RU165863U1 - REVERSIBLE ADJUSTABLE SEMICONDUCTOR BRIDGE THREE-PHASE SYNCISTOR RECTIFIER - Google Patents

Abstract

Reversible adjustable semiconductor bridge three-phase triac rectifier containing six semiconductor switches, the first outputs of the first, second and third semiconductor switches are combined and connected to the first input of the load, the second outputs of the first, second and third semiconductor switches are connected, respectively, to the first outputs of the fourth, fifth and the sixth semiconductor switch connected, respectively, to the phases A, B, C of alternating current, the second outputs of the fourth Fifth and sixth semiconductor switches are united and connected to the second input of the load, characterized in that the semiconductor switches used six triacs having bidirectional current pass on the corresponding control signal.

Description

The proposed utility model relates to adjustable semiconductor converters of a DC motor and can be used for smooth and reverse speed control of the motor.

Known three-phase semiconductor rectifier containing six semiconductor switches, which are used as six diodes. The first outputs of the first, second and third semiconductor switches, that is, the cathodes of the first, second and third diodes, are combined and connected to the first input of the load. The second outputs of the first, second, and third semiconductor switches, i.e., the anodes of the first, second, and third diodes, are connected, respectively, to the first outputs of the fourth, fifth, and sixth semiconductor switches, i.e., the cathodes of the fourth, fifth, and sixth diodes, and are connected, respectively , to phases A, B, C of alternating current. The second outputs of the fourth, fifth and sixth semiconductor switches, that is, the anodes of the fourth, fifth and sixth diodes, are combined and connected to the second input of the load (Rudenko BC Chizhenko I.M. Senko V.I. Fundamentals of converter technology / BC Rudenko. I.M Chizhenko, V.I. Senko. - M.: Higher School, 1980. - P. 49, Fig. 3.1 d).

The disadvantages of this device are the inability to control the speed of rotation of the electric motor and the difficulty of providing reverse, which requires the presence of two rectifiers or an additional switching reversing device.

The closest to the proposed model in terms of technical nature and the achieved result (prototype), which provides smooth control of the rotation speed of the DC motor, is a three-phase thyristor rectifier, which are used six thyristors. The first outputs of the first, second and third semiconductor switches, that is, the cathodes of the first, second and third thyristors, are combined and connected to the first input of the load. The second outputs of the first, second, and third semiconductor switches, i.e., the anodes of the first, second, and third thyristors, are connected, respectively, to the first outputs of the fourth, fifth, and sixth semiconductor switches, i.e., the cathodes of the fourth, fifth, and sixth thyristors connected, respectively, to phases A, B, C of alternating current. The second outputs of the fourth, fifth and sixth semiconductor switches, that is, the anodes of the fourth, fifth and sixth thyristors, are combined and connected to the second load input (Rudenko BC Chizhenko I.M. Senko V.I. Fundamentals of converter technology / BC Rudenko. I.M Chizhenko, V.I. Senko. - M.: Higher School, 1980. - P. 49, Fig. 5.22).

The main disadvantage of the described three-phase thyristor rectifier is the inability to provide reverse due to one-side voltage rectification, which requires a set of two rectifiers with a corresponding increase in size, reduced reliability and increased cost.

The proposed utility model solves the problem of providing reverse from a single rectifier with small dimensions, high reliability and low cost.

To solve the problem in a reversible adjustable semiconductor bridge three-phase triac rectifier containing six semiconductor switches, the first outputs of the first, second and third semiconductor switches are combined and connected to the first input of the load, the second outputs of the first, second and third semiconductor switches are connected, respectively, to the first outputs of the fourth, fifth and sixth semiconductor switches connected, respectively, to phases A, B, C alternately of the current, the second outputs of the fourth, fifth and sixth semiconductor switches are combined and connected to the second input of the load, according to the utility model, triacs with bi-directional current pass through the corresponding control signal are used as six semiconductor switches.

Due to the triac’s ability to pass current in both directions when the corresponding control signal is received, the triac switching method is used that allows you to get the direct and reverse polarity of the rectified voltage on one set of the rectifier, which in turn provides reverse with small dimensions, high reliability and low cost of the device.

The proposed utility model is illustrated in the drawing, where in FIG. 1 shows a power model of a reversible adjustable semiconductor bridge three-phase triac rectifier, FIG. 2 shows a clock diagram of the operation of a reversible adjustable semiconductor bridge three-phase triac rectifier in the forward direction, and in FIG. 3 is a clock diagram of the operation of a reversible adjustable semiconductor bridge three-phase triac rectifier in the backward direction.

In addition, the drawing further shows the following:

- + - plus rectified DC voltage;

- - - minus the rectified direct current voltage;

- A, B, C - phases of alternating current;

- VS1-VS6 - triacs;

- Rh is the load resistance;

- t1-t7 - times of switching triacs;

- Ud is the rectified voltage;

- Uset - three-phase network voltage.

A reversible adjustable semiconductor bridge three-phase triac rectifier contains six semiconductor switches connected via a three-phase bridge circuit, connected to a three-phase AC network and to the load.

As the semiconductor switches, six triacs 1 (VS1), 2 (VS3), 3 (VS5), 4 (VS4), 5 (VS6), 6 (VS2), with bi-directional current pass through the corresponding control signal, were used.

