TW201210180A - Method and device of DC-side injected compensation for application to 18-pulse AC-DC converter - Google Patents

Abstract

The present invention is to provide a method and a device characterized by high-power DC output voltage, high power factor and low current total harmonic distortion; the overall framework is composed of a control driver, a phase shift transformer, a three-phase bridge rectifier, a three-phase converter and an inter-phase transformer. First, a current signal detected by the current sensing circuit is fed back to a digital microprocessor; in the digital microprocessor operations, a look-up table approach is used to establish the required compensation current command, which is compared with the actual feedback compensation current to adjust the output signal; the output signal will drive the power switch of the three-phase converter through the power switch driving circuit; a hysteresis method is used to control the size and waveform of the compensation current, which is injected in the DC-side output current of the three bridge rectifiers, thereby reducing the input current total harmonic distortion and improving the power factor at the power supply side so as to provide an efficient high-power DC power supply.

Description

201210180 lQL: Three-phase converter output current 8. DC load current 匕. DC load voltage shows the chemical formula of the invention: 5. If there is a chemical formula in this case, please reveal the most obvious. 6. Invention: [Technology of invention] 】= _=============================================================================================== The pre-phase transformer is added with two solid phases and the control method is planned by the digital microprocessor to generate the complement (four) flow command ' _ pulse width modulation to generate the switch 峨, and then the force switch drive circuit 'drives the three-phase converter The power switch generates a compensation current and then injects it into three parallel six-pulse converter DC output terminals, thereby reducing the three-phase inrush current, the total current touch distortion amount and improving the power factor of the three-phase input power source. Method and apparatus for turbulence/DC converters. . [Prior Art] In the industrial field, in order to obtain a high-power DC power supply, a three-phase bridge rectifier is often used to rectify the three-phase voltage source, but for the power supply terminal, the conduction of the three-phase bridge type 3 201210180 is performed. Switching the non-linear load phenomenon of shouting is serious. 'There is a very high harmonic content. These harmonics will cause the electrical equipment to reduce the life of the equipment on the power system, and protect the electric power. The instrument H is especially serious. In recent years, in order to improve this problem, Schaeffer, in 1% and 5 years, proposed that the rectifiers are each matched with a specific phase of three-phase electricity ', together with Γ =: two! . In this way, a multi-pulse current wave IV = chopping voltage can be synthesized at the power supply end, such as a ten-pulse flow H formed by two sets of three-phase bridge rectifiers in parallel, and a three-way parallel pin eight-pulse rectification section, etc. And so on. The method of generating three-phase power sources with different phases is generally obtained by phase-shifting and variable voltage gain, and when the rectifiers of each group are connected in parallel, the closing position is not __, and the instantaneous output voltages of the rectifiers are different, and cannot be directly connected in parallel. It is necessary to use an interphase transformer to read the unbalanced voltage and to share the load current with its close-knit characteristics. The traditional eight-wave pulse converter is composed of three phase sets of three different phase twists, the power supply 'and each through-group six-pulse converter is converted into DC, and the three sets of six-pulse converters can be directly independent. The power supply or the eight-pulse output DC light power supply is connected in parallel through the three hers, and both of them can be used at the power supply terminal for the effect of the eighteen pulse wave. After the above basic multi-pulse parallel connection method, there are many methods for improving the input current spectral wave distortion, such as S. Ch〇i, p Enjeti, and Bang Sup.

Lee introduced in 1997 "a new type of 24-pulse diode rectifier system for high-power AC motor drive (New 24_pulse di〇de muscles, such as Qiu kiss interface of high-power AC motor drives)" And B. Singh and S. Gairola 201210180 proposed "Pulse Doubling in 18-pulse AC-DC Converters" in 2007, all using multi-tap phase-to-phase transformers. The diodes are connected in series to increase the current pulse wave number at the power supply terminal and reduce the total ripple distortion of the power supply terminal. However, the above method can only increase the pulse wave number, and still cannot achieve the ideal sine wave current at the power supply terminal. A new active interphase reactor for 12-pulse rectifiers provides dean P〇wer, which was proposed by S. Choi, R Enjeti and H〇ag_Hee in 1996. Utility interface)", the active phase-to-phase transformer is applied to a 12-pulse converter system. By means of a low-capacity (2 26% rated output power) converter, a triangular wave current is injected into the active phase-to-phase transformer twice. On the side, the harmonics of the power supply terminal can be effectively improved, and the low harmonic distortion current of the 1st pulse wave can be maintained when the converter is turbulent. One

