JPH05344789A - Inverter control method - Google Patents

Inverter control method

Info

Publication number
JPH05344789A
JPH05344789A JP4150249A JP15024992A JPH05344789A JP H05344789 A JPH05344789 A JP H05344789A JP 4150249 A JP4150249 A JP 4150249A JP 15024992 A JP15024992 A JP 15024992A JP H05344789 A JPH05344789 A JP H05344789A
Authority
JP
Japan
Prior art keywords
inverter
output frequency
regenerative state
frequency
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP4150249A
Other languages
Japanese (ja)
Inventor
Kazuharu Ohashi
和治 大橋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Priority to JP4150249A priority Critical patent/JPH05344789A/en
Publication of JPH05344789A publication Critical patent/JPH05344789A/en
Pending legal-status Critical Current

Links

Landscapes

  • Control Of Voltage And Current In General (AREA)
  • Stopping Of Electric Motors (AREA)
  • Control Of Multiple Motors (AREA)
  • Inverter Devices (AREA)
  • Rectifiers (AREA)

Abstract

PURPOSE:To sustain operation of an inverter unit without causing overvoltage tripping by increasing the output frequency increasing rate upon detection of regenerative state during acceleration in a system wherein a plurality of inverter units drive a plurality of induction motors having mechanically coupled drive shafts. CONSTITUTION:A plurality of induction motors IN having mechanically coupled driving shafts are driven through a plurality of inverter units 2. The inverter unit 2 comprises a converter section 3, a smoothing capacitor 4, and an inverter section 5 constituting main circuit thereof. Output signals from a DC voltage detecting circuit 6, a load current detecting circuit 7, and a frequency setting circuit 10 are fed to a frequency control section 8 which delivers an output frequency signal to a PWM circuit 9 and the inverter section 5 is then controlled based on the output from the PWM circuit 9. When the DC voltage detecting circuit 6 detects regenerative state during acceleration, increasing rate of output frequency is increased before overvoltage trip takes place and a transition is made from regenerative state to powering state.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は、複数の誘導電動機を複
数のインバータ装置で駆動するシステムにおけるインバ
ータ制御方法に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter control method in a system in which a plurality of induction motors are driven by a plurality of inverter devices.

【0002】[0002]

【従来の技術】一般に、従来より駆動軸を機械的に結合
した複数の誘導電動機を別々のインバータ装置で駆動す
るシステムが存在するが、その場合のインバータによる
誘導電動機の制御は、PWM制御により行なわれてい
る。このときのPWM制御における周波数制御につい
て、図3を用いて説明する。
2. Description of the Related Art Generally, there is a conventional system in which a plurality of induction motors having drive shafts mechanically coupled are driven by different inverter devices. In that case, the control of the induction motors by the inverters is performed by PWM control. Has been. Frequency control in the PWM control at this time will be described with reference to FIG.

【0003】図3に示すように、まず、指令周波数f*
と出力周波数fを比較して加速が必要か判断する(F−
1)。そして、F−1において、加速が必要でない場合
は、減速が必要か判断し(F−2)、減速が必要であれ
ば、減速処理する(F−3)。また、F−1で加速が必
要と判断した場合、過電流か否かを判断し(F−4)、
過電流でない場合は、Δf1 に0を代入し(F−5)、
過電流の場合、Δf1に所定の値−Δfocを代入する
(F−6)。そして、最終段にて出力周波数fに所定の
加速レートΔfとΔf1 を加算する(F−7)。そし
て、加速中過電流となると、加速をΔfocだけ遅らせ
る。この加速中過電流になった場合、加速をΔfocだけ
遅らせる動作機能をストール防止機能と称している。
As shown in FIG. 3, first, a command frequency f *
And output frequency f are compared to determine whether acceleration is required (F-
1). Then, in F-1, if acceleration is not required, it is determined whether deceleration is required (F-2), and if deceleration is required, deceleration processing is performed (F-3). Further, when it is determined that acceleration is necessary in F-1, it is determined whether or not overcurrent (F-4),
If it is not overcurrent, substitute 0 for Δf 1 (F-5),
In the case of overcurrent, a predetermined value −Δf oc is substituted for Δf 1 (F-6). Then, in the final stage, the predetermined acceleration rates Δf and Δf 1 are added to the output frequency f (F-7). When the overcurrent occurs during acceleration, the acceleration is delayed by Δf oc . If an overcurrent occurs during acceleration, the operation function of delaying the acceleration by Δf oc is called a stall prevention function.

【0004】[0004]

【発明が解決しようとする課題】しかし、複数台のイン
バータ装置と誘導電動機を並列運転させる場合、加速中
にインバータ出力周波数がばらついて、負荷の回転速度
より低い出力周波数となり、回生エネルギーが平滑コン
デンサにチャージされ、過電圧保護レベル以上となりト
リップするインバータ装置が発生する。減速時には一般
のインバータ装置には過電圧を検出すると、減速を一且
停止する過電圧ストール機能を有しており(インバータ
間でバランスし)トリップしない。
However, when a plurality of inverter devices and an induction motor are operated in parallel, the inverter output frequency fluctuates during acceleration and the output frequency becomes lower than the rotation speed of the load, and the regenerative energy is smoothed by the smoothing capacitor. The inverter device will be charged and charged to the over voltage protection level and tripped. When an overvoltage is detected in a general inverter device during deceleration, it has an overvoltage stall function that suspends deceleration (balances between inverters) and does not trip.

【0005】そこで、出力周波数がばらつく原因を図4
(a)(b)を用いて説明する。図4(a)は電流検出
のばらつきにより、あるインバータ装置のみがストール
防止機能が働き、過電圧トリップに至る様子を示したも
のである。
Therefore, the cause of the variation in the output frequency is shown in FIG.
A description will be given using (a) and (b). FIG. 4A shows a state in which only a certain inverter device has a stall prevention function due to variations in current detection, resulting in an overvoltage trip.

【0006】時刻t1 でストール防止機能が働いて、時
刻t2 以降、負荷の回転数より低い出力周波数で回生状
態となり、時刻t3 で過電圧トリップしている。また、
図4(b)は、あるインバータ装置の周波数制御におい
て加速レートがばらついて小さくなり、過電圧トリップ
に至る様子を示したものである。時刻t4 以降回生状態
となり時刻t5 で過電圧トリップする。
At time t 1 , the stall prevention function is activated, and after time t 2 , a regenerative state occurs at an output frequency lower than the rotation speed of the load, and an overvoltage trip occurs at time t 3 . Also,
FIG. 4B shows how the acceleration rate fluctuates and becomes small in frequency control of an inverter device, leading to an overvoltage trip. After time t 4, the regenerative state is entered, and an overvoltage trip occurs at time t 5 .

【0007】このように、複数台の誘導電動機の駆動軸
を機械的に結合した負荷において、誘導電動機を別々に
インバータ装置で駆動するシステムにおいては、インバ
ータ装置が過電圧トリップする場合があるという問題点
があった。また、1台のインバータ装置が過電圧トリッ
プすると残りのインバータ装置が過負荷となりトリップ
し、継続運転できない場合もある。
As described above, in a system in which the drive shafts of a plurality of induction motors are mechanically coupled to each other, in a system in which the induction motors are separately driven by the inverter device, the inverter device may trip overvoltage. was there. Further, if one inverter device trips overvoltage, the remaining inverter devices may be overloaded and tripped, and continuous operation may not be possible.

【0008】そこで、本発明は、以上の点を考慮し、駆
動軸を機械的に結合した複数の誘導電動機を別々のイン
バータ装置で駆動するシステムにおいて、インバータ装
置が過電圧トリップすることなく、継続運転できるイン
バータ制御方法を提供することを目的とする。
Therefore, in consideration of the above points, the present invention, in a system in which a plurality of induction motors having drive shafts mechanically coupled to each other are driven by separate inverter devices, the inverter devices are continuously operated without overvoltage trip. It is an object of the present invention to provide an inverter control method that can be performed.

【0009】[0009]

【課題を解決するための手段】上記目的を達成するため
に、本発明は、駆動軸を機械的に結合した複数の誘導電
動機を誘導電動機の台数以下のインバータ装置で駆動す
るシステムにおいて、インバータ装置の加速中に回生状
態を検出した場合、出力周波数の増加率を大きくするこ
とを特徴とするものである。
In order to achieve the above object, the present invention provides an inverter device in a system in which a plurality of induction motors having drive shafts mechanically coupled are driven by an inverter device having the number of induction motors or less. When the regenerative state is detected during acceleration, the increase rate of the output frequency is increased.

