JP3484508B2 - Three-phase power regulator - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a three-phase power regulator.

[0002]

2. Description of the Related Art As is well known, a power regulator adjusts the amount of power supplied to a load by inserting a switching element on a power supply line and changing the ON time of the switching element. The ignition control of the switching element is performed by generating a triangular wave (sawtooth wave) based on a power supply signal, comparing the triangular wave with a command signal (DC), and using a pulse having a duty ratio according to the command signal. I am trying. That is, for example, when the switching element is ignited based on the rising edge of the pulse, the ignition timing changes according to (elapsed time from the zero cross of the AC signal), that is, the command value.
Therefore, the period during which the switching element is on changes, and the amount of power supply per unit time changes.

In the case of the three-phase power regulator to which the present invention is applied, the above-mentioned switching elements are inserted in the power supply line of each phase of UVW, and each switching element is fired at an appropriate timing based on the command value. I am trying to do it. For stable power supply, ideally, the ignition timings of these three switching elements are shifted by 120 degrees and the ON times are equal.

The conventional three-phase power regulator is roughly classified into an analog type and a digital type. In the former analog system, three transformers connected by Y-Y are inserted into the power supply line, and the voltages U, V, W for the neutral point are obtained via the transformers. A triangular wave generating circuit and a comparator are connected in series to each power supply signal (UVW), and the same command value is given to each comparator. Then, the output of the triangular wave generating circuit (triangular wave) is given to the comparator, and when the value exceeds the command value, the switching element is turned on (ON).

The triangular wave generating circuit generates a triangular wave by making such a three voltage signal (sine wave) into a rectangular wave through a comparator and passing the signal through a charging / discharging circuit. Therefore, the triangular wave rises accurately from the zero-cross point of the power supply signal of each phase. Therefore, if the inclination of the triangular wave of each phase is the same, the firing timing also shifts by exactly 120 degrees according to the phase delay of each power supply signal. Be seen.

The latter digital method is disclosed in Japanese Patent Laid-Open No. 59-59.
As disclosed in JP-A-106879, JP-A-61-15565, etc., a single CPU produces an ignition signal for three phases, and after a zero cross is detected in place of a triangular wave generation circuit in an analog system, a predetermined A means for calculating the phase angle by counting several numbers is provided. When the phase angle corresponding to the command value is reached, the corresponding switching element is fired. Then, in order to detect the zero-cross point, a transformer is installed on the power supply line,
The output voltage of each phase of the transformer is A / D converted, and each process is performed based on the converted digital value.

[0007]

In the case of the analog system, a transformer for three phases is required, and a triangular wave generating circuit and a comparator are required for each phase, resulting in an increase in the number of parts and a cost reduction. Invite high. Furthermore, the characteristics of each element that constitutes the charge / discharge circuit when forming a triangular wave vary, the slope of the triangular wave in each phase is different, and the time from zero crossing to firing (firing timing) is different in each phase. It will be displaced, it will not be possible to fire at 120 degree intervals,
Stable driving becomes difficult.

On the other hand, in the case of the digital system, it takes more than 100 μsec to read the data (8 bi
t, 20 MHz), for example, when using a power supply frequency of 50 Hz, only 100 divisions can be made in a half cycle. As a result, the improvement of resolution is limited, and the detection of zero-cross and the control of the ignition timing of each phase can be obtained only within the above range.

The present invention has been made in view of the above background, and an object of the present invention is to solve the above problems, to detect a zero cross accurately with high resolution, and to set the ignition timing of each phase. An object of the present invention is to provide a three-phase power regulator that can be stably driven by shifting by 120 degrees, is small in size, has a small amount of heat generation, and has a command value and an output proportional to each other, and which is low in cost.

[0010]

In order to achieve the above-mentioned object, in the three-phase power regulator according to the present invention, the three-phase power supply line of each phase is selected based on the interphase voltage of any two phases. An analog single-phase controller that generates a reference pulse signal that serves as a reference for an ignition signal, and the output of the single-phase controller is digitally delayed by a predetermined phase angle to generate an ignition signal for each phase. The firing signal generating means and the driving means for firing the switching elements mounted on the power supply lines based on the firing signal received from the firing signal generating means. Further, the firing signal generating means stores the L / H state of the reference signal and shifts the stored information at a predetermined timing, and receives the output of the shift register to generate a firing signal. The control means is capable of outputting the firing signal only when there are a plurality of terminals in which the outputs of the shift register are simultaneously turned on.