However, considering the higher demand of the gods, the Weibo rules are more stringent. Therefore, the present invention proposes a DC-side injection compensation strategy that utilizes the eight-pulse-wave conversion H-red, using a low-capacity three-phase converter. (2 39% rated output power), directly injecting compensation current into the junction between the output of the three sets of six-pulse bridge rectifiers and the ballast voltage ' without increasing the enthalpy on the interphase pressure change H, Power terminal current _ Wei distortion. The three-phase converter that is proposed in this (4) is a three-phase converter that improves the traditional consumption of the social-dynamic filter on the AC side: the problem of multiple costs and the need for large capacity' and can simultaneously compensate the three-phase power supply. Production: Holding a three-phase balance 'and when the three-streamer is _, it can still be used in Wei Erbao eight-pulse wave low harmonic distortion current. In response to the attention of the world, this 适用明2 is applicable to the 18th vein of the county-made distributary side wire type _ = _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ SUMMARY OF THE INVENTION The object of the present invention is to provide a DC power supply with lower Wei distortion, high efficiency, and Cong for higher power applications. For this purpose, the present invention combines a current control_three-phase converter with a injection strategy to ten. Eight pulse wave AC/straight_turn, by compensating the current to the DC output of three parallel six-pulse rectifiers, the input current of the power supply terminal is improved from the eighteen pulse of the room to the low total harmonic distortion. Like a sine wave, and the required three-phase converter device tolerance is lower for the Lu active chopper applied to the AC side of the AC/DC converter, and the improved single-phase current is improved. The surface causes the three-phase unbalance problem. In addition, when the three-phase converter fails, the eight-pulse low-fidelity distortion pattern can still be maintained at the source end of the f-source. The active chopper's eighteen pulse converter, and the purpose of energy saving purposes. In order to achieve the above object, the present invention mainly utilizes the surface/current money of the voltage/current sensing circuit in the control driving device, and compares the value of the meter with the current value. The compensation signal processing and weaving processor, the output signal will drive the power switch of the variable current II via the power switch driving circuit towel, and instantly adjust the injected electric power = the actual amplitude, called the command value of the current. The power input terminal a is improved from the original eighteen pulse wave to a sine wave with a very low total spectral distortion to provide high efficiency, low input current harmonic distortion and is suitable for AC/DC converters in high power applications. . . The control driving device of the invention is mainly realized by a digital method, and only the current sense/circuit, the electric dust sensing circuit and the power switch chicken circuit are composed of analog components such as a resistor, a nose-magnifying σσ light light isolation driver and the like. The current and dust sensing circuit is mainly used to convert the actual current and voltage into an analogy of the digital microprocessor H /" ί S ] 6 201210180 The acceptable signal range of the digital module. The digital mode is realized by the digital microprocessor. 'If a digital signal processor (DSP) or a single-chip CPU (single-chip CPU), the planning program performs related settings, detection, calculation and generation of drive signals' and is driven by the power switch drive circuit. The power switch of the flow unit 'completes the control drive device of the present invention. The power switch used in the current transformer of the present invention is a high power semiconductor component such as a gate insulated bipolar transistor (IGBT), a bipolar junction transistor (BjT) and the like can be controlled by the control switch. [Embodiment] The DC side injection compensation strategy disclosed by the present invention is applied to the system architecture of an eight-pulse AC/DC converter. Figure 1 is shown in Figure 1. The system includes a three-phase power supply 102, a phase shifting transformer that generates three sets of three-phase power sources with a phase difference of 2 degrees, a three-phase three-phase bridge rectifier 105, and three three-phase bridge rectifiers. The phase-to-phase transformer required for parallel connection, the three-phase converter 107 for generating the compensation current, the output DC load 108, and the control drive for generating the injection current command and driving the converter power switch 109 ° The present invention constructs a current command to be compensated by means of the current sensing circuit 202 to feed back the signal to the digital microprocessor 204', and uses the voltage sensing circuit 20! and the zero-off circuit 2〇3 to power the power supply. The phase reference point is sent to the digital microprocessor 204, and the reference point adjusts the current command phase. After the ratio of the injected current to the actual feedback, the three-phase converter power switch 4〇1 is injected to inject the compensation current into the three groups. The DC output of the rectifier 105 and the phase-to-phase transformer 1〇6 end point can effectively improve the total harmonic distortion of the power supply terminal, improve its power factor and efficiency, and the advantages of the 201210180 two-phase converter 107 are relatively small. After the compensation, the power supply current can be balanced in three phases and is similar to a sine wave, etc. In order to achieve the above object, the eight-phase pulse transformer 1〇3 needs to generate three sets of phase differences of 20 by the phase shift transformer 104. The power supply, and the phase shift transformer which can generate three sets of three-phase power sources with a phase difference of 20° can be achieved by various wiring methods. The phase shifting transformer 1〇4 used in the practice of the present invention is connected by a group of delta/ddta. Phase transformer 110 and two sets of delta/P〇lyg〇n are connected to three-phase transformer U1, wherein ddta/deita is connected to two-phase transformer U0 for generating 0. Group three-phase power, and two other groups of ddta/polygon connected to three-phase The variable voltage n(1) is different from the end point of the output, resulting in two phases of phase difference of ±20. The three-phase power supply. According to Derek A. Paice, "P〇wer mectr〇nie

