CN103580520A - Inverter modulating device and method - Google Patents

Abstract

The invention discloses an inverter modulating device and method. According to the inverter modulating device and method, two modulating modes can be controlled to be switched by detecting the output power and comparing an output power value and a set power value, continuous modulating waves are adopted when the output power is lower than the set power, intermittent modulating waves are adopted when the output power is higher than the set power, and the selected modulating waves are used as driving signals of an inverter through output signals of the modulating device. According to the inverter modulating method, when the load of the inverter is light and switching loss is not obvious, the continuous modulating waves are adopted to reduce loss of an output filter to further improve efficiency; when the load of the inverter is heavy, the intermittent modulating waves are adopted to greatly reduce the switching loss of the inverter to further improve the efficiency, as a result, the efficiency of the inverter is higher than that which is achieved with a single kind of modulating waves within the full power range, the switching mode is simple and reliable, and the inverter modulating method is easy to realize.

Description

A kind of modulating device of inverter and method

Technical field

The present invention relates to inverter and modulation technique thereof, relate in particular to a kind of modulating device and method of inverter.

Background technology

Inverter is direct current to be converted to the device of alternating current, is widely used.The single modulation system of the normal use of the modulation system of inverter at present, the modulation system of every kind has certain best effort scope.Such as common continuous modulation mode, output ripple is less, can obtain good output current, and interrupted modulation system, than continuous modulation system, can reduce the switching loss of brachium pontis, and on the other hand, increase the ripple of output current, thereby increased the magnetic loss on output filter.Efficiency is a very important factor for inverter, higher inverter conversion efficiency meaning can be exported more electric energy, and for inverter itself, higher efficiency can reduce the caloric value of inverter, under the condition of identical heat abstractor, can reduce the temperature of inverter, thereby improve the reliability of inverter.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, a kind of modulating device and method of inverter is provided.

The modulating device of inverter is: A mutually continuously modulation wave generator and A mutually interrupted modulation wave generator be connected respectively 1 pin input and the 2 pin inputs of first selector, the output of first selector connects the positive input terminal of the first comparator and the positive input terminal of the second comparator simultaneously, the first triangular-wave generator connects the negative input end of the first comparator, the second triangular-wave generator connects the negative input end of the second comparator, the output of the first comparator connects the input of the first inverter and the input of the first dead band module simultaneously, the output of the first inverter connects the input of the second dead band module, the output of the first dead band module connects the input of the first driver module, the output of the second dead band module connects the input of the second driver module, the output signal of the first driver module is brachium pontis switch S _a1driving signal, the output signal of the second driver module is brachium pontis switch S _a3driving signal, the output of the second comparator connects the input of the second inverter and the input of the 3rd dead band module simultaneously, the output of the second inverter connects the input of the 4th dead band module, the output of the 3rd dead band module connects the input of the 3rd driver module, the output of the 4th dead band module connects the input of the 4th driver module, and the output signal of the 3rd driver module is brachium pontis switch S _a2driving signal, the output signal of the 4th driver module is brachium pontis switch S _a4driving signal,

B mutually continuously modulation wave generator and B mutually interrupted modulation wave generator be connected respectively 1 pin input and the 2 pin inputs of second selector, the output of second selector connects the positive input terminal of the 3rd comparator and the positive input terminal of the 4th comparator simultaneously, the first triangular-wave generator connects the negative input end of the 3rd comparator, the second triangular-wave generator connects the negative input end of the 4th comparator, the output of the 3rd comparator connects the input of the 3rd inverter and the input of the 5th dead band module simultaneously, the output of the 3rd inverter connects the input of the 6th dead band module, the output of the 5th dead band module connects the input of the 5th driver module, the output of the 6th dead band module connects the input of the 6th driver module, the output signal of the 5th driver module is brachium pontis switch S _b1driving signal, the output signal of the 6th driver module is brachium pontis switch S _b3driving signal, the output of the 4th comparator connects the input of the 4th inverter and the input of the 7th dead band module simultaneously, the output of the 4th inverter connects the input of the 8th dead band module, the output of the 7th dead band module connects the input of the 7th driver module, the output of the 8th dead band module connects the input of the 8th driver module, and the output signal of the 7th driver module is brachium pontis switch S _b2driving signal, the output signal of the 8th driver module is brachium pontis switch S _b4driving signal,

