KR970077928A - Switching circuit of voltage inverter and its control method - Google Patents

Abstract

The present invention relates to a switching circuit and a control method of a voltage inverter for compensating for dead time injected to prevent arm short-circuit current generated when the upper and lower arm switching elements of the inverter are turned on at the same time, and reducing the number of switching. According to an aspect of the present invention, there is provided a DC power conversion unit for receiving a three-phase input of AC power, rectifying with six diodes, and smoothing and outputting the rectified power with a smoothing capacitor; A control unit for outputting three phase control signals; The upper part of the three-phase inverter is combined with a signal detected by detecting the three-phase output power according to a positive or negative polarity, three phase control signals output from the controller, and an inverted phase control signal inverted through an inversion circuit, respectively. A switching control unit for outputting a driving signal for controlling the switching element and six driving signals for controlling the lower switching element of the three-phase inverter; Three phases in which six driving signals outputted from the switching control unit are received by the six switching elements, respectively, to the base terminal, and the direct current converted by the DC power converter is converted into alternating current by six switching elements and diodes. The inverter is configured to output an output, and the effect of the present invention is that six switching elements can be operated without dead time injection, and the switch is not operated during a half cycle of the output current, thereby reducing the number of switching to 50%. A voltage inverter switching circuit and a method of controlling the same can be provided.

Description

Switching circuit of voltage type inverter and its control method

Since this is an open matter, no full text was included.

14 is a configuration diagram of a switching circuit of a voltage inverter according to an embodiment of the present invention, and FIG. 16 is a detailed configuration diagram of a first phase switching control unit according to an embodiment of the present invention.

Claims (8)

An inverter switching circuit comprising: a DC power conversion unit for receiving a three-phase input of AC power, rectifying with six diodes, and smoothing and outputting the rectified power with a smoothing capacitor; A control unit for outputting three phase control signals; The upper switching of the three-phase inverter by combining a signal detected by the three-phase output current according to the positive or negative polarity, three phase control signals output from the controller, and the inverted phase control signals inverted through the inversion circuit, respectively A switching control unit for outputting a driving signal for controlling the element and six driving signals for controlling the lower switching element of the three-phase inverter; Receives six driving signals output from the switching control unit to base terminals of the six switching elements, and converts the direct current converted by the DC power conversion unit into alternating current by six switching elements and diodes, thereby outputting three-phase output. And a inverter for outputting a switching circuit of the voltage inverter. The apparatus of claim 1, wherein the switching controller comprises: a current detector configured to receive and detect three phase output currents output from the inverter; A current polarity discriminating unit for discriminating the polarity of the current detected by the current detecting unit; And a switching calculation unit configured to receive the polarity of the current determined by the current polarity determination unit and the phase control signal received by the control unit, convert the output signal into driving signals for driving six switching elements, and output the same. Switching circuit of the inverter. The switching circuit of claim 1, wherein the switching controller comprises three phase circuits, each circuit comprising: a first current detector configured to receive and detect a first phase current output from an inverter; A first resistor connected at one stage to a current output from the current detector, a first resistor connected at one end to a ground power supply, a second resistor connected to the other stage of the first resistor, and a second input terminal connected to the first resistor; A comparator connected in common with the other end of the first resistor, the negative input terminal being connected to the ground power supply in common with the one end of the second resistor, and comparing and outputting the values of the two input terminals; A first current polarity discriminating unit configured to determine and output a polarity of the current, the third end being configured of a third resistor which is a pull-up resistor connected to the output of the comparator; Receives and buffers a first buffer for receiving, buffering, and outputting a first phase control signal, a first inverting buffer for receiving and inverting the first phase control signal, and outputting the first phase control signal; A second buffer for outputting the second buffer; a second inverting buffer for receiving and inverting the output of the first current polarity discriminator; and an output of the first buffer and the second buffer; A first AND circuit for outputting a switching element drive signal; And a first switching calculation unit configured to receive and multiply two outputs of the first inverting buffer and the second inverting buffer to output a first lower switching element driving signal. Switching circuit of a voltage inverter. The switching circuit of claim 1, wherein the switching element is an insulated gate bipolar transistor. A control method of an inverter switching circuit, comprising: an input reading step of detecting output currents of three phases, receiving a phase control signal of three phases, and inverting the three phase phase control signals to produce six control signals; A current polarity determining step of determining whether the polarity of each of the three-phase output currents received at the input step is positive or negative for a period corresponding to a half period of the inverter output; According to the polarity of the current determined in the current polarity discrimination step, the three-phase phase control signal and the three-phase inversion phase control signal are converted into six switching element drive signals which do not inject dead time into the switching element under respective conditions. Switching circuit control method for a voltage inverter comprising a switching calculation and output step of outputting. The method according to claim 5, wherein the current polarity determining step, Current detection step of checking the input current; Judging whether the first phase current detected in the current detecting step is positive, if the output is positive, performing a first output; Judging whether the second phase current detected in the current detecting step is positive, and if it is positive, performing a third output; And determining whether the third phase current detected in the current detecting step is positive, and if the third phase current is positive, outputting a fifth output, and performing a sixth output if negative. The method according to claim 5, wherein the switching calculation and output step, receiving the first output of the current polarity determination step, the first phase upper switching element drive signal Sar = first phase phase control signal Sa, the first A first calculating step of setting the upper lower switching element drive signal Sarb = 0; Receiving the second output of the current polarity determining step, set the first upper switching element drive signal Sar = 0, the first phase lower switching element drive signal Sarb = the first phase phase control signal Sa A second calculating step; Receiving the third output of the current polarity determining step, setting the second phase upper switching element driving signal Sbr = second phase phase control signal Sb, the second phase lower switching element driving signal Sbrb = 0 A third calculating step; Receiving the fourth output of the current polarity determining step, setting the second phase upper switching element driving signal Sbr = 0, the second phase lower switching element driving signal Sbrb = the second phase phase control signal Sb. A fourth calculating step; Receiving the fifth output of the current polarity determining step, setting the third phase upper switching element drive signal Scr = the third phase phase control signal Sc and the third phase lower switching element drive signal Scrb = 0 A fifth calculating step; Receiving the sixth output of the current polarity discrimination step, setting the third phase upper switching element driving signal Scr = 0, the third phase lower switching element driving signal Scrb = third phase phase control signal Sc A sixth calculating step; A first switching output step of receiving a value of the first calculation step and outputting Sar to a first upper switching element and Sarb to a first lower switching element; A second switching output step of receiving a value of the second calculating step and outputting Sar to a first upper switching element and Sarb to a first lower switching element; A third switching output step of receiving the value of the third calculation step and outputting Sbr as a second upper switching element and Sbrb as a second lower switching element; A fourth switching output step of receiving the value of the first calculation step and outputting Sbr to the second lower switching element and Sbrb to the second lower switching element; A fifth switching output step of receiving a value of the first calculation step and outputting Sbr to a second upper switching element and Scrb to a third lower switching element; And a sixth switching output step of receiving the value of the first calculation step and outputting Scr to the third upper switching element and Scrb to the third lower switching element. . The method of claim 5, wherein the switching device is an insulated gate bipolar transistor. ※ Note: The disclosure is based on the initial application.