JP2718058B2 - PWM control method for three-phase voltage source inverter - Google Patents
PWM control method for three-phase voltage source inverterInfo
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- JP2718058B2 JP2718058B2 JP63102591A JP10259188A JP2718058B2 JP 2718058 B2 JP2718058 B2 JP 2718058B2 JP 63102591 A JP63102591 A JP 63102591A JP 10259188 A JP10259188 A JP 10259188A JP 2718058 B2 JP2718058 B2 JP 2718058B2
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- pwm
- arm modulation
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、三相電圧形インバータのPWM制御方法に関
するものである。Description: TECHNICAL FIELD The present invention relates to a PWM control method for a three-phase voltage source inverter.
三相誘導電動機の可変速駆動等の際に用いられる三相
電圧形インバータ（以下、三相という言葉を省略して単
に電圧形インバータということがある）のPWM（パルス
幅変調）制御法として、従来から３アーム変調方式が多
用されてきた。As a PWM (pulse width modulation) control method of a three-phase voltage-source inverter (hereinafter sometimes abbreviated as three-phase and simply referred to as a voltage-source inverter) used for variable-speed driving of a three-phase induction motor, etc. Conventionally, a three-arm modulation method has been frequently used.
以下、この３アーム変調方式の説明を行う。 Hereinafter, the three-arm modulation method will be described.
第２図は、周知の三相PWM電圧形インバータの基本回
路を示す回路図である。同図に示す変調回路Ｍの詳細を
第３図に示す。また第４図は第３図における各部の信号
波形図である。FIG. 2 is a circuit diagram showing a basic circuit of a well-known three-phase PWM voltage source inverter. FIG. 3 shows details of the modulation circuit M shown in FIG. FIG. 4 is a signal waveform diagram of each part in FIG.
第３図に示した変調回路で作成された変調信号Pu、P
v、Pwとそれらの各反転信号とにより、第２図の各アー
ムを構成するトランジスタQ1〜Q6をオン、オフ制御して
負荷Ｌに供給される負荷電圧（インバータ出力電圧）を
制御するものであることは述べるまでもないであろう。Modulation signals Pu, P generated by the modulation circuit shown in FIG.
The transistors Q1 to Q6 constituting each arm in FIG. 2 are turned on and off by v, Pw and their inverted signals to control the load voltage (inverter output voltage) supplied to the load L. It goes without saying that there is something.
第３図において、１は搬送波（三角波）発生器、２は
３アーム変調制御信号発生器、2a〜2cはそれぞれ位相が
互いに120゜ずれた正弦波Su,Sv,Swを発生する正弦波発
生器、3a〜3cはそれぞれ比較器、である。In FIG. 3, 1 is a carrier (triangular wave) generator, 2 is a 3-arm modulation control signal generator, and 2a to 2c are sine wave generators that generate sine waves Su, Sv, and Sw whose phases are shifted from each other by 120 °. , 3a to 3c are comparators, respectively.
搬送波（三角波）と各正弦波Su,Sv,Swの比較器3a〜3b
における比較の態様、及びその結果得られるPWM信号Pu,
Pv,Pwの波形は第４図に示す通りである。Comparator 3a-3b of carrier wave (triangular wave) and each sine wave Su, Sv, Sw
Mode of comparison, and the resulting PWM signal Pu,
The waveforms of Pv and Pw are as shown in FIG.
即ち３アーム変調方式では、１搬送波周期内で３アー
ム（Q1,Q4とQ3,Q6とQ5,Q2）のそれぞれが上アームと下
アームの１回ずつ、合計２回スイッチングすることによ
り、つまり三相の３アームとも常に変調を行うことによ
り所望の出力電圧を得ている。That is, in the three-arm modulation method, each of the three arms (Q1, Q4 and Q3, Q6 and Q5, Q2) switches once each of the upper arm and the lower arm within one carrier cycle, that is, three times. The desired output voltage is obtained by constantly modulating all three phase arms.