C mutually continuously modulation wave generator and C mutually interrupted modulation wave generator be connected respectively 1 pin input and the 2 pin inputs of third selector, the output of third selector connects the positive input terminal of the 5th comparator and the positive input terminal of the 6th comparator simultaneously, the first triangular-wave generator connects the negative input end of the 5th comparator, the second triangular-wave generator connects the negative input end of the 6th comparator, the output of the 5th comparator connects the input of the 5th inverter and the input of the 9th dead band module simultaneously, the output of the 5th inverter connects the input of the tenth dead band module, the output of the 9th dead band module connects the input of the 9th driver module, the output of the tenth dead band module connects the input of the tenth driver module, the output signal of the 9th driver module is brachium pontis switch S _c1driving signal, the output signal of the tenth driver module is brachium pontis switch S _c3driving signal, the output of the 6th comparator connects the input of hex inverter and the input of the 11 dead band module simultaneously, the output of hex inverter connects the input of the 12 dead band module, the output of the 11 dead band module connects the input of the 11 driver module, the output of the 12 dead band module connects the input of the 12 driver module, and the output signal of the 11 driving district module is brachium pontis switch S _c2driving signal, the output signal of the 12 driver module is brachium pontis switch S _c4driving signal,

The input end signal of the first multiplier is respectively the sampled value of A phase current and the sampled value of AC line voltage of inverter filtering device rear end, the input end signal of the second multiplier is respectively the sampled value of B phase current and the sampled value of BC line voltage of inverter filtering device rear end, the output of the first multiplier connects 1 pin input of adder, the output of the second multiplier connects 2 pin inputs of adder, the output of adder connects the negative input end of the 7th comparator, and the positive input terminal signal of the 7th comparator is setting power value P _t, the sel that the output of the 7th comparator connects first selector, second selector, third selector simultaneously selects input.

Inverter modulator approach is: adopt the switching of two kinds of modulation systems, the power output P detecting according to the output signal of adder _out, with setting power value P _tby the 7th comparator, carry out stagnant chain rate, stagnant ring power is Δ P, when the power output detecting is greater than the stagnant ring upper limit of setting power, i.e. P _out> P _tduring+Δ P2, the 7th comparator output switches to positive level from previous status, as the power output P detecting _outbe less than the stagnant ring lower limit of setting power, i.e. P _out< P _tduring-Δ P2, the output of the 7th comparator switches to negative level from previous status, first selector is controlled in the output of the 7th comparator, second selector, the output modulating wave of third selector, when the 7th comparator is output as high level, first selector, second selector, third selector is exported A continuous modulating wave mutually successively, and B is continuous modulating wave mutually, and C is continuous modulating wave mutually, when the 7th comparator is output as low level, first selector, second selector, third selector is exported A interrupted modulating wave mutually successively, B is interrupted modulating wave mutually, and C is interrupted modulating wave mutually, A phase first selector output modulating wave compares with the first triangular carrier and the second triangular carrier respectively, the two paths of signals producing more afterwards with the first triangular carrier and the 3rd triangular carrier is produced to the signal complementary with it by reverser, this two paths of signals and its complementary signal are through dead band module and driver module, the first driver module, the second driver module, the 3rd driver module, the 4th driver module Si road output signal is as the driving signal of four switching tubes of inverter A phase brachium pontis, the driving signal of B phase and C phase brachium pontis produces and is similar to A phase, by the selected modulation of corresponding phase and carrier wave ratio after, by inverter, produce complementary signal, and then by dead band module and driver module, produce the driving signal of corresponding phase,

Described continuous modulation ripple is: according to the voltage V of required output _a, V _b, V _cresultant vector V _ref,

according to V _refphase angle theta, and modulation ratio m, and 3 level space vector figure obtains V _refthe large sector zone at place and little sector zone, according to three resultant vector V in the little sector of place triangle ₁, V ₂, V ₃, V wherein ₃for redundancy vector, calculate three T action time that resultant vector is corresponding ₁, T ₂, T ₃, by T ₃time is distributed to two V ₃redundancy vector, guarantees in each switch periods, under the condition that the switch motion of every phase brachium pontis is twice, with V ₃→ V ₁→ V ₂→ V ₃→ V ₃→ V ₂→ V ₁→ V ₃7 segmentation sequences calculate corresponding A, B, T action time of each level of C brachium pontis _a, T _b, T _c, then obtain the continuous modulation ripple of three level, comprise A modulating wave continuously mutually, B is modulating wave continuously mutually, and C is modulating wave continuously mutually;