【0010】[0010]

【作用】このように構成された本発明においては、加速
中に平滑コンデンサの電圧等で回生状態を検出し、過電
圧トリップに至る前に出力周波数の増加率を大きくし、
回生状態から抜け出るように制御する。
In the present invention thus constructed, the regenerative state is detected by the voltage of the smoothing capacitor during acceleration, and the increase rate of the output frequency is increased before the overvoltage trip,
Control to get out of the regenerative state.

【0011】[0011]

【実施例】以下、本発明の一実施例について図面を用い
て説明する。まず、本実施例が適用されるシステムにつ
いて、図1を用いて説明する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, a system to which this embodiment is applied will be described with reference to FIG.

【0012】図1に示すように、本実施例は、まず、周
波数指令f* と出力周波数fとを比較して加速が必要か
判断し(F−1)、加速が必要でない場合は、減速が必
要か判断し(F−2)、減速が必要であれば、減速処理
を行なう(F−3)。
As shown in FIG. 1, the frequency command f * is first set in this embodiment . And output frequency f are compared to determine whether acceleration is required (F-1). If acceleration is not required, it is determined whether deceleration is required (F-2). If deceleration is required, deceleration processing is performed. Perform (F-3).

【0013】また、F−1において、加速が必要と判断
した場合、過電流か否かを判断し、過電流でない場合
は、Δf1 に0を代入し(F−8)、過電流の場合は、
回生状態か否かを判断し(F−9)、回生状態の場合
は、Δf1 に所定の値Δfovを代入する(F−10)。
Further, in F-1, when it is judged that acceleration is necessary, it is judged whether or not it is an overcurrent. When it is not an overcurrent, 0 is substituted into Δf 1 (F-8), and in the case of overcurrent Is
It is determined whether or not it is in the regenerative state (F-9), and in the case of the regenerative state, a predetermined value Δf ov is substituted for Δf 1 (F-10).

【0014】そして、この回生状態の場合、出力周波数
1 は通常の加速レートΔfの他に、Δf1 =Δfov
加算され(F−12)、このF−9での処理は、出力周波
数fが負荷回転数以上となって回生状態を抜出るまで継
続し、適当なΔfovの値によって、速やかに誘導電動機
を回生状態からカ行状態に移行させる。また、過電流で
あるが回生状態でない場合は、Δf1 に0を代入し(F
−11)、F−12において、出力周波数fは通常の加速レ
ートΔfが加算される。次に、本実施例を適用したシス
テムについて、図2を用いて説明する。
In this regenerative state, the output frequency f 1 is added with Δf 1 = Δf ov in addition to the normal acceleration rate Δf (F-12). This is continued until f becomes equal to or higher than the load rotation speed and the regenerative state is withdrawn, and the induction motor is promptly changed from the regenerative state to the power running state by an appropriate value of Δf ov . If the current is overcurrent but not in the regenerative state, 0 is substituted for Δf 1 (F
-11) and F-12, the normal acceleration rate Δf is added to the output frequency f. Next, a system to which this embodiment is applied will be described with reference to FIG.

【0015】図2に示すように、本システムは、交流電
源1と、この交流電源1から供給される交流電力を任意
の電圧及び周波数を有する交流電力に変換するインバー
タ装置2と、このインバータ装置2からの交流電力を基
に駆動される誘導電動機3と、この誘導電動機3に機械
的に結合される負荷4とから成り、インバータ装置2と
誘導電動機3とを複数台有している。
As shown in FIG. 2, the present system includes an AC power supply 1, an inverter device 2 for converting the AC power supplied from the AC power supply 1 into AC power having an arbitrary voltage and frequency, and this inverter device. The induction motor 3 is driven based on the AC power from the AC motor 2, and the load 4 is mechanically coupled to the induction motor 3. The inverter device 2 and the induction motor 3 are provided in plurality.

