JP3723868B2 - Rectifier control method and controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control method and a control device for a rectifier. More specifically, the present invention relates to a control method and a control device for a rectifier having a rectifier circuit provided in an input unit of an inverter device and using a thyristor as a part of a rectifier element.
[0002]
[Prior art]
Conventionally, many so-called inverter devices (inverters in a broad sense) have been designed to control electric power by converting input alternating current into direct current using a rectifier circuit (converter) using only a diode as a rectifier.
[0003]
As described above, in the conventional inverter device, the rectifier circuit is often configured as a relatively simple circuit including only a diode because the power supply voltage is a high-quality power that hardly fluctuates irregularly. .
[0004]
However, when the inverter device is used for power control of, for example, various facilities of an electric railway vehicle (for example, a ventilation device for a Shinkansen vehicle), there are the following circumstances, which is different from the case of a general industrial inverter device. Special consideration is required.
[0005]
(1) When the number of vehicles in the power feeding section is small and the electrical load in the power feeding section is small, or when power regeneration is performed on the power feeding side during vehicle deceleration, a voltage that greatly exceeds the rated voltage may be applied to the inverter device.
[0006]
(2) When the power feeding section is switched while the vehicle is running, the power supply often falls.
[0007]
(3) Voltage fluctuation is large.
[0008]
And in the inverter apparatus for railway vehicles which drive | operates under such a power supply environment, in order to ensure a favorable driving | running state, the following measures are conventionally taken.
[0009]
(A) In order to avoid the inconvenience due to the above (1), a step-down transformer is inserted into the tertiary power supply (440V), the input voltage is lowered by about 10%, and a voltage exceeding the rated voltage is applied to the inverter device. Reduce frequency.
[0010]
(B) In the case of frequent power supply sag as described in (2) above, in order to prevent an excessive inrush current to the filter capacitor attached to the rectifier circuit, an inrush current comprising an electromagnetic switch and a power resistor A suppression circuit is provided.
[0011]
However, the measures as described in the above (a) and (b) have the following problems.
[0012]
(A) In the measure described in (a) above, the weight and size of the entire device increase by installing a transformer.
[0013]
(B) Also in the measure of (b) above, the installation of the inrush current suppression circuit increases the weight and dimensions of the entire device.
[0014]
(C) Since the electromagnetic switch of the inrush current suppression circuit has a mechanical life, maintenance such as periodic replacement is required.
[0015]
In order to avoid such inconvenience, conventionally, a thyristor is used as a part of the rectifier element, and a soft start function for suppressing an inrush current to the filter capacitor at the time of power-on and a stable DC voltage. There are known half-bridge rectifier circuits in which a rectifier circuit and a function of suppressing an excessive voltage are provided to a rectifier circuit (for example, Japanese Patent Laid-Open Nos. 10-111145, 11-118520, and 09-09). 265504).
[0016]
In such a conventional half-bridge rectifier circuit, the one described in Japanese Patent Laid-Open No. 10-111145 is provided with a voltage sag detection circuit and a timer circuit for gradually opening the thyristor gate pulse phase angle. It is supposed to be.
[0017]
However, this configuration has the following problems.
[0018]
(Ii) It is not easy to appropriately set the voltage threshold value and the time threshold value of the voltage sag time for the voltage sag detection circuit to determine whether or not a voltage sag has occurred.
[0019]
(B) Since the discharge from the filter capacitor during the sag is small when the load is light, it is not always necessary to operate the soft start function when the sag recovers. However, since the voltage drop detection circuit described above is not intended to monitor the load status, even if it is not necessary to operate the soft start function, the soft start function is activated at the same time as the voltage drop is detected. Therefore, it is necessary to stop the circuit operation of the load until the operation is restored.
[0020]
In general, in the soft start function, it can be said that it is desirable to minimize the time until the DC side voltage reaches the specified value within a range where the current does not exceed the specified value. For this reason, the phase angle in each cycle during the operation of the soft start function needs to be changed, for example, in a quadratic function rather than linearly with respect to time (number of cycles). Since it is necessary to align the peak values, the circuit configuration becomes complicated. On the other hand, when the circuit is simplified by linearly changing the phase angle, the time until the DC side voltage reaches the specified value becomes long, and the responsiveness is impaired.