The theory described in Chapter 8 of Harmonics-Multipulse Methods for Clean P〇wer" shows that in the eighteen pulse converter system, the output current of the secondary side of the phase shifting transformer is 18 ≥ ±1. The 6"±1th harmonic is suppressed by the 姊 transformer after being sensed to the human side and synthesized into the power supply current, but the _ 18«±1 spectral waves are stacked on each other and become more obvious in the power supply current. Therefore, when performing FFT analysis on the power supply current of the eighteen pulse converter system, it will see that it contains a large number of 18«±1 harmonics and reduces the total touch distortion percentage, because ^, if it can be in the phase shift transformer twice The side suppresses the cell ±1 spectral wave, and the power supply current synthesized by sensing the current back to the primary side naturally does not contain -±1 spectral wave, so that only the fundamental wave is retained and approximated to sine. For this, we It is necessary to suppress the first-order spectral wave contained in the original secondary current. To find out the waveform of the current waveform without any secondary wave, the current in the secondary current of the phase-shifting transformer is The amount of change produced should have the following characteristics: this change The heart of the waveform contains ±1st harmonic component. 201210180 must be the same as the 18«±1 harmonic component of the original waveform before compensation. The phase angle of each corresponding harmonic component must be reversed. Suppressing the harmonic component; the 6«±1 harmonic component of the change waveform except for the 18±±1 harmonic must be such that the change waveform is the same as the original waveform and remains in the diode non-conducting section. Zero. From the above limitation, we find two suitable change waveforms. The 18«±1 harmonic components of the two waveforms are the same size as the original waveform, and the phase angle is just the opposite. After adding the two waveforms of the change amount waveform, it is the compensated second-order side current waveform'. After the compensated waveform is analyzed by FFr, the waveform does not contain any 18π±1 harmonic component, indicating that it is 18 «±1st harmonic component has been suppressed' so that the power supply current after the phase shift transformer is transferred to the primary side and synthesized is a sine wave containing only the fundamental component. The compensated secondary side of the transformer Current waveform, positive The rising edge of the week is sin〇.~sin3〇. The falling edge is sml40°~Sinl80°; the negative half cycle is the positive half cycle of the reverse waveform, this waveform does not contain any heart ±1 harmonic. The secondary current of the transformer becomes this waveform. We inject the compensation current center, q and • Z; in the DC output current of the two sets of bridge rectifiers. The following will start to derive the waveform representation of the compensation current. Please refer to Figure 3 for the power supply. The zero-point is the reference zero-phase three-phase bridge rectifier input current 丨 corresponding to the diode conduction function V can expand its waveform in Fourier series as shown in equation (1) (i) f [such as (10) +10.)"sin 5 (slaves +10〇) 5 -—sin l{cot +1 〇°) + sin 11(ωί +10°) (1) + ^sinl3〇i + l〇〇)__ ] Other dipoles corresponding to '2~/9 Guide money & also can be adjusted to the displacement of 201210180, +100. , -40. -160. With +80. Come to

