JP3254999B2 - PWM control self-excited rectifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-excited rectifier for converting AC power of a commercial power supply into DC power by a self-excited rectifier and supplying power to a load.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram showing a conventional example of this type of PWM control self-excited rectifier. 8, 1 is a commercial power supply, 10 is a PWM control self-excited rectifier,
Reference numeral 2 denotes a load such as an inverter connected to the output of the PWM control self-excited rectifier 10.

The PWM control self-excited rectifier 10 is an IGB
Self-extinguishing type semiconductor element such as T and diode are anti-parallel
And the main circuit 1 of the self-excited rectifier
1. Self-excited rectifier AC reactor 12, Self-excited rectifier
For smoothing the output of the power supply and the phase voltage of the commercial power supply 1
, A phase voltage detector 14 for detecting the R phase of the commercial power supply 1
Insulation converter 15 for insulating conversion of pressure, via insulation converter 15
Signal synchronized with the phase of the R-phase voltage of the commercial power supply 1
Signal (θ, θ = 0 ° -360 °)
Means 16 for generating a sine wave based on the angle signal (θ)
Sine wave generator 17 adds 120 ° to the angle signal
Value (θ₁) That generates a sine wave based on
8. Both the voltage setting value of the voltage setting device 19 and the capacitor 13
Voltage detection which detects the DC voltage at the end through the insulation converter 20
A voltage controller 2 that performs a voltage adjustment operation according to a deviation from the output value
1. The output of the voltage regulator 21 and the output of the sine wave generator 17
Phase current set value (i) obtained by multiplying_R
^*), The output of the voltage regulator 21 and the output of the sine wave generator 18
And a T-phase current set value (i
_T ^*) And the S-phase current set value (i_S ^*), And this i
_R ^*, I_S ^*, I_T ^*And the R phase obtained by the current detector 24
Current detection value (i_R), S-phase current detection value (i_S), T-phase
Flow setting value (i_T) And the current controller 2
The adjustment operation is performed at 5, 26, 27, and the current adjusters 25, 2
6, 27 from the output of each carrier signal generator 28
PWM control is performed by the comparator 29 and the output of the comparator 29 is
Main circuit 1 of self-excited rectifier by gate drive circuit 30
A gate signal to each of the self-extinguishing semiconductor devices
Configuration.

In the conventional PWM control self-excited rectifier 10 shown in FIG. 8, the angle signal generating means 16 employs a PLL comprising a well-known phase comparator, a voltage controlled oscillator and the like. An angle signal (θ, θ = 0 ° to 360 °) synchronized with the phase of the phase voltage is generated. The above-described PWM control self-excited rectifier 10 as a whole uses a known technique, and a detailed description of the operation will be omitted here.

[0005]

According to the above-described conventional angle signal generating means, for example, commutation vibration generated based on the commutation operation of a power semiconductor device of another power converter connected to a commercial power supply, The operation of the phase comparator of the PLL is disturbed by disturbance such as a power supply collapse, and as a result, the angle signal is disturbed.

An object of the present invention is to provide a PWM control self-excited rectifier which solves the above problems.

[0007]

According to a first aspect of the present invention, there is provided a self-excited rectifier for converting AC power of a commercial power supply into DC power by a self-excited rectifier and supplying power to a load. , And adjusts the voltage so that the DC voltage becomes a predetermined value, and synchronizes the current command value (DC amount) obtained by the voltage adjustment operation with the phase of the commercial power supply. Each phase current command value (AC amount) is calculated based on the angle signal, the phase current of the commercial power supply is detected so as to follow the phase current command value, and the current adjustment calculation is performed. A PWM control self-excited rectifier for generating each phase gate signal subjected to PWM control based on an output obtained by performing a current adjustment operation and a carrier signal, and controlling the self-extinguishing type semiconductor device of the self-excited rectifier using each phase gate signal. In the above, A filter for removing a noise component of a phase voltage of the commercial power supply, a polarity signal converter for converting a voltage of an output of the filter into a polarity signal, as an angle signal generating means for generating an angle signal synchronized with the phase of A PLL circuit (Phase-Loc) that oscillates at a predetermined frequency with a phase synchronized with the rising or falling of the polarity signal
(Ked Loop), and the output of the PLL circuit and at least a preset phase delay in the filter are corrected.
That from a phase correction amount and a angle signal calculator for calculating the angle signal.

According to a second aspect of the present invention, in the first aspect, the angle signal generating means determines a rated frequency of a commercial power supply from the polarity signal, and determines the value of the phase correction amount based on the determined rated frequency. A switching circuit for switching is added. According to a third aspect of the present invention, in the first aspect, the angle signal generating means determines the polarity of the phase voltage of the commercial power supply at the time of 0 ° of the angle signal. A phase correction amount adjusting circuit for increasing the correction amount by a predetermined value and, if negative, decreasing the phase correction amount by a predetermined value is added.