かかる３アーム変調方式によって得られる電圧形イン
バータの出力線間電圧の周波数スペクトルは、変調比
（制御信号の振幅／搬送波信号の振幅、であり電圧指令
値に相当する）が小さいときは、搬送波周波数の２倍の
高調波成分が支配的であるが、変調比が大きくなるにつ
れて搬送波周波数の１倍の高調波成分が支配的になるこ
とが知られている。そして、このことは、変調比が大き
い領域、つまり出力電圧の高い領域で、誘導機の電流リ
プルやトルク脈動の面で問題が起きることを示してお
り、３アーム変調方式の欠点とされている。The frequency spectrum of the output line voltage of the voltage-type inverter obtained by the three-arm modulation method is such that when the modulation ratio (amplitude of the control signal / amplitude of the carrier signal, corresponding to the voltage command value) is small, the carrier frequency It is known that a harmonic component twice as large is dominant, but as the modulation ratio increases, a harmonic component one time as large as the carrier frequency becomes dominant. This indicates that a problem occurs in terms of current ripple and torque pulsation of the induction machine in a region where the modulation ratio is large, that is, in a region where the output voltage is high, which is a drawback of the three-arm modulation system. .
他方、２アーム変調方式と呼ばれるPWM制御法が近年
提案されるに至っている。On the other hand, a PWM control method called a two-arm modulation method has recently been proposed.
第５図は、２アーム変調方式をとる場合の変調回路の
詳細を示す回路図である。また第６図は第５図における
各部の信号波形図である。FIG. 5 is a circuit diagram showing details of a modulation circuit when a two-arm modulation method is used. FIG. 6 is a signal waveform diagram of each part in FIG.
第５図において、４は２アーム変調制御信号発生器、
4a〜4cは各相毎の２アーム変調制御信号発生器、１は搬
送波（三角波）発生器、3a〜3cはそれぞれ比較器、であ
る。In FIG. 5, reference numeral 4 denotes a two-arm modulation control signal generator;
4a to 4c are 2-arm modulation control signal generators for each phase, 1 is a carrier (triangular wave) generator, and 3a to 3c are comparators.
これらの図に見られるように、２アーム変調方式で
は、制御信号の１周期を６等分して、その各区間で電圧
形インバータの３アームのうちのどれか１アームを、直
流電源のいずれか一方の極性に固定するような制御信号
を２アーム変調制御信号発生器４から発生させ、これを
搬送波（三角波）と比較することによりPWM制御信号を
得るものである。即ち１搬送波周期内で、３アームの中
のどれか１アームを直流電源のいずれか一方の極性に固
定し、他のアームがそれぞれ上アームと下アームの１回
ずつ、合計２回スイッチングすることにより所望の出力
電圧を得るものである。As shown in these figures, in the two-arm modulation method, one cycle of the control signal is divided into six equal parts, and one of the three arms of the voltage-type inverter is replaced with one of the DC power supplies in each section. The two-arm modulation control signal generator 4 generates a control signal for fixing to one of the polarities, and compares the generated control signal with a carrier (triangular wave) to obtain a PWM control signal. That is, within one carrier cycle, one of the three arms is fixed to one of the polarities of the DC power supply, and the other arms are switched twice, once for the upper arm and once for the lower arm. Thus, a desired output voltage is obtained.
即ち２アーム変調方式というのは、要約すると、１周
期のうちの特定期間（例えば60゜の間）は、１アームの
電圧を固定（飽和）させ、他の２アームのみを変調す
る。つまり各相の電位を歪ませながら線間電圧が望みの
波形になるように制御する方式であると言える。In other words, the two-arm modulation method is, in summary, to fix (saturate) the voltage of one arm and modulate only the other two arms for a specific period (for example, 60 °) of one cycle. In other words, it can be said that this method controls the line voltage to have a desired waveform while distorting the potential of each phase.
かかる２アーム変調方式は、搬送波周波数を同じにし
たとき、３アーム変調方式に比べ、スイッチング回数が
2/3倍に低減するという特性を持つ。従って逆にスイッ
チング回数を同じとすれば、搬送波周波数を1.5倍に増
加できる。そして周波数スペクトルは、変調比全般にわ
たって搬送波周波数の１倍の高調波成分が支配的である
ことが知られており、変調比が小さい領域、即ち出力電
圧が低い領域において、同一スイッチング回数の３アー
ム変調方式に比較して、支配的な高調波成分の周波数が
低いため、誘導機の電流リプルやトルク脈動が大きくな
るという面があり、これが欠点であった。Such a two-arm modulation method has a smaller number of switching times than a three-arm modulation method when the carrier frequency is the same.
It has the characteristic of reducing by 2/3 times. Accordingly, if the number of times of switching is the same, the carrier frequency can be increased by a factor of 1.5. In the frequency spectrum, it is known that a harmonic component that is one time the carrier frequency is dominant over the entire modulation ratio. In a region where the modulation ratio is small, that is, in a region where the output voltage is low, three arms having the same number of switching times are used. Since the frequency of the dominant harmonic component is lower than that of the modulation method, there is a problem that current ripple and torque pulsation of the induction machine increase, which is a drawback.
なお、２アーム変調方式については、1987年３月・社
団法人電気学会発行の書物「半導体電力変換回路」の第
110,111,125頁等に解説が述べられている。The two-arm modulation method is described in the book “Semiconductor Power Conversion Circuit” published in March 1987 by the Institute of Electrical Engineers of Japan.
The commentary is described on pages 110, 111, and 125.
以上説明したように、従来の３アームの変調方式で
は、変調比が大きい領域、つまり出力電圧の高い領域で
は、誘導機の電流リプルやトルク脈動の面で問題があ
り、２アーム変調方式では、変調比が小さい領域、即ち
出力電圧が低い領域において、同一スイッチング回数の
３アーム変調方式に比較して、誘導機の電流リプルやト
ルク脈動が大きくなるという問題があった。As described above, in the conventional three-arm modulation system, in the region where the modulation ratio is large, that is, in the region where the output voltage is high, there are problems in terms of current ripple and torque pulsation of the induction machine. In a region where the modulation ratio is small, that is, in a region where the output voltage is low, there is a problem that the current ripple and torque pulsation of the induction machine become large as compared with the three-arm modulation system in which the number of times of switching is the same.
本発明の目的は、出力電圧の全範囲にわたって誘導機
の電流リプルやトルク脈動を小さくすることのできる三
相電圧形インバータのPWM制御方法を提供することにあ
る。An object of the present invention is to provide a PWM control method for a three-phase voltage source inverter capable of reducing current ripple and torque pulsation of an induction machine over the entire range of output voltage.
上記目的達成のため、本発明では、三相電圧形インバ
ータにおいて、変調比（電圧指令値）が小さい、即ち出
力電圧が小さいときには前記インバータを３アーム変調
方式に従ってPWM制御し、その変調比（電圧指令値）が
大きい、即ち出力電圧が大きいときには前記インバータ
を２アーム変調方式に従ってPWM制御することとし、３
アーム変調方式に従ってPWM制御するときには、PWM制御
信号を得るために搬送波と比較されることになる変調制
御信号を三相正弦波からなる変調制御信号へ切り替え、
２アーム変調方式に従ってPWM制御するときには、PWM制
御信号を得るために搬送波と比較されることになる変調
制御信号を２アーム変調方式用の変調制御信号へ切り替
えることとした。To achieve the above object, according to the present invention, in a three-phase voltage-source inverter, when the modulation ratio (voltage command value) is small, that is, when the output voltage is small, the inverter is PWM-controlled according to a three-arm modulation method, and the modulation ratio (voltage Command value) is large, that is, when the output voltage is large, PWM control is performed on the inverter according to the two-arm modulation method.
When performing PWM control according to the arm modulation method, the modulation control signal to be compared with the carrier wave to obtain a PWM control signal is switched to a modulation control signal including a three-phase sine wave,
When performing the PWM control according to the two-arm modulation method, the modulation control signal to be compared with the carrier wave to obtain the PWM control signal is switched to the modulation control signal for the two-arm modulation method.
本発明では、３アーム変調方式と２アーム変調方式と
でスイッチング回数を等しくした場合、３アーム変調時
の搬送波周波数をfcとすると、支配的な高調波成分は、 ３アーム変調時において、出力電圧（変調比）が小な
らば2fc、大ならばfc、 ２アーム変調時において、出力電圧（変調比）が小な
らば1.5fc、大でも1.5fc、 となる点に着目し、変調比が小さいときには３アーム
変調方式、大きいときには２アーム変調方式を採用する
ことにより、変調比の全範囲にわたり、それぞれの各変
調方式を単独で使用する場合よりも、誘導機の電流リプ
ルやトルク脈動を小さくすることを可能にしている。In the present invention, when the number of switching times is the same between the three-arm modulation method and the two-arm modulation method, assuming that the carrier frequency at the time of the three-arm modulation is fc, the dominant harmonic component is the output voltage at the time of the three-arm modulation. (Modulation ratio) is 2fc if it is small, fc if it is large. At the time of two-arm modulation, the output voltage (modulation ratio) is 1.5fc if it is small and 1.5fc even if it is large. Sometimes, a three-arm modulation scheme is used, and when it is large, a two-arm modulation scheme is used to reduce the current ripple and torque pulsation of the induction machine over the entire range of the modulation ratio as compared with the case where each of the modulation schemes is used alone. That makes it possible.
