JPH09163751A - Pwm controlled self-excited rectifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the rise of the DC voltage of the output of a PWM control self-excited rectifier by a method wherein a current instruction value is quickly switched to the value of a regenerative current direction when the DC voltage exceeds a limit value. SOLUTION: If a regenerative current flows into a PWM controlled self-excited rectifier, the output of the regulation calculation unit 21a of a voltage regulator is reduced and approaches a regenerating region. If a DC voltage between both the ends of a capacitor 13 exceeds a limit value, a value which is obtained by adding the output value of the regulation calculation unit 21a to a negative maximum current limit value is used as the input value of the limit calculation unit 21b of the voltage regulator. Then a current instruction value is put into a regenerative state and the DC voltage between both the ends of the capacitor 13 starts decreasing. If the DC voltage between both the ends of the capacitor 13 is reduced to be below a limit value, the current instruction value is switched to the output value of the regulation calculation unit 21a. By repeating the above mentioned procedure, the DC voltage between both the ends of the capacitor 13 is suppressed to the value below the limit value even if the regenerative current keeps on flowing into the PWM control self-excited rectifier.

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 10 shown in FIG. 7, the voltage regulator 21 includes an adjustment calculator 21a.
And the current command value (DC amount) based on the output of the adjustment calculation unit 21a is a positive / negative maximum current limit value (+ _IMAX , -I).
_MAX ) and a limit calculation unit 21b for limiting so as not to exceed _MAX . Here, the maximum positive current limit value (+
I _MAX ) is the maximum allowable value of the current supplied from the main circuit 11 of the self-excited rectifier to the load 2, and the negative maximum current limit value (−I _MAX ) is the main circuit 11 of the self-excited rectifier. Represents the maximum allowable value of the current regenerated from the load 2 to the commercial power supply 1.

The above-mentioned PWM control self-exciting rectifier 10 uses a well-known technique, and a detailed description of its operation is omitted here.

[0006]

The conventional P shown in FIG. 7 is used.
In the WM control self-exciting rectifier, when the load 2 is composed of an inverter or the like, the regenerative current described above flows into the PWM control self-exciting rectifier 10 from an electric motor or the like driven by the inverter, and as a result, the capacitor 13 The DC voltage at both ends is about to rise, and this state is
The voltage regulator 21 performs the operation of suppressing the voltage.

FIG. 8 is an operation waveform diagram showing an operation state of the PWM control self-exciting rectifier 10 during the above-mentioned regeneration. FIG.
At time T ₀ , when the state in which the regenerative current flows from the load 2 continues from time T ₀ , the DC voltage across the capacitor 13 changes as shown in FIG.
As shown in (a), the output of the adjustment calculation unit 21a of the voltage regulator 21 decreases as shown in FIG. 8B due to this increase, and the regeneration region (the output of the adjustment calculation unit 21a has a negative polarity). However, due to the delay in the control operation of the adjustment calculation unit 21a, the DC voltage across the capacitor 13 continues to rise as shown in FIG. 8A, and the main circuit 11 of this self-excited rectifier is shown. There is a risk that the PWM control self-excited rectifier 10 is stopped when the overvoltage trip value exceeding the overvoltage withstand value is reached.

To solve this problem, it is possible to reduce the delay in the control operation of the adjustment calculation section 21a, but it is necessary to stabilize the control loop of the PWM control self-excited rectifier and to prevent noise. There was a limit in suppressing the disturbance. An object of the present invention is to provide a PWM control self-excited rectifier that solves the above problems.

[0009]

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 voltage A voltage regulator composed of an adjustment calculation unit that performs node calculation and a limit calculation unit that limits the current command value (DC amount) based on the output of the adjustment calculation unit so as not to exceed the positive and negative maximum current limit values. And, when the detected value of the DC voltage of the output of the self-exciting rectifier exceeds a predetermined limit value, a value obtained by adding the output value of the adjustment calculation unit and the negative maximum current limit value is the limit calculation unit. And a voltage limit control circuit for setting the input value of.

According to a second aspect of the present invention, in the PWM control self-exciting rectifier, an adjustment operation unit for adjusting the voltage and the current command value (DC amount) based on the output of the adjustment operation unit have a positive or negative maximum value. When the detected value of the DC voltage of the output of the self-excited rectifier exceeds a predetermined limit value, the adjustment operation is performed when the voltage adjuster is configured to limit the current limit value so as not to exceed the limit value. A switching control circuit for inputting the negative maximum current limit value to the limit calculation unit instead of the output value of the unit.

