JPH09163752A - Pwm controlled self-excited rectifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the interruption or the open-phase in a commercial power supply and improve the operation reliability of a PWM control self-excited rectifier by a method wherein the deviations between respective instructed phase current values and respective detected phase current values are full-wave rectified and smoothed and a power supply abnormality detector which detects that the rectified and smoothed value exceeds a predetermined judging value is provided. SOLUTION: PWM controlled self-excited rectifiers 40, 50, 60, 70 and 80 have power supply abnormality detectors 41, 51, 61, 71 and 81 respectively and, if some of the power supply abnormality detectors are operated, the operations of the corresponding PWM controlled self-excited rectifiers are stopped. For instance, in the power supply abnormality detector 41 of the PWM control self-excited rectifier 40, the respective deviations between respective instructed phase current values iR*, iS* and iT* and respective detected phase current values are obtained by adders and the obtained deviations are rectified by a full-wave rectifier and the rectified value is smoothed by a filter and, if the output value of the filter exceeds a predetermined value, a comparator is operated and an abnormality detection signal is outputted.

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 device for converting AC power of a commercial power source into DC power by a self-excited rectifier and feeding the load.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a conventional example of a PWM control self-exciting rectifier of this type. In FIG. 7, 1 is a commercial power supply, 10 is a PWM control self-exciting 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 by detecting 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
From the outputs of 6 and 27, the carrier signal generator 28 and
PWM control is performed by the comparator 29 and the output of the comparator 29 is output.
The main circuit 1 of the self-excited rectifier by the gate drive circuit 30
Gating signal to each self-extinguishing type semiconductor device of 1
It is a structure that can be obtained.

In the conventional PWM control self-exciting rectifier device 10 shown in FIG. 7, when a commercial power source 1 experiences a momentary power failure or open phase, it is detected by an AC undervoltage relay (not shown) or the like, and the PWM control self-exciting system is operated. The operation of the rectification device 10 is stopped. The above-mentioned PWM control self-exciting rectifier 10 uses a well-known technique, and therefore detailed description of its operation is omitted here.

[0005]

According to the above-mentioned conventional PWM control self-exciting rectifier, an AC voltage based on the operation of the self-exciting rectifier is input to the self-exciting rectifier during operation of the PWM control self-exciting rectifier. Because it occurs on the side terminal,
Even if an instantaneous power failure or a phase loss occurs in the commercial power supply, the AC undervoltage relay may not detect this due to the AC voltage.

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

[0007]

According to a first aspect of the present invention, there is provided a self-exciting rectifier for converting AC power of a commercial power source into DC power by a self-exciting rectifier and supplying the load, wherein an output of the self-exciting rectifier is provided. Of the DC voltage is detected, a voltage adjustment calculation is performed so that the DC voltage becomes a predetermined value, and the current command value (DC amount) obtained by the voltage adjustment calculation and the phase of the commercial power supply are synchronized. Each phase current command value (AC amount) is calculated by using the angle signal, each phase current of the commercial power source is detected so as to follow this phase current command value, and the current adjustment calculation is performed. A PWM control self-exciting rectifier that generates a PWM-controlled gate signal of each phase based on the output of the current adjustment calculation and a carrier signal, and controls the self-extinguishing type semiconductor device of the self-exciting rectifier by the gate signal of each phase. At the commercial power line The value obtained by full-wave rectifying and smoothing the deviation between each phase current command value and each phase current detection value in order to stop the operation of the PWM control self-exciting rectifier by detecting the instantaneous power failure or open phase of Is provided with a power supply abnormality detection circuit that detects that the value exceeds a predetermined determination value.

According to a second aspect of the present invention, in the PWM control self-exciting rectifier, the current command is issued in order to stop the operation of the PWM control self-exciting rectifier by detecting an instantaneous power failure or open phase of the commercial power source. A power supply abnormality detection circuit for detecting that the deviation between the value (DC amount) and the absolute value of the three-phase / two-phase converted vector of each phase current detection value exceeds a predetermined determination value is provided.

According to a third aspect of the present invention, in the PWM control self-exciting rectifier, each phase is detected in order to detect an instantaneous power failure or a missing phase of the commercial power source and stop the operation of the PWM control self-exciting rectifier. Current command value and the absolute value of the vector of the component orthogonal to this, and the three-phase / current detection value of each phase
A power supply abnormality detection circuit that detects that the deviation from the absolute value of the two-phase converted vector exceeds a predetermined determination value.

According to a fourth aspect of the present invention, in the first to third aspects, the power supply abnormality detection circuit is disabled while the PWM control self-exciting rectifier is stopped. The fifth invention is the PWM according to the first to third inventions.
While the control self-exciting rectifier is stopped, the predetermined judgment value of the power supply abnormality detection circuit is made higher than the judgment value when the PWM control self-exciting rectifier is operating.

According to the present invention, when the PWM control self-exciting rectifier is in operation, a momentary power failure or phase loss occurs in the commercial power supply, for example, the angle signal is disturbed, and the current command value and the current detection due to the disturbance are generated. Since the values do not match, the deviation value based on the current command value and the current detection value is monitored to detect the momentary power failure or open phase of the commercial power supply.

[0012]

1 is a block diagram of a PWM control self-exciting rectifier showing an embodiment of the present invention, in which components having the same functions as those of the conventional example of FIG. The description thereof will be omitted. In FIG. 1, the PWM control self-exciting rectifiers 40, 50, 60, 70, 80 are provided with power supply abnormality detection circuits 41, 51, 61, 71, 81, respectively.
When the respective power supply abnormality detection circuits operate, the operation of this PWM control self-exciting rectifier is stopped.

[0013]

FIG. 2 shows a first embodiment of the present invention.
3 is a detailed circuit configuration diagram of a power supply abnormality detection circuit 41 of the PWM control self-exciting rectifier 40 shown in FIG. Power supply abnormality detection circuit 4
In 1, the deviation between each phase current command value i _R ^* , i _S ^* , i _T ^* and each phase current detection value i _R , i _S , i _T is calculated by the addition calculator 41a, and this deviation is calculated. Full wave rectification circuit 41b
Is rectified by, and the rectified value is smoothed by the filter 41c,
When the output value of the filter 41c exceeds a predetermined judgment value, the comparator 41d operates to output an abnormal signal.

In FIG. 2, the inputs of the current regulators 25 to 27 may be used instead of the addition calculator 41a. FIG.
Shows the second embodiment of the present invention, and the PWM shown in FIG.
It is a detailed circuit block diagram of the power supply abnormality detection circuit 51 of the control self-exciting rectifier 50. In the power supply abnormality detection circuit 51, the three-phase / two-phase conversion of the detected current values i _R , i _S , and i _T of each phase is converted into three-phase / 2.
The detected current value i converted by the phase converter 51a into two phases
_a, an absolute value of a vector of i _b determined by the absolute value calculation circuit 51b, and calculates the deviation of the absolute value and the current instruction value which is the output of the voltage regulator 21 (the DC volume) in adders 51c,
When this deviation exceeds a predetermined judgment value, the comparator 51
In this configuration, d operates to output an abnormal signal.

FIG. 4 shows a third embodiment of the present invention and is a detailed circuit configuration diagram of the power supply abnormality detection circuit 61 of the PWM control self-excited rectifier 60 shown in FIG. In the power supply abnormality detection circuit 61, each phase current command value i _R ^* , i _S ^* , i _T ^*
The phases / two-phase conversion in 3-phase / 2-phase converter 61a, a current detection value converted into 2-phase i _p, the absolute value of the vector of the i _q the absolute value calculation circuit 61b, phase current detection value i _R , i
The 3-phase / 2-phase conversion of _S and i _T is performed by the 3-phase / 2-phase converter 61c, and the absolute value of the vector of the current detection values i _a and i _b converted into the 2-phase is calculated by the absolute value calculation circuit 61d. , The deviation between the output value of the absolute value calculation circuit 61b and the output value of the absolute value calculation circuit 61d is calculated by the addition calculator 61e, and when this deviation exceeds a predetermined judgment value, the comparator 61f operates to output an abnormal signal. Is output.

