JPS5840430B2 - Inverter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inverter device in which the recovery time of switching elements is accelerated and the commutation time is shortened in a collective commutation type inverter circuit.

A conventional circuit is shown in FIG.

An electric valve 2 and an electric valve 3 are connected to the DC power source 1, respectively, and AC power is supplied to a load 6 by a silice bridge 4 on the output side of the electric valve.

A diode bridge 5 is connected to the load terminal so as to feed back reactive power to the DC power supply 1.

The electric valves 2 and 3 are turned off only when commutating the silice bridge 4, but are kept on at other times.

This operation will be explained according to the time chart shown in FIG.

Time t.

In Cyrisk S3. S5. S is turned on, and electric valves 2 and 3 are also turned on.

Next, at time t1, the electric valve 2 is turned off in order to turn off the thyristor S3.

After the blocking ability of the thyristor S3 is restored, at time t2, the thyristor S6 is turned on, an on signal is also applied to the thyristor S4, and the electric valve 2 is turned on.

This completes the commutation action.

However, the drawback of this circuit is that even if the electric valve 2 or 3 is turned off, no reverse voltage is applied to the Cyrisk, so the transfer time of the storage charge in the Cyrisk becomes long.
It will take a very long time to recover the blocking ability.

Therefore, the silice bridge cannot be commutated at high frequencies, making it unsuitable for high-frequency inverters, and it has been desired to improve this problem.

In order to improve the above-mentioned points, the present invention aims to provide an inverter device that can shorten the commutation time and improve the inverter frequency limit.

An embodiment of the invention for achieving this purpose is shown in FIG.

Since the same parts as in FIG. 1 are numbered the same, the explanation will be omitted, and only the different parts will be explained.

A capacitor 9B is charged from the output side of the electric valve 2 through a rectifier 8B in series with a resistor 7B, and connected to the negative side of the DC power supply 1 through a rectifier 10B.

On the other hand, the electric valve 11B is configured to connect the negative side of the capacitor 9B to the output side of the electric valve 2, and the electric valve 12B is configured to connect the positive side of the capacitor 9B to the negative side of the DC power source 1.

In addition, a rectifier 8A is connected in series with a resistor 7A from the positive side of the DC power supply 1.
The capacitor 9A is charged through the rectifier 10A and connected to the output side of the electric valve 3 through the rectifier 10A.

The electric valve 1'lA is configured to connect the negative side of the capacitor 9A to the positive side of the DC power source 1, and the electric valve 12A is configured to connect the positive side of the capacitor 9A to the output side of the electric valve 3.

Next, for a detailed explanation of the present invention, refer to t in FIG.

FIG. 4 shows an enlarged view of a portion corresponding to the period t2.

Time t.

Since electric valve 2 is on, capacitor 9B
is charged to the power supply voltage in the circuit of DC power supply 1 → electric valve 2 → resistor 7B → rectifier 8B → capacitor 9B → rectifier 10B → DC power supply 1.

Next, at time t1, the electric valve 2 is turned off and the electric valve 11B1 is turned off.
When the electric valve 12B is turned on, the charge in the capacitor 9B cannot be directly discharged because of the rectifiers 8B and 10, and the positive side of the capacitor 9B is connected to the lower side of the diode bridge 5, and the negative side of the capacitor 9B is connected to the thyristor bridge 4 through the resistor 7B. This means that it is connected to the upper side of the .

However, since the electric valve 2 is in the OFF state, the capacitor 9B
The electric charge is electric valve 12B → lower side of diode bridge 5 →
Out of thyristor S1, thyristor S3, and thyristor S5, thyristor S1. S3. When the conducting thyristor of S5 turns off, the thyristors S1, S3. A counter pressure is applied to S5, and the blocking ability is rapidly restored.

Next, at time t2, the switch element of the silice bridge 4 to be commutated next is selected and turned on, and at the same time the electric valve 2 is turned on, and the capacitor 9B is rapidly charged again and the commutation is completed.

When the electric valve 3 is turned on and off, the same action as above occurs on the resistor 7.
A, rectifier 8A, capacitor 9A, rectifier 10A, electric valve 11A, electric valve 12A is carried out in the other commutation promotion circuit, so thyristor S4.
S, , S2 rapidly recovers the blocking ability.

In FIG. 3, the electric valve is shown with a transistor symbol, but other self-extinguishing arc electric valves operate in a similar manner.

Also, although the inverter bridge is shown with a Cyrisk symbol, other control switches can of course operate in the same way.

Furthermore, although the load is shown using a three-Japanese-style room motor, the effect is the same for single-phase, multi-phase, and DC loads.

Furthermore, capacitor charging limiting resistors 7A and 7B in FIG.
It may be replaced with a beam acdle.

Furthermore, a commutation promotion circuit consisting of a plurality of capacitor charging and discharging circuits can be provided and used by switching for each commutation.

Next, when the DC power supply 1 is varied as shown in FIG. 5, when the DC power supply 1 is low, the capacitor 9A is used.

Since the voltage of 9B is low and sufficient reverse pressure cannot be applied to the inverter bridge 4, the resistors 13A and 13 are connected from a separate power supply 15.
It is effective to configure a circuit that charges the capacitors 9A and 9B through B, and charges the capacitors 9A and 9B to a high voltage.

Furthermore, as shown in FIG.
Even if it is charged via the resistor 17, it operates in the same way.

Furthermore, in order to lower the voltage applied to the electric valves 2 and 3, a plurality of rectifiers 18 can be connected as shown in FIG. 6 to control the reverse voltage.

It is of course possible to replace the rectifier 18 with another non-linear resistance element, and a similar restriction can be achieved by a combination of a rectifier and a resistor, and even if this connection point is connected to the DC side of the inverter bridge 4, the same It has a limiting effect.

Next, as shown in Fig. 7, the effect is the same even if a circuit is used in which the charge on the capacitor 9 is reversed by discharging it through a resonant circuit consisting of a reactor 19 and a thyristor 20, thereby generating a reverse voltage. It is.

Of course, FIG. 7 can be modified as shown in FIG. 8.

Furthermore, as a method of charging a capacitor from another DC power source 15 or 16 shown in FIGS. 5 and 6, it is of course possible to charge the capacitor by using a series resonant circuit using a thyristor 21 and a reactor 22 as shown in FIG. It is.

As described above, the present invention can apply a reverse voltage to the switch elements of the inverter during commutation, thereby significantly shortening the recovery time of the switch elements and providing an inverter device that can operate efficiently up to a high frequency range.

[Brief explanation of drawings]

FIG. 1 is a connection diagram of a conventional circuit, FIG. 2 is an explanation diagram of the operation of FIG. 1, FIG. 3 is a connection diagram of a circuit showing an embodiment of the present invention, and FIG. 4 is an explanation diagram of the operation of the present invention. Figure 5, Figure 6, Figure 7,
FIGS. 8 and 9 are connection diagrams showing other different embodiments of the present invention. 1...DC power supply, 2,3...Electric valve,
4...Sirisk bridge, 5...Diode bridge, 6...Load, 7A, 7B.
・・・Resistance, 8A, 8B・・・Rectifier, 9A
, 9 10B... Rectifier, 12B... Electric valve, B... Capacitor, 10A. 11A, 11B, 12A. 13A, 13B...Resistor, 15.16...DC power supply, 18...Rectifier, 19°22...Reactor, 20,21
...Syrisk.

Claims (1)

[Claims] 1. A DC power supply, two sets of electric valves installed on the positive and negative busbars of the DC power supply, and a group of switches installed on the output side of the electric valves and controlled to open and close in a predetermined order to supply AC power to the load. and an inverter device comprising a diode bridge circuit whose DC side is connected to the DC power supply and whose AC side is connected to the load terminal to feed back the residual energy of the load to the DC power supply. two sets of capacitors arranged in a chain and charged from the DC power supply or another power supply; and during the commutation period of the switch group, the charging voltage of the capacitors is transferred to the switch group through the diode bridge circuit with opposite polarity. An impark device characterized in that two sets of discharge circuits are provided for applying voltage.