CN102594160A - Diode clamped three-level high-voltage matrix converter and modulation method thereof - Google Patents

Abstract

The invention discloses a diode clamped three-level high-voltage matrix converter and a modulation method thereof. The diode clamped three-level high-voltage matrix converter is a novel high-voltage matrix converter formed by connection of two three-phase bi-directional matrix rectifying modules which are in series connection with one diode clamped three-level inverting module. The matrix converter has the advantages of bidirectional flow of energy, sinusoidal input current, controllable power factors, compact structure, output current of good quality, no requirement for a step of direct current energy storage, strong fault-tolerant capability, and the like, and is particularly suitable for medium high-voltage motor drive and a grid-tied wind power generation system.

Description

Diode clamp type three level high-voltage matrix converter and modulator approach thereof

Technical field

The present invention relates to a kind of diode clamp type three level high-voltage matrix converter and modulator approach thereof, belong to the power electronic technology apparatus field, be applicable to high pressure, high-power applications occasion.

Background technology

Under the background of world's energy crisis, responsible departments of the government classify the speed regualtion of AC motor energy saving of system that utilizes frequency converter as implement the national energy developing policy vital measure.And conventional P WM frequency converter input is the uncontrollable rectifier bridge of three-phase, the electrochemical capacitor of intermediate demand dc energy storage, have that the input power factor is low, harmonic pollution is serious and energy can not feedback etc. shortcoming.In recent years, along with popularizing fast of conventional P WM frequency converter, it was to negative effect that peripheral equipment caused also exposed day by day.Therefore, people begin to seek to develop the novel converter plant of environmental protection and energy saving.A kind of green frequency converter and matrix converter comes to this.With respect to conventional P WM frequency converter, matrix converter has saved intermediate dc energy storage link, and power factor is controlled; Input current sinusoidal (harm that can thorough harmonic carcellation can reduce the line loss in the electric energy transmitting to greatest extent), energy can two-way flow; When regenerative electric power; Matrix converter does not need brake resistance or special converter, can electric energy directly be fed back in the electrical network, thereby play effectively energy-conservation effect.

At present, the correlative study of most matrix converters is mainly carried out around the conventional topologies structure, because the physical restriction and the topological structure self of device, the classical matrix converter is difficult to be directly applied for mesohigh high-power applications occasion.And China is in numerous areas such as electric power, metallurgy, oil, chemical industry, coal, the papermaking high-voltage high-power motor system that has been widely used; Consideration from energy-conservation, the quality of power supply and quality of production aspect; There am great demand in we to the high voltage converter product; Matrix converter has many advantageous characteristic as the outstanding representative of frequency conversion product of future generation, and nature can not be absent in the mesohigh application.

For high voltage converter; If adopt traditional two-level inversion device topological structure; Need complicated IGBT serial connection technology; And there is following problem:, might cause that the rotor winding insulation punctures 1. because of high frequency causes very high

and surge voltage; 2. HF switch produces very high device voltage stress and very big switching loss, and efficient is reduced; 3. HF switch produces wide band electromagnetic interference near communication or other electronic equipments.The multi-electrical level inverter technology can overcome above-mentioned shortcoming, and therefore many level structure becomes the effective way that realizes the high voltage large capcity frequency converter.From the angle of commercial Application, multi-electrical level inverter mainly contains three types topological structure: diode clamp structure, H bridge cascade structure and flying capacitor structure.Wherein, diode clamp structure and H bridge cascade structure are used the most extensive by industrial quarters.And at present in the matrix converter field, the matrix converter topology that is fit to the high pressure occasion mainly contains the MMM multimode matrix converter of J.Change invention; The electric capacity clamper multi-level matrix converter of S.Yong invention, but because its notion that contains storage capacitor and conventional matrix converter has bigger discrepancy.Wherein, the MMM multimode matrix converter is a kind of cascade connection multi-level matrix converter, and it is used at wind power generation and the achieving success of electric machine speed regulation field, and a day intrinsic safety river motor company has also released the middle pressure matrix converter industrial products based on this topological structure.But should topology need a large amount of power semiconductors and a large amount of Industrial Frequency Transformers, change of current control is complicated, and fault-tolerant ability is poor.For these reasons, the present invention proposes a kind of new mesohigh matrix converter topology.

Summary of the invention

Technical problem to be solved by this invention provides a kind of diode clamp type three level high-voltage matrix converter and modulator approach thereof; This diode clamp type three level high-voltage matrix converter and modulator approach thereof have that output voltage is adjustable continuously, input and output quality of power supply function admirable, need not energy-storage travelling wave tube, can realize the energy two-way flow, compact conformation, fault-tolerance be strong, advantage such as cost is relatively low.

