JPS5826569A - Method and device for controlling output current of frequency converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of an R converter, a direct current intermediate circuit, and an inverter, and the inverter is provided with six electronic switches connected as a three-phase bridge circuit. 6 types of 11 with two electronic switches closed and the other four electronic switches open! 60 of closed state combination and output current
A frequency conversion device that is associated with six phase angles at Jffia intervals, and inversely converts the target value of the phase angle of the output current in order to match the phase angle and magnitude of the output current to each target value. A control circuit for the device is provided, and its output signal selects two types of open/close state combinations corresponding to the 2 allil phase angles that sandwich the target phase angle, and these are used to match the actual phase angle with the target phase angle. The inverter is controlled so as to periodically reciprocate between the two combinations of open and closed states, and a target value for the magnitude of the output current is given to the current regulator for the intermediate circuit electrolyte, The output signal is used to control the frequency converter output current controller and the control device for carrying out this method, which controls the II converter. It is omniscient from Publication No. 112236763.

In that case, the intermediate current is controlled by a moderator that controls the frequency converter of the frequency converter, and the phase angle or frequency of the output current is controlled by a control circuit for the inverse converter. In a three-phase inverter that is equipped with six electronic switches connected as a three-phase bridge circuit, the six-phase inverter corresponds to six phase angles separated by 60 degrees of the output current.
Various open/close state combinations are obtained. Therefore, unless additional measures are taken, the output current vector will be
It will jump between different phase angles. Thereby,
At low frequencies, corresponding to motor operation at relatively low wA speeds, harmful harmonics occur, causing the motor's power dissipation to be severe and its rotation to be unsmooth. In order to avoid these drawbacks, the method according to the Federal Republic of Germany Patent Application Publication No. 228FJ76B selects two types of opening/closing state combinations corresponding to two phase angles that sandwich the target phase angle. The inverse converter is controlled to periodically reciprocate between these two combinations of open and closed states in order to match the angle and the collar phase angle.

A rotating control vector is used to effectively create the desired phase angle between two 60 degree spaced phase angles by this periodic switching. Although it is certainly possible to significantly reduce the harmonic content at low rotational speeds with this method, the circuitry for generating the control vectors is expensive.

The object of the invention is a method of the type mentioned at the outset, comprising:
It is an object of the present invention to provide a method that allows the phase angle and magnitude of an output current to match their respective target values without requiring the formation of a control vector. Among the period T of reciprocating between the two selected open/close state combinations, the open/close state combination corresponding to the phase angle smaller than the ga phase angle is tl-T(0,5+α5iitmaroncs 0O-p).
) Here, ψ is the time of the phase difference between the Shima Mukuro phase angle and the target phase angle, while the open/closed state combination corresponding to the phase angle larger than the target phase angle is 110- This is achieved by assigning the remaining time (T-tt) to the target value of the output current, which is multiplied by a correction coefficient by the correction circuit and then given to the current regulator for intermediate circuit current adjustment. be done.

According to this method, the phase angle of the output current is controlled quasi-continuously as in the omniscient method, and there is no need to form a control vector. By multiplying the target value of output current loudness by a factor k, the magnitude of the output current becomes independent of the switching time ratio between the two open/closed state combinations.

The target value of the phase angle is given as a digital signal, and the open/close state combination to be selected is indicated corresponding to the phase angle smaller than the top three positions lζ, and this open/close state combination is determined by the remaining positions. Advantageously, the difference between the phase angle corresponding to the alignment and the target phase angle is indicated. Thereby, the selection of the opening/closing state combination and the designation of the switching time ratio can be easily performed.

The target value of the phase angle can be increased linearly. in this case,
If the target value of magnitude is kept constant, the output current will have a positive arc waveform on average.