Described interrupted modulating wave is: on the basis of continuous modulation wave train, by two kinds of V ₃the effect of redundancy vector becomes as adopting the V of one of them ₃redundancy vector, guarantees that the Level hold of a phase brachium pontis in the switch week is constant, in corresponding switch periods of brachium pontis switch, is failure to actuate, and 7 segmentation continuous sequences just become the interrupted sequence of 5 segmentation, V ₁→ V ₂→ V ₃→ V ₂→ V ₁thereby, obtaining A interrupted modulating wave mutually, B is interrupted modulating wave mutually, and C is interrupted modulating wave mutually, and interrupted modulating wave is than continuous modulation ripple, and every phase brachium pontis has 1/3rd time brachium pontis switches to keep being failure to actuate in a power frequency period;

The first described triangular wave carrier expression formula u1 _tri(t) be:

${u1}_{\mathrm{tri}}\left(t\right)=\left\{\begin{array}{cc}{U}_{\mathrm{tri}}-\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N),& N\&CenterDot;T_{\mathrm{tri}}\&le;t<N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\\ \frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N-\frac{T_{\mathrm{tri}}}{2}),& N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\&le;t<T_{\mathrm{tri}}\&CenterDot;(N+1)\end{array}\right.$

The second described triangular wave carrier expression formula u2 _tri(t) be:

${u2}_{\mathrm{tri}}\left(t\right)=\left\{\begin{array}{cc}-U_{\mathrm{tri}}+\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N),& N\&CenterDot;T_{\mathrm{tri}}\&le;t<N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\\ -\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N-\frac{T_{\mathrm{tri}}}{2}),& N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\&le;t<T_{\mathrm{tri}}\&CenterDot;(N+1)\end{array}\right.$

In expression formula, parameter is: triangular carrier amplitude U _tri, triangular carrier cycle T _tri, N is integer.

The modulator approach that the present invention proposes, at inverter light load, when switching loss is not remarkable, the loss that adopts continuous modulation ripple to reduce on output filter is raised the efficiency, and when inversion heavy duty, the switching loss that adopts interrupted modulating wave to reduce significantly inverter is raised the efficiency, thereby within the scope of total power, the efficiency of inverter is than all high with the mode efficiency of single modulating wave, and switching mode is simple and reliable, easily realizes.

Accompanying drawing explanation

Fig. 1 is the circuit block diagram of the modulating device of inverter;

Fig. 2 is the T-shaped inverter circuit structure chart of three level;

Fig. 3 is a kind of circuit of realizing of rising edge time delay module;

Fig. 4 is the sequence of three level continuous modulation ripples and interrupted modulating wave;

Fig. 5 changes for carrying out the stagnant ring cutting of modulation system according to power output and setting power;

Fig. 6 is modulating wave and the drive waveforms that continuous modulation produces;

Fig. 7 is modulating wave and the drive waveforms that interrupted modulation produces.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in detail.

As shown in Figure 1, the modulating device of inverter is: A mutually continuously modulation wave generator 1 and A mutually interrupted modulation wave generator 2 be connected respectively 1 pin input and the 2 pin inputs of first selector 7, the output of first selector 7 connects the positive input terminal of the first comparator 10 and the positive input terminal of the second comparator 11 simultaneously, the first triangular-wave generator 46 connects the negative input end of the first comparator 10, the second triangular-wave generator 47 connects the negative input end of the second comparator 11, the output of the first comparator 10 connects the input of the first inverter 16 and the input of the first dead band module 22 simultaneously, the output of the first inverter 16 connects the input of the second dead band module 23, the output of the first dead band module 22 connects the input of the first driver module 34, the output of the second dead band module 23 connects the input of the second driver module 35, the output signal of the first driver module 34 is brachium pontis switch S _a1driving signal, the output signal of the second driver module 35 is brachium pontis switch S _a3driving signal, the output of the second comparator 11 connects the input of the second inverter 17 and the input of the 3rd dead band module 24 simultaneously, the output of the second inverter 17 connects the input of the 4th dead band module 25, the output of the 3rd dead band module 24 connects the input of the 3rd driver module 36, the output of the 4th dead band module 25 connects the input of the 4th driver module 37, and the output signal of the 3rd driver module 36 is brachium pontis switch S _a2driving signal, the output signal of the 4th driver module 37 is brachium pontis switch S _a4driving signal,