The first outputs of the first triac 1 (VS1), the second triac 2 (VS3), and the third triac 3 (VS5) are combined and connected to the first input 7 of load 8. The second outputs of the first triac 1 (VS1), the second triac 2 (VS3) and the third triac 3 (VS5) are connected, respectively, to the first outputs of the fourth triac 4 (VS4), the fifth triac 5 (VS6), the sixth triac 6 (VS2) connected, respectively, to the phases A, B, C of alternating current. The second outputs of the fourth triac 4 (VS4), the fifth triac 5 (VS6), the sixth triac 6 (VS2) are combined and connected to the second input 9 of load 8.

When rectifying the voltage forward, triacs 5 (VS6), 1 (VS1), 6 (VS2), 2 (VS3), 4 (VS4), 3 (VS5) function. In this case, the plus of the rectified DC voltage is located on the side of the triacs 1 (VS1), 2 (VS3), and 3 (VS5) and is connected to the first input 7 of the load 8. The second input 9 of the load is connected to the minus of the rectified DC voltage forward. When rectifying the voltage in the opposite direction, that is, backward, triacs 2 (VS3), 4 (VS4), 3 (VS5), 5 (VS6), 1 (VS1), 6 (VS2) function; while the plus of the rectified DC voltage and the positive direction of the rectifier is from the side of the triacs 4 (VS4), 5 (VS6), 6 (VS2) and is connected to the input 9 of the load 8, the output 7 of the load is connected to the minus of the rectified DC voltage (Fig. one).

The work of a reversible adjustable semiconductor bridge three-phase triac rectifier occurs as follows.

The operation of a reversible adjustable semiconductor bridge three-phase triac rectifier in the positive direction, that is, forward, is illustrated by figure 2.

At time t1, a control pulse is applied to open triac 1 (VS1) and a duty pulse to triac 5 (VS6), and from the side of triacs 1 (VS1), 2 (VS3), and 3 (VS5) (Fig. 1), a plus appears rectified DC voltage and minus the rectified DC voltage from the side of triacs 4 (VS4), 5 (VS6), 6 (VS2) (Fig. 1).

At time t2, a control pulse is applied to triac 6 (VS2) and a duty pulse to triac 1 (VS1), while triac 5 (VS6) is closed by the reverse voltage coming from open transistor 6 (VS2).

At time t3, a control pulse is supplied to triac 2 (VS3) and a duty pulse to triac 6 (VS2), while triac 1 (VS1) is closed.

At time t4, a control pulse is applied to triac 4 (VS4) and a duty pulse to triac 2 (VS3), while triac 6 (VS2) is closed.

At time t5, a control pulse is applied to triac 3 (VS5) and a duty pulse to triac 4 (VS4), while triac 2 (VS3) closes.

At time t6, a control pulse is applied to triac 5 (VS6) and a duty pulse to triac 3 (VS5), while simisor 4 (VS4) is closed.

At time t7, similarly to time tl, a control pulse is applied to triac 1 (VS1) and a duty pulse to triac 5 (VS6), while triac 3 (VS5) is closed.

Next, the process of switching on triacs is repeated.

The operation of the reversible adjustable semiconductor bridge three-phase triac rectifier in the negative direction, that is, back, is illustrated by figure 3.

At time t1, a control pulse is applied to open the triac 4 (VS4) and a duty pulse to the triac 2 (VS3), and a rectified plus appears from the side of the triacs 4 (VS4), 5 (VS6), 6 (VS2) (Fig. 1) DC voltage and minus the rectified DC voltage from the side of triacs 1 (VS1), 2 (VS3), and 3 (VS5) (Fig. 1).

At time t2, a control pulse is applied to triac 3 (VS5) and a duty pulse to triac 4 (VS4), while triac 2 (VS3) is closed by reverse voltage coming from open triac 3 (VS5).

At time t3, a control pulse is applied to triac 5 (VS6) and a duty pulse to triac 3 (VS5), while triac 4 (VS4) is closed.

At time t4, a control pulse is applied to triac 1 (VS1) and a duty pulse to triac 5 (VS6), while triac 3 (VS5) is closed.

At time t5, a control pulse is applied to triac 6 (VS2) and a duty pulse to triac 1 (VS1), while triac 5 (VS6) is closed.

At time t6, a control pulse is applied to triac 2 (VS3) and a duty pulse to triac 6 (VS2), while triac 1 (VS1) closes.

At time t7, similarly to time tl, a control pulse is applied to triac 4 (VS4) and a standby pulse to triac 2 (VS3), while triac 6 (VS2) closes.

Next, the process of switching on triacs is repeated.

Thus, based on the foregoing, we can conclude that the proposed device model produces a rectified voltage of direct and reverse polarity due to the ability of the triac to pass current in both directions and has advantages over the known ones, using the above procedure for switching on the triacs, which allows to obtain on one set of the rectifier, the direct and reverse polarity of the rectified voltage, which in turn reduces the dimensions, increases reliability and increases the eco device rating.

Claims (1)

Reversible adjustable semiconductor bridge three-phase triac rectifier containing six semiconductor switches, the first outputs of the first, second and third semiconductor switches are combined and connected to the first input of the load, the second outputs of the first, second and third semiconductor switches are connected, respectively, to the first outputs of the fourth, fifth and the sixth semiconductor switch connected, respectively, to the phases A, B, C of alternating current, the second outputs of the fourth Fifth and sixth semiconductor switches are united and connected to the second input of the load, characterized in that the semiconductor switches used six triacs having bidirectional current pass on the corresponding control signal.

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