KR920002587B1 - Inverter control system - Google Patents
Inverter control system Download PDFInfo
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- KR920002587B1 KR920002587B1 KR1019890006758A KR890006758A KR920002587B1 KR 920002587 B1 KR920002587 B1 KR 920002587B1 KR 1019890006758 A KR1019890006758 A KR 1019890006758A KR 890006758 A KR890006758 A KR 890006758A KR 920002587 B1 KR920002587 B1 KR 920002587B1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/505—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
- H02M7/515—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only
- H02M7/525—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means using semiconductor devices only with automatic control of output waveform or frequency
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
- H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
- H02P27/12—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation pulsing by guiding the flux vector, current vector or voltage vector on a circle or a closed curve, e.g. for direct torque control
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
Description
제1도는 일반적 공진형 인버터를 이용한 전동기제어시스템의 개략도.1 is a schematic diagram of a motor control system using a general resonant inverter.
제2도는 종래 델타모듈레이션 방식 출력전류제어기의 구성도.2 is a block diagram of a conventional delta modulation type output current controller.
제3도는 종래 최적화방식 출력전류제어기의 구성도.3 is a block diagram of a conventional optimization type output current controller.
제4도는 일반적 인버터 전동기의 등가회로도.4 is an equivalent circuit diagram of a general inverter motor.
제5도는 본 발명 출력전류제어시스템의 구성도.5 is a configuration diagram of the output current control system of the present invention.
제6도는 본 발명 전압벡터선정기의 출력전압벡터 선정에 대한 신호흐름도.6 is a signal flow diagram for selecting an output voltage vector of the voltage vector selector of the present invention.
제7도는 본 발명 전압벡터선정기의 출력전압벡터 설정에 대한 원리도.7 is a principle diagram for setting an output voltage vector of the voltage vector selector of the present invention.
제8도는 본 발명 전압벡터선정기의 출력전압벡터에 대한 게이팅신호의 표.8 is a table of gating signals for output voltage vectors of the voltage vector selector of the present invention.
* 도면의 주요부분에 대한 부호의 설명* Explanation of symbols for main parts of the drawings
1 : 시스템제어기 2 : 출력전류제어기1: System Controller 2: Output Current Controller
3 : 디코더 4-6 : 감산기3: decoder 4-6: subtractor
7-9 : 비교기 10 : 출력전류계산기7-9: Comparator 10: Output Current Calculator
11 : 오차전류계산기 12 : 최소오차선택기11: error current calculator 12: minimum error selector
13 : 지령전압계산기 14 : 전압벡터선정기13: Command voltage calculator 14: Voltage vector selector
15 : 게이팅신호기15: gating signal
본 발명은 3상유도전동기의 제어시스템에 관한 것으로, 특히 공진형 인버터의 출력전류를 제어하여 오차없이 목표로 하는 지령전류로 제어하기에 적당하도록 한 공진형 인버터의 최적출력 전류제어시스템에 관한 것이다.The present invention relates to a control system of a three-phase induction motor, and more particularly, to an optimum output current control system of a resonant inverter that is suitable for controlling the output current of the resonant inverter to control the target command current without error. .
일반적으로 공진형 인버터는 전동기제어나 교류부하의 제어에 광범위하게 이용되는 산업전자기기인 것으로, 제1도에 도시한 바와같이, 공진된 높은 주파수의 교류전압이 인버터(21)의 파워스위치(SW1-SW6)를 통해 유도전동기(22)를 제어하여 시스템제어기(1)를 구동하며, 이의 출력이 출력전류제어기(2)를 통해 상기 인버터(21)의 파워스위치(SW1-SW6)를 제어하여 정현파출력으로 전동기의 속도 및 토오크를 제어하는 것이다.In general, a resonant inverter is an industrial electronic device widely used for controlling a motor or controlling an AC load. As shown in FIG. 1, an AC voltage of a resonant high frequency is applied to a power switch SW1 of the
제2도는 종래 델타모듈레이션방식 출력전류제어기의 구성도로서 이에 도시한 바와같이, 출력지령전류(ia *,ib *,ic *)와 실제출력전류(ia,ib,ic)가 감산기(4,5,6)를 통해 감산연산되어 오차전류(ea,eb,ec)를 발생한 후 비교기(7-9)를 통해 부호를 판단하며, 이의 값이 디코더(3)를 통해 게이팅신호(g1-g6)를 출력하여 인버터(21)의 파워스위치(SW1-SW6)를 온, 오프시킴에 따라 출력전류가 원하는 지령치에 도달하게 된다. 즉 일예로 A상의 오차전류(ea)가 양(+)의 값을 갖게 되면 실제전류(ia)가 지령전류(ia *)보다 작은 경우이므로 파워스위치(SW1)(SW4)를 온, 오프하여 실제전류(ia)를 감소시키며, 반대로 오차전류(ea)가 음(-)의 값을 갖게 되면 스위치(SW1)(SW4)를 오프, 온하여 실제전류(ia)를 증가시킨다.A second turn and also a structure of a conventional delta-modulation scheme output current controller as illustrated to this, the output instruction current (i a *, i b * , i c *) and the actual output current (i a, i b, i c) Is subtracted through the subtractor (4, 5, 6) to generate error currents (e a , e b , e c ), and then the sign is determined by the comparator (7-9). By outputting the gating signals g1-g6 through the power switches SW1-SW6 of the
여기서 실제전류(ic)의 발생은 가산기(23)를 통해 실제전류(ia,ib)를 ic=-(ia+ib)로 연산하여 출력하는 옵티멀(optimal)전류이다.Optimal the (optimal) for calculating and outputting a current to the (i + a i b), - wherein the generation of the actual current (i c) is the actual current (i a, i b) = a i c through the
제3도는 종래 최적화방식 출력전류제어기의 구성도로서 이에 도시한 바와같이, 실제전류 ia(t), ib(t), ic(t)와 역기전력 Ea(t), Eb(t), Ec(t)를 이용하여 전압벡터 Vk(t+T)를 통해 다음시간(t+T)에 출력가능한 전류 iak(t+T), ibk(t+T), ick(t+T), (단 K=0, 1…7)를 계산하는 출력전류계산기(10)와, 상기 출력전류계산기(10)의 출력과 지령전류발생부(24)의 지령전류 ia *(t+T), ib *(t+T), ic *(t+T)사이의 오차전류를 계산하여 전압벡터(J0-J7)를 출력하는 오차전류계산기(11)와, 상기 전압벡터(J0-J7)를 판단하여 게이팅신호(g1-g6)를 출력하는 최소오차선택기(12)로 구성된다.3 is a block diagram of a conventional optimized output current controller. As shown in FIG. 3, the actual currents i a (t), i b (t), i c (t) and counter electromotive force E a (t), E b (t ), The current i ak (t + T), i bk (t + T), i ck that can be output at the next time (t + T) through the voltage vector V k (t + T) using E c (t) output current calculator 10 for calculating (t + T), (where K = 0, 1 ... 7), the output of said output current calculator 10, and the command current i a * of the
이와같이 구성된 출력전류제어기의 기술을 설명하면 파워스위치의 온, 오프하여 조합하는 전압벡터는 V0(0,0,0)…V7(1,1,1)의 8가지이며, 이중 한전압벡터 Vk(t+T), (K=0, …7)가 출력전압으로 선택되는 것으로, 전압벡터 Vk(t+T)가 출력될 때 전압, 전류관계는 제4도에 도시한 바와같은 등가회로로 표현된다.When describing the technology of the output current controller configured as described above, the voltage vector to combine the power switch on and off is V 0 (0,0,0). Eight kinds of V 7 (1,1,1), of which one voltage vector V k (t + T), (K = 0,… 7) is selected as an output voltage, and the voltage vector V k (t + T Is outputted, the voltage and current relationship is represented by an equivalent circuit as shown in FIG.
이때 전압벡터 Vk(t+T)는The voltage vector V k (t + T) is
단, Rs : 전동기의 저항, L : 인덕턴스, Ek(t+T) : 역기전력로 되는 식(1)에 의해 출력되는 ik(t+T)가 출력전류계산기(10)를 통해 계산되고, 오차전류계산기(11)에서는However, Rs: resistance of the motor, L: inductance, E k (t + T): i k (t + T) output by Eq. (1), which becomes a counter electromotive force, is calculated by the output current calculator 10. In the error current calculator 11
로 되는 식(2)에 의해 전압벡터 Jk(t+T)를 산출한다.The voltage vector J k (t + T) is calculated by the following equation (2).
이와같이 하여 상기 식(2)에 K=0…7를 대입한 후 J(t+T)가 가장작게 되는 K값을 선택하여 해당하는 전압벡터 Vk(t+T)를 선정함에 따라 가장작은 출력전류오차를 갖는 전압벡터 Vk(t+T)가 선택되며, 이의 벡터에 해당하는 게이팅신호(g1-g6)를 출력하여 최적화전류제어를 한다.In this manner, K = 0. After substituting the 7 J (t + T) has the smallest select the K value by having the smallest output current error as the selection of the voltage vector V k (t + T) in which the voltage vector V k (t + T ) Is selected, and outputs the gating signals g1-g6 corresponding to the vector to perform optimization current control.