^9x1 = * ldl hi (4) -120. , +120. -20. One 14 baht. First define the following two matrices ^9x1 =[hhhhhhhh .if b\ (2) A S2 5*3 0 0 0 0 0 0 ' T S9x3 = 0 0 0 0 0 0 0 0 S6 0 0 A 0 0 ( 3) After that, the input current of the two-phase bridge rectifier 1〇5 can be expressed by the formula (4), and the relationship between the negative Wei current and the three rectifier output currents can be obtained. )d =d id2 + id3 (5) where / is the output current of the eighteen pulse converter 103, and ^ is the output current of the three-phase bridge rectifier 105. And the value of ^ are

In order to make 'injection compensation/recognition;;3, the relationship between the three sets of rectifiers, the k, and h and the compensation current are as follows: (6), (7) and (8) ld\ lxl (6) ldl (7) L-i. Lx3 Substituting equations (6), (7) and (8) into equation (4), it can be rearranged («: 201210180 [9x1 = S 9x3 " f \ L_ 3 i, lx2 V Λ3_ j (9) according to equation (9) In the relationship between the compensation current and the compensation current, it can be inferred that if the heart is to be the compensated waveform, the compensation circuit of the age, the waveform of the ML, the waveform can be expressed by the following private sin

Xn wt e same as -2/ 3

D k π sin cot k^- - {η -2) - 3 V ; 9. π , π ^sin20c

140° (10) ωί e π 9

Where " = 1,2,3 ; moxibustion = 〇, 1, 2, .., but since the waveform described in the above formula contains a DC component, and the three-phase converter has no neutral relationship, the above description cannot be produced. The waveform, so 'we replace it with an approximate sawtooth wave that does not contain a DC component, and the approximate sawtooth wave is expressed as shown in equation (11). 18 ωΐ-k^-- π -1 + - π 3 ;9 3 v ;9 9 ( (Π) 9 π ωί e where " = 1,2,3 ; moxibustion = 0,1,2,... ο and in the digital microprocessor 2〇4, for Zenghe Yifei 11 201210180 The speed of the processor operation, without calculating the current command through the above equation, but constructing the waveform in a built-in manner, and amplifying/reducing the amplitude according to the feedback load current value, and then according to the digital microprocessor 204 The control counter restores the actual command waveform. The invention uses the control driving device 109 to generate the injection current command waveform as in the formula (Mountain 11)' and drives the power switch of the inverter to tear the compensation current to achieve the purpose of improving the total spectrum distortion of the power supply end. The control is shown in the three, mainly in digital mode, only the voltage sensing circuit 20 The sensing circuit 2〇2 and the power φ switch driving circuit 2〇5 are composed of analog components such as a resistor, a capacitor, an operational amplifier, a diode and an optically coupled isolator. The system operates using a current sensing circuit 2〇2 The load power and the two compensation currents are proportionally converted into an electrical signal range acceptable to the analog/digital module of the digital microprocessor 204, and then the voltage sensing circuit 2 (1) and the zero point detecting circuit 203 are used to connect the power terminal line to the line voltage core. The positive and negative half cycles are converted into High/L〇w signals to the digital microprocessor 2〇4. Please refer to Figure 4a, 4b and 4c for the circuit diagram. The voltage/current to be fed back first through the voltage sensor 3〇1 The current sensor 302 is converted into a current source signal output, and then the current source is adjusted by the operational amplifier 3〇3 to adjust the output signal amplitude and the DC level according to the required ratio, and is provided to the analog of the digital microprocessor 2〇4/ The digital module receives the signal, and the voltage signal needs to be converted into a High/Low signal by the Pivot circuit 305 and the comparator 3〇4 in the zero detection circuit 2〇3, and the voltage signal is excluded and eliminated. After the noise is disturbed, it is provided to The microprocessor performs the zero point judgment. The program planning and control block of the digital microprocessor is shown in Figure 6A and Figure 6B. After the load current is fed back and the compensation current command is constructed by looking up the table, the feedback voltage is used. The obtained phase zero is used to synchronize the command waveform, and then as described in the injection current control loop 501, compared with the actual injected compensation current after the feedback, to generate a power switch control signal, and the current control loop 5〇1 will compensate the current. Command and Real 12 201210180 Compared with the current, the switch control signal is sent to change the conduction of each switch, and the compensation current is injected into the output of the three sets of rectifiers 105. The three-phase converter 107 of the present invention employs a full-bridge three-phase converter as shown in FIG. Let the three-phase input phase power supply 102 be represented by the formula (12) (12-1) va = V2-^sin(iy/ -30°) vb ~jL· sin(at -150°) (12-2) vc = V2 ^ sin(iy/ + 90°) (12-3) where is the phase shift transformer 1〇4 primary side line voltage. The output voltage of the three-phase bridge rectifier i and the heart 2 can be obtained as in equation (13), equation (14) ^d\ ~ ^VLL sin(iyr ~ + — — f, free Jin + contention (4), 1,2... ^di ~ yJ^VLL sin(<yi -k- + —); (13) ωί e :吟(moxime+1)|u = 〇,i,2... (14) Please refer to Figure 5, it can be seen that the cross-connection between any two output terminals of the three-phase converter is the output voltage difference of two sets of two-phase bridge rectifiers 1〇1 as shown in equation (15)