FIG. 5 shows a fourth embodiment of the present invention and is a detailed circuit configuration diagram of a power supply abnormality detection circuit 71 of the PWM control self-exciting rectifier 70 shown in FIG. The power supply abnormality detection circuit 71 includes three-phase / two-phase converters 61a and 6 having the same functions as those in FIG.
1c, absolute value calculation circuits 61b and 61d, addition calculator 61
e, a comparator 61f and a switch 71a. The switch 71a is opened when the PWM control self-exciting rectifier device 70 is stopped and does not output an abnormal signal while the device is stopped.

Even in the power supply abnormality detection circuit of the first or second embodiment, the switch 71a is provided so that the abnormality signal is not output while the PWM control self-exciting rectifier is stopped. Good. FIG. 6 shows a fifth embodiment of the present invention and is a detailed circuit configuration diagram of a power supply abnormality detection circuit 81 of the PWM control self-excited rectifier 80 shown in FIG.

The power supply abnormality detection circuit 81 includes three-phase / two-phase converters 61a and 61c having the same function as in FIG.
1b, 61d, addition arithmetic unit 61e, comparator 61f, and a predetermined determination value in the comparator 61f are the first determination value when the PWM control self-exciting rectifier 80 is in operation, and the second determination value when it is stopped. The switching device 81a is provided, and the second determination value is set to a value larger than the first determination value so that the abnormal signal is not output as much as possible during the stop.

In the power supply abnormality detection circuit of the first or second embodiment, the switch 81a is provided so that the abnormality signal is not output as much as possible while the PWM control self-exciting rectifier is stopped. May be.

[0020]

According to the present invention, by monitoring the deviation based on the current command value and the current detection value during operation of the PWM control self-exciting rectifier, a momentary power failure or phase loss of the commercial power supply can be ensured. It is possible to provide a PWM control self-excited rectifier with high reliability in operation.

[Brief description of the drawings]

FIG. 1 is a block configuration diagram of a PWM control self-exciting rectifier showing an embodiment of the present invention.

FIG. 2 is a detailed circuit configuration diagram of a power supply abnormality detection circuit showing the first embodiment of the present invention.

FIG. 3 is a detailed circuit configuration diagram of a power supply abnormality detection circuit showing a second embodiment of the present invention.

FIG. 4 is a detailed circuit configuration diagram of a power supply abnormality detection circuit showing a third embodiment of the present invention.

FIG. 5 is a detailed circuit configuration diagram of a power supply abnormality detection circuit showing a fourth embodiment of the present invention.

FIG. 6 is a detailed circuit configuration diagram of a power supply abnormality detection circuit showing a fifth embodiment of the present invention.

FIG. 7 is a block configuration 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, 80 ... PWM control self-exciting rectifier, 11 ... Main circuit of self-exciting rectifier, 12 ... AC reactor, 13 ... Capacitor, 14 ... Phase voltage detector, 15, 20 ... Isolation converter, 1
6 ... Angle signal generating means, 17, 18 ... Sine wave generator, 1
9 ... Voltage setting device, 21 ... Voltage adjusting device, 22, 23 ... Multiplier, 24 ... Current detector, 25-27 ... Current adjusting device, 28
... carrier signal generator, 29 ... comparator, 30 ... gate drive circuit, 41, 51, 61, 71, 81 ... power supply abnormality detection circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H02M 7/21 8726-5H H02M 7/21 Z // H02M 7/48 9181-5H 7/48 F

Claims (5)

