JP3087771B2 - Current control device - Google Patents
Current control deviceInfo
- Publication number
- JP3087771B2 JP3087771B2 JP03116711A JP11671191A JP3087771B2 JP 3087771 B2 JP3087771 B2 JP 3087771B2 JP 03116711 A JP03116711 A JP 03116711A JP 11671191 A JP11671191 A JP 11671191A JP 3087771 B2 JP3087771 B2 JP 3087771B2
- Authority
- JP
- Japan
- Prior art keywords
- current
- main circuit
- electromagnet
- power supply
- voltage
- 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.)
- Expired - Fee Related
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
- F16C32/0406—Magnetic bearings
- F16C32/044—Active magnetic bearings
- F16C32/0444—Details of devices to control the actuation of the electromagnets
- F16C32/0457—Details of the power supply to the electromagnets
Description
【０００１】[0001]
【産業上の利用分野】本発明は、例えば磁気軸受や磁気
浮上装置に用いている電磁石に、電流を供給する電流制
御装置の改良に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a current control device for supplying a current to an electromagnet used for a magnetic bearing or a magnetic levitation device, for example.
【０００２】[0002]
【従来の技術】従来のスイッチング形の電流制御装置を
図２に示す。図２において、１は電流を与えたい電磁
石、２は偏差演算器、３は位相制御器、４はパルス幅変
調器、５は比較器、６は発振器、７はスイッチング主回
路、８は電流検出器である。偏差演算器２は電流指令Ｉ
s と電磁石１の電流に相当する信号Ｉf を比較し、その
差を出力する。その信号を受ける位相制御器３は少なく
とも電圧増幅器を持ち積分器や微分器で位相制御をす
る。その指令信号はパルス幅変調器４内の比較器５に与
えられ、発振器６の三角波信号と比較され方形波に整形
される。７は例えば特開昭６３−１９９５０６に示され
るような構成のスイッチング素子を用いたスイッチング
主回路であり、パルス幅変調器４の信号に応じて電磁石
１に与える印加電圧を切り替える。ハイレベルの信号を
受ければ図中の矢印の方向に電流を増加する極性の主回
路電源電圧を印加し、ローレベルの信号を受ければ逆方
向に増加する極性の主回路電源電圧を印加する。このよ
うに、パルス幅変調器４のパルス列を受けて、電流の増
加、減少を繰り返すので三角波状のリップルが生じる。
その電流は電流検出器８によって検出され、前記のよう
に偏差演算器２で指令値と比較される。以上のような構
成のもとで、指令値Ｉs より検出信号Ｉf の方が小さけ
れば偏差演算器２の信号に応じて位相制御器３が大きな
指令を出力し、パルス幅変調器４が働いてハイレベルの
時間確率が高いパルス列を出力する。そこでスイッチン
グ主回路７が電磁石１に印加する主回路電源電圧は、図
の矢印の方向に電流を増加する確率の方が高くなり、平
均的に電流が加速される。このようにして、ついには指
令値Ｉs に応じた電流が電磁石１に流れ、電流制御され
るのである。この電流制御の応答性は、主回路電源電圧
に依存する。電磁石１の電流Ｉと印加電圧ＶにはＶ＝Ｌ
（ｄＩ／ｄｔ）＋ＩＲの関係がある。この右辺第２項は
第１項に比べて一般に小さい場合が多く、電流の変化率
ｄＩ／ｄｔはおよそ印加電圧ＶとインダクタンスＬの比
Ｖ／Ｌに比例する。すなわち電流制御の応答性を示す電
流変化率は、印加電圧に比例するのである。2. Description of the Related Art FIG. 2 shows a conventional switching type current controller. In FIG. 2, 1 is an electromagnet to which a current is to be applied, 2 is a deviation calculator, 3 is a phase controller, 4 is a pulse width modulator, 5 is a comparator, 6 is an oscillator, 7 is a switching main circuit, and 8 is current detection. It is a vessel. The deviation calculator 2 calculates the current command I
s and a signal If corresponding to the current of the electromagnet 1 are compared, and the difference is output. The phase controller 3 receiving the signal has at least a voltage amplifier and controls the phase with an integrator or a differentiator. The command signal is supplied to a comparator 5 in the pulse width modulator 4 and is compared with a triangular wave signal of an oscillator 6 to be shaped into a square wave. Reference numeral 7 denotes a switching main circuit using a switching element having a configuration as disclosed in, for example, JP-A-63-199506, and switches an applied voltage to be applied to the electromagnet 1 in accordance with a signal from the pulse width modulator 4. When a high-level signal is received, a main circuit power supply voltage having a polarity increasing the current in the direction of the arrow in the figure is applied, and when a low-level signal is received, a main circuit power supply voltage having a polarity increasing in the opposite direction is applied. As described above, the current is repeatedly increased and decreased in response to the pulse train of the pulse width modulator 4, so that a triangular ripple is generated.