Vdelta ~ vd\ ~ Vd2 (15) 2 type Μ) can be used to determine the voltage between the two output terminals of the converter 1G7 is effective as shown in equation (16) 13 1 (16) 201210180 = 0.09698FU =0.07184^ ^中匕 is the crossover voltage on the DC load. Then, if it is assumed that there is a neutral point between the three output terminals of the three-phase converter, then the voltage can be re-secured, and the three-phase converter can be used to obtain the electronic memory of the virtual neutral point. The symbol definition ^=^^α=〇.〇4147^ (17) Then, the two-phase converter 1〇7 output current RMS value A is obtained by the equation (10) as shown in the equation (10) (4) = 士x 舍(18) Here, />σ=ΚίΛ=_, using equations (9) and (10), the capacity of the two-phase converter 107 used in the present invention can be determined as shown in the equation (19): VA==3xKyeX^x =0.0239pu =2.39%p〇(19) From equation (19), the three-phase converter 1 () 7 capacity required by the present invention is applied to the eight-pulse _ exchange!! Smaller, this is a very important advantage in the more demanding high-power requirements of Bobo. _ The invention utilizes a three-phase converter 1〇7 with very small capacity, and injects a compensation current into the DC output terminal of the phase bridge rectifier 1G5 and the front end of the transformer 6 () 6 to connect the power supply 2 The input current of the terminal is compensated by the original eighteen-pulse waveform _ into a sine wave waveform with a lower total harmonic distortion, and can be compensated for three-phase singularity, maintaining the three-phase balance, and when the three-machine charm 1G7 occurs (four), t source current can also maintain 201210180 in the original eighteen pulse low current distortion, very much in the high-resolution application environment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an overall system architecture of the present invention; FIG. 2 is a schematic diagram of a diode switching function of the present invention, corresponding to a three-phase bridge rectifier input current with reference to a power source and a phase; FIG. 4A, FIG. 4B and FIG. 4C are schematic diagrams of a voltage/current sensing circuit and a zero point detecting circuit according to the present invention; FIG. 5 is a schematic diagram of a three-phase converter according to the present invention; 6A and 6B are the program planning flow chart and control block diagram of the digital microprocessor of the present invention; [Main component symbol description] 101: Main hardware circuit device 102: Three-phase power supply 103: Eighteen pulse wave converter 104 : Phase-shift transformer 105 : Three-phase bridge rectifier 106 : Phase transformer 107 : Three-phase converter 108 : Output DC load 109 : Control drive 110 : delta / delta connected to three-phase transformer 111 : delta / polygon connected to three - phase Transformer 15 201210180 201 : Voltage sensing circuit 202 : Current sensing circuit 203 : Zero detecting circuit 204 : Digital microprocessor 205 : Power switching drive Dynamic circuit 301: voltage sensor 302: electric. Influenza detector 303: operational amplifier 304: comparator 305: pivot circuit 401: gate insulated bipolar transistor 402: diode 403: inductor 404: direct current Voltage source 501 : Injection current control loop