The technical solution of invention is following:

A kind of diode clamp type three level high-voltage matrix converter comprises three-phase three-winding transformer, high-voltage rectifier, three-phase diode clamper type three-level inverter and controller;

Each of three-phase three-winding transformer has an elementary winding of cover and the identical secondary winding of two covers mutually; High-voltage rectifier is in series by two identical three-phase matrix form biphase rectification device modules, and forms three lead-out terminal: P, O and N; These three lead-out terminals link to each other with dc bus positive pole, neutral point and the dc bus negative pole of three-phase diode clamper type three-level inverter respectively;

Three outputs of three-phase diode clamper type three-level inverter AC side are the output of diode clamp type three level high-voltage matrix converter;

Described high-voltage rectifier and three-phase diode clamper type three-level inverter all are controlled by controller.

Each three-phase matrix form biphase rectification device module constitutes by 6 bidirectional switchs, and each bidirectional switch is formed by two IGBT common emitter differential concatenations, and the shared same road of each bidirectional switch trigger impulse.

Three-phase diode clamper type three-level inverter is made up of the IGBT of 12 band reverse parallel connection diodes, and per 4 IGBT are connected into a brachium pontis (Q ₁～Q ₄, Q ' ₁～Q ' ₄, Q " ₁～Q " ₄), each 2 of upper and lower bridge arms, the mid point A of three brachium pontis, B, C be as the output of inversion module, on each brachium pontis, 2 clamp diode (D ₁～D ₂, D ' ₁～D ' ₂, D " ₁～D " ₂) being connected into a brachium pontis in twos, a brachium pontis upper end is connected in main brachium pontis switch (Q ₁Q ₂, Q ' ₁Q ' ₂, Q " ₁Q " ₂) between, the lower end is connected in down main brachium pontis switch (Q ₃Q ₄, Q ' ₃Q ' ₄, Q " ₃Q " ₄) between.

The elementary winding side joint of three-phase three-winding transformer has filter reactance and damping resistance, and the secondary winding side joint of three-phase three-winding transformer has filter capacitor.

A kind of modulator approach based on aforesaid diode clamp type three level high-voltage matrix converter is characterized in that the rectification stage duty ratio does $\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="d\; i"\; filenames="HDA0000135518040000042.png"\; state="\{\{state\}\}">d</figure-callout>}}_i=m\mathrm{Sin}(\mathrm{\&pi;}/6-[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\\ d_{i2}=m\mathrm{Sin}(\mathrm{\&pi;}/6+[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\end{array}\right.,$ M is the rectification stage index of modulation, 0＜m≤1, d _I1, d _I2Be duty ratio, θ is the reference current azimuth, and n is the sector number at reference current vector place, and the reference current vector is I in the sector, n=1 then, d _I1Be bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅The conducting duty ratio, d _I2Be bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆The conducting duty ratio; If the reference current vector is II in the sector, n=2 then, d _I1Be bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆The conducting duty ratio, d _I2Be bidirectional switch S ₂, S ' ₂, S ₆And S ' ₆The conducting duty ratio; If the reference current vector is III in the sector, n=3 then, d _I1Be bidirectional switch S ₂, S ' ₂, S ₆And S ' ₆The conducting duty ratio, d _I2Be bidirectional switch S ₂, S ' ₂, S ₄And S ' ₄The conducting duty ratio; If the reference current vector is IV in the sector, n=4 then, d _I1Be bidirectional switch S2, S ' ₂, S ₄And S ' ₄The conducting duty ratio, d _I2Be bidirectional switch S ₃, S ' ₃, S ₄And S ' ₄The conducting duty ratio; If the reference current vector is V in the sector, n=5 then, d _I1Be bidirectional switch S ₃, S ' ₃, S ₄And S ' ₄The conducting duty ratio, d _I2Be bidirectional switch S ₃, S ' ₃, S ₅And S ' ₅The conducting duty ratio; If the reference current vector is VI in the sector, n=6 then, d _I1Be bidirectional switch S ₃, S ' ₃, S ₅And S ' ₅The conducting duty ratio, d _I2Be bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅The conducting duty ratio.