In an apparatus for carrying out the method of the present invention, the target value of the phase angle of the output current includes a selection circuit for selecting a combination of open and closed states, and an arithmetic circuit for Ml that forms the value tl/T;
and a second arithmetic circuit that forms the value k, #
The output signal of the arithmetic circuit g2 is given to the first input terminal of the multiplication circuit, the target value of the magnitude of the output current is given to the second input terminal, and the output signal of this multiplication circuit It is advantageous that the end is connected to the desired value input end of the current regulator for the intermediate circuit voltage fIt11 node. In that case, III and the second arithmetic circuit are realized by FROM, an address signal indicating a target value of the phase angle is given to the address input terminal thereof, and a memory location connected to the output terminal in relation to the address signal is Advantageously, the value of V or k that corresponds to the desired value of the phase angle is stored.

The upper S position of the digital signal indicating the target value of the phase angle is applied to the first summing input of the Modls 6' adder, and the signal indicating the value ν is applied to the first input and Output No. 1 of the comparison circuit, in which output No. 1 of the sawtooth wave oscillator is applied to a second input terminal, is applied to a second addition input terminal of the adder, and the output signal of the adder is an open/close state combination. It is advantageous to provide a decoder circuit for the selection of . In ζζ, “Module
6. An adder is an adder that adds values from 0 to 5, and when it exceeds that value, it adds values starting from square 0.

This adder selects two types of open/closed state combinations in the correct time ratio. The decoder circuit is realized by a FROM, the output signal of the adder is given to the address input terminal as an address signal, and the memory location connected to the output terminal in relation to the address signal is selected. are stored and the outputs of these decoder circuits are advantageously connected to the switching control circuit for the electronic switches in the inversion station. If a voltage indicating the target value of t~m& is given, then this voltage is on the one hand the voltage −
The frequency converter converts the pulses into pulses of a corresponding frequency and applies the pulses to the up/down counter's input terminal, and on the other hand, the pulses are supplied via the polarity detection circuit 5 to the count direction control input terminal of this counter. It is advantageous if the output state is used as a target value for the phase angle of the output current. Thereby, the control device of the present invention can be applied even when target values of the same wave number are given.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Figure jI11 shows the origin of an omniscient frequency fine conversion device with a direct current intermediate circuit! 1 circuit diagram is shown. The input AC voltage Ue is subjected to IIR by a controllable forward converter GR. The output current of the layer conversion device GR, that is, the intermediate circuit current Iz of the frequency fine conversion device, is compared with a target value of 1 mouth oil, and a control deviation is given to a current regulator 8R that controls the layer conversion device GR. Intermediate circuit current! 2 is applied as a current source through a reactor Dr connected in series to the path 14-middle rRa to an inverter WR whose output end is connected to, for example, a motor M.

The frequency at or phase angle of the output current of the inverter WR is controlled by a control circuit 8. For this purpose, the rotor of the electric motor M is connected to a rotational speed detector such as a TAS DYNAMO TD.The actual discount 11 detected by the rotational speed detector TD/ζ is set to a target value n. 11 and the control deviation is provided to the regulator R. Mis device R according to control deviation
The target value of the phase angle of the output current vector is formed by
This phase angle target value is given to the control circuit 8 that controls the inverter WR.The inverter WR includes six electronics connected to the three-phase bridge a21m as shown in Figure 2. Switches 6 to 6 are provided. The switches 6 to 6 can be, for example, transistors, switchable thyristors or forced thyristors. As for the commutation method,
Book 1 Nyrista (Thyrlstoren) @,
Heumann/8tumpe IF% 83rd edition, 1
Possible methods include a phased arc-extinguishing method, a collective arc-extinguishing method, a phased arc-extinguishing method, and a single arc-extinguishing method, which are described in No. 184-188, published in 1974. However, the phase*a arc-extinguishing scheme still faces the constraint that the commutation circuit must be able to switch between two adjacent vectors.

In the inverter WR, one of the switches l to 6 is always lζ.
Both are closed at the same time. The combination of closed switches is 1.2: 2,3; 3,4 $4,5
;5.6;6 types of x are possible. In the example shown in FIG. 2, switches 1 and 6 are closed, so the current flows along the path shown in bold.

