JP3396775B2 - Inverter control circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an inverse converter for direct current power transmission, etc., and more particularly to a control device for an inverse converter that can be stably operated even when waveform distortion occurs in an alternating voltage. Is.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 14 shows a system diagram of DC power transmission including an inverse converter for converting DC to AC, which is the object of the present invention. 14
11 and 12 are AC systems, 21 and 22 are conversion transformers, 31 and 32 are AC / DC converters that convert AC to DC or DC to AC, 41 and 42 are DC reactors, 5
1, 52 are DC power transmission lines, 61, 62 are the AC / DC converters 3
In the control device that outputs signals for controlling 1 and 32, the detailed control block in the control device 61 is also provided in the control device 62.

The details of the control unit 61 will be described below.
Reference numeral 01 denotes a constant margin angle control circuit for maintaining a margin angle, which will be described later, at a set constant value when the AC / DC converter 31 performs an inverse conversion operation;
Is a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value commensurate with the power command value from the operation command center (not shown), 603 is a transformer for detecting the voltage of the AC system, 604 Is a harmonic amount detection circuit for detecting the amount of harmonics contained in this AC voltage, and 605 is a switching circuit 621 when the output of the harmonic amount detection circuit 604 exceeds a preset value. Is a switch drive circuit that outputs a signal for switching from the to the β set value.

Reference numeral 607 denotes a minimum value selection circuit which selects the smaller one of the output of the switching circuit 621 and the output of the constant current control circuit 602. Normally, the constant current control is performed when the AC / DC converter 31 is in the forward conversion operation. The output of the circuit 602 is selected, and during the inverse conversion operation, the output of the constant margin angle control 601 is selected. Reference numeral 608 is a pulse phase shift circuit that outputs a pulse according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. The commutation operation of the AC / DC converter 31 during the inverse converter operation will be described with reference to FIGS. 15 and 16. In FIG. 15, 1 to 6 are thyristors forming an AC / DC converter, and 1 to 6 also indicate the order of firing of the thyristors. Further, the reactor X is 2 of the conversion transformer.
Represents an impedance such as 1.

Considering the case where the thyristors 1 and 2 are ignited now, the line voltage of the U-phase and the W-phase of the AC voltage appears on the DC side of the AC / DC converter, and the current flowing at an electrical angle of 120 degrees. After the period, the operation moves to the next phase and the thyristor 3 is fired at the control angle α. At this time, since the voltage of the v-phase is usually higher than that of the u-phase, the current flowing in the u-phase is canceled by the current flowing in from the v-phase, and the thyristor 1 is cut off when the current flowing in the thyristor 1 becomes zero, and the thyristor 1 is disconnected. The current moves to 3.

The AC / DC converter repeats this commutation operation every 120 degrees to generate a DC voltage. The time from the application of the pulse to the thyristor 3 to the disconnection of the thyristor 1 is the overlapping angle u. This commutation operation must be completed while the u-phase voltage is lower than the v-phase voltage. Thyristor 1
When the voltage is cut off, v-line and w-phase line voltages appear on the DC side of the AC / DC converter. The angle until the time when the thyristor 1 is cut off and the u-phase voltage becomes equal to the v-phase voltage is an angle called a margin angle γ. The above relationship is shown in FIG.

In order to operate the inverse converter stably, it is necessary to sufficiently secure this margin angle in any case. The γ setting value of the constant margin angle control circuit 601 indicates this margin angle setting value, and is normally set to γ = 19 degrees.
However, when the voltage is distorted due to harmonics or the like, the intersection point of the voltage moves as shown by the wavy line in FIG. .

Therefore, as shown in FIG. 14, a harmonic quantity detection circuit 604 is provided, and when the quantity of harmonics contained in the voltage exceeds a certain level, the control angle β (= π set by the switching circuit 621 in advance is set. -Adjust the control angle to α). The set value of β is usually β = 60 degrees, and when this operation is performed, the control angle is advanced to the above value (β becomes large), so that the reactive power consumption of the converter is more than necessary. It increases or the inverse conversion power fluctuates significantly. On the other hand, when the amount of higher harmonic waves is below the detection level, the above operation is not performed, and thus unstable operation such as commutation failure may occur.

In order to solve the above-mentioned conventional method,
Japanese Patent Publication No. 5-68174 discloses a method of detecting the amount of harmonics and advancing the control angle linearly according to the detected amount. However, the harmonics are included in the AC voltage as described below. However, in order to ensure stable commutation operation, it is necessary to consider the magnitude of the harmonics as well as the AC voltage, DC current, and frequency. Here, AC voltage v, DC current Id,
The relationship among the commutation impedance X, the control angle α, and the allowance angle γ is
It is expressed by equation (1),

[0011]

[Equation 1]

And the integral interval is α to π-γ,
When the AC voltage contains one harmonic (Vh), v = √2V1sin θ + 2Vhsin (nθ +
Substituting φ), the following equation (2) is obtained. However,
n is the order of harmonics

2XId = V1 (cos α + cos γ) + Vh {cos (nα + φ) −cos (n (π−γ) + φ)} −−−−− (2) , There is no chance of commutation failure. As can be seen from the equation (2), the control angle α is the fundamental wave voltage V
1, DC current Id, and commutation impedance X.