The rectification stage duty ratio does $\left\{\begin{array}{c}{d}_{\mathrm{\&alpha;}}={\mathrm{<figure-callout\; id="1"\; label="d\; i"\; filenames="HDA0000135518040000042.png"\; state="\{\{state\}\}">d</figure-callout>}}_i/({\mathrm{<figure-callout\; id="1"\; label="d\; i"\; filenames="HDA0000135518040000042.png"\; state="\{\{state\}\}">d</figure-callout>}}_i+d_{i2})\\ d_{\mathrm{\&beta;}}=d_{i2}/({\mathrm{<figure-callout\; id="1"\; label="d\; i"\; filenames="HDA0000135518040000042.png"\; state="\{\{state\}\}">d</figure-callout>}}_i+d_{i2})\end{array}\right.,$ Wherein $\left\{\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="d\; i"\; filenames="HDA0000135518040000042.png"\; state="\{\{state\}\}">d</figure-callout>}}_i=m\mathrm{Sin}(\mathrm{\&pi;}/6-[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\\ d_{i2}=m\mathrm{Sin}(\mathrm{\&pi;}/6+[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\end{array}\right.,$ When the reference current vector is positioned at sector I, d _αBe bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅Conducting, other all switches of rectifier are in the duty ratio when closing, corresponding direct voltage u _Dc=2u _AbAnd d _βBe bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆Conducting, other all switches of rectifier are in the duty ratio when cutting out, and corresponding direct voltage is u _Dc=2u _Ac, the intermediate dc average voltage is u _Dc=2 (u _Abd _α+ u _Acd _β);

When the reference current vector is positioned at sector II, direct voltage u then _Dc=2 (u _Acd _α+ u _Bcd _β); When the reference current vector is positioned at sector III, direct voltage u _Dc=2 (u _Bcd _α+ u _Bad _β); When the reference current vector is positioned at sector IV, direct voltage u _Dc=2 (u _Bad _α+ u _Cad _β); When the reference current vector is positioned at sector V, direct voltage u _Dc=2 (u _Cad _α+ u _Cbd _β); When the reference current vector is positioned at sector VI, direct current u _Dc=2 (u _Cbd _α+ u _Abd _β).

The modulation signal of inverter (being described three-phase diode clamper type three-level inverter) is:

${\stackrel{\&OverBar;}{u}}_{\mathrm{io}}=2\frac{u_{\mathrm{io}}}{u_{\mathrm{dc}}},i\&Element;\{A,B,C\};$

Wherein, the inverter modulation signal before the normalization does $\left\{\begin{array}{c}{u}_{\mathrm{Ao}}=u_A^{*}+u_{\mathrm{No}}\\ u_{\mathrm{Bo}}=u_B^{*}+u_{\mathrm{No}}\\ u_{\mathrm{Co}}=u_C^{*}+u_{\mathrm{No}}\end{array}\right.,$ Wherein, $u_{\mathrm{No}}=-\frac{\mathrm{Min}\{u_A^{*},u_B^{*},u_C^{*}\}+\mathrm{Max}\{u_A^{*},u_B^{*},u_C^{*}\}}{2}$ Be zero sequence signal, $\left\{\begin{array}{c}{u}_A^{*}=U_{\mathrm{Om}}\mathrm{Cos}\left(\mathrm{\&beta;}\right)\\ u_B^{*}=U_{\mathrm{Om}}\mathrm{Cos}(\mathrm{\&beta;}-2\mathrm{\&pi;}/3)\\ u_C^{*}=U_{\mathrm{Om}}\mathrm{Cos}(\mathrm{\&beta;}+2\mathrm{\&pi;}/3)\end{array}\right.$ Output voltage for expectation.

Beneficial effect:

The novel high-pressure matrix converter that the two-way matrix rectification module of three-phase that diode clamp type three level high-voltage matrix converter of the present invention adopts two series connection and single diode clamp type tri-level inversion module link to each other and constituted.Matrix converter of the present invention has that energy two-way flow, Sinusoidal Input Currents, power factor are controlled, the output current of compact conformation, high-quality, need not good characteristics such as dc energy storage link and fault-tolerant ability be strong, is particularly suitable for mesohigh motor-driven and grid type wind generator system.

The rectification stage of the high-pressure matrix converter that the present invention carried has adopted bidirectional switch, so energy can two-way flow.Because need not the intermediate energy storage link, so compact conformation, power to volume ratio and power-weight ratio are high.Have many level characteristic in view of it simultaneously, so the output current harmonics aberration rate is littler, and allows operation under lower switching frequency, especially be fit to the high-power application scenario.Even this topological structure still can fault-tolerant operation, for example some or several switch (if S of high-voltage rectifier 4 the first half rectification modules in certain rectification module generation open fault ₁) open fault appears, and this fault is closed the Q of all switches of the first half rectification module and inverter section so by detection in time ₁, Q ' ₁And Q " ₁, constitute a two-level inverter and continue operation, therefore, the fault-tolerant ability that its tool is certain.The rectification stage bidirectional switch of the high-pressure matrix converter of this structure allows the zero current change of current, thereby control is simple, and switching loss is little, and system effectiveness is high.Based on above-mentioned characteristic, this diode clamp type three level high-voltage matrix converter is a kind of function admirable novel high-pressure frequency.

