f, valve reactor L_sConnect with N number of bridge-type submodule SM Composition, the filter reactor L in the upper brachium pontis of any one phase or lower brachium pontis in a, b, c three-phase_fOne end and company Meet reactor L_TIt is connected, filter reactor L_fThe other end and valve reactor L_sOne end be connected, valve reactance Device L_sThe other end be connected with the one end of the N number of bridge-type submodule SM being in series, upper brachium pontis and Xia Qiao Two filter reactor L on arm_fBetween parallel resonance filter C_f；N on the upper brachium pontis of a, b, c three-phase The other end of individual bridge-type submodule SM is just linking together composition bridge-type MMC DC de-icing device Pole, the other end of the N number of bridge-type submodule SM on the lower brachium pontis of a, b, c three-phase links together composition The negative pole of bridge-type MMC DC de-icing device.

Device the most according to claim 1, it is characterised in that described bridge-type submodule SM includes four Individual all-controlling power electronics device T1, T2, T3, T4, four diodes D1, D2, D3, D4, one Electric capacity C, a high-speed switch K_s；The colelctor electrode of all-controlling power electronics device T1, T2, T3, T4 divides Be not connected with the negative pole of diode D1, D2, D3, D4, all-controlling power electronics device T1, T2, T3, The emitter stage of T4 positive pole with diode D1, D2, D3, D4 respectively is connected；All-controlling power electronics device The emitter stage of T1 is just being connected composition bridge-type submodule SM with the colelctor electrode of all-controlling power electronics device T3 Pole, the emitter stage of all-controlling power electronics device T2 is connected with the colelctor electrode of all-controlling power electronics device T4 Constitute the negative pole of bridge-type submodule, the colelctor electrode of all-controlling power electronics device T1 and full-control type power electronic The colelctor electrode of device T2 is connected and connected in the positive pole of electric capacity C, the transmitting of all-controlling power electronics device T3 Pole is connected with the emitter stage of all-controlling power electronics device T4 and in the negative company of electric capacity C, high-speed switch K_s Two ends be connected with positive pole and the negative pole of bridge-type submodule SM respectively.

Device the most according to claim 1, it is characterised in that a, b, c in described bridge-type MMC The both positive and negative polarity of the N number of submodule in N number of bridge-type submodule SM that the upper brachium pontis of three-phase is in series is successively Series connection, the negative pole of n-th bridge-type submodule SM passes through valve reactor L_sWith filter reactor L_fIt is connected； N number of submodule in N number of bridge-type submodule SM that the lower brachium pontis of a, b, c three-phase is in series is just Negative pole is sequentially connected, and the positive pole of the 1st bridge-type submodule SM passes through valve reactor L_sWith filter reactor L_fIt is connected.

5. a control method based on bridge-type MMC DC de-icing device, it is characterised in that include with Lower step:

1) by modularization multi-level converter MMC submodule capacitor voltage command value U_{C_rate}Deduct submodule The mean value U of the measured value of capacitance voltage_{C_avg}, obtain error, after error is carried out signal transacting, obtain module Change multilevel converter MMC ac-side current to gain merit axle component reference value i_dref, described signal processing method is Proportional integral regulates；

2) by modularization multi-level converter MMC reactive power command value Q_refDeduct wattless power measurement value Q, obtains error, obtains modularization multi-level converter MMC AC electricity after error is carried out signal transacting Meritorious axle component reference value i of stream_qref；

3) by modularization multi-level converter MMC ac-side current i_a、i_bAnd i_cCarry out Park Transformation to obtain Ac-side current is gained merit axle component measured value i_dWith idle axle component measured value i_q, by modularization multi-level converter MMC nets side three-phase voltage u_a、u_bAnd u_cCarry out Park Transformation to obtain voltage on line side and gain merit axle component measured value u_sdWith idle axle component measured value u_sq,

4) modularization multi-level converter MMC ac-side current is gained merit axle component reference value i_drefDeduct reality Measured value i_dObtain electric current to gain merit axle component error value, after error amount is carried out signal transacting, deduct feedforward amount ω₀Li_q, Deduct voltage on line side again to gain merit axle component measured value u_sd, obtain modularization multi-level converter MMC AC Voltage is gained merit axle component u_cd；