그런데 상기와 같은 종래 델타모듈레이션방식 전류제어기에 있어서는 구성이 매우 단순하여 설계가 용이하게 되지만 오차의 크기를 고려하지 못한 상태에서 부호만을 판단하므로 출력전류제어에 정밀도가 떨어지게 되는 문제점이 있었다.By the way, in the conventional delta modulation current controller as described above, the design is very simple and easy to design, but there is a problem in that the accuracy of output current control is lowered because only the sign is judged in the state of not considering the magnitude of the error.
또한 종래 최적화방식 출력전류제어기에 있어서는 정밀한 출력전류제어를 수행할 수는 있으나, 마이크로프로세서를 이용하여 설계할 경우 계산량이 방대하고, 복잡하게 되므로 실제로 출력전류제어기로 사용되지 못하게 되는 문제점이 있었다.In addition, in the conventional optimized output current controller, precise output current control can be performed. However, when designing using a microprocessor, the calculation amount is enormous and complicated, so there is a problem in that it cannot be actually used as an output current controller.
본 발명의 목적은 이와같은 종래의 문제점을 개선하기 위해 창안한 것으로 설계를 단순화하면서 최적화전류제어방식을 통해 정밀한 출력제어를 가능하게 한 공진형 인버터의 최적출력제어시스템을 제공하고자 한다.An object of the present invention is to provide an optimum output control system for a resonant inverter which enables precise output control through an optimized current control method while simplifying the design.
이와같은 목적을 달성하기 위해 본 발명은 인버터의 3상출력을 2상으로 변화하여 현재전류치를 출력한 후 출력전류지령치를 받아 출력지령전압을 산출하고, 지령전압에 가장 오차가 적게 접근하는 전압벡터를 선정한 후 게이팅신호를 출력하여 출력전류를 최적화제어하게 구성함을 특징으로 하는 것으로, 이하 첨부한 도면에 의해 상세히 설명한다.In order to achieve the above object, the present invention changes the three-phase output of the inverter into two phases, outputs a current current value, receives an output current command value, calculates an output command voltage, and has a voltage vector approaching the command voltage with the least error. It is characterized in that the configuration to configure the output current by controlling the output current by outputting the gating signal, it will be described in detail by the accompanying drawings.
제5도는 본 발명 출력전류제어시스템의 구성도로서 이에 도시한 바와같이, 실제전류 ia(t), ib(t), 가산기(23)를 통해 -(ia(t)+ib(t)로 얻어지는 실제전류 ic(t)를 2상출력전류 iq(t), id(t)로 변환하는 3상/2상변환기(25)와, 상기 2상출력전류 iq(t), id(t)를 수용하고, 역기전력 E(t)과 함께 지령전류발생부(24)의 지령전류 iq *(t+T), id *(t+T)를 수용하여 지령전압 Vq *(t+T), Vd *(t+T)을 계산하는 지령전압계산기(13)와, 상기 지령전압 Vq *(t+T), Vd *(t+T)을 수용하여 오차가 적게 하는 전압벡터 Vk(t+T)를 선정하는 전압벡터선정기(14)와, 상기 전압벡터 Vk(t+T)에 의해 게이팅신호(g1~g6)를 발생하여 인버터를 제어하는 게이팅신호기(15)로 구성한다.5 is a configuration diagram of the output current control system of the present invention, as shown therein, through the actual current i a (t), i b (t) and the adder 23-(i a (t) + i b ( a three-phase / two-phase converter 25 for converting the actual current i c (t) obtained by t) into a two-phase output current i q (t) and i d (t), and the two-phase output current i q (t ), i d (t) and the command voltage i q * (t + T), i d * (t + T) of the
이와같이 구성된 본 발명은 3상교류전류 ia(t), ib(t), ic(t)가 ia(t)+ib(t)+ic(t)=0와 같이 평행을 이루게 되어 3상/2상변환기(25)에 인가되므로 3상/2상변환기(25)에서는 2상출력전류 iq(t), id(t)는 출력되어 지령전압계산기(13)에 인가된다. 이와같이 하여 지령전압계산기(13)에서는 지령전류발생부(24)로부터의 지령전류 iq *(t+T), id *(t+T)가 있을때 제4도에 도시한 등가회로에 의해The present invention constructed in this way are in line, such as three-phase alternating currents i a (t), i b (t), a i c (t) i a ( t) + i b (t) + i c (t) = 0 Since the two-phase output current i q (t), i d (t) is output from the three-phase / two-phase converter 25 is applied to the command voltage calculator 13 do. In this way, the command voltage calculator 13 uses the equivalent circuit shown in FIG. 4 when the command currents i q * (t + T) and i d * (t + T) from the command
단, T : 지령치의 출력시간간격, Rs : 전동기의 고정자저항T: Output time interval of command value, Rs: Stator resistance of motor
L : 전동기의 고정자인덕턴스, Eq(t+T), Ed(t+T) : 역기전력L: Stator inductance of the motor, E q (t + T), E d (t + T): Back EMF
와같이 연산되어 출력지령전압 Vq *(t+T), Vd *(t+T)을 계산한 후 전압벡터선정기(14)에 인가되며, 이때 역기전력 Eq(t+T), Ed(t+T)은 Eq(t), Ed(t)으로 가정한다.After calculating the output command voltage V q * (t + T), V d * (t + T), it is applied to the voltage vector selector 14, where the counter electromotive force E q (t + T), E Assume that d (t + T) is E q (t), E d (t).