Description of drawings

Fig. 1 is a diode clamp type three level high-voltage matrix converter topological structure.

Fig. 2 is three level matrix converter middle dc voltages.

Fig. 3 is Fig. 3 input current vector.

Fig. 4 is rectifier switch signal schematic representation (sector I).

Fig. 5 is three level matrix converter inversion end multi-carrier modulation sketch mapes.

Fig. 6 is a three level high-voltage matrix converter system control block diagram.

Fig. 7 is input voltage (phase voltage) and input current waveform.

Fig. 8 is an output current wave.

Fig. 9 is the output line voltage waveform.

Embodiment

Below will combine accompanying drawing and specific embodiment that the present invention is explained further details:

A kind of diode clamp type three level high-voltage matrix converter as shown in Figure 1, it (comprises filter reactance and damping resistance by input filter 1, filter capacitor 2), three-phase three-winding transformer 3, two high-voltage rectifiers that the two-way matrix form rectifier module of identical three-phase is in series 4With a conventional three-phase diode clamper type three-level inverter 5Constitute.

Input filter is a second order LC low pass filter, it should be noted that filter capacitor should be arranged on three-phase three winding isolation transformers 3Pair side, as much as possible with high-voltage rectifier 4The interchange input side is approaching, to alleviate the pressure to the matrix converter semiconductor device such as transformer leakage inductance.This LC filter filtering on the one hand makes input current reach electrical network quality of power supply required standard from the high order harmonic component of matrix converter, and on the other hand, prevention that also can be to a certain degree is from the influence to the matrix converter output current such as the voltage harmonic of electrical network.Wherein, filter reactance only needs a cover, and filter capacitor 2Need two covers.High-voltage rectifier 4Be in series by the two-way matrix form rectifier module of two cover three-phases, series system is as shown in Figure 1, high-voltage rectifier 4Output three terminal: P, O and N are arranged.Identical when the control signal of the two-way matrix form rectifier module of this two cover three-phase, U is then arranged _PO=U _ONHigh-voltage rectifier is made up of bidirectional switch; Thereby the two-way flow of power ability, it is connected by two matrix form rectification modules, thereby can in the safe voltage scope that switching device can bear, realize the commutating voltage multiplication; Can realize high-voltage inverted for the inversion end provides higher available direct voltage.High-voltage rectifier 4The P of output, O and N respectively with conventional three-phase diode clamper type three-level inverter 5Dc bus anodal, neutral point and dc bus negative pole link to each other.Output voltage is by diode clamp type three-level inverter 5Synthetic; Become direct voltage when being as shown in Figure 2 with routine its DC bus-bar voltage of using that different is; Common modulation strategy such as carrier modulation still are suitable at this with control Vector Modulation thought, but need to become the adverse effect of direct voltage to synthesising output voltage when modulation signal is eliminated through revising.More than being diode clamp type three level high-voltage matrix converter topology related content, next is relative modulation strategy.

Modulation strategy comprises two parts: rectification stage modulation strategy and inversion modulation strategy.

Suppose input voltage:

$\left\{\begin{array}{c}{u}_a=U_{\mathrm{im}}\cos \left({\mathrm{\&omega;}}_{i}t\right)\\ u_b=U_{\mathrm{im}}\cos ({\mathrm{\&omega;}}_{i}t-2\mathrm{\&pi;}/3)\\ u_c=U_{\mathrm{im}}\cos ({\mathrm{\&omega;}}_{i}t+2\mathrm{\&pi;}/3)\end{array}\right.---\left(1\right)$

With reference to figure 3, according to the current space vector composition principle, the rectification stage duty ratio has

$\left\{\begin{array}{c}{d}_{i1}=m\sin (\mathrm{\&pi;}/6-[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\\ d_{i2}=m\sin (\mathrm{\&pi;}/6+[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\end{array}\right.---\left(2\right)$