In a fourth aspect based on the first aspect, the angle signal generating means determines the polarity of the phase voltage of the commercial power supply, and the angle signal at the time when the determined polarity changes from negative to positive. And a phase correction amount adjusting circuit for increasing or decreasing the phase correction amount by a predetermined value according to the value of. According to the present invention, the above-described disturbance of the phase voltage can be cut by providing the angle signal generating means with the filter for removing the noise component of the phase voltage of the commercial power supply, and the phase delay due to this filter is corrected by the phase correction amount. Like that.

[0010]

FIG. 1 is a block diagram of a PWM control self-excited rectifier according to an embodiment of the present invention, in which components having the same functions as those of the conventional example shown in FIG. The description is omitted here. That is, in FIG. 1, the PWM control self-excited rectifiers 40, 50, 60, 7
0 is the angle signal generating means 41, 51, 61, 7 respectively.
1 is provided.

FIG. 2 is a block diagram showing a first embodiment of the present invention.
FIG. 3 is a detailed circuit configuration diagram of an angle signal generation unit 41 of the WM control self-excited rectifier 40. In FIG. 2, an angle signal generating means 4 for generating an angle signal θ synchronized with the phase of the commercial power supply 1
Reference numeral 1 denotes an R-phase voltage of the commercial power supply 1 which is input through the insulation converter 15 and removes a noise component of the voltage.
, A polarity signal converter 43 composed of, for example, a Schmitt circuit, which converts the output voltage into a polarity signal, a PLL circuit 44 which oscillates at a predetermined frequency with a phase synchronized with the rise or fall of the polarity signal, and a PLL circuit 44 And an angle signal calculator 45 for digitally adding the output of the above and a preset phase correction amount θ _C to output an angle signal θ.

The phase correction amount θ _C in FIG. 2 is a value for correcting the phase delay of the fundamental wave of the commercial power supply 1 by the filter 42 and the phase delay by the PLL 44 composed of a phase comparator, a voltage controlled oscillator and the like. From this value, the phase and angle signal θ at 0 ° of the fundamental wave of the commercial power supply 1 are 0 °.
Synchronize with the phase at the time. FIG. 3 is a detailed circuit configuration diagram of the angle signal generating means 51 of the PWM control self-excited rectifier 50 according to the second embodiment of the present invention, which is the same as that of the first embodiment of the present invention shown in FIG. Those having functions are denoted by the same reference numerals.

In FIG. 3, the angle signal generating means 51 includes a filter 42, a polarity signal converter 43, a PLL circuit 44, and an angle signal calculator 45.
And a switching circuit 52 for switching to one of the phase correction amounts θ _C1 and θ _C2 based on the determined rated frequency.

The phase correction amounts θ _C1 and θ _C2 in FIG. 3 are values for correcting the phase lag of the filter 42 and the PLL 44 depending on whether the rated frequency of the commercial power supply 1 is 50 Hz or 60 Hz, for example. The phase when the fundamental wave of the power supply 1 is 0 ° is synchronized with the phase when the angle signal θ is 0 °. FIG. 4 shows a PW according to a third embodiment of the present invention.
FIG. 3 is a detailed circuit configuration diagram of the angle signal generating means 61 of the M-control self-excited rectifier 60, in which components having the same functions as those of the first embodiment of the present invention shown in FIG.

In FIG. 4, an angle signal generating means 61 includes, in addition to a filter 42, a polarity signal converter 43, a PLL circuit 44, and an angle signal calculator 45, the R phase of the commercial power supply 1 at the time of 0 ° of the angle signal. The polarity and the digital value of the phase voltage are fetched, and if the polarity is positive, the phase correction amount θ _C is increased based on the digital value, and if the polarity is negative, the phase correction amount is decreased based on the digital value. D converter 62a
And a phase correction amount adjusting circuit 62 composed of a correction amount calculating circuit 62b.

FIG. 5 is a waveform diagram for explaining the operation of the phase correction amount adjusting circuit 62. Referring to FIG.
The phase voltage of the R phase of the commercial power supply 1 via the
The digital value is converted into a digital value by the A / D converter 62a, and the digital value of the A / D converter 62a at each time of 0 ° of the angle signal θ is taken into the correction amount calculation circuit 62b (FIG. 5).
(B)) In response to this digital value, the correction amount calculation circuit 62b increases the previous phase correction amount θ _C if the digital value is a positive value (FIG. 5 (c)), and Is a negative value, the previous phase correction amount θ _C is decreased to obtain the phase when the fundamental wave of the commercial power supply 1 is 0 ° (FIG. 5).
(See FIG. 5A) and the phase when the angle signal θ is 0 ° (see FIG. 5B).