Va,,Ve: three-phase power input phase voltage B, 4, (: three-phase power input line current LLULLLLLG: phase-shift transformer input current A, 乂, A: phase shift transformer resistance Z·,, 怠, /3 , /4, ζ·5, z6, /7, /8, ζ·9: three-phase bridge rectifier input current, ",": three-phase bridge rectifier output voltage core, kb · three-phase bridge rectifier Output current Μ, B2, Q: Converter output current fc 201210180 Heart: DC load current C: DC load voltage 匕·· Converter input DC voltage • Three-phase converter between any two output terminals Cross-pressure L"a: three-phase transformer, between any two output terminals

Seven, the scope of application for patents: the installation of the converter i a kind of high-power m pressure transmission 找 find / DC transfer 'including the ability to move the squatter. Provide two sets of phase difference of 2 〇. The three-phase power supply voltage 敫rt eye bridge type--: composed of power semiconductor components, the three-phase AC voltage> melon into a pulsating DC voltage electric transformer: three windings to withstand the instantaneous output of three sets of rectifiers in parallel The device is composed of a power semiconductor switch and has a DC voltage source converted into a three-phase AC current conversion function, and a three-inductor device for generating an injection control circuit: 1 voltage sensing circuit, - zero point detecting circuit, four motor sensing circuit, - digital microprocessor and a switch driving circuit for generating a command for injecting current 'and outputting a converter power switch driving signal. A DC load: the load of the input power is the DC surface. >2. The device for the high-power direct current output/transmission/straight/claw conversion H as described in the 5th patent of the Japanese Patent Application No. 5, wherein the difference between the three _ bits is generated. Three-phase I S] 17

Claims (1)

201210180 Heart: DC load current C: DC load voltage 匕 · · Converter input DC voltage • Three-phase converter between the two output terminals of the cross-pressure L"a: three-phase converter, any two Between output endpoints Seven, the scope of application for patents: the installation of the converter i a kind of high-power m pressure transmission 找 find / DC transfer 'including the ability to move the squatter. Provide two sets of phase difference of 2 〇. The three-phase power supply voltage 敫rt eye bridge type--: composed of power semiconductor components, the three-phase AC voltage> melon into a pulsating DC voltage electric transformer: three windings to withstand the instantaneous output of three sets of rectifiers in parallel The device is composed of a power semiconductor switch and has a DC voltage source converted into a three-phase AC current conversion function, and a three-inductor device for generating an injection control circuit: 1 voltage sensing circuit, - zero point detecting circuit, four motor sensing circuit, - digital microprocessor and a switch driving circuit for generating a command for injecting current 'and outputting a converter power switch driving signal. A DC load: the load of the input power is the DC surface. >2. The device for the high-power direct current output/transmission/straight/claw conversion H as described in the 5th patent of the Japanese Patent Application No. 5, wherein the difference between the three _ bits is generated. Three-phase I S] 17 201210180 The phase shift of the power supply consists of a noodle device of any wire type. 3. The output of the AC/DC converter used for high-power DC output, as described in the scope of the patent scope of the invention, wherein the electric measuring circuit, the current sensing circuit and the zero-point measuring circuit of the driving device are controlled. It consists of an electrical/current sensor, an operational amplifier and a comparator, which converts the system towel and the current to a low electrical signal, and then adjusts the amplitude to the value of the value to provide a basis for controlling the gamma (4) off-axis signal. φ 4. The device for the AC/DC converter for high-power DC ink output according to the first item of the middle-definition scope, wherein the control drive device obtains the electrocardiographic current sound number, and then generates an injection after being controlled by the control drive circuit. The current command generates the switch drive k number for the high value of the crane converter _ electronic off, so that the converter output current has a controllable function to improve the total harmonic distortion of the power terminal current. The apparatus for verifying the high-power DC voltage output of the AC/DC converter according to the first aspect of the patent application, wherein the power-on relationship of the converter is a high-power solid-state electronic switch, and the electron-based power semiconductor The tree is composed. Zhan 6. The current waveform injected in the DC side injection compensation strategy of this patent is to find the difference between the output of the under-side output current and the injection & 'The best waveform of the injection current waveform and the approximation waveform are described in equations (ίο) and (11). real