B mutually continuously modulation wave generator 3 and B mutually interrupted modulation wave generator 4 be connected respectively 1 pin input and the 2 pin inputs of second selector 8, the output of second selector 8 connects the positive input terminal of the 3rd comparator 12 and the positive input terminal of the 4th comparator 13 simultaneously, the first triangular-wave generator 46 connects the negative input end of the 3rd comparator 12, the second triangular-wave generator 47 connects the negative input end of the 4th comparator 13, the output of the 3rd comparator 12 connects the input of the 3rd inverter 18 and the input of the 5th dead band module 26 simultaneously, the output of the 3rd inverter 18 connects the input of the 6th dead band module 27, the output of the 5th dead band module 26 connects the input of the 5th driver module 38, the output of the 6th dead band module 27 connects the input of the 6th driver module 39, the output signal of the 5th driver module 38 is brachium pontis switch S _b1driving signal, the output signal of the 6th driver module 39 is brachium pontis switch S _b3driving signal, the output of the 4th comparator 13 connects the input of the 4th inverter 19 and the input of the 7th dead band module 28 simultaneously, the output of the 4th inverter 19 connects the input of the 8th dead band module 29, the output of the 7th dead band module 28 connects the input of the 7th driver module 40, the output of the 8th dead band module 29 connects the input of the 8th driver module 41, and the output signal of the 7th driver module 40 is brachium pontis switch S _b2driving signal, the output signal of the 8th driver module 41 is brachium pontis switch S _b4driving signal,

C mutually continuously modulation wave generator 5 and C mutually interrupted modulation wave generator 6 be connected respectively 1 pin input and the 2 pin inputs of third selector 9, the output of third selector 9 connects the positive input terminal of the 5th comparator 14 and the positive input terminal of the 6th comparator 15 simultaneously, the first triangular-wave generator 46 connects the negative input end of the 5th comparator 14, the second triangular-wave generator 47 connects the negative input end of the 6th comparator 15, the output of the 5th comparator 14 connects the input of the 5th inverter 20 and the input of the 9th dead band module 30 simultaneously, the output of the 5th inverter 20 connects the input of the tenth dead band module 31, the output of the 9th dead band module 30 connects the input of the 9th driver module 42, the output of the tenth dead band module 31 connects the input of the tenth driver module 43, the output signal of the 9th driver module 42 is brachium pontis switch S _c1driving signal, the output signal of the tenth driver module 43 is brachium pontis switch S _c3driving signal, the output of the 6th comparator 15 connects the input of hex inverter 21 and the input of the 11 dead band module 32 simultaneously, the output of hex inverter 21 connects the input of the 12 dead band module 33, the output of the 11 dead band module 32 connects the input of the 11 driver module 44, the output of the 12 dead band module 33 connects the input of the 12 driver module 45, and the output signal of the 11 driving district module 44 is brachium pontis switch S _c2driving signal, the output signal of the 12 driver module 45 is brachium pontis switch S _c4driving signal,

The input end signal of the first multiplier 50 is respectively the sampled value of A phase current and the sampled value of AC line voltage of inverter filtering device rear end, the input end signal of the second multiplier 51 is respectively the sampled value of B phase current and the sampled value of BC line voltage of inverter filtering device rear end, the output of the first multiplier 50 connects 1 pin input of adder 49, the output of the second multiplier 51 connects 2 pin inputs of adder 49, the output of adder 49 connects the negative input end of the 7th comparator 48, and the positive input terminal signal of the 7th comparator 48 is setting power value P _t, the sel that the output of the 7th comparator 48 connects first selector 7, second selector 8, third selector 9 simultaneously selects input.

Inverter modulator approach is: adopt the switching of two kinds of modulation systems, the power output P detecting according to the output signal of adder 49 _out, with setting power value P _tby the 7th comparator 48, carry out stagnant chain rate, stagnant ring power is Δ P, when the power output detecting is greater than the stagnant ring upper limit of setting power, i.e. P _out> P _tduring+Δ P2, the 7th comparator 48 outputs switch to positive level from previous status, as the power output P detecting _outbe less than the stagnant ring lower limit of setting power, i.e. P _out< P _tduring-Δ P2, the output of the 7th comparator 48 switches to negative level from previous status, first selector 7 is controlled in the output of the 7th comparator 48, second selector 8, the output modulating wave of third selector 9, when the 7th comparator 48 is output as high level, first selector 7, second selector 8, third selector 9 is exported A continuous modulating wave mutually successively, B is continuous modulating wave mutually, C is continuous modulating wave mutually, when the 7th comparator 48 is output as low level, first selector 7, second selector 8, third selector 9 is exported A interrupted modulating wave mutually successively, B is interrupted modulating wave mutually, C is interrupted modulating wave mutually, A phase first selector output modulating wave compares with the first triangular carrier and the second triangular carrier respectively, the two paths of signals producing more afterwards with the first triangular carrier and the 3rd triangular carrier is produced to the signal complementary with it by reverser, this two paths of signals and its complementary signal are through dead band module and driver module, the first driver module, the second driver module, the 3rd driver module, the 4th driver module Si road output signal is as the driving signal of four switching tubes of inverter A phase brachium pontis, the driving signal of B phase and C phase brachium pontis produces and is similar to A phase, by the selected modulation of corresponding phase and carrier wave ratio after, by inverter, produce complementary signal, and then by dead band module and driver module, produce the driving signal of corresponding phase,