As the single-phase controller,
For example, the zero-cross detection means for detecting the zero-cross of the interphase voltage, and from the time when the zero-cross detection means detects the zero-cross, the charging circuit is charged, and the charging circuit is switched when a fixed amount is charged, and the time constant is further changed. When the reference wave is large, a reference wave generation unit that generates a reference wave whose inclination after switching is increased by charging and a reference wave output from the reference wave generation unit are compared with a command value. And a comparison means for outputting a reference signal which is an ON signal.

[0012] Preferably, the firing signal generating means is
A shift register that stores the L / H state of the reference signal and shifts the stored information at a predetermined timing is provided, and a firing signal is generated based on an output from a desired output terminal of the shift register. It is to be. Further, the ignition signal generation means includes, in addition to the shift register, control means for receiving an output of the shift register and generating an ignition signal, and the control means simultaneously turns on the outputs of the shift register. It is more preferable to enable the firing signal to be output only when there are a plurality of terminals that are open.

[0013]

With the single-phase controller, the reference pulse signal which is the source of the firing signal is generated based on an arbitrary interphase voltage. At this time, since it is processed by analog, the zero cross of the interphase voltage is accurately detected. After the zero crossing, the reference wave that rises based on the interphase voltage signal is compared with the command value, and an ON signal is output when the reference wave exceeds the command value.
This becomes the reference signal.

On the basis of this reference signal, the ignition signal generation means generates an ignition signal for the switching element installed in each phase. That is, the power supply signal of a certain phase is delayed by 30 degrees from the zero cross of the interphase voltage, and the power supply signals of the remaining two phases are deviated by ± 120 degrees from the power supply signal.
Therefore, the ignition signal is output when the reference signal is turned on and deviated by a predetermined phase angle. The ignition signals of the respective phases are digitally processed based on the same reference signal and output with a delay of a predetermined phase angle, so that the ignition timings of the respective phases are accurately deviated by 120 degrees.

Since the firing signal can be output only when there are a plurality of terminals in which the outputs of the shift register are simultaneously turned on, the switching element is prevented from being erroneously fired. That is, assuming that only one reference signal is on, the switching elements corresponding to the remaining two are off, so even if the switching element corresponding to that one is turned on (ignition), the current Does not flow, but at this time, there is a risk that the remaining two switching elements will be turned on by mistake due to noise or the like. Then, power is supplied faster than the actual command value. However, in the present invention, the ignition signal is not output when only one of them is on, and the occurrence of such a situation is suppressed.

According to the present invention, the reference wave approximates to a sine wave (sin curve), so that the output voltage changes linearly with respect to the command value. Therefore, it becomes easy to control.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a three-phase power regulator according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the present invention. As shown in the figure, three-phase (U
The triacs 10a to 10c, which are switching elements, are inserted in the power supply line of VW), and the triac 10a is inserted.
Power is supplied to the three-phase load 11 via 10c.

Any two of the three phases (U phase, V in this example)
The single-phase controller 20 is attached to the interphase voltage (extracted by the power supply device 12) of the phase), and the reference signal (pulse) that is a reference for generating the ignition signal for the triacs 10a to 10c is generated therein. Then, the signal is sent to the ignition signal generator 30 in the next stage.

In the firing signal generator 30, the triacs 10a to 10a inserted in the respective phases based on the given reference signal.
Generate respective firing signals for 10c. The firing signals thus generated are out of phase with each other by 120 degrees.

The output of the ignition signal generation unit 30 is given to the ignition signal output unit 40, receives the ignition signal (trigger pulse) given from the ignition signal generation unit 30, and receives the actual triacs 10a-10c. It is designed to give an ON signal to the gate.

Next, each part will be described in detail. First, as shown in FIG. 2, a power supply device 12 for extracting an interphase voltage includes a transformer 12a connected between two phases of a power supply line and a full-wave rectifier (diode bridge) 12b connected to a secondary side of the transformer 12a. And a switching regulator 12c connected to the two terminals of the full-wave rectifier 12b. As a result, when a sine wave is input to the primary side of the transformer 12a as shown in the figure, it is dropped to the logic level by the transformer 12a and corresponds to its magnitude synchronized with the input waveform (zero-cross timing coincides). The full-wave rectified waveform (see FIG. 3) is output from the other two terminals of the full-wave rectifier 12b.

The single-phase controller 20 includes a zero-cross detection circuit 21 arranged on the input side, a reference wave generator 22 for receiving the output of the detection circuit 21 and generating a substantially triangular reference waveform, and a reference wave generator thereof. A comparator 23 for comparing the output voltage of 22 with a command value given from the outside is provided.