Wherein, m is the rectification stage index of modulation, d _I1, d _I2Be duty ratio, θ is the reference current azimuth, and n is the sector number at reference current vector place, for example the reference current vector among Fig. 3 in the sector I, n=1 then, d _I1Be bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅The conducting duty ratio, d _I2Be bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆The conducting duty ratio.If the reference current vector is II in the sector, n=2 then, d _I1Be bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆The conducting duty ratio, d _I2Be bidirectional switch S ₂, S ' ₂, S ₆And S ' ₆The conducting duty ratio.If the reference current vector is III in the sector, n=3 then, d _I1Be bidirectional switch S ₂, S ' ₂, S ₆And S ' ₆The conducting duty ratio, d _I2Be bidirectional switch S ₂, S ' ₂, S ₄And S ' ₄The conducting duty ratio.If the reference current vector is IV in the sector, n=4 then, d _I1Be bidirectional switch S ₂, S ' ₂, S ₄And S ' ₄The conducting duty ratio, d _I2Be bidirectional switch S ₃, S ' ₃, S ₄And S ' ₄The conducting duty ratio.If the reference current vector is V in the sector, n=5 then, d _I1Be bidirectional switch S ₃, S ' ₃, S ₄And S ' ₄The conducting duty ratio, d _I2Be bidirectional switch S ₃, S ' ₃, S ₅And S ' ₅The conducting duty ratio.If the reference current vector is VI in the sector, n=6 then, d _I1Be bidirectional switch S ₃, S ' ₃, S ₅And S ' ₅The conducting duty ratio, d _I2Be bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅The conducting duty ratio.

In order to maximize the direct current utilance, duty ratio has been carried out the normalization processing

$\left\{\begin{array}{c}{d}_{\mathrm{\&alpha;}}=d_{i1}/(d_{i1}+d_{i2})\\ d_{\mathrm{\&beta;}}=d_{i2}/(d_{i1}+d_{i2})\end{array}\right.---\left(3\right)$

According to Fig. 3, when the reference current vector is positioned at sector I, d _αBe bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅Conducting, other all switches of rectifier are in the duty ratio when cutting out, corresponding direct voltage u _Dc=2u _AbAnd d _βBe bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆Conducting, other all switches of rectifier are in the duty ratio when cutting out, and corresponding direct voltage is u _Dc=2u _Ac, the corresponding switch signal is as shown in Figure 4, and therefore, the intermediate dc average voltage can be expressed as

u _dc＝2(u _abd _α+u _acd _β) (4)

Be positioned at sector II if work as the reference current vector, then direct voltage u _Dc=2 (u _Acd _α+ u _Bcd _β); When the reference current vector is positioned at sector III, direct voltage u _Dc=2 (u _Bcd _α+ u _Bad _β); When the reference current vector is positioned at sector IV, direct voltage u _Dc=2 (u _Bad _α+ u _Cad _β); When the reference current vector is positioned at sector V, direct voltage u _Dc=2 (u _Cad _α+ u _Cbd _β); When the reference current vector is positioned at sector VI, direct current u _Dc=2 (u _Cbd _α+ u _Abd _β).

If the output voltage of expectation

$\left\{\begin{array}{c}{u}_A^{*}=U_{\mathrm{om}}\cos \left(\mathrm{\&beta;}\right)\\ u_B^{*}=U_{\mathrm{om}}\cos (\mathrm{\&beta;}-2\mathrm{\&pi;}/3)\\ u_C^{*}=U_{\mathrm{om}}\cos (\mathrm{\&beta;}+2\mathrm{\&pi;}/3)\end{array}\right.---\left(5\right)$

The present invention adopts carrier modulation to realize the inversion modulation of this high-pressure matrix converter, and usually, the enforcement of carrier modulation need be selected suitable modulating ripple and carrier wave.At first, according to desired output voltage, the inverter modulation signal does

$\left\{\begin{array}{c}{u}_{\mathrm{Ao}}=u_A^{*}+u_{\mathrm{no}}\\ u_{\mathrm{Bo}}=u_B^{*}+u_{\mathrm{no}}\\ u_{\mathrm{Co}}=u_C^{*}+u_{\mathrm{no}}\end{array}\right.---\left(6\right)$

Wherein, zero sequence signal satisfies: $-u_{\mathrm{Dc}}/2-\mathrm{Min}\{u_A^{*},u_B^{*},u_C^{*}\}\&le;u_{\mathrm{No}}\&le;u_{\mathrm{Dc}}/2-\mathrm{Max}\{u_A^{*},u_B^{*},u_C^{*}\},$ For simplicity, the present invention gets

$u_{\mathrm{no}}=-\frac{\min \{u_A^{*},u_B^{*},u_C^{*}\}+\max \{u_A^{*},u_B^{*},u_C^{*}\}}{2}---\left(7\right)$