여기서 제7도는 본 발명 전압벡터선정기(14)의 출력전압벡터 설정에 대한 원리도로서 이에 도시한 바와같이, 전압벡터선정지령치 Vq *, Vd *의 위치를 q-d의 좌표축에 표시하여 Vd *2+Vq *2=으로 되는 일정영역을 벡터(VO)로 설정하고, 벡터(V1-V6)로 설정한 상태에서 상기 벡터(V1-V6)를 Vd *=, Vd *=-로 되는 직선에 의해 등간격으로 분할하여 벡터선정영역을 설정한 것을 나타낸 것으로, 일예로 벡터 1선정영역에 의해 벡터(V6)을 표시함을 나타낸 것이다.7 is a principle diagram for setting an output voltage vector of the voltage vector selector 14 according to the present invention. As shown therein, the positions of the voltage vector selection command values V q * and V d * are displayed on the coordinate axis of qd, and V is shown. d * 2 + V q * 2 = Set the constant area to be the vector (VO) and set the vector (V1-V6) to V d * = , V d * =- This shows that the vector selection region is set by dividing the data at equal intervals by a straight line. For example, the vector V6 is displayed by the vector selection region.
이와같이 하여 제6도의 신호흐름도에 의해 전압벡터선정기(14)의 출력전압벡터선정기능을 설명하면 다음과 같다.In this way, the output voltage vector selection function of the voltage vector selector 14 is described with reference to the signal flow diagram in FIG.
우선 전압벡터선정지령치 (Vd *+Vq *)가보다 적게 되면 벡터 0선정영역을 통해 벡터(VO)를 설정하며,보다 크게 되면 Vq *>0, Vd *>로 되는 상태에서 벡터 6선정영역을 통해 벡터(V5)를 설정하고, Vq *<0, Vd *>-로 되는 상태에서 벡터 5선정영역을 통해 벡터(V5)를 설정한다.First, the voltage vector line setpoint (V d * + V q * ) If less, the vector (VO) is set through the
이후 Vd *<로되면 -Vd *>인 상태에서 벡터 2선정영역을 통해 벡터(V2)를 설정하고, -Vd *<인 상태에서 벡터 1선정영역을 통해 벡터(V6)를 설정한다. 또한 Vd *<-로 되면 -Vd *>-인 상태에서 벡터 3영역을 통해 벡터(V3)를 설정하고 -Vd *<-인 상태에서 벡터 4영역을 통해 벡터(V4)를 설정한다.V d * < -V d * > Set the vector (V2) through the vector 2-selection area and set -V d * < In the state of V, vector V6 is set through the
이와같이하여 발생된 전압벡터선정기(14)의 출력(V1-V6)은 게이팅신호기(15)를 통해 제8도에 도시한 표와같이, 게이팅신호(g1-g6)를 발생하여 인버터의 파워스위치(SW1-SW6)의 온, 오프를 결정함에 따라 새로운 출력전류가 발생된다.The output V1-V6 of the voltage vector selector 14 generated in this way generates the gating signals g1-g6 through the
이상에서 상세히 설명한 바와같이 본 발명은 공진형 인버터의 출력제어기를 전압벡터선정방식으로 간단하게 설계하여 최적의 출력전류제어를 가능하게 하므로 인버터의 정밀도향상 및 인버터를 사용하는 시스템의 고정밀도 제어를 가능하게 할 수 있는 효과가 있다.As described in detail above, the present invention enables the optimum output current control by simply designing the output controller of the resonant inverter using the voltage vector selection method, thereby improving the precision of the inverter and controlling the high precision of the system using the inverter. It can be effective.
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