6 types of opening/closing state combinations, 6s* phase angle of output current, and 6 types of output current vector b if considered as a vector
to n correspond. As shown in No. 31II, the six types of phase angles are evenly distributed over 36 times, so the interval is 600. The length of vector 1 is determined by intermediate circuit current Iz.

The output current vector I of the inverter is )! 111! Rather than making a complete turn, the dancer jumps from one discrete position to the dance position, for example from n to 5. Therefore, harmonics occur in the output current, which greatly increases the power loss of the connected motor! At low wA speeds, the rotation of the motor is not smooth; at high rotational speeds, this harmful phenomenon hardly appears. This is because the effects of very fast jumps are suppressed by the mechanical smoothing effect of the motor y.

In order to direct the output current vector of the inverter WR in any direction between the two discrete vectors, the two discrete vectors, e.g. The switching is carried out in a reciprocating manner.@The direction of the output current vector Ir thereby effectively formed between the two discrete vectors is related to the time ratio of the switching.The shorter the switching period T, The approximation to the desired vector is rapidly performed. During time t1, for example, discrete vector 11 is selected, while at time t! mT-t
A discrete vector mouth is selected between 17- and 6° of C.
By changing l, the effectively formed output current vector rr moves between the discrete vectors r17f''i.

According to the method lζ explained below, the effective current vector r
The magnitude and phase angle of r can be arbitrarily determined, or it can be rotated with a constant angular velocity and constant magnitude. Thereby, the current applied to the electric motor M can be averaged into a positive arc waveform, that is, a waveform with a small harmonic content, which allows the electric motor to rotate smoothly.

Below we will discuss how to choose the switching time ratio between two adjacent discrete vectors to form an effective current vector hill of arbitrary phase angle and magnitude! We will discuss how to select the intermediate circuit current.

It is also possible to obtain a positive arc waveform output current by keeping the size of the effective current vector constant and changing its phase angle continuously. First, find the dissociation between an arbitrary switching time ratio H/T between 1 and 0 and the effective current vector n.
- Melt. The average value of the effective current vector Ir is expressed by . If the period T is relatively short, the vector ! ! Since the
(It is expressed as Rite.(Rite is expressed as Cartesian coordinate components Irx, Ir
If it is decomposed into y, it becomes. Also, if we take the 1.7 axis as shown in Figure 3, Itxw
I fist cos 3 0° engineering sxm engineering c
os 3 0゜11y wm -I * 5in30
' Icy W I sin 30°. By substituting these into equation (3), we get
The components are time independent, ie straight lines parallel to the y-axis.

Therefore, it moves on a straight line connecting the tips of effective current vectors Ir and n. The same holds true for other door-shaped parts created by the discrete vectors n to 5, so the tip of the effective current vector rr moves on the side of the hexagon that connects the tips of the discrete vectors 几 to n. Next, the relationship between the phase difference ψ of the effective current vector G with respect to the discrete vector It and the switching time ratio H/T is determined. From this relationship, it follows that the effective current vector Ir is, for example, the phase difference specified by the regulator! In order to have for the discrete vector r1, it can be seen how the switching time ratio H/T between the discrete vector rs and 1 should be chosen. Since the angle α between the X-axis and the effective current plot n is Irw, we substitute equation (5) into these and ψ−30
Using the relationship '-g, it becomes Isso0.5+α54tin(30°-9)(ma). Therefore, in order to reduce the phase difference of IIJ by ψ4, the switching time ratio B/T may be selected using the equation (7).

However, as mentioned above, the methods explained so far,
The tip of the effective current vector n moves on the sides of the hexagon. That is, the size of the hill changes as a function of the phase difference ψ and thus also as a function of the switching time ratio t1/T4. However, it is desirable that the tip of the effective current vector G moves on a circle, that is, the magnitude of Ir is unrelated to the phase difference. To do this, it is sufficient to multiply the magnitude of the intermediate circuit current If by a correction coefficient k related to the phase difference D of the effective current vector n. - This correction coefficient can be found as follows.