The current is detected by the current detector 8 and compared with the command value in the deviation calculator 2 as described above. Under the above arrangement, the smaller the better the command value I s from the detection signal I f in accordance with a deviation calculator 2 outputs a signal of the phase control device 3 large command, the pulse width modulator 4 It works and outputs a pulse train with a high level time probability. Therefore, the main circuit power supply voltage applied to the electromagnet 1 by the switching main circuit 7 has a higher probability of increasing the current in the direction of the arrow in the figure, and the current is accelerated on average. In this way, finally flows into the current electromagnet 1 according to the command value I s, is being current controlled. The responsiveness of this current control depends on the main circuit power supply voltage. V = L for the current I and the applied voltage V of the electromagnet 1
(DI / dt) + IR. Generally, the second term on the right side is generally smaller than the first term, and the current change rate dI / dt is approximately proportional to the ratio V / L of the applied voltage V to the inductance L. That is, the current change rate indicating the response of the current control is proportional to the applied voltage.
【０００３】[0003]
【発明が解決しようとする課題】上記のように、印加電
圧が電流変化率の大きさを変えて、電流制御ループの応
答性に影響を与えるのは、スイッチング素子に与えるＯ
Ｎ−Ｏｆｆの指令が１００％ＯＮになった時である。な
ぜなら、ＯＮ−Ｏｆｆのパルス列が与えられている時、
電流は順方向と逆方向の流れを繰り返してノコギリ波を
成し、指令値に追従しているからである。従って、最大
応答周波数が印加電圧に影響されることになるのであ
る。主回路電源電圧が上昇すれば電流制御の応答性は向
上し、下降すれば応答性も悪くなるのである。このよう
に電源変動により電流制御系の応答性が影響を受ける
と、その外に設けられた制御ループの特性を最大限にあ
げている場合などに影響を受けることがある。元来、不
安定系を成す磁石の吸引力を利用して非接触支持する磁
気軸受などでは、系の設計を最適にしている時に、各要
素の利得が小さくなっても、大きくなっても安定性を損
なう場合があるのである。主回路電源の電圧が電流ルー
プの特性に影響する場合もそうであり、これを回避する
ため安定化電源を用いていたが、高価になるだけでなく
複雑になるという課題があった。As described above, the reason that the applied voltage changes the magnitude of the current change rate and affects the responsiveness of the current control loop is that O applied to the switching element.
This is when the N-Off command is turned on 100%. Because when ON-Off pulse train is given,
This is because the current repeats forward and reverse flows to form a sawtooth wave and follows the command value. Therefore, the maximum response frequency is affected by the applied voltage. As the main circuit power supply voltage increases, the responsiveness of the current control improves, and as the main circuit power supply voltage decreases, the responsiveness deteriorates. When the responsiveness of the current control system is affected by the power supply fluctuation as described above, the response may be affected when the characteristics of a control loop provided outside the system are maximized. Originally, for magnetic bearings that support non-contact by utilizing the attractive force of a magnet that forms an unstable system, when the system design is optimized, even if the gain of each element is small or large, it is stable. In some cases, it may impair the performance. This is also the case when the voltage of the main circuit power supply affects the characteristics of the current loop. In order to avoid this, a stabilized power supply has been used, but there has been a problem that it is not only expensive but also complicated.