FIG. 13 illustrates the fundamental wave voltage V1 on the horizontal axis and the correction control angle Δα on the vertical axis with the direct current Id and the harmonic content as parameters. Here, the harmonic content rate represents the ratio of Vh / V1, and FIG. 13 shows an example of the second harmonic wave V2 as Vh, and V2 = 0.2,
V2 = 0.4 is the ratio. Then, V2 = 0.
2 shows changes in the V1 vs. Δα curve when Id was changed to 0.1, 0.7 and 1.3 for 2 and 0.4, and α
Since ≧ 90 degrees, this curve is used for αma
It is on the right side of the curve of x = 90 degrees.

From this figure, if the degree of fluctuation is Id = 0.7 to 1.3, there is no large fluctuation in Δα.
It can be seen that when d becomes 0.1, Δα is greatly affected. From this, Id = 0.7 to 1.3 can be represented by one curve. As for the range of Id = 0.1 to 0.7, it is difficult to represent it with one curve.
The range of Id is appropriately divided to have a plurality of curves.

Further, since the commutation impedance depends on the frequency, in other words, if the control angle α is determined by the frequencies of the fundamental wave voltage, the DC current and the AC voltage, the operation can be performed at the proper control angle α. Become. Japanese Patent Fair 5-68174
In the method of the publication, the effect is exerted when the DC current, AC voltage, frequency, etc. are constant, but in the event of an AC system failure in which the fundamental wave voltage drops significantly, AC voltage, DC current,
The frequency etc. fluctuates greatly and it is not possible to advance the proper control angle.

[0017]

Since the conventional control device for the inverse converter is constructed as described above, waveform distortion occurs in the AC voltage, fluctuations in the AC voltage, fluctuations in the DC current, fluctuations in the frequency. When such a phenomenon occurs, commutation failure or the like occurs, and there is a problem that the converter cannot operate stably.

Except for the disadvantages of the prior art described above, the object of the present invention is to perform the inverse conversion without a large change in the transmitted power, the reactive power, etc. even when the AC voltage has a waveform distortion or the frequency changes. It is to provide a control device capable of stably operating a container.

[0019]

(1) A control circuit of an inverse converter according to the present invention converts direct current such as direct current power transmission into alternating current.
In the controller of the inverse converter,
The magnitude of the AC voltage of the AC system and the harmonics of the AC system
The magnitude of the wave voltage and the magnitude of the frequency of the AC system
According to the correction, the ignition allowance angle or control angle is corrected.
It

(2) Further, the inverse converter according to (1) above
In the control circuit, the magnitude of the harmonic voltage of the AC system is
Harmonics of any order contained in the AC voltage of the AC system
Magnitude of voltage or included in the AC voltage of the above AC system
Magnitude of harmonic voltage of arbitrary multiple orders with different orders
It is what

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a control device for an inverse converter for direct current transmission etc. according to the first embodiment, and shows only one end relevant to the present invention. In FIG. 1, 11 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs an inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 604 is a harmonic amount detection circuit that detects the amount of harmonics contained in this AC voltage, and 610 is a control angle correction circuit that inputs the output of this harmonic amount detection circuit 604 and the AC voltage and calculates and outputs the control angle to be corrected. The circuit, 606, is an adder.

Reference numeral 607 denotes a minimum value selection circuit which selects a smaller one of the output of 601 and the output of the constant current control circuit 602. Normally, when the AC / DC converter 31 is in the forward conversion operation, the constant current control circuit 602 has a minimum value. The output is selected, and in the case of the inverse conversion operation, the output of the constant margin angle control 601 is selected. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
4 is input. The harmonic amount detection circuit calculates the amount of harmonics contained in the AC voltage from the input AC voltage waveform using a method such as Fourier analysis, and outputs the harmonic amount to the control angle correction circuit 610. The control angle correction circuit 610 receives the harmonic amount and the AC fundamental wave voltage as inputs, and outputs a control angle correction value Δα using a non-linear correction curve, an example of which is shown in FIG. In the DC power transmission used for the power supply line, the DC current Id is almost constant, so that only one Id curve in FIG. 13 needs to be selected, and the configuration can be simplified. (Note that Id is constant in the first to fourth embodiments.)

The adder 606 adds the set γ setting value and the above Δα and outputs a margin angle command value to the constant margin angle control circuit 601. The constant margin angle control circuit 601 is an adder 606.
The control angle α is output so that the margin angle command value output from is obtained.

As described above, according to this embodiment, even if the AC voltage includes waveform distortion, the margin angle γ is set in advance in accordance with the magnitude of the waveform distortion. Since stable operation is possible and the margin angle is increased according to the size of the waveform distortion, the reactive power required by the converter can be increased more than necessary, or the transmitted power can be increased unnecessarily as in the past. There is no lowering.

Embodiment 2. The second embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram showing a configuration of a control device for an inverse converter for DC power transmission or the like according to the second embodiment, and shows only one end relevant to the present invention. In FIG. 2, 11 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 is performing an inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 6041 denotes a harmonic quantity detection circuit for detecting the m-th order harmonic quantity contained in this AC voltage, 6042 denotes a harmonic quantity detection circuit for detecting the n-th order harmonic quantity contained in this AC voltage, and 6043 denotes this AC quantity. A harmonic quantity detection circuit for detecting the p-th harmonic quantity contained in the voltage, 6101, 61
02 and 6103 are the respective harmonic amount detection circuits 6041 and 6
042, 6043 output and AC fundamental wave voltage are input,
It is a control angle correction circuit for calculating and outputting a control angle to be corrected.

Reference numeral 606 is an adder, and 607 is a minimum value selection circuit for selecting a smaller one of the output of 601 and the output of the constant current control circuit 602, which is normally set when the AC / DC converter 31 is in the forward conversion operation. The output of the current control circuit 602 is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
41, 6042, and 6043. In each harmonic amount detection circuit, the corresponding harmonic amount included in the AC voltage is calculated from the input AC voltage waveform by using a method such as Fourier analysis, and each harmonic amount is supplied to the control angle correction circuits 6101, 6102, 6103. Is output.

Control angle correction circuits 6101, 6102, 61
03 receives the above-mentioned respective harmonic amounts and the AC fundamental wave voltage, and outputs control angle correction values Δαm, Δαn, and Δαp using a non-linear correction curve of which an example is shown in FIG. The adder 606 sets the set γ setting value and the above Δαm, Δαn, and Δαp.
Is added to output a margin angle command value to the constant margin angle control circuit 601. The constant margin angle control circuit 601 outputs the control angle α so that the margin angle command value output from the adder 606 is obtained.

As described above, according to this embodiment, even if the AC voltage includes a waveform distortion, the correction angle can be determined for each harmonic component, so that fine control can be performed.
In addition, the margin angle γ is set in advance according to the magnitude of the waveform distortion, so that the inverse converter can be operated stably, and the margin angle is increased according to the magnitude of the waveform distortion. As described above, the reactive power required by the converter is not increased more than necessary, and the transmitted power is not unnecessarily reduced.

Embodiment 3. Embodiment 3 of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing the configuration of a control device for an inverse converter for DC power transmission or the like according to the third embodiment, and shows only one end relevant to the present invention. In FIG. 3, 11 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 604 is a harmonic amount detection circuit that detects the amount of harmonics contained in this AC voltage, and 610 is a control that receives the output of this harmonic amount detection circuit 604 and the AC fundamental wave voltage as input and calculates and outputs the control angle to be corrected. Corner correction circuit, 606
Is an adder.

Reference numeral 607 denotes a minimum value selection circuit for selecting a smaller signal of the output of 601 and the output of the constant current control circuit 602, and normally, when the AC / DC converter 31 is in the forward conversion operation, the constant current control circuit 602 is operated. The output is selected, and in the case of the inverse conversion operation, the output of the constant margin angle control 601 is selected. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
4 is input. The harmonic amount detection circuit calculates the amount of harmonics contained in the AC voltage from the input AC voltage waveform using a method such as Fourier analysis, and outputs the harmonic amount to the control angle correction circuit 610.

The control angle correction circuit 610 receives the amount of higher harmonic waves and the AC fundamental wave voltage as input, and uses the non-linear correction curve shown in FIG. 13 as an example to obtain the control advance angle correction value Δβ (whether the control angle is returned or advanced). In the case of FIG. 13, since it is a correction value, | Δα | = | Δβ |) is output. The adder 606 adds the output of the constant margin angle control circuit 601 and the control advance angle correction value, and advances the control advance β to the minimum value selection circuit 607.
Is output. In the case of the reverse converter operation, the control advance angle β is selected and the AC / DC converter 31 is ignited at the timing of the control advance angle β via the pulse phase shift circuit 608.

As described above, according to this embodiment, even if the AC voltage includes waveform distortion, the margin angle γ is set in advance according to the magnitude of the waveform distortion. It has characteristics that stable operation is possible and the operation is fast because the control angle is directly corrected. Moreover, since the margin angle is increased according to the magnitude of the waveform distortion, it is possible to make the reactive power required by the converter larger than necessary or reduce the transmitted power unnecessarily as in the past. There is no.

Fourth Embodiment Embodiment 4 of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram showing the configuration of a control device for an inverse converter for DC power transmission or the like according to the fourth embodiment, and shows only one end relevant to the present invention. In FIG. 4, 11 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 5152 is a DC transmission line.

Reference numeral 601 denotes a constant margin angle control circuit for keeping the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 6041 is a harmonic amount detection circuit for detecting the m-th order harmonic amount contained in this AC voltage, and 6042 is contained in this AC voltage. A harmonic amount detecting circuit for detecting the n-th harmonic amount, 6043 is a harmonic amount detecting circuit for detecting the p-th harmonic amount contained in this AC voltage, 6101, 6
102 and 6103 are harmonic wave amount detection circuits 6041,
It is a control angle correction circuit which receives the outputs of 6042 and 6043 and the AC fundamental wave voltage and calculates and outputs the control angle to be corrected.

Reference numeral 606 is an adder, and 607 is a minimum value selection circuit for selecting the smaller signal of the output of 601 and the output of the constant current control circuit 602, which is normally set when the AC / DC converter 31 is in the forward conversion operation. The output of the current control circuit 602 is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
41, 6042, and 6043. Each harmonic amount detection circuit calculates the corresponding harmonic amount contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and outputs each harmonic amount to the control angle correction circuits 6101, 6102, 6103. Output.