Size of effective current vector n ζ In5 = % horizontal 7? 21-, so by substituting equation (5) into this, we get. It is necessary to select the correction coefficient k so that the magnitude of the effective current vector Ir is equal to the magnitude of the discrete vectors Io to Io. A correction coefficient that satisfies this condition is. In this way, the correction coefficient k is determined as a function of the switching time ratio tl/T. By substituting equation (7) into equation (1G), the correction coefficient k as a function of the phase difference ψ of the effective current vector Ir can be obtained as: cos (ψ−30°) (1) 1.5 .

Equation (11) shows what coefficient l゛ζ should be multiplied by the magnitude of the intermediate circuit voltage @Iz in order to prevent the magnitude of the effective current vector Ir from changing with rotation. 0 22- From the above explanation, there is a method to form an effective current vector Ir of constant size that rotates quasi-continuously at an arbitrary angular velocity when six types of open/close state combinations are possible in the inverter. Shown. A circuit for implementing this method will be described below.

It is assumed that a target value ψ of the magnitude and phase angle of the output current, that is, a phase angle and a target value of the magnitude of the effective current vector It with reference to, for example, the discrete vector b, are given. These setpoint values can be provided, for example, by a higher-level regulator. The effective current vector {circumflex over (n)} is always located in a door-shaped section sandwiched by any two adjacent discrete vectors among the discrete vectors knee to zero.

Let ψ be the phase angle of the effective current vector Ir with respect to the smaller numbered discrete vector of the two discrete vectors sandwiching this door-shaped portion. The target value of the phase angle is given as a digital signal, and the top three positions indicate the open/close state combination to be selected corresponding to the smaller phase angle, and the remaining positiongons indicate the open/close state combination to be selected. The difference ψ between the phase angle corresponding to the alignment and the target phase angle and the I11 phase angle is shown. An example of the configuration of this digital signal is as follows.

9g 100xxxx ... 101xxxx ... 000xxxx ... '-,,--ノψ In other words, the top three positions add the values from 0 to 5, and beyond that, start from 0 and add again @Mo
dnlo 6” is detected in the adder.

FIG. 4 shows a control circuit with which the method according to the invention can be realized in a block circuit diagram.

Target phase angle of effective current vector n? The upper three positions of the digital signal indicating g operate as described above.
odnlo 6" is given to the all input terminal of the adder. As a result, the discrete vector (II in Fig. 3) with the smaller phase angle of the two discrete vectors sandwiching the effective current petator Ir is To enable periodic switching to the discrete vector with the larger phase angle (n in Figure 2), the summing interrogator uses the second vector as described next.
◎ Positions other than the top three positions of the digital signal indicating the target phase angle, that is, the position between the discrete vector with the smaller phase angle and the effective current vector n. The position indicating the phase difference - is given to the arithmetic circuit R1 which determines the switching time ratio tl/T according to the equation (0). It may be a FROM which stores the value of the switching time ratio tx/T as a function of the phase difference D in equation (7) in a storage location connected to the output in relation to the address signal given. The value of the switching time ratio tl/T outputted to the output terminal is applied to the input terminal 2! of III of the comparator circuit V as a corresponding voltage signal after undergoing D-person conversion. It is compared with the sawtooth wave voltage signal given from the sawtooth wave oscillation 98G25- to the second input terminal zt of the comparator circuit V. If this sawtooth wave voltage signal becomes larger than the voltage signal from the arithmetic circuit V, the output terminal of the comparator circuit V is immediately During the rest of the time, the output signal of the comparator circuit V is R01.The output signal of the 0 comparator circuit V is applied to the input terminal of adder A III2.

The frequency of the sawtooth oscillator is chosen equal to the desired switching frequency between the two open and closed state combinations, and the amplitude of the sawtooth voltage is equal to the magnitude of the voltage signal from the arithmetic circuit R1 corresponding to ti/T-1. equally selected.

Therefore, the comparison circuit V operates as shown in No. 5ai. In other words, the sawtooth waveform voltage indicated by a solid line in the upper diagram of FIG.
During the 11-hour period when the voltage between the voltages 1 and 1 is smaller than the voltage ゛ from
OI, while the former is greater than the latter ttmT-t
During the time l, the output signal of the comparator circuit V is 1 x 1.

As a result, the number of the discrete vector with the smaller phase angle among the two discrete vectors sandwiching the desired effective current vector Ir is displayed as the output signal of the adder at time t1. and the other t! During the time W T -tl, the number plus 1 is shown, that is, the number of the discrete vector with the larger phase angle. Addition good people”
Modulo @”Since it is an adder, add 1 to number 5.
O is shown as the number added. This process is continuously repeated at a period T determined by the sawtooth oscillator 8G. In this way, two discrete vectors are selected that sandwich the desired effective current vector Ir, and switching is performed periodically back and forth between them at the correct switching time ratio. The number of the discrete vector obtained by the output signal of the adder is determined by the decoder D in the open/close state of the electronic switch II! Can be associated with combinations. This correspondence can be easily realized, for example, in the decoder D as a FROM that stores such a table. The correction of the magnitude of the intermediate circuit current is performed as follows. Target value of output current magnitude 1
11sall is applied to the input terminal of multiplication circuit M's Ill. The signal point indicating the phase difference ψ of the effective current vector Ir is sent to the second input of the multiplier circuit M via an arithmetic circuit Rm which forms a correction coefficient k as a phase difference relationship according to equation (n). given at the end. The arithmetic circuit R2 can be realized, for example, by an F ROM like the arithmetic circuit Rs. From the output terminal of the multiplier circuit M, a correction coefficient a is applied to III5all as the target value Izsoll of the loudness of the intermediate circuit current.
The signal multiplied by k is Jl! Served. As a single multiplier circuit M, for example, a target value III 5oil is applied to the analog input terminal.
Also, the correction coefficient kJE is calculated from the calculation BIIiBa at the digital input terminal.
The given one-to-one converter can be used.

In many cases, a higher-order regulator provides a target value f for the frequency of the output current, rather than a target value f for the phase angle. In this case, 1, 6! I! (7) By adding a circuit, it is possible to convert the frequency standard f into the target value ψ of the phase angle. In Figure 6, when the voltage indicating the target value of frequency is 1 ★, the voltage is -
It is converted into a pulse of a corresponding frequency by the frequency conversion @SU and is applied to the count input terminal of the upda kunka kunta 2, and on the other hand, the pulse of this kakunta 2 is passed through the polarity detection circuit P.
The output state of this counter 2 is used as the target value f of the phase angle of the output current. Up ~ Top 3 of Dakunkakunta 2
It is advantageous to perform the counting operation so that the voltage returns to 0 after counting F at 5t in the same way as the adder.If the voltage indicating the target value of the frequency is positive, the polarity The positive output signal of the detection circuit P is applied to the count direction control input terminal V to perform up-counting, and on the other hand, if the above-mentioned 29- voltage is negative, the negative output signal of the polarity detection circuit P is inverted by the inverter INV. A positive signal is applied to the count direction control input terminal R to perform down counting.