[Claims] 1. A self-exciting rectifier for converting AC power of a commercial power source to DC power by a self-exciting rectifier and feeding the load, wherein a DC voltage of an output of the self-exciting rectifier is detected. The voltage adjustment calculation is performed so that the voltage becomes a predetermined value, and the current command value (AC) of each phase is calculated by the current command value (DC amount) obtained by the voltage adjustment calculation and the angle signal synchronized with the phase of the commercial power supply. Amount), and detects each phase current of the commercial power source so as to follow the current command value for each phase, adjusts the current, and outputs the adjusted current of each phase and the carrier signal. In the PWM control self-excited rectifier device, which generates a PWM-controlled gate signal for each phase, and controls the self-extinguishing type semiconductor element of the self-excited rectifier by the gate signal for each phase, an instantaneous power failure or an open phase of the commercial power source. To detect Serial PW
In order to stop the operation of the M control self-exciting rectifier, it is detected that the value obtained by full-wave rectifying the deviation between the phase current command value and the phase current detection value exceeds a predetermined determination value. PWM having a power supply abnormality detection circuit
Controlled self-exciting rectifier. 2. A self-exciting rectifier for converting AC power of a commercial power source into DC power by a self-exciting rectifier and feeding the load, wherein a DC voltage output from the self-exciting rectifier is detected. The voltage adjustment calculation is performed so that the voltage becomes a predetermined value, and the current command value (AC) of each phase is calculated by the current command value (DC amount) obtained by the voltage adjustment calculation and the angle signal synchronized with the phase of the commercial power supply. Amount), and detects each phase current of the commercial power source so as to follow the current command value for each phase, adjusts the current, and outputs the adjusted current of each phase and the carrier signal. In the PWM control self-excited rectifier device, which generates a PWM-controlled gate signal for each phase, and controls the self-extinguishing type semiconductor element of the self-excited rectifier by the gate signal for each phase, an instantaneous power failure or an open phase of the commercial power source. To detect Serial PW
In order to stop the operation of the M control self-exciting rectifier, three phases of the current command value (DC amount) and the current detection value of each phase /
A PWM control self-excited rectification device comprising a power supply abnormality detection circuit for detecting that a deviation from an absolute value of a two-phase converted vector exceeds a predetermined judgment value. 3. A self-exciting rectifier for converting AC power of a commercial power source into DC power by a self-exciting rectifier and feeding the load, wherein a DC voltage output from the self-exciting rectifier is detected. The voltage adjustment calculation is performed so that the voltage becomes a predetermined value, and the current command value (AC) of each phase is calculated by the current command value (DC amount) obtained by the voltage adjustment calculation and the angle signal synchronized with the phase of the commercial power supply. Amount), and detects each phase current of the commercial power source so as to follow the current command value for each phase, adjusts the current, and outputs the adjusted current of each phase and the carrier signal. In the PWM control self-excited rectifier device, which generates a PWM-controlled gate signal for each phase, and controls the self-extinguishing type semiconductor element of the self-excited rectifier by the gate signal for each phase, an instantaneous power failure or an open phase of the commercial power source. To detect Serial PW
In order to stop the operation of the M-controlled self-exciting rectifier, the absolute value of each phase current command value and the vector of the component orthogonal thereto, and the absolute value of the vector obtained by three-phase / two-phase conversion of each phase current detection value Is provided with a power supply abnormality detection circuit for detecting that the deviation from the above exceeds a predetermined judgment value.
WM control self-excited rectifier. 4. The PWM control self-excited rectifier according to claim 1, wherein the power supply abnormality detection circuit is disabled while the PWM control self-excited rectifier is stopped. PWM control self-exciting rectifier. 5. The PWM control self-exciting rectifier according to claim 1, wherein the PWM control self-exciting rectifier stops the predetermined control value of the power supply abnormality detection circuit while the PWM control self-exciting rectifier is stopped. The self-excited rectifier is set to a value higher than the judgment value during operation P
WM control self-excited rectifier.