Described continuous modulation ripple is: according to the voltage V of required output _a, V _b, V _cresultant vector V _ref,

according to V _refphase angle theta, and modulation ratio m, and 3 level space vector figure obtains V _refthe large sector zone at place and little sector zone, according to three resultant vector V in the little sector of place triangle ₁, V ₂, V ₃, V wherein ₃for redundancy vector, calculate three T action time that resultant vector is corresponding ₁, T ₂, T ₃, by T ₃time is distributed to two V ₃redundancy vector, guarantees in each switch periods, under the condition that the switch motion of every phase brachium pontis is twice, with V ₃→ V ₁→ V ₂→ V ₃→ V ₃→ V ₂→ V ₁→ V ₃7 segmentation sequences calculate corresponding A, B, T action time of each level of C brachium pontis _a, T _b, T _c, then obtain the continuous modulation ripple of three level, comprise A modulating wave continuously mutually, B is modulating wave continuously mutually, and C is modulating wave continuously mutually;

Described interrupted modulating wave is: on the basis of continuous modulation wave train, by two kinds of V ₃the effect of redundancy vector becomes as adopting the V of one of them ₃redundancy vector, guarantees that the Level hold of a phase brachium pontis in the switch week is constant, in corresponding switch periods of brachium pontis switch, is failure to actuate, and 7 segmentation continuous sequences just become the interrupted sequence of 5 segmentation, V ₁→ V ₂→ V ₃→ V ₂→ V ₁thereby, obtaining A interrupted modulating wave mutually, B is interrupted modulating wave mutually, and C is interrupted modulating wave mutually, and interrupted modulating wave is than continuous modulation ripple, and every phase brachium pontis has 1/3rd time brachium pontis switches to keep being failure to actuate in a power frequency period;

The first described triangular wave carrier expression formula u1 _tri(t) be:

${u1}_{\mathrm{tri}}\left(t\right)=\left\{\begin{array}{cc}{U}_{\mathrm{tri}}-\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N),& N\&CenterDot;T_{\mathrm{tri}}\&le;t<N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\\ \frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N-\frac{T_{\mathrm{tri}}}{2}),& N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\&le;t<T_{\mathrm{tri}}\&CenterDot;(N+1)\end{array}\right.$

The second described triangular wave carrier expression formula u2 _tri(t) be:

${u2}_{\mathrm{tri}}\left(t\right)=\left\{\begin{array}{cc}-U_{\mathrm{tri}}+\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N),& N\&CenterDot;T_{\mathrm{tri}}\&le;t<N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\\ -\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N-\frac{T_{\mathrm{tri}}}{2}),& N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\&le;t<T_{\mathrm{tri}}\&CenterDot;(N+1)\end{array}\right.$

In expression formula, parameter is: triangular carrier amplitude U _tri, triangular carrier cycle T _tri, N is integer.

Operation principle:

Fig. 2 is the applied three-level inverter of the present invention, and the full-bridge brachium pontis consisting of 12 full control switches that have an anti-paralleled diode comprises the S of A phase brachium pontis _a1, S _a2, S _a3, S _a4, the S of B phase brachium pontis _b1, S _b2, S _b3, S _b4, the S of C phase brachium pontis _c1, S _c2, S _c3, S _c4, brachium pontis output connects LCL filter.AC line voltage sample value v _ac, BC line voltage sample value v _bc, A phase current sampling value i _a, B phase current sampling value i _bdetection power link for the present invention;

As shown in Figure 3, a kind of circuit of realizing of dead band module is by one and door, a resistance and an electric capacity form, when input signal is rising edge, uprised by low with input 1 level of door, with input 2 level of door be electric capacity pin one level, by zero, charge to high level with input 2 level of door, when input 2 level with door are less than input high level threshold value, with gate output terminal 3 output low levels, when input 2 level with door charge to input high level threshold value, with gate output terminal 3 output switching activities to high level, to input the output of rising edge signal lag, rising edge time delay is determined by resistance capacitance size,