[0021]
In addition, the prior art described in the above-mentioned Japanese Patent Application Laid-Open No. 11-118520 is based on the result of comparing the DC part voltage with the reference value in order to stabilize the DC part voltage with respect to the problem (2). The thyristor gate pulse phase angle is feedback controlled.
[0022]
However, in general, the relationship between the thyristor / gate pulse phase angle and the DC voltage is not linear, and the error often increases even when feedback control is performed. For this reason, PI control is often performed by adding an integrator to the feedback control adjustment unit. However, in this method, when the input voltage changes suddenly, it may take time to settle the output value of the integrator to the original value, and may not be able to cope with it. That is, in such a case, there is a problem that the direct current section voltage becomes excessive or excessive and the operation of the inverter device is interrupted or a failure may occur.
[0023]
[Problems to be solved by the invention]
The present invention has been made in view of such a problem of the prior art, and has a rectifier circuit in which a thyristor is used as a part of a rectifier that can easily and accurately rectify even when a fluctuation in power supply voltage is large. It aims at providing the control method and control apparatus of a rectifier.
[0024]
[Means for Solving the Problems]
  The rectifier control method according to the present invention includes a rectifier in which a rectifier circuit is formed as a half bridge by a diode and a thyristor.The ignition circuit that forms the ignition of the thyristor is controlled by an ignition angle control unit having an ignition angle reference table.A control method,
  The firing angle reference table includes an inrush current suppression processing table for performing an inrush current suppression process in a voltage range equal to or lower than a load operation start voltage, and a voltage range of a load operation start voltage and a regenerative operation start voltage. And a DC current stabilization processing table for performing a process of stabilizing the DC current,
  Detects the AC side voltage value and the DC side voltage value, and for the combination of the detected AC side voltage value and DC side voltage value.For each tableThe thyristor is fired at a preset firing angle.
[0025]
In the control method of the rectifier of the present invention,The inrush current suppression processing table isWhen the detected AC voltage value is high and the DC voltage value is low, the firing angleButsmallAs configured to beWhen the detected AC voltage value is low and the DC voltage value is high, the firing angleButbigConfigured to beIs preferred.
[0026]
In the control method of the rectifier of the present invention,The DC current stabilization processing table isWhen the detected AC voltage value is high and the DC voltage value is high, the firing angleButsmallAs configured to beWhen the detected AC voltage value is low and the DC voltage value is low, the firing angleButbigConfigured to beIs preferred.
[0027]
Furthermore, in the method for controlling a rectifier according to the present invention, the DC voltage value is detected immediately after each zero cross of the AC voltage, and the AC voltage value is detected at an appropriate time when the electrical angle of the AC voltage is 45 degrees to 60 degrees. It is preferable to make it.
[0028]
Furthermore, in the method for controlling a rectifier according to the present invention, it is preferable to output an ignition pulse when a forward direction is applied between the anode and the cathode of the thyristor.
[0029]
Furthermore, in the method for controlling a rectifier according to the present invention, it is preferable to calculate the firing angle for a combination of an AC voltage value and a DC voltage value not included in the table by an interpolation method.
[0030]
On the other hand, the control device for a rectifier of the present invention is a rectifier in which a rectifier circuit is formed as a half bridge by a diode and a thyristor.The ignition circuit that forms the ignition of the thyristor is controlled by an ignition angle control unit having an ignition angle reference table.A control device,
  The firing angle reference table includes an inrush current suppression processing table for performing an inrush current suppression process in a voltage range equal to or lower than a load operation start voltage, and a voltage range of a load operation start voltage and a regenerative operation start voltage. And a DC current stabilization processing table for performing a process of stabilizing the DC current,
  Detects the AC side voltage value and the DC side voltage value, and for the combination of the detected AC side voltage value and DC side voltage value.For each tableThe thyristor is configured to be fired at a preset firing angle.