第１図は本発明の一実施例を示す回路図である。同図
において、１は搬送波（三角波）発生器、２は３アーム
変調制御信号発生器、3a〜3cはそれぞれ比較器、４は２
アーム変調制御信号発生器、５は関数発生器、６は切換
スイッチ、７は比較器、である。FIG. 1 is a circuit diagram showing one embodiment of the present invention. In the figure, 1 is a carrier (triangular wave) generator, 2 is a 3-arm modulation control signal generator, 3a to 3c are comparators, 4 is 2
5 is a function generator, 6 is a changeover switch, and 7 is a comparator.
回路動作を説明する。関数発生器５は、周波数指令fm
＊を入力されて電圧指令λを出力する。周波数指令fm＊
と電圧指令λは、ともに３アーム変調制御信号発生器２
と２アーム変調制御信号発生器４に入力され、それぞれ
の変調制御信号発生器は所要の制御信号を出力する。The circuit operation will be described. The function generator 5 receives the frequency command fm
* Is input and a voltage command λ is output. Frequency command fm *
And the voltage command λ are the three-arm modulation control signal generator 2
And the two-arm modulation control signal generator 4, and each modulation control signal generator outputs a required control signal.
また電圧指令λは、比較器７にも入力され、予め設定
されている電圧指令レベルλｒと比較される。比較器７
の出力によって切換スイッチ６を切り換え、３アーム変
調制御信号発生器２と２アーム変調制御信号発生器４の
何れかからの出力信号を搬送波（三角波）発生器１から
の三角波と比較器3a〜3cにおいて比較してPWM制御信号
を得る。The voltage command lambda, is also input to the comparator 7 is compared with the voltage command level lambda r that is set in advance. Comparator 7
The changeover switch 6 is switched according to the output of the control signal generator 2 and the output signal from either the three-arm modulation control signal generator 2 or the two-arm modulation control signal generator 4 is compared with the triangular wave from the carrier (triangle wave) generator 1 and the comparators 3a to 3c And obtain a PWM control signal.
ここで切換スイッチ６における切り換えは、 λ≦λｒならば、３アーム変調側、 λ＞λｒならば、２アーム変調側、 とすることにより、変調比の全範囲、即ち出力電圧の全
範囲で誘導機の電流リプルやトルク脈動を低減すること
ができる。Here switching in the change-over switch 6 is, if λ ≦ λ r, 3-arm modulation side, if λ> λ r, 2-arm modulation side, by a full range of the entire range, i.e. the output voltage of the modulation ratio As a result, current ripple and torque pulsation of the induction machine can be reduced.
本発明によれば、そのときの変調比（出力電圧）に対
して、高調波成分の周波数の高い方を用いるように、３
アーム変調方式と２アーム変調方式を切り換えて使い分
けるので、出力電圧の全範囲にわたって、各アーム変調
方式を単独で用いる場合に比較して、誘導機の電流リプ
ルやトルク脈動を低減できるという利点がある。その結
果、誘導電動機等のトルク脈動の少ない円滑な可変速運
転が可能になる。According to the present invention, for the modulation ratio (output voltage) at that time, 3
Since the arm modulation method and the two-arm modulation method are selectively used, there is an advantage that the current ripple and torque pulsation of the induction machine can be reduced over the entire range of the output voltage as compared with the case where each arm modulation method is used alone. . As a result, smooth variable speed operation of the induction motor or the like with less torque pulsation becomes possible.