As shown in FIG. 2, the zero cross detection circuit 21 includes a Zener diode 21a and a comparator 21.
b, the full-wave rectified waveform (in FIG. 3) is shifted downward by the Zener diode 21a (see in FIG. 3), and the waveform is applied to the inverting input terminal of the comparator 21b. Since the non-inverting input terminal of the comparator 21b is grounded, the output of the comparator 21b becomes H when the shifted voltage becomes negative. Therefore, a rectangular wave (pulse) is output in the vicinity of zero crossing of the UV interphase voltage (see FIG. 3).

The reference wave generator 22, as shown in FIG.
A switch 22a composed of a transistor is provided on the input side,
The switch 22b is inserted between the inverting input terminal of the comparator 22b and the ground. The non-inverting input terminal of the comparator 22b has a predetermined voltage V1 obtained by dividing the power supply voltage Vcc by a voltage dividing means composed of two series resistors.
Is given as a reference voltage. And the comparator 2
The output of 2b is given to the charging circuit 22c, and the output of the charging circuit 22c is fed back to the inverting input terminal of the comparator 22b via a predetermined feedback loop.

The charging circuit 22c has two capacitors C
1, C2 and three resistors R1 to R3 are properly connected in series and parallel, and two capacitors C1 and C1 are connected in series.
It is configured by including a transistor Tr1 capable of short-circuiting both ends of the ground-side capacitor C2 of the two.

Therefore, when the zero-cross signal output from the zero-cross detection circuit 21 changes from H to L, the transistor 22a on the input side is turned off (the switch is opened),
The voltage at the inverting input terminal of the comparator 22b (initially 0 when switched to L) is compared with the reference voltage V1. Therefore, the output of the comparator 22b becomes H, so that the transistor Tr1 of the charging circuit 22c is turned on and the capacitor C2 is short-circuited. Therefore, the charging circuit 22c is configured as shown in FIG.
The circuit configuration is as shown in (A), and the power supply voltage Vcc is
The capacitor C1 is charged with a time constant determined by RC. As a result, the output voltage of the charging circuit 22c gradually rises.

As the output voltage increases, the voltage at the inverting input terminal of the comparator 22b also increases (t0 in FIG. 6).
Voltage fluctuation characteristics from t1 to t1). This rising curve is almost proportional to the change in the output voltage of the charging circuit 22c. Then, when a certain time has passed from the zero cross, the comparator 22b
The voltage (voltage fed back from the charging circuit 22c) applied to the inverting input terminal of the voltage exceeds the reference voltage V1.
Then, the output of the comparator 22b becomes L, the transistor Tr1 of the charging circuit 22c is turned OFF, and the terminals of the capacitor C2 are opened.

As a result, the charging circuit 22c operates as shown in FIG.
The equivalent circuit shown in (B) changes and the time constant changes, so the rate of change (increase) in the output voltage of the charging circuit 22c also changes (increases). Therefore, as shown in FIG. 6A, the voltage at the inverting input terminal of the comparator 22b (after t1) rapidly rises.

When the power supply signal crosses zero, a pulse signal is input to the gate of the transistor constituting the switch 22a, the switch 22a is turned on once, and the inverting input of the comparator 22b also falls to the ground, so that it becomes zero. After that, by repeating the above process,
A reference wave close to a sin wave as shown in FIG. 6A is output every time the power supply signal crosses zero. Then, the waveform is directly output from the reference wave generation circuit 22 and given to the comparator 23.

As described above, the comparator 23 compares the command value (4 to 20 mA with voltage conversion), and the comparator 2 while the voltage of the reference wave is equal to or higher than the command value.
The output of 3 becomes H. Therefore, the higher the command value, the shorter the ON-time pulse is output (see FIG. 6B).

In this example, the charging characteristics (shape of the reference wave) are made non-linear in this way, and moreover, the characteristics are approximated to a sin curve, so that the relationship between the command value and the output voltage is as shown in FIG. 7 (A). It becomes almost linear.

When a triangular wave that has been generally used in the past is used as a reference wave, the relationship between the command value and the output is a cos curve as shown in FIG.
If the charging circuit is simply a CR (there is no switching in the middle as in the above-described embodiment), the relationship between the command value and the output is an S-shaped curve, as shown in FIG. Both are non-linear, and the linearity is lower than that of this embodiment. The linearity is the worst when the triangular wave is used.
However, considering the circuit configuration, the case of using a triangular wave is the simplest, and the present embodiment is the most complicated. Therefore, in the present invention, as to which of the above three is adopted as the reference wave, a desired one can be used in consideration of required accuracy and the like.