[0031]
  In the control device of the rectifier of the present invention,The inrush current suppression processing table isWhen the detected AC voltage value is high and the DC voltage value is low, the firing angleButsmallAs configured to beWhen the detected AC voltage value is low and the DC voltage value is high, the firing angleButbigConfigured to beIs preferred.
[0032]
  In the control device of the rectifier of the present invention,The DC current stabilization processing table isWhen the detected AC voltage value is high and the DC voltage value is high, the firing angleButsmallAs configured to beWhen the detected AC voltage value is low and the DC voltage value is low, the firing angleButbigConfigured to beIs preferred.
[0033]
Furthermore, in the control device for the rectifier of the present invention, the DC voltage value is detected immediately after each zero cross of the AC voltage, and the AC voltage value is detected at an appropriate time when the electrical angle of the AC voltage is 45 degrees to 60 degrees. It is preferable that it is configured to be made.
[0034]
Furthermore, in the control device of the rectifier according to the present invention, it is preferable that the thyristor is configured so as to output an ignition pulse when being applied in the forward direction between the anode and the cathode.
[0036]
Furthermore, it is preferable that the controller for the rectifier of the present invention is configured to calculate an ignition angle for a combination of an AC voltage value and a DC voltage value that are not in the table by an interpolation method.
[0037]
[Action]
Since the present invention is configured as described above, it is possible to suppress the inrush current and stabilize the DC voltage in the rectifier while simplifying the configuration and reducing the size and ensuring the quick response.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.
[0039]
FIG. 1 is a block diagram showing a schematic configuration of a converter device to which a rectifier control method according to an embodiment of the present invention is applied.
[0040]
This converter device K is provided in, for example, an inverter device (not shown) for a ventilator of a Shinkansen vehicle, and the AC power transmitted to each vehicle via a railway overhead line is converted into direct current. The power is converted into electric power and supplied to an inverse conversion circuit (inverter in a narrow sense, not shown).
[0041]
Specifically, the converter device K includes a thyristor rectification / smoothing circuit unit 10 in which at least a part of the rectifying element is formed of a thyristor, an ignition circuit 20 for igniting the thyristor of the thyristor rectification / smoothing circuit unit 10, The arc circuit 20 includes a firing angle control unit 30 that controls the thyristor to fire at an appropriate firing angle as a main component.
[0042]
FIG. 2 shows a more specific configuration of the converter device K.
[0043]
The thyristor rectifying / smoothing circuit unit 10 includes a half-bridge rectifier circuit (hereinafter simply referred to as a rectifier circuit) 13 formed by forming two thyristors 11A and 11B and two diodes 12A and 12B in a single-phase mixed bridge circuit, And a smoothing circuit 15 including a smoothing capacitor 14 connected in parallel.
[0044]
Here, each thyristor 11A, 11B is arranged in the lower arm of the bridge circuit, and this indicates whether each thyristor 11A, 11B can be triggered, that is, whether a forward voltage is applied between the anode and the cathode. This is for facilitating formation of a detection circuit used for determination.
[0045]
The starting circuit 20 includes a gate drive circuit 21 that starts the thyristors 11A and 11B. Specifically, the gate drive circuit 21 includes an RS flip circuit (reset set flip circuit) including a gate 1 and a gate 2, a gate 3 including an AND circuit, and a primary for noise removal and signal stabilization. A delay circuit, a gate 4 composed of an AND circuit, and a pulse generation circuit having a switching transistor are provided (see FIG. 5).
[0046]
The firing angle control unit 30 detects the input AC voltage Vac detected by the input AC detection unit 10a and its phase detection signal, and the ignition voltages Vta of the thyristors 11A and 11B detected by the ignition voltage detection units 11a and 11b. , Vtb, that is, the detection signal of the voltage between the anode and the cathode in the thyristors 11A and 11B and the voltage between the smoothing capacitors 14 detected by the intermediate DC voltage detection unit 14a, that is, the detection signal of the intermediate DC voltage Vdc are analog- Based on the A / D converter 31 for digital conversion and the detection signals analog-digital converted by the A / D converter 31, the gate drive circuit 21 inputs the firing angle for firing each thyristor 11A, 11B. An ignition angle reference table (inrush current suppression processing test) expressed three-dimensionally by the AC voltage Vac and the intermediate DC voltage Vdc. Bull, and sets with reference to the DC voltage stabilization table) (3-dimensional table) 40, and a thyristor control unit 32 which performs various control.
[0047]
Further, the converter device K of this embodiment is provided with a regenerative resistor 51 and a regenerative transistor 52 that operate during a regenerative operation, and based on a detection signal of the intermediate DC voltage Vdc input to the smoothing circuit 15. The overvoltage detection / regeneration control unit 50 that detects the overvoltage and controls the regenerative transistor 52 is provided. The configuration of the overvoltage detection / regeneration control unit 50 is the same as that of the conventional one, and a detailed description thereof is omitted.
[0048]
Here, the thyristor control unit 32 avoids this because there is a possibility that an inrush current to the filter capacitor (smoothing circuit 15) is generated when the power is turned on or after the input voltage is suddenly reduced, thereby destroying the main circuit components. The control is performed so as to suppress the inrush current. The thyristor control unit 32 also performs DC voltage stabilization processing for stabilizing the intermediate DC voltage Vdc input to the smoothing circuit 15.
[0049]
The ignition angle control unit 30 and the overvoltage detection / regeneration control unit 50 configured as described above are realized by, for example, a microcomputer.
[0050]
Hereinafter, the inrush current suppression process and the DC voltage stabilization process performed by the firing angle control unit 30 will be described in detail with reference to FIGS. 3 and 4.
[0051]
First, the inrush current suppression process will be described.
[0052]
In order to suppress the inrush current, when it is determined that the AC side voltage value (Vac) is larger than the DC side voltage value (Vdc), the firing angles of the thyristors 11A and 11B are narrowed down, that is, It is effective to delay the starting angle by delaying the starting point (decreasing the starting angle). Then, the peak value of the AC voltage cut out by the thyristors 11A and 11B becomes small, and the inrush current is suppressed.
[0053]
In order to realize such control, it is necessary to set an appropriate firing angle for each half cycle of the input AC voltage based on the AC side voltage value (Vac) and the DC side voltage value (Vdc). For this reason, in this embodiment, an appropriate firing angle corresponding to the AC side voltage value (Vac) and the DC side voltage value (Vdc) is determined in advance as a three-dimensional table (inrush current suppression processing table). Prepared and referred to this, the firing angle is set for each half cycle of the input AC. (Note that this three-dimensional table will be described in detail later.)
[0054]
More specifically, as shown in FIG. 3 and FIG. 4, immediately after detecting each zero cross of the AC input voltage, an interrupt is applied by event capture, and immediately after this, the DC side voltage value (Vdc) is detected, and then AC The side voltage value (Vac) is detected.
[0055]
Since the detection of the AC side voltage value (Vac) is made for the purpose of detecting the maximum value of the AC side voltage value (Vac), the time point when the AC side voltage value (Vac) becomes the maximum value. However, in consideration of the time required for calculating the firing angle, the electrical angle of the AC voltage is set to an appropriate time between 45 degrees and 60 degrees. Based on the detected AC side voltage value (Vac), the maximum value in the half cycle is estimated assuming that the AC side voltage is a sine wave. Note that the procedure for setting the AC input voltage detection timing shown in FIG. 4 may be omitted after it has been performed once.
[0056]
The detected DC side voltage value (Vdc) and AC side voltage value (Vac) are each converted into a digital signal by the A / D converter 31, and the AC side voltage value (Vac) converted into the digital signal is converted into the digital signal. As described above, the maximum value of the AC side voltage value (Vac) in the half cycle is calculated based on.
[0057]
Next, using the maximum value of the DC side voltage value (Vdc) converted into the digital signal and the calculated AC side voltage value (Vac), the firing angle corresponding to the combination is selected from the inrush current suppression processing table, The timing for generating the thyristor gate pulse (ignition pulse) is calculated based on the ignition angle.
[0058]
Thereafter, the calculated firing pulse generation timing is set as a trigger pulse command by a timer by the output conveyor.
[0059]
Accordingly, in response to the trigger pulse command set by the timer, an ignition pulse (trigger pulse) is output to the thyristors 11A and 11B, and the thyristors 11A and 11B are turned on. That is, the thyristors 11A and 11B are fired at a desired firing angle. The generation of this ignition pulse (trigger pulse) will be described in detail later.
[0060]
Conventionally, when the above-described control is realized by an analog circuit, it is common to gradually increase the firing angle using an integration timer circuit. However, with this method, it is difficult to determine under what conditions the integration timer reset should be performed if there is an instantaneous fluctuation or loss of the power supply while the filter capacitor is being charged. Performance may not be obtained.
[0061]
However, in this embodiment, since the firing angle is controlled according to the setting value in the table, instead of the conventional feedback control, the inrush current can be effectively suppressed even when the power supply voltage fluctuates greatly. It becomes possible.
[0062]
Next, the DC voltage stabilization process will be described.
[0063]
In Shinkansen vehicles, the fluctuation of the power supply voltage is large, and the input AC voltage value is often higher by 25% or more than the rated value (this is because the rated value of the overhead line voltage is 25 kV, but the no-load voltage is This is because 30 kV is the design value.) Therefore, DC voltage stabilization processing is performed to keep the output DC voltage value constant regardless of fluctuations in the input voltage value. Here, as in the inrush current suppression processing, the firing angles of the thyristors 11A and 11B are controlled with reference to a preset table (DC voltage stabilization processing table).
[0064]
That is, the AC side voltage value (Vac) and the DC side voltage value (Vdc) are detected every half cycle of the input AC voltage, and the DC side voltage value (Vdc) is expected to be higher than a preset value based on the detection result. If it is, the firing angle corresponding to the combination of the AC side voltage value (Vac) and the DC side voltage value (Vdc) in the DC voltage stabilization processing table is selected, and the thyristors 11A and 11B are fired. Delay to lower the peak value. In other words, the firing angle is reduced (the firing angle is delayed), and the peak value is lowered.
[0065]
On the other hand, if it is predicted from the detected values of the AC side voltage value (Vac) and the DC side voltage value (Vdc) that the DC side voltage value (Vdc) is lower than a preset value, the DC voltage stabilization The firing angle corresponding to the combination of the AC side voltage value (Vac) and the DC side voltage value (Vdc) in the conversion processing table is selected, and the firing angles of the thyristors 11A and 11B are advanced (the firing angle is changed). Increase) to increase the peak value.
[0066]
More specifically, as shown in FIG. 3 and FIG. 4, immediately after detecting each zero cross of the AC input voltage, an interrupt is applied by event capture, and immediately after this, the DC side voltage value (Vdc) is detected, and then AC The side voltage value (Vac) is detected.
[0067]
These detected DC side voltage value (Vdc) and AC side voltage value (Vac) are each converted into a digital signal by the A / D converter 31, and the AC side voltage value (Vac) converted into this digital signal is also converted. ), The maximum value of the AC side voltage value (Vac) in a half cycle is calculated as described above.
[0068]
Next, using the maximum value of the DC side voltage value (Vdc) converted into the digital signal and the calculated AC side voltage value (Vac), the firing angle corresponding to the combination is selected from the DC voltage stabilization processing table. The timing for generating the thyristor gate pulse (ignition pulse) is calculated based on the ignition angle.
[0069]
Thereafter, the calculated firing pulse generation timing is set as a trigger pulse command by a timer by the output conveyor.
[0070]
Accordingly, in response to the trigger pulse command set by the timer, an ignition pulse (trigger pulse) is output to the thyristors 11A and 11B, and the thyristors 11A and 11B are turned on. That is, the thyristors 11A and 11B are fired at a desired firing angle.
[0071]
Next, generation of an ignition pulse (trigger pulse) will be described with reference to FIGS.
[0072]
The thyristors 11A and 11B cannot be turned on even when an ignition pulse (trigger pulse) is applied unless a voltage is applied in the forward direction. Therefore, even if an ignition pulse (trigger pulse) is output according to the trigger pulse command generated by the above procedure, the ignition may fail depending on the conditions.
[0073]
In order to prevent this, the gate drive circuit 21 is configured to output the trigger pulse for the first time when the ignition is enabled if the conditions for enabling the ignition are not satisfied when the trigger pulse is output. Yes. Details will be described below.
[0074]
A zero cross signal of the input AC voltage is input to the gate 1 so that the RS flip circuit is reset every half cycle of the input AC voltage, and the ignition pulse from the ignition angle control unit 30 is applied to the gate 2. (Trigger pulse) command is input. The output of the RS flip circuit is input to the gate 3. Further, the thyristor 11A (11B) is applied to the gate 3 in the forward direction from the ignition voltage detector 11a (11b) that detects the ignition voltage Vta (Vtb) of the thyristor 11A (11B). A trigger enable signal indicating is input. Thereby, the gate 3 is turned on and outputs an on signal when the trigger pulse command and the trigger enable signal are on.
[0075]
The output of the gate 3 is branched and input to the gate 4 and the primary delay circuit. The output of the first-order lag circuit is inverted and input to the gate 4. As a result, noise associated with the output signal from the gate 3 is removed, and the signal is stabilized. A trigger enable signal indicating that the inverter device is in operation is also input to the gate 4. This is because it is meaningless to generate a trigger pulse unless the inverter device is in operation.
[0076]
The output of the gate 4 is input to the base of the switching transistor for switching. That is, if each of the trigger pulse command, trigger enable signal, and trigger enable signal is on, the switching transistor is turned on and a trigger pulse (ignition pulse) is output to the thyristor 11A (11B).
[0077]
Since the gate drive circuit 21 is configured as described above, the trigger pulse is always output to the thyristors 11A and 11B when the thyristors 11A and 11B are applied in the forward direction. Therefore, the thyristors 11A and 11B are reliably fired.
[0078]
Next, the inrush current suppression processing table and the DC voltage stabilization processing table will be described with reference to FIG. FIG. 7 is a graph showing how to create the inrush current suppression processing table and the DC voltage stabilization processing table.
[0079]
In the example shown in FIG. 7, the rated voltage of the input AC voltage is 440 V in terms of effective value, and the load operation start voltage and the rated voltage of the intermediate DC voltage are 400 V and 620 V, respectively. Further, the regenerative operation start voltage of the intermediate DC voltage and the overvoltage abnormality threshold are 784 V and 833 V, respectively. A region below the load operation start voltage is defined as an inrush current suppression processing region, and a region between the load operation start voltage and the regenerative operation start voltage is defined as a direct current stabilization processing region. Here, the area above the line connecting the rated point (440 Vrms, 620 V) and the origin (0 Vrms, 0 V) (the black area in the figure) is an uncontrollable area, and the thyristor is not fired.
[0080]
As shown in FIG. 7, in the inrush current suppression process, in order to suppress the inrush current and ensure quick response, when the AC voltage value is high and the DC voltage value is low, the firing angle is reduced. While the ignition angle control is performed, when the AC voltage value is low and the DC voltage value is high, the ignition angle control is performed so that the ignition angle becomes large. In other words, an improved soft start is made. In FIG. 7, when the AC voltage value is high and the DC voltage value is high, and when the AC voltage value is low and the DC voltage value is low, the circuit element is prevented from being destroyed in the overvoltage region, and the undervoltage region. This is because the thyristor is not ignited because sufficient power cannot be supplied to the load.
[0081]
Further, in the DC voltage stabilization process, for the reasons described above, when the AC voltage value is high and the DC voltage value is high, the ignition angle control is performed so that the ignition angle is reduced, while the AC voltage value is When the DC voltage value is low and the ignition voltage is low, the ignition angle is controlled so that the ignition angle becomes large. That is, pseudo feedback control is performed to stabilize the DC voltage. In FIG. 7, when the AC voltage value is high and the DC voltage value is low, and when the AC voltage value is low and the DC voltage value is high, the circuit element is prevented from being destroyed in the overvoltage region, and the undervoltage region. This is because the thyristor is not ignited because sufficient power cannot be supplied to the load.
[0082]
Next, an example of a procedure for creating the inrush current suppression processing table and the DC voltage stabilization processing table will be described with reference to FIGS. 8 and 9. The table is set so that the DC voltage changes by 50 V every control cycle (AC half cycle). The voltage setting value is not limited to the above, and can be set arbitrarily.
[0083]
(1) The input AC voltage Vac is detected, and the maximum value Vacp is estimated.
[0084]
(2) The intermediate DC voltage Vdc is detected.
[0085]
(3) Calculate the firing angle of the thyristor according to the following distinction.
[0086]
(3-1) When the difference between the target value Vdcr of the intermediate DC voltage and the current value Vdc is 50 volts or more:
The firing angle α is calculated by the following equation (1).
[0087]
Vacp · sinα = Vdc + 50 (1)
[0088]
That is,
α = arcsin {(Vdc + 50) / Vacp}
It becomes.
[0089]
(3-2) When the difference between the target value Vdcr of the intermediate DC voltage and the current value Vdc is less than 50 volts:
The firing angle α is calculated by the following equation (2).
[0090]
Vacp · sinα = Vdcr (2)
[0091]
That is,
α = arcsin {Vdcr / Vacp}
It becomes.
[0092]
As described above, in the converter device K according to the embodiment, when the voltage sag occurs, the firing angle is set with reference to the preset rush voltage suppression processing table, so that the voltage sag detection circuit becomes unnecessary, and the voltage sag is reduced. It is not necessary to set a voltage threshold value for determining whether or not it has occurred, and a time threshold value for the instantaneous drop time. That is, the configuration can be simplified.
[0093]
In addition, even if a voltage drop occurs when the load is light, the firing angle is not unnecessarily reduced, so the time required for the load to return to the operable state is minimized, ensuring responsiveness. The
[0094]
Furthermore, lack of quick response to a sudden change in input voltage and fluctuations in the DC voltage as in the case of performing PI type feedback control are suppressed.
[0095]
Furthermore, there is no need for mode switching between soft start and DC part voltage stabilization control, which can be realized by a single microcomputer (thyristor control part), and the apparatus can be downsized.
[0096]
As mentioned above, although this invention has been demonstrated based on embodiment, this invention is not limited only to this embodiment, A various change is possible. For example, in the embodiment, a single-phase alternating current is described as an example, but the application of the present invention is not limited to a single-phase alternating current, and can be applied to a multi-phase alternating current by appropriately modifying, for example, a three-phase alternating current. It can also be applied to exchanges. Further, the firing angle for the combination of the AC side voltage value and the DC side voltage value that are not in the firing angle reference table may be calculated by an interpolation method.
[0097]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to suppress the inrush current to the rectifier and stabilize the output voltage while ensuring the simplification and downsizing of the configuration and ensuring the quick response. An effect is obtained.
[0098]
Further, according to the preferred embodiment of the present invention, since the trigger pulse is output when the thyristor is applied in the forward direction, an excellent effect that the thyristor is reliably fired can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram of a converter device to which a rectifier control method according to an embodiment of the present invention is applied.
FIG. 2 is a circuit diagram of a converter device used in the embodiment.
FIG. 3 is an explanatory diagram of a control method according to the embodiment;
FIG. 4 is a flow church showing a control procedure of the embodiment.
FIG. 5 is an operation explanatory diagram of a gate drive circuit.
FIG. 6 is a flowchart showing a trigger pulse generation procedure;
FIG. 7 is a graph showing a relationship between a thyristor firing angle and an AC voltage / DC voltage.
FIG. 8 is an example of a graph of a voltage used for calculating an ignition angle.
FIG. 9 is another example of the graph.
[Explanation of symbols]
10 Thyristor rectification / smoothing circuit
10a Input AC detector
11A, 11B Thyristor
11a, 11b ignition voltage detector
15 Smoothing circuit
20 ignition circuit
21 Gate drive circuit
30 firing angle controller
31 A / D converter
32 Thyristor controller
40 Firing angle reference table (3D table)
50 Overvoltage detection / regenerative control unit
K converter device

Claims (12)

A control method for controlling a firing circuit for firing a thyristor in a rectifier comprising a rectifier as a half bridge with a diode and a thyristor, using a firing angle control unit having a firing angle reference table ,
The firing angle reference table includes an inrush current suppression processing table for performing an inrush current suppression process in a voltage range equal to or lower than a load operation start voltage, and a voltage range of a load operation start voltage and a regenerative operation start voltage. And a DC current stabilization processing table for performing a process of stabilizing the DC current,
The AC side voltage value and the DC side voltage value are detected, and the point of the thyristor is determined by the firing angle preset in each table for the combination of the detected AC side voltage value and the DC side voltage value. A method of controlling a rectifier characterized by forming an arc. The inrush current suppression processing table is configured such that when the detected AC voltage value is high and the DC voltage value is low, the firing angle is reduced, and the detected AC voltage value is low and the DC voltage value is high. 2. The method of controlling a rectifier according to claim 1, wherein the firing angle is configured to be large. The DC current stabilization processing table is configured such that when the detected AC voltage value is high and the DC voltage value is high, the firing angle is reduced, and the detected AC voltage value is low and the DC voltage value is the method of the rectifier device according to claim 1, characterized in that it is configured such that firing angle is increased is low when.   2. The rectifier according to claim 1, wherein the DC voltage value is detected immediately after each zero crossing of the AC voltage, and the AC voltage value is detected at an appropriate time when the electrical angle of the AC voltage is 45 degrees to 60 degrees. Control method.   2. The method of controlling a rectifier according to claim 1, wherein an ignition pulse is outputted when an anode and a cathode of the thyristor are applied in a forward direction. The method of the rectifier device of claim 1, wherein the calculating the firing angle for the combination of the not in the table AC voltage and the DC voltage value by interpolation. A control device for controlling a starting circuit for starting a thyristor in a rectifier comprising a rectifier as a half bridge with a diode and a thyristor, by means of a starting angle control unit having a starting angle reference table ,
The firing angle reference table includes an inrush current suppression processing table for performing an inrush current suppression process in a voltage range equal to or lower than a load operation start voltage, and a voltage range of a load operation start voltage and a regenerative operation start voltage. And a DC current stabilization processing table for performing a process of stabilizing the DC current,
The AC side voltage value and the DC side voltage value are detected, and the point of the thyristor is determined by the firing angle preset in each table for the combination of the detected AC side voltage value and the DC side voltage value. A control device for a rectifying device, wherein the control device is configured to form an arc. The inrush current suppression processing table is configured such that when the detected AC voltage value is high and the DC voltage value is low, the firing angle is reduced, and the detected AC voltage value is low and the DC voltage value is high. 8. The control device for a rectifier according to claim 7, wherein the ignition angle is configured to increase. The DC current stabilization processing table is configured such that when the detected AC voltage value is high and the DC voltage value is high, the firing angle is reduced, and the detected AC voltage value is low and the DC voltage value is lower when it is configured to firing angle is increased the control unit of the rectifier device according to claim 7, wherein. The DC voltage value is detected immediately after each zero cross of the AC voltage, and the AC voltage value is detected at an appropriate time in which the electrical angle of the AC voltage is 45 degrees to 60 degrees. 8. The control device for the rectifier according to 7 . 8. The control device for a rectifier according to claim 7 , wherein an igniting pulse is output between the anode and the cathode of the thyristor when applied in the forward direction. 8. The control device for a rectifier according to claim 7 , wherein an ignition angle for a combination of an AC voltage value and a DC voltage value not included in the table is calculated by an interpolation method.

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