Control angle correction circuits 6101, 6102, 61
Reference numeral 03 is a control angle correction value Δβm, Δβn, Δβp (whether the control angle is returned or advanced) by using the above-mentioned respective harmonic amounts and the AC fundamental wave voltage as inputs and using a non-linear correction curve whose example is shown in FIG. It is expressed as α and β, and in the case of FIG. 13, since it is a correction value, | Δ
α | = | Δβ |) is output. The adder 606 is the above Δβ.
The constant margin angle control circuit 601 and m, Δβn, and Δβp are added to the output of the constant margin angle control circuit 601, and the minimum value selection circuit 60 is added.
Control proceeds to 7 and β is output. In the case of the reverse converter operation, the control advance angle β is selected and the AC / DC converter 31 is ignited at the timing of the control advance angle β via the pulse phase shift circuit 608.

As described above, according to this embodiment, even if the AC voltage contains a waveform distortion, the correction angle can be determined for each harmonic component, so that fine control is possible.
Further, since the margin angle γ is set in advance according to the magnitude of the waveform distortion, the inverse converter can be stably operated, and the control angle is directly corrected, so that the operation is fast. . Moreover, since the margin angle is increased according to the magnitude of the waveform distortion, it is possible to make the reactive power required by the converter larger than necessary or reduce the transmitted power unnecessarily as in the past. There is no.

Embodiment 5. Embodiment 5 of the present invention will be described below with reference to the drawings. FIG. 5 is a block diagram showing a configuration of a control device for an inverse converter for DC power transmission or the like according to the fifth embodiment, and shows only one end relevant to the present invention. In FIG. 5, 11 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 604 is a harmonic amount detection circuit for detecting the amount of harmonics contained in this AC voltage, and 810 is the DC transmission line 5
A direct current detector for detecting the value of the direct current flowing in 1; 61
Reference numeral 0 is a control angle correction circuit that receives the output of the harmonic amount detection circuit 604, the output of the DC current detector, and the AC voltage as input, and calculates and outputs the control angle to be corrected.

Reference numeral 606 is an adder, and 607 is a minimum value selection circuit for selecting the smaller signal of the output of 601 and the output of the constant current control circuit 602, which is normally set when the AC / DC converter 31 is in the forward conversion operation. The output of the current control circuit 602 is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
4 is input. The harmonic amount detection circuit 604 calculates the amount of harmonics contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and the control angle correction circuit 6
10, and the DC current detector 810 outputs the current value flowing in the DC power transmission line to the control angle correction circuit 610.

The control angle correction circuit 610 inputs the harmonic amount, the AC fundamental wave voltage, and the DC current, and outputs the control angle correction value Δα using a non-linear correction curve, an example of which is shown in FIG. The adder 606 adds the set γ setting value and the above Δα, and outputs a margin angle command value to the constant margin angle control circuit 601. The constant margin angle control circuit 601 outputs the control angle α so that the margin angle command value output from the adder 606 is obtained.

As described above, according to this embodiment, even if the AC voltage includes a waveform distortion, the margin angle γ is increased in advance according to the magnitude of the waveform distortion and the operating state (the value of the DC current). Since it is set, stable operation of the inverse converter can be performed in any operating condition, and the margin angle is increased according to the size of the waveform distortion. It does not increase the power more than necessary or reduce the transmitted power unnecessarily.

Sixth Embodiment Embodiment 6 of the present invention will be described below with reference to the drawings. FIG. 6 is a block diagram showing the configuration of a control device for an inverse converter for direct current transmission etc. according to the sixth embodiment, and shows only one end relevant to the present invention. In FIG. 6, 11 is an AC system, 21 is a conversion transformer 31 is an AC / DC converter that converts AC into DC or DC into AC, 41 is a DC reactor, and 5152 is a DC transmission line.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 6041 is a harmonic amount detection circuit for detecting the m-th order harmonic amount contained in this AC voltage, and 6042 is contained in this AC voltage. A harmonic amount detection circuit that detects the n-th harmonic amount, 6043 is a harmonic amount detection circuit that detects the p-th harmonic amount included in this AC voltage, and 810 is a DC current value flowing through the DC transmission line 51. It is a direct current detector for detecting.

Reference numerals 6101, 6102, and 6103 are control angle corrections for inputting the outputs of the harmonic amount detection circuits 6041, 6042, and 6043, the output of the DC current detector 810, and the AC voltage, and calculating and outputting the control angle to be corrected. Circuit, 606
Is an adder, and 607 is a minimum value selection circuit for selecting a smaller one of the output of 601 and the output of the constant current control circuit 602. Normally, the constant current control circuit 602 is used when the AC / DC converter 31 is in the forward conversion operation. Is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
41, 6042, and 6043. Each harmonic amount detection circuit calculates the corresponding harmonic amount contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and outputs each harmonic amount to the control angle correction circuits 6101, 6102, 6103. Output. In addition, the DC current detector is the transmission line 5
The DC current value flowing through the control angle correction circuit 6101, 61
02, 6103.

Control angle correction circuits 6101, 6102, 61
03 receives the above-mentioned respective harmonic amounts, DC current value and AC fundamental wave voltage, and outputs control angle correction values Δαm, Δαn and Δαp using a non-linear correction curve of which an example is shown in FIG. The adder 606 sets the set γ setting value and the above Δαm, Δ
αn and Δαp are added and the margin angle command value is output to the constant margin angle control circuit 601. The constant margin angle control circuit 601 is an adder 6
The control angle α is output so that the margin angle command value output from 06 is obtained.