According to the control method and control device of the present invention described above, in a frequency converter having a DC intermediate circuit, the vector of the output current can be arbitrarily adjusted, and the vector can be adjusted at a constant angular velocity and a constant magnitude. , it can also be rotated. As a result, the output current has a positive arc waveform in an ideal case. The degree of approximation to the positive arc waveform is better as the frequency of switching back and forth between two types of open/close state combinations is higher (in other words, the shorter the switching period T is). In order to perform at least one round trip during each period of the output current, the switching period T must be within 1/6 of the period of the output current. The shortest permissible switching period is determined primarily by the permissible switching frequency of the commutator-equipped cyrisk. This frequency is at least equal to the highest output frequency of the inverter arrangement, so that multiple switchings can be carried out without reduction in commutation time when operating the inverter device 30- at least in the frequency range below. However, in a high frequency range, the harmonic content of the output current is of such a degree that it hardly poses a problem, as described above. Therefore, in many cases, it is sufficient to carry out the method of the invention only in the m range where the frequency of the inverse converter is low, and to control in the usual manner in the normal crawling range where the frequency is high.

[Brief explanation of drawings]

Fig. 1 is a principle circuit diagram of an omniscient frequency converter having a direct current intermediate circuit, and Fig. 2 is an inverse converter Wl' in Fig. 1.
FIG. 3 is a diagram showing the output current vector of the frequency converter, and FIG. 4 is the principle of the inverse converter control circuit 5 in FIG. 1. Circuit diagram, Figure 5 is an explanatory diagram of the function of the comparison circuit V in Figure 4,
#I6 is a principle circuit diagram of a circuit added when a target frequency value is given. M: Adder, D: Decoder, Dr: Reactor, GR:
Layer conversion device, M: Multiplier circuit, M: Motor 1P polarity detection circuit, R: Articulator %R, t・R2: Arithmetic circuit, S: Control circuit, SG: Voltage-frequency converter, SR: Current articulator ,
TD: rotation speed detector, WR: inverse conversion device, 1 to 6: electronic switch.

Claims (1)