FIG. 6 shows a fourth embodiment of the present invention.
FIG. 3 is a detailed circuit configuration diagram of the angle signal generating means 71 of the WM control self-excited rectifier 70, in which components having the same functions as those of the first embodiment of the present invention shown in FIG. 6, the angle signal generating means 71 includes a filter 42, a polarity signal converter 43, a PLL circuit 44, an angle signal calculator 45, and a Schmitt circuit for determining the polarity of the R-phase voltage of the commercial power supply 1. A detector 72a and a correction amount calculation circuit 72b which takes in the value of the angle signal θ at the time when the determined polarity changes from negative to positive, and increases or decreases the previous phase correction amount θ _{C in accordance} with the value of θ. And a phase correction amount adjustment circuit 72 composed of

FIG. 7 is a waveform diagram for explaining the operation of the phase correction amount adjusting circuit 72. In FIG.
The polarity of the R-phase voltage of the commercial power supply 1 (FIG. 7 (a)) through the polarity converter 72a is determined by the polarity converter 72a (FIG. 7 (b)), and the polarity at the time when the determined polarity changes from negative to positive. wherein the value of the angle signal theta uptake (FIG. 7 (c)), the fundamental wave of the commercial power supply 1 by corresponding to the value of the theta increase or decrease the previous phase correction amount theta _C (see FIG. 7 (d)) Is 0 ° (see FIG. 7A) and the phase when the angle signal θ is 0 ° (see FIG. 7A).
(See (c))).

[0019]

According to the present invention, by providing a filter for removing a noise component of a phase voltage of a commercial power supply in the angle signal generating means, for example, a power semiconductor of another power converter connected to the commercial power supply Since the angle signal θ can be prevented from being disturbed by disturbance such as commutation vibration and power supply collapse generated based on the commutation operation of the device, the operation reliability of the PWM control self-excited rectifier is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a PWM control self-excited rectifier according to an embodiment of the present invention.

FIG. 2 is a detailed circuit configuration diagram of the angle signal generating means according to the first embodiment of the present invention;

FIG. 3 is a detailed circuit configuration diagram of an angle signal generating means according to a second embodiment of the present invention;

FIG. 4 is a detailed circuit configuration diagram of an angle signal generating means according to a third embodiment of the present invention.

FIG. 5 is a waveform chart for explaining the operation of FIG. 4;

FIG. 6 is a detailed circuit configuration diagram of an angle signal generating means according to a fourth embodiment of the present invention.

FIG. 7 is a waveform chart for explaining the operation of FIG. 6;

FIG. 8 is a block diagram of a PWM control self-excited rectifier showing a conventional example.

[Explanation of symbols]

1: commercial power supply, 2: load, 10, 40, 50, 60, 7
0: PWM control self-excited rectifier, 11: main circuit of self-excited rectifier, 12: AC reactor, 13: capacitor, 1
4: phase voltage detector, 15, 20: insulation converter, 16, 4
1, 51, 61, 71... Angle signal generating means, 17, 18
... Sine wave generator, 19 ... Voltage setter, 21 ... Voltage regulator, 22,23 ... Multiplier, 24 ... Current detector, 25-2
7 current regulator, 28 carrier signal generator, 29 comparator, 30 gate drive circuit, 42 filter, 43
Polarity detector, 44 ... PLL, 45 ... Angle signal calculator, 5
2. Switching circuit, 62, 72: Phase correction amount adjustment circuit.

Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 7/219 H02M 1/12 H02M 7/21 H02M 7/48

Claims (4)

(57) [Claims] 1. A self-excited rectifier for converting AC power of a commercial power supply into DC power by a self-excited rectifier and supplying power to a load, wherein the DC voltage of the output of the self-excited rectifier is detected, and the DC voltage is detected. A voltage adjustment operation is performed so as to have a predetermined value, and a current command value (DC amount) obtained by the voltage adjustment operation and an angle signal synchronized with the phase of the commercial power supply are used for each phase current command value (AC Amount), the phase current of the commercial power supply is detected so as to follow the phase current command value, and the current adjustment calculation is performed. The output of the phase current adjustment calculation and the carrier signal are calculated. In the PWM control self-excited rectifier which generates a PWM-controlled gate signal of each phase and controls the self-extinguishing type semiconductor element of the self-excited rectifier by each phase gate signal, an angle synchronized with the phase of the commercial power supply Generate signal A filter for removing a noise component of a phase voltage of the commercial power supply, a polarity signal converter for converting a voltage output from the filter to a polarity signal, and a synchronous signal for rising or falling of the polarity signal. PLL circuit (Phase-
Locked Loop), and the output of the PLL circuit and at least the preset
A PWM control self-excited rectifier, comprising: an angle signal calculator for calculating the angle signal from a phase correction amount for correcting a phase delay in a filter . 2. The PWM control self-excited rectifier according to claim 1, wherein the angle signal generating means determines a rated frequency of a commercial power supply from the polarity signal, and the phase correction amount is determined based on the determined rated frequency. A PWM control self-excited rectifier, characterized by adding a switching circuit for switching the value of (1). 3. The PWM control self-excited rectifier according to claim 1, wherein the angle signal generating means determines the polarity of the phase voltage of the commercial power supply at 0 ° of the angle signal, and determines the determined polarity. A self-excited PWM control device characterized by adding a phase correction amount adjusting circuit for increasing the phase correction amount by a predetermined value if the value is positive, and decreasing the phase correction amount by a predetermined value if the value is negative. 4. The PWM control self-excited rectifier according to claim 1, wherein the polarity of the phase voltage of the commercial power supply is determined by the angle signal generating means, and the polarity at the time when the determined polarity changes from negative to positive. A PWM control self-excited rectifier further comprising a phase correction amount adjusting circuit for increasing or decreasing the phase correction amount by a predetermined value according to the value of the angle signal.