The firing signal generator 30 includes a shift register 31, which is a storage element, and a clock generator 32, which generates a clock signal for operating the shift register 31.
According to the ON / OFF state of a predetermined output terminal of the shift register 31, it is possible to prevent only one triac from turning on (when turning on, two or all predetermined triacs turn on). An output logic circuit 33 that generates and outputs a predetermined trigger signal, and a waveform shaping circuit 34 that receives the output of the output logic circuit 33 and generates a firing signal.

The shift register 31 is of 16 bits (8 bits × 2), and the state of the reference signal (H / H) given from the single-phase controller 20 each time the clock signal from the clock generation circuit 32 is input by one pulse. L) is sequentially fetched and the previously fetched information is shifted one by one. Here, it is H when the reference signal is on.

The shift timing of the shift register 31, that is, the clock frequency is adjusted so that the timing at which the phase changes by 10 degrees is synchronized with the shift timing. Specifically, assuming that the frequency is 50 Hz, (1/50) × (10/360) = 0.55, and the clock may be generated by 0.55 msec. Although not shown, the clock generating circuit 32 for generating such a clock has a crystal oscillator and a counter as a basic configuration, and divides the oscillation frequency of the crystal by the counter to output a pulse having a desired frequency. Has become.

The outputs of the third bit, the ninth bit and the fifteenth bit of the shift register 31 are respectively U
The control rectangular wave signals u, w, and v for the phase, W phase, and V phase are used.

Therefore, each output u of the shift register 31
Regarding w and v, after the single-phase reference signal is turned on, the control rectangular wave signal u is turned on 30 degrees later, the control rectangular wave signal w is turned on 90 degrees later, and the control rectangular wave signal w is delayed 150 degrees. The rectangular wave signal v turns on. Then, the ON period is the same as the pulse width of the single-phase reference signal. As a result, a rectangular wave obtained by shifting the single-phase reference signal by 30, 90, or 120 degrees is obtained from each output terminal.

The reason for doing this is as follows.
First, as shown in FIG. 8, u is set to 30 degrees because the UV phase entering the power supply circuit is advanced by 30 degrees with respect to the U phase. In other words, the time when the reference wave generated based on the UV phase is delayed by 30 degrees from the time when the reference wave exceeds the command value corresponds to the time when the power signal of the U phase actually exceeds the command value. Also, V phase is U
"30 + 120" because it is 120 degrees out of phase
A delay of 150 degrees corresponds to when the V-phase power supply signal actually exceeds the command value. In addition, the W phase has an additional 120
Since they are out of alignment, based on the formula that calculates the V phase,
This is a point of 270 degrees (30 + 240), which would require at least 27 bits or more as a shift register, increasing the memory capacity. Therefore, in this embodiment, 90 degrees (= 270) which is an inverted phase of 270 degrees.
-180) is used for control to reduce the memory.

An example of the operation of the shift register 31 will be described. As shown in FIG. 9A, the state of a certain timing (for convenience, an initial value) is the shift register 3.
It is assumed that the 1st to 10th bits of the output terminal 1 are H, and the 10th bit is when the reference signal ON is on (pulse width). Then, every time the clock enters
Shift bit by bit. Then, each output terminal (rectangular wave signals for control u, w,
The state of v) is as shown in FIG.

The output logic circuit 33 controls the state (H) of each of the control rectangular wave signals output from the shift register 31.
/ L) based on the actual triac 10a-10c
A gate signal is generated which is the timing of generation of the ignition signal for turning on. That is, as shown in FIG.
In order to supply electric power to the Y-connection three-phase load 11, it is necessary to turn on at least two or more elements. By the way, looking at FIG. 9, since u and w are H at clocks 1 and 2, when the corresponding triacs 10a and 10c are turned on, a current flows between UWs as shown in FIG. However, at clocks 3 and 4, since only w is H, no current flows even if only the corresponding triac 10c is turned on (correct operation in this state). However, due to noise, other triacs 10a
Alternatively, when 10b is ignited and turned on, a current may flow, and once it flows, it continues to flow until the voltage becomes 0, so that more power is supplied than necessary and the phase control cannot be performed correctly. Therefore, in the output logic circuit 33, the triac is turned on only when two or more control rectangular wave signals are H, and stable driving is ensured.