As shown in Figure 4, modulating wave used in the present invention produces the vector V of being synthesized by voltage _refin 3 level space vector, first determine the position of sector, according to three resultant vector V of correspondence at place, little sector ₁, V ₂, V ₃, if Fig. 4 is when resultant vector is in I-2 sector, V ₁for PPN, V ₂for PON, V ₃for PPO/OON, calculate the action time of each vector, continuous modulating wave is that 7 segmentations are in I-2 sector, order is PPO → PPN → PON → OON → PON → PPN → PPO, in a switch periods, every phase brachium pontis switching tube action twice, and interrupted modulating wave is 5 segmentations, in I-2 sector, order is PPN → PON → OON → PON → PPN, in a switch periods, has a phase brachium pontis switching tube to be failure to actuate, other two-phase brachium pontis switching tube actions twice, other sectors are all by that analogy;

Fig. 5 is according to setting power value P _tand stagnant ring power Δ P realizes modulation system and switches, according to the current operating state of inverter respectively in A, B, C the continuous modulation wave producer of every phase and interrupted generator generate continuous modulation ripple and the interrupted modulating wave of available control output.Now, by power monitoring link monitoring current power, by the AC line voltage v after inverter filtering device device _ac, A phase output current i _a, BC line voltage v _bc, B phase output current i _bby the first multiplier, the second multiplier, adder can obtain current power output P _out;

When invertor operation is during at smaller power, power output is less than the stagnant ring lower limit of setting power, keeps P _out< P _t-Δ P2, the Level hold that the 7th comparator is relatively exported is high level, this high level is controlled first selector, second selector, the once output A of third selector is continuous modulating wave mutually, and B is continuous modulating wave mutually, C is continuous modulating wave mutually, continuous modulation ripple and triangular carrier more afterwards by oppositely producing complementary signal, and then produce dead band through dead band module, output is as the driving signal of inverter leg switching tube.If Fig. 6 is that three level connect modulating wave and corresponding driving thereof; .

When inverter power is slowly increased by small-power, when power output being detected, surpass on the stagnant ring of setting power in limited time, i.e. P _out> P _t+ Δ P2, the output level of the 7th comparator original high level of serving as reasons changes low level into, first selector is controlled in this level saltus step, second selector, the output of third selector by original A continuous modulating wave mutually, B is continuous modulating wave mutually, C is continuous modulating wave mutually, change into A interrupted modulating wave mutually, B is interrupted modulating wave mutually, and C is interrupted modulating wave mutually, by interrupted modulating wave and triangular carrier more afterwards by the reverse complementary signal of generation, and then producing dead band through dead band module, output is as the driving signal of inverter leg switching tube.Be illustrated in figure 7 the interrupted modulating wave of three level and corresponding driving thereof;

When inverter keeps relatively high power output, keep P _out> P _t+ Δ P2, the output of the 7th comparator is continuously low level, control first selector, second selector, the output of third selector remains respectively A interrupted modulating wave mutually, and B is interrupted modulating wave mutually, C is interrupted modulating wave mutually, interrupted modulating wave and triangular carrier more afterwards by oppositely producing complementary signal, and then produce dead band through dead band module, export the driving signal as inverter leg switching tube;

Otherwise, when inverter power is slowly reduced by high-power, when detect power output lower than the stagnant ring of setting power under in limited time, i.e. P _out< P _t-Δ P2, the 7th output level comparing is changed into high level by original low level, first selector is controlled in this level saltus step, second selector, the output of third selector by original A interrupted modulating wave mutually, B is interrupted modulating wave mutually, C is interrupted modulating wave mutually, change into output A continuous modulating wave mutually, B is continuous modulating wave mutually, and C is modulating wave continuously mutually, by interrupted modulating wave and triangular carrier more afterwards by the reverse complementary signal of generation, and then producing dead band through dead band module, output is as the driving signal of inverter leg switching tube.

Claims (2)

1. the modulating device of an inverter, it is characterized in that A mutually continuously modulation wave generator (1) and A mutually intermittently modulation wave generator (2) be connected respectively 1 pin input and the 2 pin inputs of first selector (7), the output of first selector (7) connects the positive input terminal of the first comparator (10) and the positive input terminal of the second comparator (11) simultaneously, the first triangular-wave generator (46) connects the negative input end of the first comparator (10), the second triangular-wave generator (47) connects the negative input end of the second comparator (11), the output of the first comparator (10) connects the input of the first inverter (16) and the input of the first dead band module (22) simultaneously, the output of the first inverter (16) connects the input of the second dead band module (23), the output of the first dead band module (22) connects the input of the first driver module (34), the output of the second dead band module (23) connects the input of the second driver module (35), the output signal of the first driver module (34) is brachium pontis switch S _a1driving signal, the output signal of the second driver module (35) is brachium pontis switch S _a3driving signal, the output of the second comparator (11) connects the input of the second inverter (17) and the input of the 3rd dead band module (24) simultaneously, the output of the second inverter (17) connects the input of the 4th dead band module (25), the output of the 3rd dead band module (24) connects the input of the 3rd driver module (36), the output of the 4th dead band module (25) connects the input of the 4th driver module (37), and the output signal of the 3rd driver module (36) is brachium pontis switch S _a2driving signal, the output signal of the 4th driver module (37) is brachium pontis switch S _a4driving signal,