【0016】また、インバータ装置2は、交流電力を直
流電力に変換するコンバータ部5と、このコンバータ部
5から直流電力を平滑化する平滑コンデンサ6と、この
平滑コンデンサ6からの平滑された直流電力を任意の電
圧・周波数を有する交流電力に変換するインバータ部7
と、平滑コンデンサ6の直流電圧Vを検出する電圧検出
回路8と、負荷電流Iを検出する電流検出回路9と、周
波数指令f* を設定する周波数指令設定回路10と、この
周波数指令設定回路10からの周波数指令f* 、電圧検出
回路8から検出された直流電圧V及び電流検出回路9か
ら検出された負荷電流Iを基に、出力周波数信号fを生
成する周波数制御部11と、この周波数制御部11からの出
力周波数信号fを基に、インバータ部7をパルス幅変調
(PWM)制御するPWM回路12とから構成されてい
る。
The inverter device 2 includes a converter section 5 for converting AC power into DC power, a smoothing capacitor 6 for smoothing the DC power from the converter section 5, and a smoothed DC power from the smoothing capacitor 6. Inverter unit 7 for converting power into AC power of arbitrary voltage and frequency
A voltage detection circuit 8 for detecting the DC voltage V of the smoothing capacitor 6, a current detection circuit 9 for detecting the load current I, and a frequency command f *. And the frequency command f * from this frequency command setting circuit 10 . , A frequency control section 11 for generating an output frequency signal f based on the DC voltage V detected by the voltage detection circuit 8 and the load current I detected by the current detection circuit 9, and an output frequency from the frequency control section 11. A PWM circuit 12 for controlling the pulse width modulation (PWM) of the inverter unit 7 based on the signal f.

【0017】そして、本システムにおいては、加速中に
電圧検出回路8にて回生状態を検出し、過電圧トリップ
に至る前に出力周波数の増加率を大きくし、誘導電動機
3を回生状態からカ行状態へ移行するように制御する。
In the present system, the voltage detection circuit 8 detects the regenerative state during acceleration, increases the increase rate of the output frequency before the overvoltage trip, and changes the induction motor 3 from the regenerative state to the running state. Control to shift to.

【0018】以上のように、本実施例においては、加速
中に回生状態となった誘導電動機をカ行状態に移行さ
せ、インバータ装置が過電圧トリップすることなく、継
続運転させることができる。
As described above, in the present embodiment, the induction motor, which is in the regenerative state during acceleration, can be shifted to the power running state and the inverter device can be continuously operated without overvoltage trip.

【0019】また、本発明の他の実施例としては、先の
実施例における過電流状態判別処理(図1中F−4)及
びΔf1 =−Δfoc処理(図1中F−8)を削除する
か、或いはΔf1 =−Δfoc処理をΔf1 =0として
(図1中F−11と同様な処理)、加速中ストール防止機
能がなくなり、ストール防止機能に起因する出力周波数
ばらつきによる過電圧トリップの回避方法や、図1中F
−10において、Δf1 =0、Δf1 =Δfov´のように
加速レートΔfを変更するか、Δf1 =−Δfov、Δf
=Δfov´のように一時的加転値Δf1 、加速レートΔ
fの両方を変更して出力周波数の増加率を大きくする方
法がある。
Further, as another embodiment of the present invention, the overcurrent state discrimination processing (F-4 in FIG. 1) and the Δf 1 = −Δf oc processing (F-8 in FIG. 1) in the previous embodiment are performed. Either delete or set Δf 1 = -Δf oc processing to Δf 1 = 0 (processing similar to F-11 in FIG. 1), the stall prevention function during acceleration disappears, and overvoltage due to output frequency variation caused by the stall prevention function. How to avoid trips and F in Figure 1
At −10, the acceleration rate Δf is changed like Δf 1 = 0, Δf 1 = Δf ov ′, or Δf 1 = −Δf ov , Δf
= Δf ov ′, the temporary acceleration value Δf 1 , the acceleration rate Δ
There is a method of changing both f to increase the increase rate of the output frequency.

【0020】更に、本発明の実施例として回生状態の平
滑コンデンサ電圧レベルに応じて、出力周波数一時間加
算値Δfovの値を変化させて、最短で回生状態を抜出す
制御方法もある。
Further, as an embodiment of the present invention, there is also a control method in which the value of the output frequency one-hour addition value Δf ov is changed in accordance with the smoothing capacitor voltage level in the regenerative state to extract the regenerative state in the shortest time.

【0021】また、本発明の適用システムとしては、図
2に示したシステム以外に、誘導電動機があるギア比で
機械的に結合したシステムで、インバータ装置によって
一定の比率で周波数指令f* が異なる比例制御の場合に
も適用することができる。
In addition to the system shown in FIG. 2, the system to which the present invention is applied is a system in which an induction motor is mechanically coupled at a certain gear ratio, and a frequency command f * is provided at a constant ratio by an inverter device . Can be applied to the case of different proportional control.