As described above, according to this embodiment, even if the AC voltage includes a waveform distortion, the correction angle can be determined for each harmonic component in accordance with the operating state, so that fine control is possible. . In addition, the margin angle γ is set in advance according to the magnitude of the waveform distortion, so that the inverse converter can be operated stably, and the margin angle is increased according to the magnitude of the waveform distortion. As described above, the reactive power required by the converter is not increased more than necessary, and the transmitted power is not unnecessarily reduced.

Embodiment 7. Embodiment 7 of the present invention will be described below with reference to the drawings. FIG. 7 is a block diagram showing the configuration of a control device for an inverse converter for DC power transmission or the like according to the seventh embodiment, and shows only one end relevant to the present invention. In FIG. 7, 11 is an AC system, 21 is a conversion transformer 31 is an AC / DC converter that converts AC into DC or DC into AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 604 is a harmonic amount detection circuit for detecting the amount of harmonics contained in this AC voltage, and 810 is the DC transmission line 5
A direct current detector for detecting the value of the direct current flowing in 1; 61
Reference numeral 0 denotes a control angle correction circuit that receives the output of the harmonic amount detection circuit 604, the output of the DC current detector 810, and the AC voltage and calculates and outputs the control angle to be corrected.

Reference numeral 606 is an adder, and 607 is a minimum value selection circuit for selecting the smaller signal of the output of 601 and the output of the constant current control circuit 602, which is normally set when the AC / DC converter 31 is in the forward conversion operation. The output of the current control circuit 602 is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
4 is input. The harmonic amount detection circuit calculates the amount of harmonics contained in the AC voltage from the input AC voltage waveform using a method such as Fourier analysis, and outputs the harmonic amount to the control angle correction circuit 610. Further, the direct current detector 810 outputs a direct current value. The control angle correction circuit 610 receives the harmonic amount, the DC current value, and the AC fundamental wave voltage as inputs, and
The control advance angle correction value Δβ using the non-linear correction curve shown in FIG. (Α and β are expressed depending on whether the control angle is returned or advanced, and in the case of FIG. 13, since it is the correction value, | Δα | = | Δβ | Will be output).

The adder 606 adds the output of the constant margin angle control circuit 601 and the control advance angle correction value, and outputs the control advance β to the minimum value selection circuit 607. In the case of the reverse converter operation, the control advance angle β is selected and the AC / DC converter 31 is ignited at the timing of the control advance angle β via the pulse phase shift circuit 608.

As described above, according to this embodiment, the margin angle γ is set in advance according to the magnitude of the waveform distortion even if the AC voltage includes the waveform distortion. Stable operation is possible, and it is possible to make corrections according to operating conditions.Moreover, since the control angle is directly corrected, the operation is fast, and the margin angle is increased according to the magnitude of waveform distortion. Unlike the conventional case, the reactive power required by the converter is not made unnecessarily large and the transmitted power is not unnecessarily reduced.

Embodiment 8. Embodiment 8 of the present invention will be described below with reference to the drawings. FIG. 8 shows the configuration of a control device for an inverse converter for direct current transmission etc. according to the eighth embodiment. It is a block diagram and shows only one end relevant to the present invention. In FIG. 8, 11 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 5152 is a DC transmission line.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 6041 denotes a harmonic quantity detection circuit for detecting the m-th order harmonic quantity contained in this AC voltage, 6042 denotes a harmonic quantity detection circuit for detecting the n-th order harmonic quantity contained in this AC voltage, and 6043 denotes this AC quantity. A harmonic amount detection circuit for detecting the p-th harmonic amount included in the voltage, and a direct current detector 810 for detecting the value of the direct current flowing through the direct current transmission line 51.

Reference numerals 6101, 6102, and 6103 are control angle corrections for inputting the outputs of the harmonic amount detection circuits 6041, 6042, and 6043, the output of the DC current detector 810, and the AC voltage, and calculating and outputting the control angle to be corrected. Circuit, 606
Is an adder, and 607 is a minimum value selection circuit for selecting a smaller one of the output of 601 and the output of the constant current control circuit 602. Normally, the constant current control circuit 602 is used when the AC / DC converter 31 is in the forward conversion operation. Is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
41, 6042, and 6043. Each harmonic amount detection circuit calculates the corresponding harmonic amount contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and outputs each harmonic amount to the control angle correction circuits 6101, 6102, 6103. Output. Further, the DC current detection circuit 810 detects the value of the DC current flowing in the DC power transmission line 51, and outputs it to the control angle correction circuits 6101, 6102, 6103.

Control angle correction circuits 6101, 6102, 61
Reference numeral 03 is a control angle correction value Δβm, Δβn, Δβp (returning the control angle) using the non-linear correction curve whose example is shown in FIG. Depending on the progress, the expression becomes α and β. In the case of FIG. 13, since it is a correction value, | Δα | = | Δβ |) is output. The adder 606 adds the above Δβm, Δβn, and Δβp and the constant margin angle control circuit 601 adds the output of the constant margin angle control circuit 601.
Control advances to the minimum value selection circuit 607 and outputs β. In the case of the reverse converter operation, the control advance angle β is selected and the AC / DC converter 31 is ignited at the timing of the control advance angle β via the pulse phase shift circuit 608.

