JPS5875475A - Controlling method for dc power supply and manufacture thereof - Google Patents

Abstract

PURPOSE:To suppress the exciting inrush current of the titled power supply by a method wherein, when the DC power supply consisting of a transformer and a rectifier is controlled by a thyristor provided on the primary side of the transformer 1, power application is started from the commutation phase next to the final phase of power application when the operation is stopped. CONSTITUTION:The DC power supply is formed by the transformer 1 and the rectifier 2 which was provided on the secondary side of the transformer, a switching element whereon a thyristor 3 and a diode 6 are connected in antiparalled form is connected to each phase on the primary side of the transformer 1, and starting, stopping and controlling operations are performed. At this time, the thyristor of final current application phase at the time when operation is stopped is detected by a detecting device 10 using the signal of the voltage dividers 11-13 which were provided on the thyristors 3-5, and based on the above, the phase next to the optimum power application phase is determined by a power application phase selecting device 14, and a gate signal is outputted. Accordingly, power application can be started from the direction where the residual magnetism of the tranformer 1 will be cancelled when starting, and the exciting inrush current can be suppressed.

Description

Detailed Description of the Invention (1) Technical Field of the Invention The present invention is directed to a DC power supply device equipped with a rectifier consisting of a transformer and a diode bridge. The present invention relates to a control method and device for a DC power supply device.

(2) Prior Art Conventionally, in DC power supplies that handle high voltages or high currents, when controlling the DC output, the DC output is not controlled on the DC side (the secondary side of the transformer), but on the AC side (the primary side of the transformer). ) may be controlled. This is because the Thyrisk element used in high voltage or high current circuits on the DC side is expensive, so an inexpensive diode element is used in place of the Thyrisk element in such a part, and a diode element is used in place of the Thyrisk element on the AC side. This is because by providing a thyristor element, which is relatively easy to handle, and controlling the thyristor element using this element, an economical device can be obtained.

Figure 1 shows an overview of this type of conventional DC power supply. In Figure 6, 1 is a three-phase transformer, and 2 is this 3-phase transformer.
A diode bridge is provided on the secondary side of the phase transformer 1, and these constitute a rectifier. In addition, 3,4゜5Fi thyristor element, 6.7.8 is a diode element, and the above-mentioned 3. Primary winding of phase transformer 1 1m1111
1 (R, S, T phase). Further, reference numeral 9 denotes a dart signal generating device that sequentially supplies dart signals to the darts of the silisk elements 3 and 4.5.

In such a device, r from the dirt signal generator-9
-) Turning on the AC power by controlling the ignition of the thyristor elements 3, 4゜5 in combination with the diode 6.7゜8 according to the signal and operating the switching element as an AC switch; It is not possible to interrupt or control the DC output. Here, the switching element that operates as an AC switch is a device that operates at high speed and is highly reliable because it does not have mechanical components compared to conventional oil breaker or direct air breaker.

(3) Problems with the prior art However, in the conventional device as described above,
Cyrisk elements 3, 4.5 and diodes g, 't,
When the switching element constituted by s operates, there is a problem in that the excitation inrush current of the three-phase transformer 1 is generated as a very large value due to its operating characteristics. The inrush current of the transformer is greatly affected by the residual magnetism of the iron core. This is because the operating point moves, and the magnetic flux density of the iron core further increases due to the energization at the time of starting the device, causing the iron core to become saturated and the excitation current to increase rapidly.

[Such excitation inrush current can be several tens of times higher than the steady current in some cases], and may affect other equipment due to a temporary drop in system voltage, malfunction of protective devices such as relays, or damage to the power supply equipment. Therefore, it is desirable to keep the value as small as possible, as it may cause damage to the component equipment.

(4) Purpose of the Invention The present invention has been made in view of the above-mentioned circumstances, and its purpose is to reliably suppress the excitation inrush current of the transformer at startup to solve the nine problems mentioned above. An object of the present invention is to provide a method and device for controlling a DC power supply device.

(5) Overview of the invention First, as mentioned above, the excitation inrush current of a transformer is largely influenced by the residual magnetism of the iron core, and this depends on the final energized phase when the transformer is stopped. The iron core is magnetized and generates residual magnetism, and the operating point of the iron core moves, so that the magnetic flux density of the iron core increases to J! This is due to the iron core becoming saturated and the excitation current increasing rapidly.

Therefore, when starting the operation of the device, it is sufficient to start with energization in a direction that cancels out the Fi transfer magnetism, and this phase is the phase following the last energized phase, or a phase that is 120 degrees behind the final energized phase.

The present invention manages the final energized phase when the device is stopped and the subsequent energized phase when it starts up, and starts energizing from the commutation phase (120 degrees delayed phase) after the final energized phase at the start of operation. By starting, the above-mentioned promise will be achieved.

(6) Embodiments of the Invention In the following, embodiments of the present invention shown in the drawings will be observed. Figure 2 shows an example of the configuration of a control device for a DC power supply according to the present invention, and in the figure, the same parts as in Figure 1 are given the same reference numerals for observation.

In FIG. 2, reference numeral 10 denotes a final energized phase detection device, which detects the voltage between the anode and cathode terminals of the thyristor elements 3, 4, and 50 of each of the three phases based on voltage signals from voltage dividers 11, 12, and 13. , to determine the cyrisk element of the last energized phase when the operation is stopped. Further, 14 is an energized phase selection device at the start of operation, which determines the optimal energized phase and the next phase (120 degree delayed phase) of the optimal energized phase based on the detection signal from the iIl final energized energized phase detection device, This is given to the gate signal generator 9' at the time of a start command. That is, this control device is composed of a final energized phase detection device 10, an energized phase selection device 14, and a dart signal generator 9'.

Next, the operation of this device configured as described above will be described. The last energized phase detection device 10 detects the voltage divider 1 when the operation is stopped.
Analyzing the voltage signal from 1.12.13, the last energized phase thyristor element when the operation is stopped is a thyristor element! ,4.
1), and provides the determination signal to the energized phase selection device fix4. When a start command is input, the energized phase selection device 14 gives a signal to the dart signal generator [9/] to energize the last energized phase 120 (delayed phase) during three-phase operation. The gate signal causes the thyristor element to conduct. That is, if the thyristor elements are commutated in the order of 3.4.5 by the r-t signal from the dirt signal generator 9', for example, the element in the last energized phase at the time of shutdown is the thyristor. If it were element 5, energization would start from thyristor element 3 at the start of operation), and the excitation inrush of three-phase transformer 1 would be suppressed.

In this way, the thyrisk element 3. 4.5 and diode elements ti, v, s connected in anti-parallel to connect a switching element in series and start.
In DC power supply equipment that controls stop and DC output,
Final energized phase detection for determining the thyrisk element of the last energized phase when the DC power supply is stopped, based on the voltage between the terminals of the thyrisk elements J and 4.5 detected by the voltage divider 11.12.13. The thyristor element of the commutation phase next to the last energized phase (the phase delayed by 120 degrees in electrical angle) is determined based on the judgment signal from the final energized phase detection unit fjtxo and the final energized phase detection unit, and the determined content is transmitted at the time of the operation start command. The energized phase selection device 14 to output and this energized phase selection device fk1
A dirt signal generator [9/
This constitutes a control device for a DC power supply.

Therefore, the three-phase transformer 1 that occurs when starting up the DC power supply
The magnetizing inrush current can be reliably suppressed, and all of the conventional problems described above can be solved.

(7) Modified example of the invention In the above embodiment, the thyristor element in the final energized phase during operation stop was determined based on the voltage signal between the terminals of the thyristor element from the voltage divider 11, 12, and 13. As shown in the figure, the determination is made based on the current signal from the electric field detector 15.16.1'j/ which is installed in each of the three phases and detects the primary current of the three-phase transformer 1. ! LL.

In addition, the present invention can be modified and implemented in various ways without changing the gist thereof.

(8) As described in detail, according to the present BAt, the transformer primary current t
Or, the thyristor element of the last energized phase when the operation is stopped is determined based on the voltage signal between the terminals of the thyristor element, and when the operation is started according to the start command, energization is started from the thyristor element of the commutation phase next to the last energized phase. As a result, it is possible to provide an extremely reliable control device for a DC power supply device that can reliably suppress the excitation inrush current of a three-phase transformer.

[Brief explanation of the drawing]

FIG. WJ1 is a circuit diagram showing an example of a conventional DC power supply device, FIG. 2 is a circuit diagram showing one embodiment of the present invention, and FIG. 3 is a circuit diagram showing another embodiment of the present invention. 1...3-phase transformer, 2...diode rectifier, 3~
5...Thyristor element, 6-8...Diode element, 9,9'...f-) signal generator, 10...Final energized phase detection device, 11-13...Voltage divider, I4 ... Energized phase selection device, 15-17... Current detector. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3

Claims (3)

[Claims] (1) One of the transformers connected to a rectifier consisting of a transformer and a diode rectifier provided on the secondary side of the transformer.
In a DC power supply device that controls starting, stopping, and DC output by connecting a switching element in which a silice element and a diode element are connected in antiparallel in series to the next winding 1 m@, after the said DC power supply device is stopped. When starting up, the commutation phase (electrical angle 12
A control method for a DC power supply device in which energization (ignition) is started from a thyristor element force (phase delayed by 0 degrees). (2) A rectifying device consisting of a transformer and a diode rectifier provided on the secondary side of the transformer is connected to the primary winding side of the transformer in anti-parallel connection with a silisk element and a diode element. A thyristor element in the last energized phase when the DC power supply is stopped based on the voltage between the terminals of the thyristor element, in which switching elements are connected in series to control start, stop, and DC output. a final energized phase detection device, and a thyristor element for the next commutation phase (phase delayed by 120 electrical degrees) of the last energized phase based on the determination signal from this final energized phase detection device; Equipped with an energizing phase selection device that outputs the determined content when an operation start command is issued, and a dart signal generation device that gives a gate signal to the thyristor element of the current phase to start energization based on the output from the energization phase selection device. A control device for a DC power supply device. (3) One of the transformers in a rectifier consisting of a transformer and a diode rectifier provided on the secondary side of the transformer.
In a DC power supply device that controls starting, stopping, and DC output by connecting a switching element formed by connecting a thyristor element and a diode element in antiparallel in series on the next winding side, the switching element is a final energized phase detection device that determines the thyristor element of the last energized phase when the DC power supply is running or stopped; and a determination signal from the final energized phase detector that determines the next commutation of the last energized phase. An energized phase selection device that determines the thyristor element of a phase (O phase with a delay of 120 degrees in electrical angle) and outputs the determined content at the time of an operation start command; Give f−) signal to start energizing f
-) A control device for a DC power supply device, characterized by comprising a signal generator.