【0022】[0022]

【発明の効果】以上述べてきたように、本発明によれ
ば、駆動軸を機械的に結合した複数の誘導電動機を複数
のインバータ装置で駆動するシステムにおいて、加速中
に回生状態となった誘導電動機をカ行状態に移行させ、
インバータ装置が過電圧トリップすることなく継続運転
できる。
As described above, according to the present invention, in a system in which a plurality of induction motors having drive shafts mechanically coupled to each other are driven by a plurality of inverter devices, the induction which is in a regenerative state during acceleration. Move the electric motor to the running state,
The inverter device can continue to operate without overvoltage trip.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明の一実施例を示す周波数制御フローチャ
ート。
FIG. 1 is a frequency control flowchart showing an embodiment of the present invention.

【図2】本発明の一実施例を適用したシステムを示す概
要構成図。
FIG. 2 is a schematic configuration diagram showing a system to which an embodiment of the present invention is applied.

【図3】従来のインバータ制御方法を示す周波数制御フ
ローチャート。
FIG. 3 is a frequency control flowchart showing a conventional inverter control method.

【図4】従来のインバータ制御方法による過電圧トリッ
プの概念図。
FIG. 4 is a conceptual diagram of an overvoltage trip by a conventional inverter control method.

【符号の説明】[Explanation of symbols]

2…インバータ装置 3…誘導電動機 2 ... Inverter device 3 ... Induction motor

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 FI 技術表示箇所 H02P 3/18 101 B 7346−5H ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification code Internal reference number FI Technical indication H02P 3/18 101 B 7346-5H

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 駆動軸を機械的に結合した複数の誘導電
動機を複数のインバータ装置で駆動するシステムにおい
て、前記インバータ装置の加速中に回生状態を検出した
場合、出力周波数の増加率を大きくすることを特徴とす
るインバータ制御方法。
1. In a system for driving a plurality of induction motors having drive shafts mechanically coupled by a plurality of inverter devices, when a regenerative state is detected during acceleration of the inverter devices, an increase rate of the output frequency is increased. An inverter control method characterized by the above.
JP4150249A 1992-06-10 1992-06-10 Inverter control method Pending JPH05344789A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4150249A JPH05344789A (en) 1992-06-10 1992-06-10 Inverter control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4150249A JPH05344789A (en) 1992-06-10 1992-06-10 Inverter control method

Publications (1)

Publication Number Publication Date
JPH05344789A true JPH05344789A (en) 1993-12-24

Family

ID=15492822

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4150249A Pending JPH05344789A (en) 1992-06-10 1992-06-10 Inverter control method

Country Status (1)

Country Link
JP (1) JPH05344789A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107836077A (en) * 2015-07-09 2018-03-23 三菱电机株式会社 Control device of electric motor

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107836077A (en) * 2015-07-09 2018-03-23 三菱电机株式会社 Control device of electric motor
CN107836077B (en) * 2015-07-09 2020-07-07 三菱电机株式会社 Motor control device

Similar Documents

Publication Publication Date Title
EP0401057B1 (en) Variable-speed driving system
JPH0132760B2 (en)
JP2000236679A (en) Control method of power converter for motor control
US5576606A (en) Asynchronous motor power supply control system
JP4524855B2 (en) PWM control inverter
JPH05344789A (en) Inverter control method
JP2980469B2 (en) Inverter device
JP2906636B2 (en) Inverter control device for induction motor
JPH07177751A (en) Power supply unit for motor
JP2000184736A (en) Adjustable speed device
JP2880808B2 (en) Inverter device
JP2717468B2 (en) Inverter device
JP3050610B2 (en) Power supply
JP2004304909A (en) Regenerative absorption system of inverter for hybrid vehicle
JP2002204594A (en) Motor control equipment
JPH05229785A (en) Motor overload detection device for hoist
JPH0767311B2 (en) Current and torque limiting circuit for AC motor drive inverter device
JPS61196795A (en) Inverter control system
JPH1042590A (en) Voltage-type inverter
JPH0591793A (en) Inverter device
JPH01198296A (en) Controller for ac variable speed motor
JPS59117495A (en) Operating method of motor
JPS6074986A (en) Controlling method of voltage type inverter device
JP2004173454A (en) Ac electric motor control method and ac control device
JPH04334990A (en) Starting method by inverter of ac motor in no stoppage-state