第１図は本発明の一実施例を示す回路図、第２図は周知
の三相PWM電圧形インバータの基本回路を示す回路図、
第３図は第２図における変調回路の詳細を示す回路図、
第４図は第３図における各部の信号波形図、第５図は２
アーム変調方式をとる場合の変調回路の詳細を示す回路
図、第６図は第５図における各部の信号波形図、であ
る。 符号の説明 １……搬送波（三角波）発生器、２……３アーム変調制
御信号発生器、3a〜3c……比較器、４……２アーム変調
制御信号発生器、５……関数発生器、６……切換スイッ
チ、７……比較器FIG. 1 is a circuit diagram showing one embodiment of the present invention, FIG. 2 is a circuit diagram showing a basic circuit of a known three-phase PWM voltage source inverter,
FIG. 3 is a circuit diagram showing details of the modulation circuit in FIG. 2,
FIG. 4 is a signal waveform diagram of each part in FIG. 3, and FIG.
FIG. 6 is a circuit diagram showing details of the modulation circuit when the arm modulation method is adopted, and FIG. 6 is a signal waveform diagram of each part in FIG. DESCRIPTION OF SYMBOLS 1 ... Carrier (triangular wave) generator, 2 ... 3-arm modulation control signal generator, 3a to 3c ... Comparator, 4 ... 2-arm modulation control signal generator, 5 ... Function generator, 6 Changeover switch 7 Comparator
Claims (1)
電圧指令値が小さいときには前記インバータを３アーム
変調方式に従ってPWM制御し、その出力電圧指令値が大
きいときには前記インバータを２アーム変調方式に従っ
てPWM制御する三相電圧形インバータのPWM制御方法にお
いて、 ３アーム変調方式に従ってPWM制御するときには、PWM制
御信号を得るために搬送波と比較されることになる変調
制御信号を三相正弦波からなる変調制御信号へ切り替
え、２アーム変調方式に従ってPWM制御するときには、P
WM制御信号を得るために搬送波と比較されることになる
変調制御信号を２アーム変調方式用の変調制御信号へ切
り替えることを特徴とする三相電圧形インバータのPWM
制御方法。In a three-phase voltage-source inverter, when the output voltage command value is small, the inverter is PWM-controlled according to a three-arm modulation scheme, and when the output voltage command value is large, the inverter is PWM-controlled according to a two-arm modulation scheme. In the PWM control method of the three-phase voltage source inverter, when performing the PWM control according to the three-arm modulation method, the modulation control signal to be compared with the carrier to obtain the PWM control signal is a modulation control signal including a three-phase sine wave. To PWM control according to the two-arm modulation method.
PWM of a three-phase voltage source inverter characterized by switching a modulation control signal to be compared with a carrier wave to obtain a WM control signal to a modulation control signal for a two-arm modulation scheme
Control method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63102591A JP2718058B2 (en) | 1988-04-27 | 1988-04-27 | PWM control method for three-phase voltage source inverter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63102591A JP2718058B2 (en) | 1988-04-27 | 1988-04-27 | PWM control method for three-phase voltage source inverter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01274669A JPH01274669A (en) | 1989-11-02 |
| JP2718058B2 true JP2718058B2 (en) | 1998-02-25 |
Family
ID=14331477
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63102591A Expired - Lifetime JP2718058B2 (en) | 1988-04-27 | 1988-04-27 | PWM control method for three-phase voltage source inverter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2718058B2 (en) |
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| KR101266278B1 (en) * | 2009-04-16 | 2013-05-22 | 메이덴샤 코포레이션 | Method of controlling power conversion device |
| JP5298003B2 (en) * | 2009-12-28 | 2013-09-25 | 株式会社日立製作所 | Elevator speed control apparatus and speed control method |
| JP5825945B2 (en) * | 2011-09-09 | 2015-12-02 | 三菱重工業株式会社 | Inverter control device, inverter device, and air conditioner |
| WO2023153420A1 (en) * | 2022-02-10 | 2023-08-17 | ニデック株式会社 | Power conversion device and motor module |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2577738B2 (en) * | 1987-05-20 | 1997-02-05 | 三菱電機株式会社 | PWM inverter device |
-
1988
- 1988-04-27 JP JP63102591A patent/JP2718058B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7053587B2 (en) | 2004-02-10 | 2006-05-30 | Denso Corporation | Apparatus for controlling three-phase AC motor on two-phase modulation technique |
| CN100492858C (en) * | 2004-02-10 | 2009-05-27 | 株式会社电装 | Apparatus for controlling three-phase AC motor based on two-phase modulation technique |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01274669A (en) | 1989-11-02 |
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