B mutually continuously modulation wave generator (3) and B mutually intermittently modulation wave generator (4) be connected respectively 1 pin input and the 2 pin inputs of second selector (8), the output of second selector (8) connects the positive input terminal of the 3rd comparator (12) and the positive input terminal of the 4th comparator (13) simultaneously, the first triangular-wave generator (46) connects the negative input end of the 3rd comparator (12), the second triangular-wave generator (47) connects the negative input end of the 4th comparator (13), the output of the 3rd comparator (12) connects the input of the 3rd inverter (18) and the input of the 5th dead band module (26) simultaneously, the output of the 3rd inverter (18) connects the input of the 6th dead band module (27), the output of the 5th dead band module (26) connects the input of the 5th driver module (38), the output of the 6th dead band module (27) connects the input of the 6th driver module (39), the output signal of the 5th driver module (38) is brachium pontis switch S _b1driving signal, the output signal of the 6th driver module (39) is brachium pontis switch S _b3driving signal, the output of the 4th comparator (13) connects the input of the 4th inverter (19) and the input of the 7th dead band module (28) simultaneously, the output of the 4th inverter (19) connects the input of the 8th dead band module (29), the output of the 7th dead band module (28) connects the input of the 7th driver module (40), the output of the 8th dead band module (29) connects the input of the 8th driver module (41), and the output signal of the 7th driver module (40) is brachium pontis switch S _b2driving signal, the output signal of the 8th driver module (41) is brachium pontis switch S _b4driving signal,

C mutually continuously modulation wave generator (5) and C mutually intermittently modulation wave generator (6) be connected respectively 1 pin input and the 2 pin inputs of third selector (9), the output of third selector (9) connects the positive input terminal of the 5th comparator (14) and the positive input terminal of the 6th comparator (15) simultaneously, the first triangular-wave generator (46) connects the negative input end of the 5th comparator (14), the second triangular-wave generator (47) connects the negative input end of the 6th comparator (15), the output of the 5th comparator (14) connects the input of the 5th inverter (20) and the input of the 9th dead band module (30) simultaneously, the output of the 5th inverter (20) connects the input of the tenth dead band module (31), the output of the 9th dead band module (30) connects the input of the 9th driver module (42), the output of the tenth dead band module (31) connects the input of the tenth driver module (43), the output signal of the 9th driver module (42) is brachium pontis switch S _c1driving signal, the output signal of the tenth driver module (43) is brachium pontis switch S _c3driving signal, the output of the 6th comparator (15) connects the input of hex inverter (21) and the input of the 11 dead band module (32) simultaneously, the output of hex inverter (21) connects the input of the 12 dead band module (33), the output of the 11 dead band module (32) connects the input of the 11 driver module (44), the output of the 12 dead band module (33) connects the input of the 12 driver module (45), and the output signal of the 11 driving district's module (44) is brachium pontis switch S _c2driving signal, the output signal of the 12 driver module (45) is brachium pontis switch S _c4driving signal,

The input end signal of the first multiplier (50) is respectively the sampled value of A phase current and the sampled value of AC line voltage of inverter filtering device rear end, the input end signal of the second multiplier (51) is respectively the sampled value of B phase current and the sampled value of BC line voltage of inverter filtering device rear end, the output of the first multiplier (50) connects 1 pin input of adder (49), the output of the second multiplier (51) connects 2 pin inputs of adder (49), the output of adder (49) connects the negative input end of the 7th comparator (48), the positive input terminal signal of the 7th comparator (48) is setting power value P _t, the sel that the output of the 7th comparator (48) connects first selector (7), second selector (8), third selector (9) simultaneously selects input.