Easy in order to handle, the normalization that modulation signal carries out shown in (8) is handled:

${\stackrel{\&OverBar;}{u}}_{\mathrm{io}}=2\frac{u_{\mathrm{io}}}{u_{\mathrm{dc}}},i\&Element;\{A,B,C\}---\left(8\right)$

The inversion modulation of this matrix converter and the modulation strategy of conventional diode clamp type three-level inverter are different; Because the middle dc voltage of matrix converter is synthetic by certain compound mode by two sections line voltages of power supply; Therefore, its each complete inversion is made up of two sub-inversion processes modulation period jointly, and Fig. 5 is a typical inversion process; Suppose that its reference current vector is positioned at sector I, the leading portion direct voltage is 2u so _Ab, carrier cycle is d _αT _sThe back segment direct voltage is 2u _Ac, carrier cycle is d _βT _s, we know according to (3), d _α, d _βBe the function of reference current azimuth, so carrier cycle becomes when being, simultaneously, be not difficult to find middle dc voltage u _DcAlso one is variations per hour.

Can know that according to Fig. 5 the key that realizes this matrix converter inversion modulation is the generation with the variable period carrier signal of asking for of modulation signal, wherein, modulation signal is asked for by formula (8); The cycle information of variable period carrier signal is provided by formula (3), is respectively d _αT _sAnd d _βT _s, T wherein _sBe the system modulation cycle.Because the present invention has adopted positive and negative inversed stack mode multi-carrier modulation technology, therefore have two carrier generators, in order to produce the variable period isosceles triangle carrier signal of 180 ° of two-way phase place mutual deviations, its waveform is as shown in Figure 5.They can be by realizations such as counter in CPLD or the field programmable gate array (FPGA) and comparators.

Embodiment 1:

Describe with reference to 6 pairs of topological structures of the present invention of figure and control idea.Main circuit comprises filter reactance and damping resistance among Fig. 6 1, filter capacitor 2, three-phase three-winding transformer 3, high-voltage rectifier 4, three-phase diode clamper type three-level inverter 5And drive circuit 8Totally six parts, control circuit is by sample circuit 6And controller 7Form.Filter reactance and damping resistance 1Left end a, b, c link to each other with the three-phase of three phase network respectively, its right-hand member and three-phase three-winding transformer 3Former side's winding link to each other.Three-phase three-winding transformer 3Two cover secondary side's winding and filter capacitors 2Parallel connection, more respectively with high-voltage rectifier 4The interchange input side of two cover three-phase matrix form rectifiers link to each other, wherein, the secondary side's winding configuration of two covers is identical.High-voltage rectifier 4Three lead-out terminal: P, O and N again respectively with three-phase diode clamper type three-level inverter 5Anodal, neutral point of dc bus and dc bus negative pole link to each other.Three-phase diode clamper type three-level inverter 5Lead-out terminal A, B, C can connect various inductive loads.Wherein, high-voltage rectifier 4By 12 bidirectional switchs 9Form, and bidirectional switch 9Form by two common emitter IGBT differential concatenations again, and shared same drive signal.Three-phase diode clamper type three-level inverter 5, constituting by the IGBT of 12 band reverse parallel connection diodes, per 4 IGBT are connected into a brachium pontis Q ₁～Q ₄, Q ' ₁～Q ' ₄And Q " ₁～Q " ₄, each 2 of the top and the bottom of each brachium pontis, the mid point of three brachium pontis is as the output of inversion module.On each brachium pontis, (be respectively D by 2 clamp diodes ₁～D ₂, D ' ₁～D ' ₂And D " ₁～D " ₂A brachium pontis of corresponding A BC phase) series connection constitutes a brachium pontis, and parallelly connected with two IGBT in the middle of the main brachium pontis, and promptly the upper end of 3 brachium pontis is connected in main brachium pontis switch Q respectively ₁Q ₂, Q ' ₁Q ' ₂And Q " ₁Q " ₂Between, the lower end is connected in down main brachium pontis switch Q respectively ₃Q ₄, Q ' ₃Q ' ₄And Q " ₃Q " ₄Between.

Sample circuit 6Be responsible for three-phase three-winding transformer 2Pair side voltage u _a, u _b, u _cSignal condition, controller 7Mainly be made up of DSP and CPLD, wherein DSP is responsible for work such as sampling, calculating, after calculating finishes, information needed is passed to CPLD, accomplishes all modulation assignment by CPLD at last, and each switching signal is transferred to drive circuit 8Thereby reach each switching purposes of control.