By modularization multi-level converter MMC ac-side current idle axle component reference value i_qrefDeduct measured value i_qObtain electric current idle axle component error value, after error amount is carried out signal transacting, add feedforward amount ω₀Li_d, then Plus voltage power-less axle component measured value u_sq, obtain modularization multi-level converter MMC AC voltage without Merit axle component u_cq；L is the side reactance of equivalent AC net, ω₀For electrical network fundamental frequency；

5) gain merit axle component u by modularization multi-level converter MMC AC voltage_cdDivide with voltage power-less axle Amount u_cqCarry out Parker inverse transformation and obtain modularization multi-level converter MMC AC three-phase voltage reference value v_m, wherein m=a, b, c；

6) by modularization multi-level converter MMC DC current command value I_dcrefDeduct DC current measures I_dc, obtain error, after error is carried out signal transacting, obtain modularization multi-level converter MMC DC voltage Reference value U_dcref；

7) with modularization multi-level converter MMC direct voltage reference value U_dcref1/2 to deduct modularization many Level converter MMC AC voltage a phase reference value va, obtains the reference value of bridge arm voltage in a phase Vpa_ref, uses direct voltage reference value U_dcref1/2 deduct modularization multi-level converter MMC AC Voltage b phase reference value vb, obtains reference value vpb_ref of bridge arm voltage in b phase, uses direct voltage reference value U_dcref1/2 deduct modularization multi-level converter MMC AC voltage c phase reference value vc, obtain c Go up reference value vpc_ref of bridge arm voltage mutually,

With modularization multi-level converter MMC direct voltage reference value U_dcref1/2 plus modularization how electric Flat transverter MMC AC voltage a phase reference value va, obtains reference value vna_ref of bridge arm voltage under a phase, Use direct voltage reference value U_dcref1/2 plus modularization multi-level converter MMC AC voltage b phase Reference value vb, obtains reference value vnb_ref of bridge arm voltage under b phase, uses direct voltage reference value U_dcref's 1/2 adds modularization multi-level converter MMC AC voltage c phase reference value vc, obtains brachium pontis under c phase Reference value vnc_ref of voltage；

8) by reference value vpm_ref of bridge arm voltage on abc three-phase, divided by submodule capacitor voltage reference value UC_rate, rounds and obtains upper brachium pontis conducting number, by reference value vnm_ref of bridge arm voltage under abc three-phase, Divided by submodule capacitor voltage reference value UC_rate, round and obtain lower brachium pontis conducting number, upper and lower bridge arm is led Logical number is sent to grading ring joint respectively, generates and triggers pulse, controls turning on and off of full-controlled device, it is achieved Control to each bridge arm voltage.

Method the most according to claim 5, it is characterised in that described signal processing method is proportional integral Regulation.

Method the most according to claim 5, it is characterised in that the conversion square used in described Park Transformation Battle array P_abc/dqFor:

$P_{abc/dq}=\frac{2}{3}\left[\begin{array}{ccc}cos\mathrm{\α}& cos(\mathrm{\α}-2\mathrm{\π}/3)& cos(\mathrm{\α}+2\mathrm{\π}/3)\\ sin\mathrm{\α}& sin(\mathrm{\α}-2\mathrm{\π}/3)& sin(\mathrm{\α}+2\mathrm{\π}/3)\end{array}\right]$

Wherein α=ω₀T, ω₀For electrical network fundamental frequency, t is the time.

Method the most according to claim 5, it is characterised in that described equivalent AC net side reactance L is bridge The 1/2 of arm reactance is plus connecting reactance, i.e.

$L=L_T+\frac{L_s+L_f}{2}.$

Method the most according to claim 5, it is characterised in that the conversion used in described Parker inverse transformation Matrix P_dq/abc ^-1For:

${P_{dq/abc}}^{-1}=\left[\begin{array}{cc}cos\mathrm{\α}& sin\mathrm{\α}\\ cos(\mathrm{\α}-2\mathrm{\π}/3)& sin(\mathrm{\α}-2\mathrm{\π}/3)\\ cos(\mathrm{\α}+2\mathrm{\π}/3)& sin(\mathrm{\α}+2\mathrm{\π}/3)\end{array}\right]$

Wherein α=ω₀T, ω₀For electrical network fundamental frequency, t is the time.