According to a third aspect of the present invention, in the PWM control self-exciting rectifier, an adjustment operation unit for performing the adjustment operation of the voltage and the current command value (DC amount) based on the output of the adjustment operation unit have a positive or negative maximum value. A voltage regulator composed of a limiting calculator for limiting the current limit value so as not to exceed the current limit value, and the adjustment when the detected value of the DC voltage of the output of the self-excited rectifier exceeds a first limit value. Output value of arithmetic unit and 0% of the output
When the detected value of the DC voltage of the output of the self-excited rectifier exceeds a second limit value larger than the first limit value, And a switching control circuit for inputting the negative maximum current limit value to the limit calculation unit instead of the output value of the adjustment calculation unit.

Further, a fourth aspect of the present invention is the PWM control self-excitation.
Type rectifier, the adjustment operation for adjusting the voltage.
The calculation unit and the current command value based on the output of the adjustment calculation unit
(DC amount) is controlled so that it does not exceed the maximum positive and negative current limit values.
A voltage regulator composed of a limit calculator for limiting
n (n = 1, 2 ... N) limit value (V _L1<V_L2<・ ・
・ <V_LN) And the nth (n = 1, 2 ... N) command value (V
₁ ^*> V _Two ^*＞ ・ ・ ・ ＞ V_N ^*) And the self-excited
The detected value of the DC voltage of the output of the rectifier exceeds the nth limit value.
The output value of the adjustment calculation unit and the nth command value
Input a smaller value to the limit calculation unit by comparing,
The detected value of the DC voltage output from the self-excited rectifier is the Nth control value.
When the (N + 1) th limit value that is greater than the limit value is exceeded,
The negative maximum current limit instead of the output value of the adjustment calculator
And a switching control circuit for inputting a value to the limit calculation unit
You.

According to the first to fourth aspects of the present invention, when the detected value of the DC voltage of the output of the PWM control self-exciting rectifier exceeds a predetermined limit value, the rise suppressing operation by the control operation of the voltage regulator is performed. Instead, by rapidly changing the current command value (DC amount) to a value in the direction of the regenerative current, it is possible to quickly shift to the regenerative operation and reduce the increase in the DC voltage of the output of the PWM control self-exciting rectifier. .

[0014]

1 is a block diagram of a PWM control self-exciting rectifier showing a first embodiment of the present invention, in which the same symbols are given to those having the same functions as those of the conventional example of FIG. Is attached and the description thereof is omitted. In FIG. 1, PWM
The control self-excited rectifier 40 includes a main circuit 1 of the self-excited rectifier.
The DC voltage across the capacitor 13, which is the output of No. 1, is detected through the insulation converter 20, and when the detected DC voltage exceeds a predetermined limit value ( _VL ), the adjustment calculation of the voltage controller 21. The output value of the part 21a and the maximum negative current limit value (-I
_MAX ) and a value obtained by adding
A voltage limit control circuit 41 having an input value of 1b is provided.

Operation of the PWM control self-exciting rectifier 40
Will be described below with reference to the operation waveform diagram shown in FIG.
I do. In FIG. 2, time T₀More load 2 to regenerative current
If the current continues to flow, the direct current across the capacitor 13
The voltage starts to rise as shown in Fig. 2 (a), and
The output of the adjustment calculator 21a of the voltage regulator 21 is shown in FIG.
As shown in (b), the regeneration area decreases (regulation calculation unit 21
The output of a goes toward the negative polarity region). Time T
₁Then, as shown in FIG.
DC voltage is the limit value (V _L), The voltage regulator 21
Output value of the adjustment calculation unit 21a and the maximum negative current limit value (-
I_MAX) And the value obtained by adding
As shown in FIG. 2 (c), the input value of 21b is used.
The current command value (DC amount) suddenly enters the regeneration state, and
As shown in (a), the DC voltage across the capacitor 13 is
Start decreasing. Time T_TwoThen, as shown in FIG.
The DC voltage across the capacitor 13 is the limit value (V_L)less than
When it decreases, the voltage regulator 21 in the decreasing state shown in FIG.
Of the current command value (DC amount) to the output value of the adjustment calculation unit 21a
Switch. By repeating such an operation, the load 2
Capacitor 1 even if the regenerative current continues to flow from
DC voltage at both ends of 3 is the limit value (V_L) Suppressed below
You.