Aspect algorithm, implementation step is: the first step, gather voltage u _a, u _b, u _c,, calculate the input current reference vector according to the requirement of power factor.Second step belonged to the sector based on the input current reference vector, selected the rectifier switch combination, and calculated the dutycycle of each switch combination based on formula (2) and (3), and calculated the intermediate means DC voltage, for follow-up inversion modulation is got ready.The 3rd step, read desired output voltage, according to (6), the normalization modulation signal is asked in (7) and (8).The 4th step, calculate gained information by CPLD based on above each step, finally generate the driving signal of this each switch of high-pressure matrix converter.

The case explanation:

At the input line voltage is 3300V, and the former pair side of transformer no-load voltage ratio is 1: 1, and output reference voltage is 5500V/30Hz, and output loading is the load of series connection resistance sense, R=20 Ω, and L=50mH, the input filter parameter is: L _s=0.6mH, R _s=3 Ω, C _f=30 μ F, sample frequency and switching frequency are 10KHz.

The MATLAB/Simulink environmentDown system has been carried out emulation, Fig. 7 is input voltage (phase voltage) and input current waveform, and input current is sinusoidal, and the base unit power factor.Fig. 8 is an output current wave, because the characteristic of many level, the current waveform quality is fine.Fig. 9 is the output line voltage waveform, can find out that obviously its output line voltage has many level characteristic.

Claims (7)

1. a diode clamp type three level high-voltage matrix converter is characterized in that, comprises three-phase three-winding transformer, high-voltage rectifier, three-phase diode clamper type three-level inverter and controller;

Each of three-phase three-winding transformer has an elementary winding of cover and the identical secondary winding of two covers mutually; High-voltage rectifier is in series by two identical three-phase matrix form biphase rectification device modules, and forms three lead-out terminal: P, O and N; These three lead-out terminals link to each other with dc bus positive pole, neutral point and the dc bus negative pole of three-phase diode clamper type three-level inverter respectively;

Three outputs of three-phase diode clamper type three-level inverter AC side are the output of diode clamp type three level high-voltage matrix converter;

Described high-voltage rectifier and three-phase diode clamper type three-level inverter all are controlled by controller.

2. diode clamp type three level high-voltage matrix converter according to claim 1; It is characterized in that; Each three-phase matrix form biphase rectification device module constitutes by 6 bidirectional switchs; Each bidirectional switch is formed by two IGBT common emitter differential concatenations, and the shared same road of each bidirectional switch trigger impulse.

3. diode clamp type three level high-voltage matrix converter according to claim 2 is characterized in that,

Three-phase diode clamper type three-level inverter is made up of the IGBT of 12 band reverse parallel connection diodes, and per 4 IGBT are connected into a brachium pontis (Q ₁～Q ₄, Q ' ₁～Q ' ₄, Q " ₁～Q " ₄), each 2 of upper and lower bridge arms, the mid point A of three brachium pontis, B, C be as the output of inversion module, on each brachium pontis, 2 clamp diode (D ₁～D ₂, D ' ₁～D ' ₂, D " ₁～D " ₂) being connected into a brachium pontis in twos, a brachium pontis upper end is connected in main brachium pontis switch (Q ₁Q ₂, Q ' ₁Q ' ₂, Q " ₁Q " ₂) between, the lower end is connected in down main brachium pontis switch (Q ₃Q ₄, Q ' ₃Q ' ₄, Q " ₃Q " ₄) between.

4. according to each described diode clamp type three level high-voltage matrix converter of claim 1-3; It is characterized in that; The elementary winding side joint of three-phase three-winding transformer has filter reactance and damping resistance, and the secondary winding side joint of three-phase three-winding transformer has filter capacitor.

