JPH0837779A - Inverter apparatus - Google Patents

Abstract

PURPOSE:To obtain an inverter apparatus by which stored energy in an anode reactor and a snubber capacitor is shifted to a capacitor having a comparatively large capacitance is regenerated to a DC power supply by a method wherein a snubber-energy regeneration circuit is installed. CONSTITUTION:In a state that a switching element S1 is set conductive and that a load current I0 flows, the switching element S1 is turned off at the time t0. Then, the load current is shifted to a series circuit which is composed of a diode D3 and a capacitor C1, vibrations by a reactor L1 and capacitors C1, C2 are started, and an electric charge which has been charged in the capacitor C2 is discharged and become zero V. When the capacitor C1 is charged to (E+ER) V, a diode D2 is set conductive, the load current flows to the diode D2, and a commutating operation is completed. By the above operation, the capacitor C2 voltage becomes zero V, and energy which has been stored is discharged through a load circuit and regenerated to a DC power supply.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device using a self-arc-extinguishing type semiconductor switching device such as a GTO, which is suitable for high frequency operation, in which device loss is reduced.

[0002]

2. Description of the Related Art FIG. 4 is a circuit diagram showing an example of one phase of a conventional inverter device.

In FIG. 4, S1 and S2 are self-turn-off switch elements, C1 and C2 are snubber capacitors, and L1 and L.
Reference numeral 2 is an anode reactor, R1, R2, R3 and R4 are resistors, D1, D2, D3, D4, D9 and D10 are diodes, and E is a DC power supply.

In this circuit, the anode reactors L1 and L
Reference numeral 2 shows the effect of suppressing the rise of current (di / dt) at the time of turning on the self-extinguishing switches S1 and S2 and reducing the turn-on loss. The snubber capacitors C1 and C2 bypass the delay current due to an inductive load when the self-extinguishing switches S1 and S2 are turned off, so that the voltage applied to the self-extinguishing switches S1 and S2 rises (dv / d).
It serves to suppress t) and reduce turn-off loss.

However, these all store energy, and the self-extinguishing switch element is turned on,
The energy must be zero before turning off.

Therefore, the anode reactors L1 and L
2 is consumed by the resistors R3 and R4, and the energy of the snubber capacitors C1 and C2 is turned on when the self-extinguishing switches S1 and S2 are turned on.
It is performed by consuming the discharge by 1 and R2.

For this reason, the energy is consumed by the resistance, resulting in an inefficient inverter device. This loss occurs at each turn-on and turn-off, and therefore increases as the operating frequency increases.

[0008]

In recent years, for the purpose of downsizing the inverter device, improving the quality of the output waveform of the inverter, and improving the response speed, it becomes more necessary to raise the operating frequency, and the problem of switching loss becomes remarkable. Therefore, various circuits have been proposed in which the resistor does not consume the stored energy of the reactor and the capacitor. But,
There are problems that the circuit becomes complicated and energy is not effectively regenerated.

The present invention was devised in view of the above-mentioned points, and an object thereof is to provide an inverter device that effectively regenerates a DC power supply without consuming the stored energy of the anode reactor and the snubber capacitor in a resistor. To provide.

[0010]

[Means for Solving the Problems] In other words, means for achieving the object are as follows: a first anode reactor and first and second diodes having reverse polarity first and second diodes respectively connected in parallel. Connecting the series circuit of the self-extinguishing switch element and the second anode reactor in the positive and negative electrodes of the DC power supply, and connecting the third diode and the first capacitor in parallel with the first self-extinguishing switch element. An inverter device in which a series circuit of a second capacitor and a fourth diode is connected in parallel with the second self-extinguishing switch element, the positive electrode of a DC power source and the third A series circuit of a third capacitor and a fifth diode is connected between the connection point of the diode and the first capacitor with a reverse polarity, and the second capacitor and the fourth capacitor are connected.
A series circuit of a sixth diode and a fourth capacitor is connected in reverse polarity between the diode connection point of and the negative electrode of the DC power supply, and the energy of the third and fourth capacitors is regenerated to the DC power supply. It is something that is done.

[0011]

By providing the snubber energy regenerating circuit having the above-mentioned structure, the stored energy of the anode reactor and the snubber capacitor is transferred to the capacitor having a relatively large capacitance and then regenerated to the DC power supply.

The details will be described together with the following embodiments.

[0013]

1 is a circuit diagram showing an embodiment of one phase of an inverter device of the present invention, and FIG. 2 is a waveform diagram for explaining the operation of the inverter device shown in FIG. FIG. 3 is a circuit diagram showing an embodiment in which the inverter device of the present invention is constituted by a three-phase inverter circuit.

1 and 3, D5, D6, D7,
D8 is a diode, C3 and C4 are regeneration capacitors, S
3, 3 and 4 are snubber regenerative circuit switches, L3 and L4 are regenerative reactors, and those having the same reference numerals as those in FIG. 4 indicate parts having the same function.

FIG. 1 shows a circuit for one phase of the inverter device of the present invention and a snubber energy regeneration circuit.
Between the positive and negative poles of the DC power source E, a reactor L1 (hereinafter simply referred to as a reactor L1 for suppressing a rising current (di / dt) of the self-extinguishing switch elements S1 and S2 (hereinafter simply referred to as a switch) is turned on. Anode reactor),
The switches S1 and S2 and the anode reactor L2 are connected in series, and flywheel diodes D1 and D2 (hereinafter simply referred to as diodes) are connected in antiparallel to the switches S1 and S2, respectively. In an inverter device formed by connecting a series circuit of a snubber diode D3 (hereinafter simply referred to as a diode) and a snubber capacitor C1 (hereinafter simply referred to as a capacitor), or a diode D4 and a capacitor C2,
That is, from the circuit of FIG.
R2, R3, R4 and diodes D9, D10 are removed, the positive electrode of the DC power source and the diode D3
A series circuit of a capacitor C3 (hereinafter simply referred to as a capacitor) having a relatively large capacity and a diode D5 is connected between a connection point of the capacitor C1 and the capacitor C1, and a negative electrode of the DC power source and a connection point of the diode D4 and the capacitor C2. A series circuit of a gondensa C4 and a diode D6 is connected between the two.

The snubber energy regeneration circuit is shown in FIG.
In the above example, a series circuit of the switch element S3 and the reactor L3 is connected between the connection point of the capacitor C3 and the diode D5 and the DC power supply positive electrode, and the connection point of the switch element S3 and the reactor L3 is connected between the DC power supply negative electrode. Diode D7
And a first chopper circuit connected to each other, a series circuit of a reactor L4 and a switch element S4 connected between the negative electrode of the DC power source and the connection point of the capacitor C4 and the diode D6,
It is composed of a second chopper circuit in which a diode D8 is connected between the connection point of the switch element S4 and the reactor L4 and the positive electrode of the DC power supply.

The operation of the present invention will be described with respect to the case where current flows to the load when the switch element S1 is conducting. The following assumptions are made in the explanation. (1) Switch elements and diodes are ideal. (2) The load is inductive and can be regarded as a constant current during the commutation operation period. (3) The capacitances of the capacitors C3 and C4 are sufficiently large, do not change during the commutation period, and maintain the ER voltage.

FIG. 2 is a waveform diagram for explaining the operation of the inverter device of FIG.

In FIG. 2, when the switch element S1 is turned on and the load current I0 is flowing and the switch element S1 is turned off at time t0, the load current shifts to the series circuit of the diode D3 and the capacitor C1 and the reactor L1. When the capacitors C1 and C2 start to vibrate, the electric charge charged in the capacitor C2 is discharged to zero V, and the capacitor C1 is charged to (E + ER) V,
The diode D2 becomes conductive, the load current starts flowing through the diode D2, and the commutation is completed. At this time, a gate signal is applied to the switch element S2, but it does not flow as a current.

By the above operation, the capacitor C2 becomes 0 V, and the stored energy is discharged through the load circuit and regenerated to the DC power source. Further, the current of the reactor L1 also becomes zero, the energy is transferred to the load circuit and the capacitor C1, and no loss occurs.

Next, when the switch element S1 is turned on at time t1, (the application of the gate signal to the switch element S2 is blocked immediately before this) the electric charge accumulated in the capacitor C1 is diode D5, capacitor C3.
At the same time that the circuit of the reactor L1 starts discharging, the current to the load circuit is also shared, and the current to the load circuit flowing through the diode D2 decreases correspondingly.

When this current becomes zero and the diode D2 becomes non-conductive, the current flowing through the reactor L1 and the switch element S1 becomes equal to or more than the load current I0, and the capacitor C2 is charged.

For this charging, the voltage of the capacitor C2 is (E +
Until ER) V, diode D6 conducts and charging stops thereafter.

At this time, the voltage of the capacitor C1 becomes zero,
All the energy stored in the capacitor C1 is transferred to the capacitor C3 and no loss occurs.

Although the above description has been made with respect to the case where the load current flows out to the load side, the case where the load current flows in from the load side can be similarly explained.

However, the energy of the reactor L1 and the capacitor C1 is transferred to the capacitor C3 and the reactor L1.
2. Since the energy of the capacitor C2 is transferred to the capacitor C4, when the switching elements S1 and S2 are repeatedly turned on and off, the voltages of the capacitors C3 and C4 increase, and the voltage is discharged so that the voltage becomes almost constant at ER. The means to make it necessary.

Therefore, in the example of FIG. 1, a chopper circuit is used. When the switch element S3 is turned on,
A current starts to flow from the capacitor C3 to the reactor L3 and increases linearly. Here, when the switch element S3 is turned off, the energy stored in the reactor L3 is regenerated to the DC power source E via the diode D7. .

That is, the voltage of the capacitor C3 can be maintained constant by controlling the conduction ratio of the switch element S3.

The voltage of the capacitor C4 can also be kept constant by the chopper circuit of the switch element S4, the reactor L4 and the diode D8.

FIG. 3 is a circuit diagram showing an embodiment in which the inverter device of the present invention is constituted by a three-phase inverter circuit. As shown in the figure, one snubber energy regenerating circuit may be provided in common for three phases.

Although the GTO is used as the switch element in the embodiments of FIGS. 1 and 3, any element can be used as long as it is a self-turn-off type switch element such as an IGBT, a bipolar transistor, a MOSFET, an SI thyristor. Needless to say, the same operation can be realized. Also,
As the snubber regenerative circuit, the chopper circuit is shown in FIGS. 1 and 3, but any circuit that can send power from the capacitors C3 and C4 to the DC power source E may be used.

[0032]

As described above, the present invention provides an efficient inverter device that effectively regenerates energy to a DC power source without consuming the energy emission of the snubber capacitor and the anode reactor by resistance. .

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of one phase of an inverter device.

FIG. 2 is a waveform diagram for explaining the operation of the inverter device of FIG.

FIG. 3 is a circuit diagram showing an embodiment in which the inverter device of the present invention is configured by a three-phase inverter circuit.

FIG. 4 is a circuit diagram showing an example of one phase of a conventional inverter device.

[Explanation of symbols]

 C1, C2 Snubber capacitor C3, C4 Regeneration capacitor D1 to D10 Diode E DC power supply L1, L2 Anode reactor L3, L4 Regeneration reactor R1 to R4 Resistance S1 to S4 Switch element

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuto Nakajima 2-4-1, Nishitsutsujigaoka, Chofu-shi, Tokyo Tokyo Electric Power Co., Inc. Technical Research Institute (72) Inventor Junichi Inoue 338 Kamisakuyanagi, Yamato, Kanagawa Prefecture Address 1 Toyo Denki Seizo Co., Ltd. Technical Research Institute (72) Inventor Katsuji Iida 338, Ogino, Kamisakuyanagi, Yamato City, Kanagawa Prefecture 1 Toyo Denki Seizo Co., Ltd. Technical Research Institute (72) Inventor Koichi Harada Kamiwa, Kanagawa Prefecture Kusanagi character 338, Ogino 1 Toyo Denki Seizo Co., Ltd., Technical Research Laboratory (72) Inventor, Kubo Takao, Kanagawa Prefecture, Yamato, Kanagawa Prefecture

Claims (1)

[Claims] 1. A series of a first anode reactor, first and second self-extinguishing switch elements having first and second diodes having opposite polarities in parallel connection, respectively, and a second anode reactor. A circuit connected to the positive and negative poles of a DC power source, and a series circuit of a third diode and a first capacitor connected in parallel with the first self-arc-extinguishing switch element; An inverter device in which a series circuit of a second capacitor and a fourth diode is connected in parallel with an element, a positive electrode of a DC power source,
A series circuit of a third capacitor and a fifth diode is connected between the connection point of the third diode and the first capacitor with reverse polarity, and a connection point of the second capacitor and the fourth diode. And a series circuit of a sixth diode and a fourth capacitor are connected between the negative pole of the DC power supply and the negative polarity of the DC power supply in reverse polarity to regenerate the energy of the third and fourth capacitors to the DC power supply. Inverter device characterized by.