【０００４】[0004]
【課題を解決するための手段】本発明は、電磁石への供
給電流を制御する電流制御装置において、前記電磁石に
電流を供給するスイッチング主回路と、電流指令値と前
記電磁石電流検出値とを比較してその偏差を出力する偏
差演算器と、前記偏差を入力し、前記スイッチング主回
路のパワー電源電圧に応じて時定数の変化する可変フィ
ルタと、この可変フィルタの出力を入力する位相制御器
と、この位相制御器の出力を入力するパルス幅変調器
と、このパルス幅変調器の出力に応じて前記スイッチン
グ主回路から電磁石に与える印加電圧を切り換えるよう
にしたことを特徴とするものである。According to the present invention, there is provided a current control device for controlling a current supplied to an electromagnet, wherein a switching main circuit for supplying a current to the electromagnet is compared with a current command value and the electromagnet current detection value. A deviation calculator that outputs the deviation, a variable filter that receives the deviation, changes a time constant according to the power supply voltage of the switching main circuit, and a phase controller that receives the output of the variable filter. A pulse width modulator to which an output of the phase controller is inputted, and a voltage applied from the switching main circuit to the electromagnet is switched in accordance with an output of the pulse width modulator.
【０００５】[0005]
【作用】本発明によれば、電源電圧が最も低くなった時
を初期状態とすると、その時の該電圧の検出信号は最も
小さくなり、その信号を受けた可変フィルタは時定数が
最も小さくなって、全体としての電流制御ループは、あ
る特性をもつことになる。この時、電源電圧が最も高く
なったとすると、電源電圧の検出信号は最も高くなり、
その信号を受けた可変フィルタの時定数が最も大きくな
る。電源電圧が高くなってｄＩ／ｄｔが大きくなるが、
制御ループ内に設けた可変フィルタにより時定数を大き
くして動特性を低下させたため、これらが相殺してルー
プ特性が一定に保たれるのである。従って電源電圧が変
動しても、電流制御特性が変化しない系を構成できるの
である。According to the present invention, when the time when the power supply voltage becomes the lowest is set as the initial state, the detection signal of the voltage at that time becomes the smallest, and the variable filter receiving the signal has the smallest time constant. , The current control loop as a whole will have certain characteristics. At this time, if the power supply voltage becomes the highest, the detection signal of the power supply voltage becomes the highest,
The time constant of the variable filter receiving the signal becomes the largest. Although the power supply voltage increases and dI / dt increases,
Since the dynamic characteristics are lowered by increasing the time constant by the variable filter provided in the control loop, these are canceled out and the loop characteristics are kept constant. Therefore, a system in which the current control characteristics do not change even when the power supply voltage changes can be configured.
【０００６】[0006]
【実施例】図１は本発明の具体的実施例をあらわす図で
ある。１〜８は図２のものと同じであり９が可変フィル
タ、１０が電圧検出器である。電圧検出器１０はスイッ
チング主回路７の主回路電源電圧を検出し、対応する電
圧信号を出力する。可変フィルタ９は偏差演算器２の出
力信号を入力とし、位相制御器３に出力信号を与えるロ
ーパスフィルタであるが、その時定数が、該電圧検出器
１０の信号により制御され、大きな入力に対しては時定
数を大きくし、小さな入力に対しては時定数を小さくす
る働きがある。そして、この入力信号と時定数の大きさ
が比例関係にある。このような系において、主回路電源
電圧がとりうる最も低い電圧と、最も高い電圧の場合に
ついて説明する。まず、最も低い電圧ＶL になっている
時を考えると、ｄＩ／ｄｔはＶL ／Ｌに等しい。この時
パルス幅変調器４のパルス列が１００％ＯＮの状態にな
る直前の状態とすると、電圧検出器１０の信号はｖL と
最も小さく、可変フィルタの時定数もＴL と最も小さ
く、フィルタは１／（１＋ＴL Ｓ）の伝達特性を持ち、
高周波域ではおよそ１／ＴL Ｓの特性に等しくなる。次
に、最も高い電圧ＶH になった時のことを考えると、ｄ
Ｉ／ｄｔはＶH ／Ｌになり、主回路部の電流変化率は
（ＶH ／Ｌ）／（ＶL ／Ｌ）＝ＶH ／ＶL 倍大きくな
る。ＶH を検出した電圧検出器１０は対応する信号ｖH
を可変フィルタ９に与えるのでフィルタの伝達特性は１
／（１＋ＴH Ｓ）になり、高周波域ではおよそ１／ＴH
Ｓの特性となる。フィルタの高周波域特性は（１／ＴH
Ｓ）／（１／ＴL Ｓ）＝ＴL ／ＴH ＝ｖL ／ｖH ＝ＶL
／ＶH倍となるので、全体としては（ＶH ／ＶL ）×
（ＶL ／ＶH ）＝１となり、一定となる。すなわち主回
路電源電圧が変わっても可変フィルタが補償するので高