2. the inverter modulator approach that use is installed as claimed in claim 1, is characterized in that the switching of two kinds of modulation systems, the power output P detecting according to the output signal of adder (49) _out, with setting power value P _tby the 7th comparator (48), carry out stagnant chain rate, stagnant ring power is Δ P, when the power output detecting is greater than the stagnant ring upper limit of setting power, i.e. P _out> P _tduring+Δ P2, the 7th comparator (48) output switches to positive level from previous status, as the power output P detecting _outbe less than the stagnant ring lower limit of setting power, i.e. P _out< P _tduring-Δ P2, the output of the 7th comparator (48) switches to negative level from previous status, first selector (7) is controlled in the output of the 7th comparator (48), second selector (8), the output modulating wave of third selector (9), when the 7th comparator (48) is output as high level, first selector (7), second selector (8), third selector (9) is exported A continuous modulating wave mutually successively, B is continuous modulating wave mutually, C is continuous modulating wave mutually, when the 7th comparator (48) is output as low level, first selector (7), second selector (8), third selector (9) is exported A interrupted modulating wave mutually successively, B is interrupted modulating wave mutually, C is interrupted modulating wave mutually, A phase first selector output modulating wave compares with the first triangular carrier and the second triangular carrier respectively, the two paths of signals producing more afterwards with the first triangular carrier and the 3rd triangular carrier is produced to the signal complementary with it by reverser, this two paths of signals and its complementary signal are through dead band module and driver module, the first driver module, the second driver module, the 3rd driver module, the 4th driver module Si road output signal is as the driving signal of four switching tubes of inverter A phase brachium pontis, the driving signal of B phase and C phase brachium pontis produces and is similar to A phase, by the selected modulation of corresponding phase and carrier wave ratio after, by inverter, produce complementary signal, and then by dead band module and driver module, produce the driving signal of corresponding phase,

Described continuous modulation ripple is: according to the voltage V of required output _a, V _b, V _cresultant vector V _ref,

according to V _refphase angle theta, and modulation ratio m, and 3 level space vector figure obtains V _refthe large sector zone at place and little sector zone, according to three resultant vector V in the little sector of place triangle ₁, V ₂, V ₃, V wherein ₃for redundancy vector, calculate three T action time that resultant vector is corresponding ₁, T ₂, T ₃, by T ₃time is distributed to two V ₃redundancy vector, guarantees in each switch periods, under the condition that the switch motion of every phase brachium pontis is twice, with V ₃→ V ₁→ V ₂→ V ₃→ V ₃→ V ₂→ V ₁→ V ₃7 segmentation sequences calculate corresponding A, B, T action time of each level of C brachium pontis _a, T _b, T _c, then obtain the continuous modulation ripple of three level, comprise A modulating wave continuously mutually, B is modulating wave continuously mutually, and C is modulating wave continuously mutually;

Described interrupted modulating wave is: on the basis of continuous modulation wave train, by two kinds of V ₃the effect of redundancy vector becomes as adopting the V of one of them ₃redundancy vector, guarantees that the Level hold of a phase brachium pontis in the switch week is constant, in corresponding switch periods of brachium pontis switch, is failure to actuate, and 7 segmentation continuous sequences just become the interrupted sequence of 5 segmentation, V ₁→ V ₂→ V ₃→ V ₂→ V ₁thereby, obtaining A interrupted modulating wave mutually, B is interrupted modulating wave mutually, and C is interrupted modulating wave mutually, and interrupted modulating wave is than continuous modulation ripple, and every phase brachium pontis has 1/3rd time brachium pontis switches to keep being failure to actuate in a power frequency period;

The first described triangular wave carrier expression formula u1 _tri(t) be:

${u1}_{\mathrm{tri}}\left(t\right)=\left\{\begin{array}{cc}{U}_{\mathrm{tri}}-\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N),& N\&CenterDot;T_{\mathrm{tri}}\&le;t<N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\\ \frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N-\frac{T_{\mathrm{tri}}}{2}),& N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\&le;t<T_{\mathrm{tri}}\&CenterDot;(N+1)\end{array}\right.$

The second described triangular wave carrier expression formula u2 _tri(t) be:

${u2}_{\mathrm{tri}}\left(t\right)=\left\{\begin{array}{cc}-U_{\mathrm{tri}}+\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N),& N\&CenterDot;T_{\mathrm{tri}}\&le;t<N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\\ -\frac{2U_{\mathrm{tri}}}{T_{\mathrm{tri}}}(t-T_{\mathrm{tri}}\&CenterDot;N-\frac{T_{\mathrm{tri}}}{2}),& N\&CenterDot;T_{\mathrm{tri}}+\frac{T_{\mathrm{tri}}}{2}\&le;t<T_{\mathrm{tri}}\&CenterDot;(N+1)\end{array}\right.$

In expression formula, parameter is: triangular carrier amplitude U _tri, triangular carrier cycle T _tri, N is integer.

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