[Claims] 1) There are 611 electronic switches consisting of a forward converter, a direct current intermediate circuit and an inverter, connected to the inverter as a three-phase bridge circuit, of which two This is a frequency conversion device in which six types of open/close state combinations, in which an electronic switch is closed and four other electronic switches are opened, are associated with six types of phase angles of the output current at 60 degree intervals. In order to match the angle and magnitude to their respective target values, the target value of the phase angle of the output current is given to the control circuit for the inverter, and the output signal corresponds to two types of phase angles that sandwich the target phase angle. Two types of open/close state combinations are selected, and the inverter is controlled to periodically reciprocate between these two open/close state combinations in order to match the actual phase angle with the target phase angle. The target value of the output current is given to the current regulator for the intermediate circuit type FI adjustment, and the Yamariki Detective 8 is turned on.
9. In a method for controlling the output current of a frequency converter that performs a synchronization, among the period T of reciprocating between the selected open/close state combinations of 28 tA, the open/close state combination corresponding to the phase angle smaller than the target phase angle is selected. is t1=T (0,5+〇,5p tan (30'-ψ)] where ψ is assigned the time of the phase difference between the phase angle in question and the 0 definite phase angle, and from the other eye 111 phase The remaining time (T-tl) is assigned to the opening/closing state combination corresponding to a phase angle larger than 30°) and then the intermediate circuit voltage fit (r z )'
Frequency converter output current control method in which the current regulator (SR) for ftJ4 node is given to the 4I model 0 , and the top three positions indicate the open/close state combination to be selected corresponding to the smaller phase angle,
Also, the phase angle and target value corresponding to this open/closed state combination are determined by the remaining positron. 1. A frequency-conversion device output current control method, characterized in that a leap difference (ψ) from a phase angle is indicated. 3) In accordance with the control method described in claim 1 or 2, the am value (ψg) of the phase angle is linearly large.
<What is done (i-Featured frequency converter output current control method. 4) Consists of a layer converter, a DC current intermediate circuit, and an inverter, and the inverter is used as a three-phase bridge circuit! 1! There are six electronic switches connected to each other, two of which are closed and the other four electronic switches are open, resulting in six types of open/close state combinations and six types of output current at 60 degree intervals. In a frequency conversion device in which the phase angle is associated with the phase angle, the target value of the phase angle of the output current is given to the control circuit for the inverse conversion device in order to match the phase angle and amplitude of the output current to their respective target values. , 2m1 corresponding to the phase angle of 2411g sandwiching the target phase angle by its output signal.
In order to select M opening/closing state combinations and match the actual phase angle with the target phase angle, these 24 types of opening/closing states 1lIII are selected.
The inverter is controlled so that it periodically reciprocates between the L adjustment, and the target value of the output current is given to the power ai4 node for adjusting the intermediate circuit power fIL, and the output signal is used to A frequency conversion device output current control device that controls a forward conversion IF device, and which controls the opening/closing state 1 of two selected buildings.
Of the period T of reciprocating between 11 combinations, the target phase,
For the open/closed state combination corresponding to a phase angle smaller than
-9)) Here, D is the time m of the leap phase difference between the phase angle and the target phase angle, and the remaining open/closed state combinations corresponding to phase angles larger than 0° are on the other hand. The time (T-t□) is set by 1llJi, and the target value l11soll of the magnitude of the output current is multiplied by the correction coefficient by the correction circuit, and then the intermediate gJ circuit current (I, ) and the power RI11 moderator for illπ are calculated. (8R)R: In a frequency converter output current control device characterized in that the target value (ψ) of the phase angle of the output current is given, a selection i path (A) for selecting an open/close state combination; The first forming the value tl/T
(Rt) and a second arithmetic circuit (R1) that forms the value k, and the output signal of the second arithmetic circuit (S) is fed to the multiplication circuit (first input The target value (III 5 ojj ) of the magnitude of the output current is given to the input terminals 1 and 2 of this circuit (M), and the output terminal of this calculation circuit (M) is Intermediate circuit electric fit (I
I) A frequency conversion device output current control device, characterized in that it is connected to a target value input terminal of a current regulator (SR) for regulation. The first and second arithmetic circuits (R1, R) are processed by FROM, and the target value (-) of the phase angle is given to the address input terminal of the address signal. A frequency converter output current control device, characterized in that a value of d or k corresponding to a target value (ψg) of a phase angle is stored in a storage location connected to an output terminal. 6) In the control device according to claim #I, the target value (pg) is given as a digital signal, and the top three positions correspond to the smaller phase angle. indicates the opening/closing state combination to be selected, and the difference (by the residual positilon) between the phase angle corresponding to this opening/closing state combination and the target phase angle (
ψ) is shown, the top three positions mentioned above are "Mo
It is applied to the first addition input terminal of the dulo 6'' 11alK generator (A), and a signal indicating the value of 1 is applied to the first input terminal, and a sawtooth wave oscillator (8G ) is applied to the second input terminal of the comparator circuit (V), and the output signal of the comparator circuit (V) is given to the second input terminal.
12 of the addition inputs and the addition It)
Frequency conversion device output current control device 0 characterized in that the output signal of (A) is fed to a decoder circuit (D) for selection of open/closed state combinations 7) Claim i! l In the control device described in paragraph 6, the decoder circuit (D) is realized by an FROM.
6. Otherwise, the output signal of the adder (A) is given to the address input terminal as an address signal, and the opening/closing state combination to be selected is stored in the memory location connected to the output terminal in relation to the address signal. A frequency converter output current control device, characterized in that these decoder circuit output ends are connected to an opening/closing control circuit for an electronic switch in the inverter. 8) 111PV - In the control device according to any one of am 4 to 7 of the claim, when a voltage indicating the target value Cf' of the frequency rather than the target value of the phase angle of the output current is applied, this On the one hand, the voltage is transferred to a voltage-to-frequency converter (
SU) is converted into a pulse of a corresponding frequency and applied to the count input terminal of the up-ducer y counter (Z),
On the other hand, the polarity detection circuit (P) is applied to the count direction control input terminal of this counter (Z), and the force state of this counter (Z) is determined as the target value of the phase angle of the output current (
A frequency converter output current control device characterized in that it is used in a ψ) binding.