Specifically, it is implemented by a logic circuit as shown in FIG. As a result, for example, assuming that the control rectangular wave signals u, v, w are as shown in FIG.
V and W are all L, and other than that, the corresponding control rectangular wave signal is H and the gate is H. And
When each gate U, V, W switches from L to H is the firing timing for the corresponding triac 10a-10c.

The waveform shaping circuit 34 is a circuit for outputting a trigger pulse having a short pulse width when each of the above gates is switched from L to H, and thereafter maintaining the L state. Timing (gate is from L to H
The ignition signal is surely generated only when (when switching to).

Specifically, as shown in FIG. 13, a differentiation circuit 34a and a Schmitt trigger circuit 34b are provided, and an inverted signal of the gate signal is given to the differentiation circuit 34a, and the differentiation circuit 34a changes the gate signal to L. The time when it changes from H to H is detected, and a trigger pulse is generated. By providing the differentiating circuit 34a in this way, the trigger pulse is output only when there is a sudden change from L to H, and it is erroneous when the H level slightly changes due to noise. The firing signal is not output. Then, the Schmitt trigger circuit 34b outputs a single rectangular wave having a short pulse width as the trigger pulse. This rectangular wave becomes the firing signal.

As described above, in this example, since at least two or more gates are turned on, the command value (phase angle) can be controlled in the range of 0 to 120 degrees. . That is, when the angle exceeds 120 degrees, there is no place where a plurality of u, v, and w gate signals (trigger pulses) are simultaneously turned on.

The drive circuit 40 receives the ignition signal and drives the triacs 10a to 10c. As shown in FIG. 14, the drive circuit 40 is provided with a transistor serving as a switch 41 on the input side, and between the power supply voltage Vcc and the ground. The switch 41 and the phototriac coupler 42 connected in series are arranged. Further, the triacs 10a to 10c to be controlled are connected to the light receiving side of the phototriac coupler 42. As a result, when the ignition signal is received, the switch 4
Since the transistor forming 1 is turned on, the switch is closed and a current flows through the phototriac coupler 42 to emit light. Upon receiving the light emission, the light receiving side is also turned on, the power source and the load are electrically connected to each other through the phototriac coupler 42, and power is supplied, and accordingly, the triac 10a is ignited. In the figure, reference numeral 43 is a snubber circuit composed of an RC series circuit, and reference numeral 44 is a varistor. Since the drive circuit 40 having the same structure as the conventional drive circuit can be used, detailed description thereof will be omitted. Further, the drive circuit 40 having the above-described configuration is connected to each of the triacs 10a to 10c and ignites at a predetermined timing (shifted by 120 degrees).

As described above, in this example, the zero-cross of the power supply signal is detected by the analog method using the zero-cross detection circuit 21, so that the error can be accurately detected without the error due to the sampling time which is a drawback of the digital method. Further, since the firing timing for the triac inserted in each power supply line is generated by the digital circuit such as the shift register 31 based on one interphase voltage (between UV in this example), each triac 10a to 10c is generated. The firing timing of can be accurately shifted by 120 degrees.

Next, using the above-mentioned embodiment, when the ignition timing (command value) is 0 degree (delay phase from Xerox (hereinafter the same)), 30 degrees, 60 degrees, 90 degrees, and 120 degrees,
The waveforms of the layers U, V, W and the relationship between the interphase voltage between UV and the output voltage RS are shown in FIGS. In addition,
The trigger pulse shown in the lower part of each figure is the output from the above shift register 31 (control rectangular wave signals u, v, w).
Is.

As is apparent from FIG. 15, when the firing angle command value is 0 degree, all the gate signals are always ON, so that the U, V and W phases are always supplied to the three-phase load. (The corresponding triac is ignited at the same time when each power signal passes through the zero crossing), so that it synchronizes with the UV interphase voltage,
A beautiful sine wave is output. Then, as each command value for ignition increases, the time from zero crossing to ignition becomes longer, and there is no power supply to the load during that time, so the output voltage RS is the sine indicated by the two-dot chain line as shown in the figure. Wave (U
The waveform becomes distorted with respect to V), and the power supply amount thereof also decreases (FIGS. 16 to 18). And the firing command angle is 120
As shown in FIG. 19, the output voltage RS becomes zero because the gates are always turned off. The relationship of the output voltage with respect to each firing command value decreases linearly as shown in FIG. 20, and becomes zero at 120 degrees.

Although the triac is used as the switching element in the above-mentioned embodiments, the present invention is not limited to this, and may be composed of a thyristor and a diode connected in parallel, and various modifications can be made. is there. When the thyristor is used, the output logic circuit 33 becomes unnecessary.