5. the modulator approach based on the described diode clamp type of claim 3 three level high-voltage matrix converter is characterized in that the rectification stage duty ratio does $\left\{\begin{array}{c}{d}_{i1}=m\mathrm{Sin}(\mathrm{\&pi;}/6-[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\\ d_{i2}=m\mathrm{Sin}(\mathrm{\&pi;}/6+[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\end{array}\right.,$ M is the rectification stage index of modulation, 0＜m≤1, d _I1, d _I2Be duty ratio, θ is the reference current azimuth, and n is the sector number at reference current vector place, and the reference current vector is I in the sector, n=1 then, d _I1Be bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅The conducting duty ratio, d _I2Be bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆The conducting duty ratio; If the reference current vector is II in the sector, n=2 then, d _I1Be bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆The conducting duty ratio, d _I2Be bidirectional switch S ₂, S ' ₂, S ₆And S ' ₆The conducting duty ratio; If the reference current vector is III in the sector, n=3 then, d _I1Be bidirectional switch S ₂, S ' ₂, S ₆And S ' ₆The conducting duty ratio, d _I2Be bidirectional switch S ₂, S ' ₂, S ₄And S ' ₄The conducting duty ratio; If the reference current vector is IV in the sector, n=4 then, d _I1Be bidirectional switch S ₂, S ' ₂, S ₄And S ' ₄The conducting duty ratio, d _I2Be bidirectional switch S ₃, S ' ₃, S ₄And S ' ₄The conducting duty ratio; If the reference current vector is V in the sector, n=5 then, d _I1Be bidirectional switch S ₂, S ' ₃, S ₄And S ' ₄The conducting duty ratio, d _I2Be bidirectional switch S ₃, S ' ₃, S ₅And S ' ₅The conducting duty ratio; If the reference current vector is VI in the sector, n=6 then, d _I1Be bidirectional switch S ₃, S ' ₃, S ₅And S ' ₅The conducting duty ratio, d _I2Be bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅The conducting duty ratio.

6. the modulator approach of diode clamp type three level high-voltage matrix method parallel operation according to claim 5 is characterized in that the rectification stage duty ratio does $\left\{\begin{array}{c}{d}_{\mathrm{\&alpha;}}=d_{i1}/(d_{i1}+d_{i2})\\ d_{\mathrm{\&beta;}}=d_{i2}/(d_{i1}+d_{i2})\end{array}\right.,$ Wherein $\left\{\begin{array}{c}{d}_{i1}=m\mathrm{Sin}(\mathrm{\&pi;}/6-[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\\ d_{i2}=m\mathrm{Sin}(\mathrm{\&pi;}/6+[\mathrm{\&theta;}-(n-1)\mathrm{\&pi;}/3\left]\right)\end{array}\right.,$ When the reference current vector is positioned at sector I, d _αBe bidirectional switch S ₁, S ' ₁, S ₅And S ' ₅Conducting, other all switches of rectifier are in the duty ratio when closing, corresponding direct voltage u _Dc=2u _AbAnd d _βBe bidirectional switch S ₁, S ' ₁, S ₆And S ' ₆Conducting, other all switches of rectifier are in the duty ratio when cutting out, and corresponding direct voltage is u _Dc=2u _Ac, the intermediate dc average voltage does

u _dc＝2(u _abd _α+u _acd _β)；

When the reference current vector is positioned at sector II, direct voltage u then _Dc=2 (u _Acd _α+ u _Bcd _β); When the reference current vector is positioned at sector III, direct voltage u _Dc=2 (u _Bcd _α+ u _Bad _β); When the reference current vector is positioned at sector IV, direct voltage u _Dc=2 (u _Bad _α+u _Cad _β); When the reference current vector is positioned at sector V, direct voltage u _Dc=2 (u _Cad _α+ u _Cbd _β); When the reference current vector is positioned at sector VI, direct current u _Dc=2 (u _Cbd _α+ u _Abd _β).

7. modulator approach based on claim 5 or 6 described diode clamp type three level high-voltage matrix converters is characterized in that the modulation signal of inverter is:

${\stackrel{\&OverBar;}{u}}_{\mathrm{io}}=2\frac{u_{\mathrm{io}}}{u_{\mathrm{dc}}},i\&Element;\{A,B,C\};$

Wherein, the inverter modulation signal before the normalization does $\left\{\begin{array}{c}{u}_{\mathrm{Ao}}=u_A^{*}+u_{\mathrm{No}}\\ u_{\mathrm{Bo}}=u_B^{*}+u_{\mathrm{No}}\\ u_{\mathrm{Co}}=u_C^{*}+u_{\mathrm{No}}\end{array}\right.,$ Wherein, $u_{\mathrm{No}}=-\frac{\mathrm{Min}\{u_A^{*},u_B^{*},u_C^{*}\}+\mathrm{Max}\{u_A^{*},u_B^{*},u_C^{*}\}}{2}$ Be zero sequence signal, $\left\{\begin{array}{c}{u}_A^{*}=U_{\mathrm{Om}}\mathrm{Cos}\left(\mathrm{\&beta;}\right)\\ u_B^{*}=U_{\mathrm{Om}}\mathrm{Cos}(\mathrm{\&beta;}-2\mathrm{\&pi;}/3)\\ u_C^{*}=U_{\mathrm{Om}}\mathrm{Cos}(\mathrm{\&beta;}+2\mathrm{\&pi;}/3)\end{array}\right.$ Output voltage for expectation.

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