JPS63161877A - Inverter device - Google Patents

Abstract

PURPOSE:To prevent overcharge by connecting a charge limiting circuit including a Zener diode limiting the charging charges of a second capacitor at a predetermined voltage value in parallel with the second capacitor. CONSTITUTION:An inverter device is constituted by connecting a choke coil 1, a thyristor 2 and a first capacitor 3 in series with input terminals T1, T2, and a primary winding P for a transformer 4 is connected to the capacitor 3. Load 5 is connected to a secondary winding S for the transformer 4, and one terminal of a feedback winding S0 is connected to a gate for the thyristor 2 through a diode 11 and a second capacitor 6 and the other terminal to the node of the thyristor 2 and the first capacitor 3. In this case, the series body of a Zener diode 8 and a diode 9 is juxtaposed to the second capacitor 6 as a charge limiting circuit 20, and a resistor 12, a diode 13 and a capacitor 15 are disposed in an array with the thyristor 2. Accordingly, the wasteful charging of the second capacitor 6 is prevented. &z:14: starting circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an improvement in an inverter device having a gate-controlled rectifying element such as a thyristor.

<Prior Art> An inverter device that triggers and turns on a gate-controlled rectifying element by discharging a capacitor to cause automatic oscillation is known, for example, from Japanese Patent Publication No. 50-23731.

<Problems to be Solved by the Invention> Even in the conventional inverter device described above, the time from capacitor charging to stopping and discharging start must be determined by appropriately selecting the values of the capacitor and resistor provided in the gate circuit. could be arbitrarily optimized.

However, there is no consideration given to the case where the charging voltage to the capacitor changes due to load fluctuations, or how to handle the charge after the element is turned on, resulting in poor response, and even if you try to increase the frequency, the thyristor For reasons such as the inability to erase invalid gate signals, sufficiently high-speed switching operations could not be expected.

The present invention has been made in view of these points, and aims to provide an inverter device that is capable of stable operation up to a high frequency range by optimizing the trigger signal.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides an oscillating circuit on the primary winding side of a transformer having a first capacitor through a choke coil and a gate-controlled rectifier. While connecting a DC power source to the transformer, the second capacitor can be charged with the output from the feedback winding of the transformer, and after the gate-controlled rectifier is once turned off, the charge charged in the second capacitor is generates a gate pulse by discharging the gate pulse, and repeats the operation of triggering the gate-controlled rectifying element again with the gate pulse to generate automatic oscillation, thereby extracting pseudo-sine wave energy from the secondary winding of the transformer. In the inverter device, we propose a configuration in which a charge limiting circuit including a Zener diode is provided in parallel with the second capacitor to limit the charge charged to the second capacitor.

<Function> As described above, in the present invention, since a charge limiting circuit including a Zener diode that limits the charged charge to a predetermined voltage value is connected in parallel to the second capacitor, unnecessary overcharging is prevented. It can prevent and quickly eliminate ineffective and wasteful cate pulses.

As a result, the inverter device of the present invention can operate at a higher speed than the conventional example, in other words, can operate in a higher frequency range.

<Embodiment> The drawings show a preferred embodiment of an inverter device constructed according to the present invention.

The terminals T, , T2 are input terminals of the series power supply, and the terminal T1 side is the positive input in this case.

A choke coil 1, a thyristor 2 as a gate-controlled rectifier, and a first capacitor 3 are connected in series between the terminals T and T2, and the capacitor 3 is connected to the primary winding P of the transformer 4. Bypassed by

A load 5 is connected to the secondary winding S of the transformer 4, and a return line S is connected. One end is connected to the gate of the thyristor 2 via a diode 11 and a second capacitor 6 with the end of the winding being a closed cell, and the other end is connected to the connection point between the thyristor 2 and the first capacitor 3 via a resistor 7. has been done.

As an example of the charge limiting circuit 20 constructed according to the present invention, in this embodiment, there is a series circuit of a Zener diode 8 and a diode 9 that are connected in opposite directions to each other, and this is connected in parallel to the second capacitor 6. There is. In the illustrated polarity relationship, the cathode of diode 9 is connected to the cathode of thyristor 2 by a resistor IO.

Furthermore, a resistor 1 is connected between the gate and cathode of thyristor 2.
2, a parallel circuit of a diode 13 and a capacitor 15 is inserted, and on the other hand, a starting circuit 14 is connected to the gate of the thyristor 2, which operates only when the water circuit is started and generates a starting gate trigger pulse. There is.

In the figure, the primary winding P of the transformer 4 is coupled to the secondary winding S and the feedback winding S0 through leakage paths, but such leakage paths are formed between the respective windings. You can do so, or conversely, you can stop combining leakage paths.

The present inverter device having such a configuration operates as follows.

When a DC positive polarity is applied to the terminal T and a DC negative polarity is applied to the terminal T2, charging starts in the starting circuit 14, and after a set time, a gate trigger pulse for starting is applied to the gate of the thyristor 2.

As a result, when the thyristor 2 is turned on, charging of the first capacitor 3 via the choke coil 1 begins.

Thereafter, the current begins to be shunted to the primary stone wire P of the transformer 4, and an oscillating current is generated within the closed circuit between the first capacitor 3 and the primary winding P.

Therefore, a timing occurs when the voltage between the anode and cathode of thyristor 2 is reversed in polarity, and the thyristor 2
turns off.

At this time, the choke coil 1 generates a back electromotive voltage and works to assist the commutation of the thyristor 2. However, in any case, when the thyristor 2 is turned off, the primary winding P of the transformer 4 and the feedback winding S0 A voltage of the same phase is induced between
A current quickly flows through the closed circuit consisting of the resistor 7, the diode 13, the second capacitor 6, and the diode 11, and the voltage reaches the voltage set by the charge limiting circuit 20 consisting of the series circuit of the Zener diode 8 and the diode 9. The capacitor 6 charges the battery.

When the above induced voltage starts to decrease, the second capacitor 6
The charges stored in the thyristor 2 are rapidly discharged through the resistors 12 and 10, and this current provides a gate pulse to the gate of the thyristor 2, turning it on again.

These operations are repeated, and as a result, the inverter device automatically oscillates, and a vibration output waveform extremely close to a sine wave is obtained in the secondary winding S.

However, in the present invention, as described above, the charging charge is limited to a predetermined voltage value in parallel to the second capacitor 6,
Since a charge limiting circuit 20 including a Zener diode 8 is connected for shaping, unnecessary charging can be prevented and therefore invalid or wasteful gate pulses can be quickly dissipated.

This means that high-speed operation is possible, or in other words, high-frequency operation is possible.

Furthermore, in this embodiment, the diode 13 provides a quick charging path, while the resistor 12.10 provides a quick discharging path, so that the above effect is further enhanced.

Return i2 winding S. Since this is useless, the reverse current induced in the Feedback winding S0
It may also be operated to short-circuit the reverse current flowing through.

Rather, such a method is preferable because the load on the feedback winding S0 is stabilized, resulting in less waveform distortion, and the effect of further speeding up the discharging of the second capacitor 6 by reversing the phase can be obtained.

The current limiting resistor 7 is also a feedback winding S in the illustrated case. Although the diode II is connected to the terminal opposite to that provided in the diode 11, the same effect can of course be obtained even if it is connected in series with the diode 11.

Furthermore, in the above, it is assumed that the power applied between terminals T+ and Tz is DC, but it goes without saying that it is possible to rectify and use AC power by adding ordinary rectifier circuit components such as coils, capacitors, diodes, etc. The present invention can also be effectively utilized when using elements other than thyristors as gate-controlled rectifying elements.

Note that although the capacitor 15 is used to stabilize the operation of the thyristor 2, it may not be particularly necessary.

<Effects> According to the present invention, the following effects can be exhibited as this type of inverter device.

■ The switching speed of the gate-controlled rectifier can be increased, and stable pseudo-sine wave output can be obtained even at high frequencies.

■ Responsiveness to load fluctuations is improved, input current can be easily controlled, and large output can be obtained.

(2) Turn-off of the gate-controlled rectifier r is performed smoothly, so less heat is generated and stable operation is achieved.

■ Can be realized with a simple circuit configuration and has high cost benefits.

[Brief explanation of the drawing]

The drawing is a schematic diagram of a preferred embodiment of an inverter device constructed according to the present invention. In the figure, 1 is a choke coil, 2 is a gate-controlled rectifier f
3 is the first capacitor, 4 is the transformer, 6 is the second capacitor, 8 is the Zener diode, 9
, 11 and 13 are diodes, and 20 is a charge limiting circuit. Procedure Neho Seishi (spontaneous) January 26, 1986

Claims (1)

[Claims] A DC power source is connected to the oscillating circuit on the primary winding side of the transformer having the first capacitor via a choke coil and a gate-controlled rectifier, while the feedback winding of the transformer A second capacitor can be charged with the output of the gate, and after the gate-controlled rectifier is once turned off, a gate pulse is generated by discharging the charge charged in the second capacitor. In an inverter device that repeatedly triggers the gate-controlled rectifier element to generate self-oscillation and extracts pseudo-sine wave energy from the secondary winding of the transformer; An inverter device comprising: a charge limiting circuit including a Zener diode that limits the charge charged to the second capacitor.