[0050]

As described above, in the three-phase power regulator according to the present invention, since the reference signal is generated based on the interphase voltage of any two phases, only one transformer or the like is required, and the heat generation amount is suppressed. it can. Since the single-phase control for outputting the reference signal from the detection of the zero cross to the shaping of the reference wave and the comparison with the command value is configured by the analog circuit, the zero cross can be accurately detected.

Further, since the ignition signal for actually igniting the switching element is formed by digitally processing one reference signal generated by the analog method and shifting it by a predetermined angle, the ignition signal of each phase is generated. Ignition timing is 12
It shifts by 0 degrees.

Further, since each processing is performed based on one interphase voltage, only one circuit such as a transformer for extracting the voltage is required, and the number of parts can be reduced, the size can be reduced, and the amount of heat generation can be reduced. .

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a three-phase power regulator according to the present invention.

FIG. 2 is a diagram showing an internal configuration of a power supply device and a zero-cross detector.

FIG. 3 is a diagram showing an operating principle of a zero detection circuit.

FIG. 4 is a diagram showing a circuit configuration of a reference wave generation unit.

FIG. 5 is a diagram showing an operation principle of a charging circuit in the reference wave generation unit.

FIG. 6 is a diagram showing output characteristics of a reference wave generation unit.

FIG. 7 is a diagram illustrating an operation of a modified example of the reference wave generation unit.

FIG. 8 is a diagram showing a correlation between phase differences of power supply signals.

FIG. 9 is a timing chart showing the operating principle of the shift register.

FIG. 10 is a diagram illustrating a state of power supply to a three-phase load.

FIG. 11 is a diagram showing an internal configuration of an output logic circuit.

FIG. 12 is a timing chart showing an example of the operation of the output logic circuit.

FIG. 13 is a diagram showing an internal configuration of a waveform shaping circuit.

FIG. 14 is a timing chart illustrating the operation of the waveform shaping circuit.

FIG. 15 is a diagram showing an internal configuration of a drive circuit.

FIG. 16 is a diagram showing a state of each waveform when a firing angle command is 0 degree.

FIG. 17 is a diagram showing a state of each waveform when a firing angle command is 30 degrees.

FIG. 18 is a diagram showing a state of each waveform when a firing angle command is 60 degrees.

FIG. 19 is a diagram showing a state of each waveform when a firing angle command is 90 degrees.

FIG. 20 is a diagram showing a state of each waveform when a firing angle command is 120 degrees.

FIG. 21 is a diagram showing a relationship of output voltage with respect to each firing command in the present embodiment.

[Explanation of symbols]

10a to 10c Triac (switching element) 11 Three-phase load 20 Single-phase controller 21 Zero-cross detection circuit 22 Reference wave shaping circuit 23 Comparator 30 ignition signal 31 shift register (memory element) 32 clock generator 33 output logic circuit 34 Waveform shaping circuit 40 drive circuit

Continuation of the front page (56) Reference JP-A-3-3663 (JP, A) JP-A-3-102507 (JP, A) Actual development Sho 62-105514 (JP, U) US Pat. No. 4499534 (US, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G05F 1/455 H02M 1/08

Claims (2)

(57) [Claims] 1. An analog single-phase controller that generates a reference pulse signal that serves as a reference for an ignition signal of each phase based on an interphase voltage of any two phases of a three-phase power supply line, and the single phase thereof. An ignition signal generating unit that generates an ignition signal for each phase by delaying a predetermined phase angle by digital processing with respect to the output of the controller, and each power source based on the ignition signal received from the ignition signal generating unit. A shift register for activating a switching element mounted on the line, wherein the ignition signal generating means stores the L / H state of the reference signal and shifts the stored information at a predetermined timing. And a control means for receiving the output of the shift register and generating an ignition signal, the control means having a plurality of terminals to which the outputs of the shift register are simultaneously turned on. 3-phase power regulator which enables outputs only ignition signal when present. 2. The single-phase controller detects a zero-cross of the inter-phase voltage, and a zero-cross detecting means, and when the zero-cross detecting means detects the zero-cross, charges the charging circuit and charges a fixed amount. A reference wave generation unit that generates a reference wave that increases the slope after switching by switching the charging circuit and further charging with different time constants, and the reference wave and the command value output from the reference wave generation unit. 3. The three-phase power regulator according to claim 1, further comprising: a comparator that outputs a reference signal that becomes an ON signal when the reference wave is large.