FIG. 3 shows a second embodiment P of the present invention.
FIG. 8 is a block configuration diagram of a WM control self-exciting rectifier, which has the same function as that of the conventional example in FIG. In FIG. 3, the PWM control self-exciting rectifier 50 includes a DC voltage across the capacitor 13, which is the output of the main circuit 11 of the self-exciting rectifier, to the insulation converter 2.
0, and when the detected DC voltage exceeds a predetermined limit value ( _VL ), the output value of the adjustment calculator 21a of the voltage regulator 21 is replaced with the maximum negative current limit value (- I
There is provided a switching control circuit 51 for inputting ( _MAX ) to the limit calculation unit 21b of the voltage regulator 21.

Operation of the PWM control self-exciting rectifier 50
Will be described below with reference to the operation waveform diagram shown in FIG.
I do. In FIG. 4, time T₀More load 2 to regenerative current
If the current continues to flow, the direct current across the capacitor 13
The voltage starts rising as shown in Fig. 4 (a),
The output of the adjustment calculator 21a of the voltage regulator 21 is shown in FIG.
As shown in (b), the regeneration area decreases (regulation calculation unit 21
The output of a goes toward the negative polarity region). Time T
₁Then, as shown in FIG.
DC voltage is the limit value (V _L), The voltage regulator 21
Negative maximum current limit instead of the output value of the adjustment calculator 21a
Value (-I_MAX) To the limit calculator 21b of the voltage regulator 21
Input the current command value as shown in Fig. 4 (c).
(DC amount) rapidly changes to the regenerative state, and is shown in Fig. 4 (a).
So that the DC voltage across capacitor 13 begins to decrease
You. Time T _TwoThen, as shown in FIG.
DC voltage at both ends of 3 is the limit value (V_L) Reduce to
And the adjusting performance of the decreasing voltage regulator 21 shown in FIG.
The current command value (DC amount) is switched to the output value of the calculator 21a.
You. By repeating such operations, regeneration from load 2 is performed.
Both ends of the capacitor 13 even if the current continues to flow
DC voltage of the limit value (V_L) It is suppressed below.

FIG. 5 shows P showing a third embodiment of the present invention.
FIG. 8 is a block configuration diagram of a WM control self-exciting rectifier, which corresponds to the third and fourth inventions described above, and particularly shows “N = 1” for the fourth invention. Those having the same functions as those in the example are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 5, the PWM control self-exciting rectifier 60 detects the DC voltage across the capacitor 13, which is the output of the main circuit 11 of the self-exciting rectifier, through the insulation converter 20. When the limit value (V _L1 ) of 1 is exceeded, the output value of the adjustment calculator 21b of the voltage adjuster 21 is compared with the 0% value as the _first current command value (V ₁ ^* ), whichever is determined. When a small value is input to the limit calculation unit and the detected value of the DC voltage of the output of the self-exciting rectifier exceeds a second limit value ( _VL2 ) larger than the first limit value ( _VL1 ), The negative maximum current limit value (−I _MAX ) is replaced with the output value of the adjustment calculator 21b of the voltage regulator 21.
The switching control circuit 61 is provided for inputting to the restriction calculator 21b.

Operation of the PWM control self-excited rectifier 60
Will be described below with reference to the operation waveform diagram shown in FIG.
I do. In FIG. 6, time T₀More load 2 to regenerative current
If the current continues to flow, the direct current across the capacitor 13
The voltage starts to rise as shown in Fig. 6 (a), and
The output of the adjustment calculator 21a of the voltage regulator 21 is shown in FIG.
As shown in (b), the regeneration area decreases (regulation calculation unit 21
The output of a goes toward the negative polarity region). Time T
₁Then, as shown in FIG.
DC voltage is the limit value (V _L1), The voltage regulator 21
Output value of the adjustment calculation unit 21b and the first current command value (V₁
^*) As 0% value, and whichever is smaller
By inputting into the notation limit calculation unit, it is shown in FIG.
, The current command value (DC amount) shifts to the regeneration area.
Start regenerative operation. Time T_TwoThen, as shown in FIG.
The DC voltage across the capacitor 13 is the limit value (V_L2)
Then, the output value of the adjustment calculation unit 21b of the voltage regulator 21 becomes
Instead, the negative maximum current limit value (-I_MAX) To voltage regulator 2
By inputting into the limit calculation unit 21b of No. 1, as shown in FIG.
As shown in, the current command value (DC amount) rapidly changes to the regenerative state.
Then, as shown in FIG.
DC voltage begins to decrease. Time T_ThreeThen, as shown in FIG.
The DC voltage across the capacitor 13 is
_L2) When decreasing below, the decreasing voltage shown in Fig. 6 (b)
The current command value is set to the output value of the adjustment calculator 21a of the adjuster 21.
(DC amount) is switched, and DC at both ends of the capacitor 13
The rise in voltage is suppressed.

[0020]

According to the present invention, when the DC voltage of the output of the PWM control self-exciting rectifier exceeds a predetermined limit value,
Instead of the rise suppression operation by the control operation of the voltage regulator, the current command value (DC amount) is rapidly changed to the value in the direction of the regenerative current, so that the operation quickly shifts to the regenerative operation, and the output of the PWM control self-exciting rectifier It is possible to reduce the increase of the DC voltage of 1 and to prevent the PWM control self-exciting rectifier from being stopped when the overvoltage trip value is reached.

[Brief description of the drawings]

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

FIG. 2 is a waveform chart illustrating the operation of FIG.

FIG. 3 is a block diagram showing a PWM control self-excited rectifier according to a second embodiment of the present invention;

FIG. 4 is a waveform chart for explaining the operation of FIG. 3;

FIG. 5 is a block configuration diagram of a PWM control self-exciting rectifier showing a third embodiment of the present invention.

6 is a waveform diagram illustrating the operation of FIG.

FIG. 7 is a block configuration diagram of a PWM control self-excited rectifier showing a conventional example.

FIG. 8 is a waveform chart for explaining the operation of FIG. 7;

[Explanation of symbols]

1 ... Commercial power supply, 2 ... Load, 10, 40, 50, 60 ... P
WM control self-exciting rectifier, 11 ... Main circuit of self-exciting rectifier, 12 ... AC reactor, 13 ... Capacitor, 14 ...
Phase voltage detector, 15, 20 ... Insulation converter, 16 ... Angle signal generating means, 17, 18 ... Sine wave generator, 19 ... Voltage setting device, 21 ... Voltage regulator, 22, 23 ... Multiplier, 24 ...
Current detectors 25 to 27 ... Current regulators, 28 ... Carrier signal generators, 29 ... Comparators, 30 ... Gate drive circuits, 4
1 ... Voltage limit control circuit, 51, 61 ... Switching control circuit.

Claims (4)

[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 adjustment operation for adjusting the voltage. Part and this tone A DC voltage of the output of the self-excited rectifier, and a voltage regulator including a limit calculation unit that limits the current command value (DC amount) based on the output of the calculation unit so as not to exceed a positive and negative maximum current limit value. A voltage limit control circuit that uses a value obtained by adding the output value of the adjustment calculator and the negative maximum current limit value as an input value of the limit calculator when the detected voltage value exceeds a predetermined limit value; A PWM control self-excited rectifying device comprising: 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 adjustment operation for adjusting the voltage. Part and this tone A DC voltage of the output of the self-excited rectifier, and a voltage regulator including a limit calculation unit that limits the current command value (DC amount) based on the output of the calculation unit so as not to exceed a positive and negative maximum current limit value. And a switching control circuit for inputting the negative maximum current limit value to the limit calculation unit instead of the output value of the adjustment calculation unit when the detected voltage value exceeds a predetermined limit value. PWM control self-excited rectifier. 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 adjustment operation for adjusting the voltage. Part and this tone A DC voltage of the output of the self-excited rectifier, and a voltage regulator including a limit calculation unit that limits the current command value (DC amount) based on the output of the calculation unit so as not to exceed a positive and negative maximum current limit value. When the detected voltage value exceeds the first limit value, the output value of the adjustment calculation unit is compared with the 0% value of the output, and the smaller value is input to the limit calculation unit, When the detected value of the DC voltage of the output of the exciter-type rectifier exceeds a second limit value that is larger than the first limit value, the negative maximum current limit is replaced by the output value of the adjustment calculator and the limit calculator is changed. A PWM control self-excited rectifying device, comprising: 4. 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 adjustment operation for adjusting the voltage. Part and this tone A voltage regulator including a limit calculator that limits the current command value (DC amount) based on the output of the calculator so as not to exceed the positive and negative maximum current limit values, and the n-th (n = 1.2) ... N limit value (V _L1 <V _L2 <・
.. <V _LN ) and the command value (V ₁ ^* > V ₂ ^* >...> V _N ^* ) of the n-th (n = 1, 2 ... N), the output of the self-excited rectifier When the detected value of the DC voltage exceeds the nth limit value, the output value of the adjustment calculator is compared with the nth command value, and the smaller value is input to the limit calculator, When the detected value of the DC voltage of the output of the excitation rectifier exceeds the (N + 1) th limit value which is larger than the Nth limit value,
A PWM control self-excited rectifier comprising: a switching control circuit that inputs the negative maximum current limit value to the limit calculation unit instead of the output value of the adjustment calculation unit.