As described above, according to this embodiment, even if the AC voltage includes a waveform distortion, since the correction angle can be determined for each harmonic component, fine control can be performed, and the operating condition can be improved. The characteristics are that the operation can be performed quickly because the control angle is directly corrected. In addition, the margin angle γ is set in advance according to the magnitude of the waveform distortion, so that the inverse converter can be operated stably, and the margin angle is increased according to the magnitude of the waveform distortion. As described above, the reactive power required by the converter is not increased more than necessary, and the transmitted power is not unnecessarily reduced.

Ninth Embodiment The ninth embodiment of the present invention will be described below with reference to the drawings. FIG. 9 is a block diagram showing the configuration of a control device for an inverse converter for direct current transmission etc. according to the ninth embodiment, and shows only one end relevant to the present invention. In FIG. 9, 11 is an AC system, 21 is a conversion transformer 31 is an AC / DC converter that converts AC into DC or DC into AC, 41 is a DC reactor, and 5152 is a DC transmission line.

Reference numeral 601 denotes a constant margin angle control circuit for keeping the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 604 is a harmonic amount detection circuit for detecting the amount of harmonics contained in this AC voltage, and 850 is a frequency detector for detecting the frequency value of the AC voltage. Reference numeral 610 is a control angle correction circuit which receives the output of the harmonic amount detection circuit 604 and the output of the frequency detector 850 and the AC voltage and calculates and outputs the control angle to be corrected.

Reference numeral 606 is an adder, and 607 is a minimum value selection circuit for selecting the smaller signal of the output of 601 and the output of the constant current control circuit 602. Normally, when the AC / DC converter 31 is in the forward conversion operation. When the output of the constant current control circuit 602 is selected and the inverse conversion operation is performed, the output of the constant margin angle control 601 is selected. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
4 is input. The harmonic amount detection circuit 604 calculates the amount of harmonics contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and the control angle correction circuit 6
10 and the frequency detector 850 outputs the frequency value of the AC voltage to the control angle correction circuit 610.

The control angle correction circuit 610 inputs the harmonic amount, the frequency value and the AC fundamental wave voltage and outputs a control angle correction value Δα using a non-linear correction curve of which an example is shown in FIG. Although the frequency parameter is not described in FIG. 13, since XId influences the commutation operation as shown in Expression (2), the Id is corrected according to the frequency change, and thus the correction of FIG. You can use curves. The adder 606 adds the set γ setting value and the above Δα, and outputs a margin angle command value to the constant margin angle control circuit 601. The constant margin angle control circuit 601 outputs the control angle α so that the margin angle command value output from the adder 606 is obtained.

As described above, according to this embodiment, even if the AC voltage includes waveform distortion, the margin angle γ is set large in advance according to the magnitude of the waveform distortion, and the frequency on the AC side. It is possible to perform stable operation of the inverse converter because it can be corrected according to the fluctuation of, and also to increase the margin angle according to the size of the waveform distortion and the fluctuation of the frequency.
Unlike the conventional case, the reactive power required by the converter is not made unnecessarily large and the transmitted power is not unnecessarily reduced.

Tenth Embodiment The tenth embodiment of the present invention will be described below with reference to the drawings. FIG. 10 is a block diagram showing the configuration of a control device for an inverse converter for DC power transmission or the like according to the tenth embodiment, and shows only one end relevant to the present invention. In FIG. 10, 1
1, 1 is an AC system, 21 is a conversion transformer 31 is an AC / DC converter that converts AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for keeping the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 6041 denotes a harmonic quantity detection circuit for detecting the m-th order harmonic quantity contained in this AC voltage, 6042 denotes a harmonic quantity detection circuit for detecting the n-th order harmonic quantity contained in this AC voltage, and 6043 denotes this AC quantity. A harmonic amount detection circuit that detects the p-th harmonic amount included in the voltage, and 850 is a frequency detector that detects the frequency value of the AC voltage.

Reference numerals 6101, 6102, and 6103 are control angle correction circuits for inputting the outputs of the harmonic amount detection circuits 6041, 6042, and 6043, the output of the frequency detector 850, and the AC voltage, and calculating and outputting the control angle to be corrected. 606 is an adder, 607 is the output of 601 and the constant current control circuit 6
In the minimum value selection circuit that selects the smaller one of the outputs of 02, the output of the constant current control circuit 602 is normally selected when the AC / DC converter 31 is in the forward conversion operation, and the constant margin angle is selected in the reverse conversion operation. The output of control 601 is selected. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
41, 6042, and 6043. Each harmonic amount detection circuit calculates the corresponding harmonic amount contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and outputs each harmonic amount to the control angle correction circuits 6101, 6102, 6103. Output. Further, the frequency detector 850 determines the frequency value of the AC voltage by the control angle correction circuits 6101 and 6102.
It is output to 6103.

Control angle correction circuits 6101, 6102, 61
Reference numeral 03 designates the above-mentioned respective harmonic amounts, frequency values and AC fundamental wave voltage, and outputs control angle correction values Δαm, Δαn and Δαp using a non-linear correction curve of which an example is shown in FIG. Figure 1
Although the frequency parameter is not described in 3, the Xid affects the commutation operation as shown in the equation (2). Therefore, by correcting the Id according to the frequency change, FIG.
A correction curve of 3 can be used. The adder 606 adds the set γ setting value and the above Δαm, Δαn, and Δαp, and outputs a margin angle command value to the constant margin angle control circuit 601. The constant margin angle control circuit 601 outputs the control angle α so that the margin angle command value output from the adder 606 is obtained.

As described above, according to this embodiment, even if the AC voltage includes a waveform distortion, the correction angle can be determined for each harmonic component, so that fine control is possible and the frequency on the AC side can be controlled. It becomes possible to make a correction according to the fluctuation of. Also,
The margin angle γ is set in advance according to the magnitude of the waveform distortion, so that the inverse converter can be operated stably, and the margin angle is increased according to the magnitude of the waveform distortion. In addition, the reactive power required by the converter is not made unnecessarily large and the transmitted power is not unnecessarily reduced.

Eleventh Embodiment The eleventh embodiment of the present invention will be described below with reference to the drawings. FIG. 11 is a block diagram showing the configuration of a control device for an inverse converter for direct current transmission etc. according to the eleventh embodiment, and shows only one end relevant to the present invention. In FIG. 11, 1
Reference numeral 1 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 604 is a harmonic amount detection circuit that detects the amount of harmonics contained in this AC voltage, 850 is a frequency detector that detects the frequency value of the AC voltage, and 610 is the output of this harmonic amount detection circuit 604 and frequency detector 850. Is a control angle correction circuit that receives the output of AC and an AC voltage as input and outputs a control angle to be corrected. Reference numeral 606 is an adder.

Reference numeral 607 denotes a minimum value selection circuit for selecting a smaller one of the output of 601 and the output of the constant current control circuit 602, which is normally the constant current control circuit 602 when the AC / DC converter 31 is in the forward conversion operation. The output is selected, and in the case of the inverse conversion operation, the output of the constant margin angle control 601 is selected. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified and controls the AC / DC converter life 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
4 is input. The harmonic amount detection circuit calculates the amount of harmonics contained in the AC voltage from the input AC voltage waveform using a method such as Fourier analysis, and outputs the harmonic amount to the control angle correction circuit 610. The frequency detector 850 also outputs a frequency value.

The control angle correction circuit 610 receives the harmonic amount, the frequency value and the AC fundamental wave voltage as input, and uses the non-linear correction curve shown in FIG. 13 as an example to control the advance angle correction value Δβ (returns the control angle). Depending on the progress, the expression becomes α and β. In the case of FIG. 13, since it is a correction value, | Δα | = | Δβ |) is output. Although the frequency parameter is not described in FIG. 13, since XId influences the commutation operation as shown in Expression (2), the Id is corrected according to the frequency change, and thus the correction of FIG. You can use curves.

The adder 606 adds the output of the constant margin angle control circuit 601 and the control advance angle correction value, and outputs the control advance β to the minimum value selection circuit 607. In the case of the reverse converter operation, the control advance angle β is selected and the AC / DC converter 31 is ignited at the timing of the control advance angle β via the pulse phase shift circuit 608.

As described above, according to this embodiment, the margin angle γ is set in advance according to the magnitude of the waveform distortion even if the AC voltage includes the waveform distortion, so that the inverse converter It has the characteristics that stable operation is possible and the operation is fast because the control angle is directly corrected. Furthermore, since the margin angle is increased according to the magnitude of the waveform distortion, the reactive power required by the converter is increased more than necessary, or the transmitted power is unnecessarily reduced, as in the past. Never.

Twelfth Embodiment The twelfth embodiment of the present invention will be described below with reference to the drawings. FIG. 12 is a block diagram showing the configuration of a control device for an inverse converter for DC power transmission or the like according to the twelfth embodiment, and shows only one end relevant to the present invention. In FIG. 12, 1
1 is an AC system, 21 is a conversion transformer, 31 is an AC / DC converter for converting AC to DC or DC to AC, 41 is a DC reactor, and 51 and 52 are DC transmission lines.

Reference numeral 601 denotes a constant margin angle control circuit for maintaining the margin angle at a set constant value when the AC / DC converter 31 performs the inverse conversion operation.
Reference numeral 602 denotes a constant current control circuit for controlling the current flowing through the AC / DC converter 31 so as to have a current setting value corresponding to a power command value from an operation command center (not shown), and 603 a transformer for detecting the voltage of the AC system. Reference numeral 6041 denotes a harmonic quantity detection circuit for detecting the m-th order harmonic quantity contained in this AC voltage, 6042 denotes a harmonic quantity detection circuit for detecting the n-th order harmonic quantity contained in this AC voltage, and 6043 denotes this AC quantity. A harmonic amount detection circuit that detects the p-th harmonic amount included in the voltage, and 850 is a frequency detector that detects the frequency value of the AC voltage.

Reference numerals 6101, 6102, and 6103 receive the outputs of the harmonic amount detection circuits 6041, 6042, and 6043, the frequency value of the frequency detector 850, and the AC voltage, respectively.
A control angle correction circuit for calculating and outputting a control angle to be corrected, 60
6 is an adder, and 607 is a minimum value selection circuit that selects the smaller one of the output of 601 and the output of the constant current control circuit 602, which is normally a constant current control circuit when the AC / DC converter 31 is in the forward conversion operation. The output of 602 is selected, and the output of the constant margin angle control 601 is selected during the inverse conversion operation. Reference numeral 608 denotes a pulse phase shift circuit that outputs a pulse having a phase shift characteristic according to the magnitude of the selected signal. This pulse is amplified to control the AC / DC converter 31, and the AC / DC converter outputs a desired DC voltage.

Next, the operation will be described. Transformer 603
AC voltage including harmonics is transmitted through the harmonic amount detection circuit 60.
41, 6042, and 6043. Each harmonic amount detection circuit calculates the corresponding harmonic amount contained in the AC voltage from the input AC voltage waveform by using a method such as Fourier analysis, and outputs each harmonic amount to the control angle correction circuits 6101, 6102, 6103. Output. Further, the frequency detection circuit 850 detects the frequency value of the AC voltage, and the control angle correction circuit 6101,
It outputs to 6102 and 6103.

Control angle correction circuits 6101, 6102, 61
Reference numeral 03 indicates the control angle correction values Δβm, Δβn, and Δβp (whether the control angle is returned or advanced) by using the above-mentioned respective harmonic amounts, frequency values, and AC voltage as inputs and using a non-linear correction curve whose example is shown in FIG. In the case of FIG. 13, since it is a correction value, | Δα | = | Δβ |) is output.

Although the frequency parameter is not shown in FIG. 13, since XId influences the commutation operation as shown in the equation (2), by correcting Id according to the frequency change, Thirteen correction curves can be used. The adder 606 adds the above Δβm, Δβn, and Δβp and the constant margin angle control circuit 601 adds the output of the constant margin angle control circuit 601.
Control advances to the minimum value selection circuit 607 and outputs β. In the case of the reverse converter operation, the control advance angle β is selected and the AC / DC converter 31 is ignited at the timing of the control advance angle β via the pulse phase shift circuit 608.

As described above, according to this embodiment, even if the AC voltage includes a waveform distortion, since the correction angle can be determined for each harmonic component, fine control is possible. It has a feature that it can be corrected according to the frequency fluctuation of. In addition, the margin angle γ is set in advance according to the magnitude of the waveform distortion, so that the inverse converter can be operated stably, and the margin angle is increased according to the magnitude of the waveform distortion. As described above, the reactive power required by the converter is not increased more than necessary, and the transmitted power is not unnecessarily reduced.

[0095]

As described above, according to the present invention,
The magnitude of the AC voltage of the AC system connected to the inverse converter,
The harmonic voltage of the AC system and the AC voltage of the AC system
Depending on the magnitude of the frequency, the ignition allowance or control angle
Since the AC voltage is corrected, harmonics are included in the AC voltage.
Even if commutation failure can be prevented, stable operation of the reverse converter is possible.
Become.

(2) Also, the magnitude of the harmonic voltage of the AC system
Is the order of any order included in the AC voltage of the AC system.
Magnitude of harmonic voltage or AC voltage of the above AC system
Of harmonic voltages of arbitrary multiple orders with different orders included in
Since the size is set, the high frequency of the order corresponding to the system is
It is possible to select an appropriate high frequency voltage
Become.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a control device for an inverse converter according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control device for an inverse converter according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a control device for an inverse converter according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a control device for an inverse converter according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a control device for an inverse converter according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a control device for an inverse converter according to a sixth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a control device for an inverse converter according to a seventh embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a control device for an inverse converter according to an eighth embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a control device for an inverse converter according to a ninth embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a control device for an inverse converter according to a tenth embodiment of the present invention.

FIG. 11 is a block diagram showing the configuration of a control device for an inverse converter according to an eleventh embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a control device for an inverse converter according to a twelfth embodiment of the present invention.

FIG. 13 is an operational characteristic diagram for deriving a correction control angle according to the present invention.

FIG. 14 is a diagram showing a configuration of a conventional inverse converter control device.

FIG. 15 is a diagram for explaining the operation of a conventional inverse converter control device.

FIG. 16 is a diagram illustrating an operation of a conventional inverse converter control device.

[Explanation of symbols]

11 AC system 21 Conversion transformer 31 AC / DC converter 41 DC reactor 51, 52 DC transmission line 601 Constant margin angle control circuit 602 Constant current control circuit 603 Transformer 604, 6041, 6042, 6043 Harmonic amount detection circuit 850 Frequency detection The control angle correction circuit 606 is an adder 607, a minimum value selection circuit 608, a phase shift circuit 810, and a direct current detector.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 7/515 H02M 7/155

Claims (2)

(57) [Claims] 1. A reverse transformation for converting direct current into alternating current, such as direct current power transmission.
In the controller of the converter, the magnitude of the AC voltage of the AC system connected to the inverse converter,
The harmonic voltage of the AC system and the AC voltage of the AC system
Depending on the magnitude of the frequency, the ignition allowance or control angle
Of an inverse converter characterized by the fact that
circuit. 2. The control circuit of the inverse converter according to claim 1.
There are, the magnitude of the harmonic voltage of the AC system, the exchange of the AC system
The magnitude of the harmonic voltage of any order contained in the voltage, or
Are the orders of different orders included in the AC voltage of the AC system.
It is characterized by the magnitude of the harmonic voltage of the desired multiple orders.
Inverter control circuit.