周波域の特性を一定に保つ働きがある。FIG. 1 is a diagram showing a specific embodiment of the present invention. Reference numerals 1 to 8 are the same as those in FIG. 2; 9 is a variable filter, and 10 is a voltage detector. Voltage detector 10 detects a main circuit power supply voltage of switching main circuit 7 and outputs a corresponding voltage signal. The variable filter 9 is a low-pass filter that receives the output signal of the deviation calculator 2 and supplies the output signal to the phase controller 3. The time constant of the variable filter 9 is controlled by the signal of the voltage detector 10. Has the effect of increasing the time constant and decreasing the time constant for small inputs. The magnitude of the time constant is proportional to the input signal. In such a system, the case where the main circuit power supply voltage can be the lowest and the highest can be described. First, when the lowest voltage V L is considered, dI / dt is equal to V L / L. At this time, assuming that the pulse train of the pulse width modulator 4 is in a state immediately before being turned on 100%, the signal of the voltage detector 10 is the smallest, v L , the time constant of the variable filter is also the smallest, T L, and the filter is has the transfer characteristic of 1 / (1 + T L S ),
In the high frequency range, the characteristic is approximately equal to 1 / T L S. Next, when the highest voltage V H is considered, d
I / dt becomes VH / L, and the current change rate of the main circuit portion is ( VH / L) / ( VL / L) = VH / VL times larger. The voltage detector 10 that has detected V H outputs a corresponding signal v H
Is given to the variable filter 9, so that the transfer characteristic of the filter is 1
/ Becomes (1 + T H S), in the high frequency range of approximately 1 / T H
It becomes the characteristic of S. The high-frequency characteristics of the filter are (1 / TH
S) / (1 / T L S) = T L / T H = v L / v H = V L
/ V H times, so (V H / V L ) ×
(V L / V H ) = 1, which is constant. That is, even if the main circuit power supply voltage changes, the variable filter compensates, and thus has the function of keeping the characteristics in the high frequency range constant.
【０００７】[0007]
【発明の効果】以上のように、スイッチング素子を用い
てパルス幅変調し、電流制御をする系において、主回路
電源変動が生じても可変フィルタの働きで高周波域の動
特性が変化することなく一定に保たれるので、上位の制
御ループに影響を与えることなく安定した系を保持する
ことができる。従ってスイッチング形の安定化電源を用
いることなく整流形のシンプルで安価な、故障の少ない
電源を用いることができ、系全体の信頼性も向上する効
果がある。As described above, in a system in which pulse width modulation is performed by using a switching element and current is controlled, even if a main circuit power supply fluctuates, the dynamic characteristics of a high frequency region do not change due to the function of a variable filter. Since it is kept constant, a stable system can be maintained without affecting the upper control loop. Therefore, it is possible to use a simple, inexpensive, and inexpensive power supply of a rectifying type without using a switching-type stabilized power supply, which has the effect of improving the reliability of the entire system.
【図面の簡単な説明】[Brief description of the drawings]
【図１】本発明の一実施例を示す図である。FIG. 1 is a diagram showing one embodiment of the present invention.
【図２】従来例を示す図である。FIG. 2 is a diagram showing a conventional example.
１ 電磁石 ２ 偏差演算器 ３ 位相補償器 ４ パルス幅変調器 ５ 比較器 ６ 発振器 ７ スイッチング主回路 ８ 電流検出器 ９ 可変フィルタ 10 電圧検出器 DESCRIPTION OF SYMBOLS 1 Electromagnet 2 Deviation calculator 3 Phase compensator 4 Pulse width modulator 5 Comparator 6 Oscillator 7 Switching main circuit 8 Current detector 9 Variable filter 10 Voltage detector
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭48−12443（ＪＰ，Ａ) 特開 昭63−199506（ＪＰ，Ａ) 特開 昭55−146505（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) F16C 32/04 G05F 1/10 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-48-12443 (JP, A) JP-A-63-199506 (JP, A) JP-A-55-146505 (JP, A) (58) Field (Int.Cl. 7 , DB name) F16C 32/04 G05F 1/10
Claims (1)
装置において、前記電磁石に電流を供給するスイッチン
グ主回路と、電流指令値と前記電磁石電流検出値とを比
較してその偏差を出力する偏差演算器と、前記偏差を入
力し、前記スイッチング主回路のパワー電源電圧に応じ
て時定数の変化する可変フィルタと、この可変フィルタ
の出力を入力する位相制御器と、この位相制御器の出力
を入力するパルス幅変調器と、このパルス幅変調器の出
力に応じて前記スイッチング主回路から電磁石に与える
印加電圧を切り換えるようにしたことを特徴とする電流
制御装置。1. A current control device for controlling a current supplied to an electromagnet, comprising: a switching main circuit for supplying a current to the electromagnet; and a deviation for comparing a current command value with the detected electromagnet current and outputting a deviation thereof. An arithmetic unit, a variable filter that receives the deviation, and changes a time constant according to the power supply voltage of the switching main circuit, a phase controller that receives an output of the variable filter, and an output of the phase controller. A current control device wherein a pulse width modulator to be inputted and a voltage applied from the switching main circuit to an electromagnet are switched according to an output of the pulse width modulator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03116711A JP3087771B2 (en) | 1991-04-19 | 1991-04-19 | Current control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03116711A JP3087771B2 (en) | 1991-04-19 | 1991-04-19 | Current control device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04321812A JPH04321812A (en) | 1992-11-11 |
| JP3087771B2 true JP3087771B2 (en) | 2000-09-11 |
Family
ID=14693925
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03116711A Expired - Fee Related JP3087771B2 (en) | 1991-04-19 | 1991-04-19 | Current control device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3087771B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104516379A (en) * | 2013-09-30 | 2015-04-15 | 珠海格力节能环保制冷技术研究中心有限公司 | Bias voltage adjustment method and device of magnetic levitation system |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4036567B2 (en) * | 1999-01-27 | 2008-01-23 | 株式会社荏原製作所 | Control type magnetic bearing device |
-
1991
- 1991-04-19 JP JP03116711A patent/JP3087771B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104516379A (en) * | 2013-09-30 | 2015-04-15 | 珠海格力节能环保制冷技术研究中心有限公司 | Bias voltage adjustment method and device of magnetic levitation system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04321812A (en) | 1992-11-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2596314B2 (en) | Switching power supply circuit | |
| JP3574394B2 (en) | Switching power supply | |
| EP2299575B1 (en) | Improved feedback control of a dc/dc power converter | |
| US5959443A (en) | Controller circuit for controlling a step down switching regulator operating in discontinuous conduction mode | |
| US6828766B2 (en) | Voltage regulator | |
| US6518738B1 (en) | Switching regulator control circuit with proactive transient response | |
| EP0519471B1 (en) | Amplification circuit | |
| US4988942A (en) | Switched resistor regulator control when transfer function includes discontinuity | |
| US20040046683A1 (en) | DC stabilized power supply | |
| KR19990030033A (en) | Switching Regulator Improves Efficiency at Small Loads | |
| WO2002047244A1 (en) | Frequency limitation and overload detection in a voltage regulator | |
| EP1724908A1 (en) | Circuit and method for reducing overshoot in a switching regulator | |
| JPH11196566A (en) | Step-up dc-dc converter | |
| JP2790263B2 (en) | Current mode control converter circuit | |
| EP0608974B1 (en) | Base current-control circuit of an output transistor | |
| JP3087771B2 (en) | Current control device | |
| US5262692A (en) | Variable voltage switched current control | |
| JPH06188660A (en) | Power amplifier circuit | |
| JP2841085B2 (en) | Switching voltage regulator with stabilized loop gain | |
| JPH06335238A (en) | Power supply device | |
| JPH0783221B2 (en) | Power amplifier for generating magnetic attraction | |
| JP3065098B2 (en) | Brushless DC motor drive circuit | |
| JP7449802B2 (en) | power supply | |
| JPH04359675A (en) | Control circuit for switching power supply | |
| JP2679581B2 (en) | Switching power supply circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |