JPH0680392U - Voltage source inverter device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a simple device that can be downsized and improved in performance by sharing power supply suppression and instantaneous regenerative voltage suppression with a single resistor. [Composition] A contactor or a control semiconductor element is provided between the DC output of the rectifier and the filter capacitor, and a series circuit of a resistor and a self-extinguishing element for dynamic braking is connected between the DC output of the rectifier to connect the resistor and the self-extinguishing element. It comprises a diode between the midpoint of the arc element and the filter capacitor.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a voltage source inverter device having a dynamic braking circuit.

[0002]

[Prior art]

 A general voltage source inverter device having a dynamic braking circuit is as shown in FIG. FIG. 2 shows the configuration of the main part of the conventional example. 1 is a commercial power source, 2 is a rectifier that converts 1 input of the commercial power source into a DC voltage, 3 is a contactor, 4 and 9 are resistors, and 5 is a filter capacitor. Reference numeral 6 is an inverse converter for converting DC voltage into AC, 7 is a load motor, 8 is a transistor, and 10 is a diode.

Here, the transistor 8 is connected in series with the resistor 9, and is controlled by the transistor 8 so that the voltage of the filter capacitor 5 does not exceed a certain value when the inverse converter 6 is in the regeneration mode. The diode 10 is a snubber diode that causes the filter capacitor 5 to absorb the surge voltage of the transistor 8. Further, the contactor 3 is opened for a fixed time after the power is turned on, the filter capacitor 5 is charged while suppressing the making current through the resistor 4, and the contactor 3 is opened after a fixed time after the charging is completed. Here, since the operation of the inverse converter 6 is well known, its detailed description is omitted.

[0004]

[Problems to be solved by the device]

 In the conventional device of this type, the resistor 4 for suppressing the making current and the resistor 9 for dynamic braking both have a large watt (W) number, and have a drawback that they occupy space. Although the resistance for dynamic braking is usually an external option, if there is no resistance for dynamic braking during sudden acceleration or deceleration, the DC voltage of the inverse converter will rise rapidly, and even if continuous regeneration is not possible, it will be instantaneous. There is a demand to permanently install a resistor to prevent overvoltage.

[0005]

[Means for Solving the Problems]

 Therefore, the present invention has a simple structure in which a series circuit including a resistor and a self-extinguishing element for dynamic braking is provided between the rectifier DC positive side output and the negative side output.

[0006]

[Action]

 With such a solution, when the power is turned on, the charging current flows through the filter capacitor through the resistor and the snubber diode, and at the time of regeneration, the voltage of the filter capacitor passes through the contactor and the resistor, and the self-extinguishing element for power generation braking (conduction). ).

[0007]

【Example】

 FIG. 1 shows a main part configuration of an embodiment of the present invention represented in a manner similar to FIG. 2, and 11 is a resistor. In the figure, those having the same reference numerals as those in FIG. In FIG. 1, in particular, a series circuit of a resistor 11 and a transistor 8 is provided between the DC outputs of the rectifiers 2, where the resistor 11 serves both to suppress the making current and for dynamic braking. .

That is, when the power is turned on, the contactor 3 is “open”, so that the charging current flows through the filter capacitor 5 through the resistor 9 and the diode 10. Further, at the time of regeneration when the charging current flows from the inverse converter 6 to the filter capacitor 5, the contactor 3 is "closed" because the inverter is operating, and the filter capacitor 5 to the contactor 3, the resistor 9 and the By supplying the charging current of the filter capacitor 5 through the transistor 8, the dynamic braking operation is performed. Naturally, the surge voltage of the transistor 8 is absorbed by the filter capacitor 5 via the diode 10.

Here, since the resistor 11 has a small W number because it has a built-in inverter, in the case of regeneration for a long time, an external resistor having a large W number should be provided in parallel with this resistor 11. That is clear.

[0010]

[Effect of device]

 As described in detail above, according to the present invention, a single resistor can be used for both the power-on current suppression and the instantaneous regenerative voltage suppression, so that the device can be downsized and its performance can be improved. Various devices can be provided.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a main configuration of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a conventional example.

[Explanation of symbols]

 1 Commercial power supply 2 Rectifier 3 Contactor 4 Resistor 5 Filter capacitor 6 Inverter converter 7 Load motor 8 Transistor 9 Resistor 10 Diode 11 Resistor

Claims (1)

[Scope of utility model registration request] 1. A commercial power supply is converted into a DC voltage by a rectifier,
In a voltage source inverter device in which a filter capacitor is provided at the DC output of the rectifier and an inverse converter that converts both ends of the filter capacitor into an AC output by using a DC power supply, a contactor is provided between the DC output of the rectifier and the filter capacitor. Alternatively, a control semiconductor element is provided, and a series circuit of a resistor and a self-extinguishing element for dynamic braking is connected between the DC output of the rectifier, and a diode is provided between an intermediate point of the resistor and the self-extinguishing element and the filter capacitor. A voltage source inverter device comprising: