RU4186U1 - BRIDGE INVERTER AND ITS CONTROL DIAGRAM - Google Patents

Abstract

1. The bridge inverter and its control circuit, containing the first and second switches, each of which has first, second and control terminals, first and second diodes, first and second terminals for connecting the positive and negative terminals of an external constant voltage source, respectively, the third and fourth terminals for connecting the inverter load, the first terminal of the first key being connected to the first terminal, the second to the fourth terminal, the first terminal of the second terminal connected to the third terminal, the cathode of the first diode connected to the first m clamp, the anode with the third clamp, the cathode of the second diode connected to the fourth clamp, the anode with the second clamp, characterized in that the circuit contains a control device having first and second inputs for separate key management, a third common control input, first and second outputs control the first and second key, respectively, from the first to the sixth conclusions for connecting the power source, the first and second elements AND, an inverter, a trigger device having a first and second terminals for connecting a power source and an output, the first and second th transistors, a zener diode, a third diode, first to fourth resistors, a variable resistor, first to sixth capacitors, a shunt resistor (shunt), a fifth terminal for connecting an external control element, a sixth terminal for connecting a voltage source to power the control circuit, the second the output of the second key is connected to the second terminal via a shunt, the control terminals of the first and second keys are connected to the first and second outputs of the control device, respectively, the first and third terminals for connecting power supplies

Description

Bridge inverter and its control circuit

The utility model relates to electrical engineering, and more specifically, to power semiconductor frequency converters (inverters) for powering valve motors and their control circuits.

Known bridge inverter and its control circuit (see Patent EPO (EP) N 0397314 Н02 Р 6/02. РЖ. Inventions of the world. N 20, 1991, Issue 107. S. 29.), which is intended for filing power supply to a multiphase switchable reactive electric machine. The phase shoulders of the inverter consist of the upper and lower keys connected in series with the phase windings of the machine. The upper reverse diode is connected in parallel with the serial circuit formed by the upper key and the phase winding. The lower reverse diode is connected in parallel to the serial circuit formed by the lower key and the corresponding phase winding. Serial circuits are connected to an external DC source. The control circuit consists of several current-measuring units, each of which is connected to the corresponding phase arm of the inverter and generates a signal proportional to the instantaneous value of the phase current flowing through it. The circuit has a block for generating a reference current and several comparators. Each comparator connected to the corresponding measuring unit compares the measured current value with the reference one and generates a signal with the first logical level when the measured current exceeds the reference current by the first set value, and a signal with the second logical level when the measured current is less than the reference current by the second set value .

The disadvantage of this bridge inverter and its control circuit is the complexity of the control circuit associated with setting the deviation of the actual current relative to the reference by two specified values.

This utility model is designed to simplify the bridge inverter and its control circuit,

H 02 M 7/48

- g

the first and second keys, each of which has first, second and control terminals, of the first and second diodes; comprising first and second terminals for connecting the positive and negative terminals of an external constant voltage source, respectively; the third and fourth terminals for connecting the load of the inverter, the first terminal of the first key being connected to the first terminal, the second to the fourth terminal; the first terminal of the second key is connected to the third terminal; the cathode of the first diode is connected to the first clamp, the anode to the third clamp; the cathode of the second diode is connected to the fourth terminal, the anode to the second terminal, according to this statement, introduced; a control device (CU), which has the first and second inputs for separate key management, the third common control input, the first and second control outputs first and second; m KROCHOM, respectively, the first and second conclusions for connecting the device’s power supply, as well as the conclusions for connecting - power supply of the output stages of the UU: the fifth and sixth - of the first key, the third and fourth - of the second key; the first and second logical elements AND, each of which has first and second inputs and outputs; an inverter having an input and an output; a trigger device having first and second terminals for connecting a power source and an output; first and second transistors; zener diode; third diode; the first is the fourth resistors; variable resistor; the first is the sixth capacitor; shunt resistor (shunt); fifth clamp for connecting an external control element; the sixth terminal for connecting the voltage source to power the control circuit; wherein the second terminal of the second key is connected to the second terminal via a shunt; the control outputs of the first and second keys are associated with the first and second outputs of the UE, respectively; the first and third conclusions for connecting the power supplies of the UU are connected to the sixth clamp, the second and fourth to the second clamp, the sixth to the fourth clamp, the fifth is connected to the fourth clamp through the second capacitor and is connected to the cathode of the third diode, the anode of which is connected to the venom clamp ; the first and second inputs of the control unit are connected to the outputs of the first and second elements And, respectively; the second input of the second element K is connected to the collector of the first transistor to which are connected

- 3 one terminal of the second resistor and one terminal of the fifth capacitor; the emitter of the first transistor and the other terminal of the fifth capacitor are connected to the second terminal, the base of the first transistor is connected to the second terminal of the second key through the fourth resistor and to the second terminal through the sixth capacitor; the other terminal of the second resistor is connected to a sixth terminal; one terminal of the fourth capacitor is connected to the first input of the first element AND, this input is also connected to the collector of the second transistor through a third resistor and to the sixth terminal through a variable resistor; the emitter of the second transistor and the other terminal of the fourth capacitor are connected to the second terminal, the base of the second transistor is connected to the fifth terminal through the third capacitor; between the sixth and second terminals the first capacitor and a zener diode are connected (the anode - to the second terminal), the first .and the second terminal are also connected to them .; to connect the power source of the launcher, respectively; the fifth clamp is connected to the sixth through the first resistor and to the inverter input; the inverter output is connected to the first input of the second element; the output of the trigger device is connected to the second input of the first element I.

In particular cases of execution described below, the utility model may additionally be characterized by one or more of the following features:

- the first element And is equipped with an additional third input associated with the output of the inverter;

- the second element And is equipped with an additional third input associated with the first input of the first element

The circuit is equipped with a fifth resistor connected between the control and the second terminal of the first key, and a sixth resistor connected between the control terminal of the second key and the second terminal:

-the circuit is equipped with a seventh resistor connected between the third input of the control unit and the second clamp, and a thermistor connected between the third input of the control unit and the sixth clamp, and the thermistor is attached to one of the heating surfaces in the product; /

 4 - the circuit is equipped with a ninth resistor connected between the pin and the sixth clamp;

-the circuit is equipped with a seventh and eighth clamps for connecting to an external AC voltage source, a rectifier having two inputs connected to the seventh and eighth g-clamps, and two outputs connected to the first and second clamps, respectively, the seventh capacitor connected between first and second clamps; as well as the tenth and eleventh resistors connected between the sixth terminal and the seventh and eighth terminals, respectively.

In the future, the utility model is explained with reference to the accompanying drawings, which show:

-Fig. 1 is a diagram of a bridge inverter and its control circuit;

-Fig. 2 - the same, with added elements for special cases of implementation.

To facilitate the explanation of the work, we establish a correspondence between the names of the elements in the formula and the description of the field; 5th model and their positional references in the drawings; the first (upper) key is 1, the second (lower) key is 2; the first diode is 3, the second is 4, the third is 17; the first clamp is 5, the second is 6, the third is 7, the fourth is 8, the fifth is 30, the sixth is 31, the seventh is 38, the eighth is 39: the control device is 9; trigger device - 13; the first element And 10, the second - 11; inverter - 12; the first transistor is 14, the second 15; Zener diode - 16; the first resistor is 18, the second is 18, the third is 20, the fourth is 21, the fifth is 32, the sixth is 33, the seventh is 34, the eighth is 36, the ninth is 37, the tenth is 42, the eleventh is 43; variable resistor - 22; the first capacitor is 23, the second is 24, the third is 25, the fourth is 26. the fifth is 27, the sixth is 28, the seventh is 41; shunt - 29; thermoresist - 35; rectifier - 40.

The control device §-is a microcircuit for which there is a correspondence between the outputs. Of the outputs according to the formula and description and numbering | childbirth in the drawings is as follows; the first entrance is 10, the second is 12, the clubs are 11; the first exit is 7, the second 1; the first output for plug in power supplies is me, the second

 5 start according to the formula and description and numbering of CONCLUSIONS in the drawings the following: the first output for connecting a power source 3, the second - 1; output - 2.

The bridge inverter and its control circuit are powered by an external DC power source having a positive terminal 5 and negative 6. A load is connected to the terminals of the inverter 7 and 8, for example, a phase winding of a jet, inductive motor. Thus, the load current flows from terminal 5 to terminal 6, provided that keys 1 and 2 are opened simultaneously, slowly decreases (with the inductive nature of the load) through the reverse diode 3 when the lower key is closed, and quickly counts through both reverse diodes when both are closed keys under the action of reverse polarity applied to the load.

Keys 1 and 2 are controlled using device 9, which consists of three blocks: input circuits and output drivers for controlling the upper and lower keys. All these blocks have pseudo-galvanic isolation from each other and, accordingly, independent conclusions for connecting power supplies. The input circuits have separate control inputs for the upper and lower switches 10 and 12, respectively, when they are applied. For which high-level voltages, a command is issued to open the corresponding key and low-voltage to open, and a common control input 11, when high-level voltages are applied to it opening of both keys is forbidden. The supply voltage of the input circuits is supplied to pins 9 and 13. The output drivers have outputs 7 and 1 for connecting to the control pins of the upper and lower keys, respectively, as well as pins for connecting power sources: 6 and 5 - drivers of the upper key, 3 and 2 drivers of the lower .

The terminal 31 relative to terminal 6 is supplied with a voltage supplying the control circuit, for example, from an external source of power, or, in special cases, from terminal 5 through a resistor, and, in case of power, the inverter is supplied from an ac mains voltage (terminals 38.39) with rectifier 40 and filter co-detectors 41, from terminals 38.39 through resistors 42, 43, respectively.

Elements 16 and 23 are designed to stabilize the voltage supplying the control circuit. In this case, the control circuit, input circuits, and the lower key control driver are powered directly, and the upper key control driver is supplied from a charged capacitor 24, which is charged only when the diode 17 is open, which occurs when the inverter load is connected to terminals 7, 8 a closed key 1 and an open diode 4 (during a fast decay of the load current), or with a closed key 1 and an open key 2.

The latter situation is used to initially charge the capacitor 24 when the power is turned on. For the initial closing of the upper key 2, a trigger device 13 is introduced, connected through the AND element to the control input of the upper key. The device 13 is a voltage sensor across the capacitor 23 (power supply control circuit) or a manual start device from a button or switch. In the first case, the voltage of the low level is maintained at the output of the device 13 until a certain voltage is established on the charging capacitor 23. At this time, the capacitor 24 is also charged. The voltage sensor can be, for example, an integral mm or consist of a zener diode and a resistor connected in series. In the second case, the low level voltage at the output 13 appears when a manual control is exposed (for example, the Start button). It is possible to start without using the device 13, for which it is necessary to initially turn the engine of the variable resistor 22 to the maximum resistance position or, by applying a variable resistor with a built-in switch, break the circuit through the resistor 22 before starting, which will lead to a delay or prohibition of the initial charge of the capacitor 26 and , therefore, will set a low logic level at the output of element 10.

The initial opening of the key 2 is ensured by external conditions, for example, the starting position of the rotor of the jet, induction motor, in which the signal from the position sensor of the rotor of the motor (clamp. 30 draws a signal to open the lower key.

The signal from terminal 30 to a single control element with a digital output, for example, a rotor position sensor, is reactive. Inductively, the induction motor acts on the input 12 of device 9 via an inverter 12 and element 11. When a high level voltage appears on terminal 30 at terminal 12 9, a low level voltage appears that covers the lower key. Otherwise, this signal does not prohibit the opening of the lower key.

A single vibrator is assembled on elements 18, 25, 15, 20, 22, and 26, which, after starting for a period of time determined by a timing circuit consisting of a variable resistor 22 and capacitor 26, generates a low-level voltage pulse at the output, which is fed to the first input element 10 and closes the upper key 1. The start of the one-shot is carried out from the signal of the control element (clamp 30) of a high level through 25. In this case, the transistor 15 opens for a short time and through it and the resistor 20 the capacitor 26 is quickly discharged. After the transistor 15 is turned on, the capacitor 26 is charged through a variable resistor 22 for a certain time, regulated by a resistor 22. The time of this charge determines the duration of the pulse of a single-shot.

On the elements 29, 14, 21, 28, 27 and 19, an inverter current protection circuit is assembled. When the current flowing through the shunt 29 reaches a certain value, a voltage drop of 29 becomes sufficient to open the transistor 14 through the resistor 21, and a low voltage appears on its collector connected through the And 11 element to the output 12 of the device 9, closing the key 2 . In this case, the capacitor 27 is discharged through the open transistor 14. After the key 2 is closed, the voltage drop at the shunt 29 decreases, and the transistor 14 closes, after which the capacitor 27 is charged through the resistor 19, and for a time dependent о of the charge time, the ban on opening the key 2 remains. The capacitor 28 serves to increase the noise immunity.

Thus, at a low resolution voltage level at terminal 30, the load current is limited by the lower key control circuit, which is closed for a time determined by the circuit of the resistor 19 capacitor 27 each time the current reaches a certain value, and during this time the load current slowly drops off through the public key 1 and diode 3.

: .Gu the appearance of a high voltage level at terminal 30, both keys are closed: key 2 - directly, and key 1 - for a time determined by a single-shot. In this case, the load current drops rapidly.

At the end of the pulse, the upper switch opens at the output of the single-vibrator; when a low level voltage appears at terminal 30, the lower switch opens. The load current begins to flow only with both public keys. Thus, the duration of the pause between the pulses of the load current is determined by the maximum of the pulse durations at the output of the single vibrator and the pulse of positive polarity at terminal 30. The single vibrator serves, for example, to limit the speed of a jet induction motor.

It should be noted that a single-shot can control the lower key, and the signal at terminal 30 is the top one, for which you need to change the connections between the connected inputs of the elements 10 and 11. You can also, in the particular case of using an inverter with a load, for which it is more desirable simultaneous opening of keys, provide elements 10 and 11 with additional third inputs and act on the upper and lower keys with the above signals simultaneously, as described above. Such options do not fundamentally change the operation of the device.

The outputs 7 and 1 of the device 9 and the control inputs of the keys 1 and 2, respectively, can be connected through resistors that limit the control current of the keys.

In the particular case, if quick closure of the keys 1 and 2 is required, the circuit is equipped with resistors 32 and 33, included, as described above.

In the particular case of the use of the inverter in devices that are subject to fire safety requirements, the circuit is equipped with a resistor 34 and a thermistor 35, turned on as described above. In this case, the thermistor must be attached to a surface subject to heat, for example, to a radiator or upper key case or the motor case serving as the load of the inverter. These resistors form a voltage divider with a division coefficient that changes with increasing temperature of the thermistor. When the temperature exceeds a certain level, the voltage at the terminal

11 of device 9 will rise to a threshold voltage, and both keys will close.

In order to protect against false positives of a single-shot, the base of the transistor 15 should be connected to the terminal 6 through a resistor 36.

In order to limit the current when opening the transistor 15, clamp 30 and the capacitor 25 should be connected through a resistor.

The technical effect of this utility model is the simplicity of its implementation, low cost and high reliability, achieved due to the lack of a secondary power source for the control circuit and other effective circuit solutions.

The authors: . Kolomeytsev V.L.

,

9:; Uleimanov U. M. Krainev D.V. Prokopets I.A., .j. ,, i-7Kolomeytsev L.F.

Zvezdunov D.A., Pakhomin S.A.

Claims (8)

1. The bridge inverter and its control circuit, containing the first and second switches, each of which has first, second and control terminals, first and second diodes, first and second terminals for connecting the positive and negative terminals of an external constant voltage source, respectively, the third and fourth terminals for connecting the inverter load, the first terminal of the first key being connected to the first terminal, the second to the fourth terminal, the first terminal of the second terminal connected to the third terminal, the cathode of the first diode connected to the first m clamp, the anode with the third clamp, the cathode of the second diode connected to the fourth clamp, the anode with the second clamp, characterized in that the circuit contains a control device having first and second inputs for separate key management, a third common control input, first and second outputs control the first and second key, respectively, from the first to the sixth conclusions for connecting the power source, the first and second elements AND, an inverter, a trigger device having a first and second terminals for connecting a power source and an output, the first and second th transistors, a zener diode, a third diode, first to fourth resistors, a variable resistor, first to sixth capacitors, a shunt resistor (shunt), a fifth terminal for connecting an external control element, a sixth terminal for connecting a voltage source to power the control circuit, the second the output of the second key is connected to the second terminal via a shunt, the control terminals of the first and second keys are connected to the first and second outputs of the control device, respectively, the first and third terminals for connecting power supplies the control device is connected to the sixth clamp, the second and fourth to the second clamp, the sixth to the fourth clamp, the fifth is connected to the fourth clamp through the second capacitor and connected to the cathode of the third diode, the anode of which is connected to the sixth clamp, the first and second inputs of the control device are connected with the outputs of the first and second elements And, accordingly, the second input of the second element And is connected to the collector of the first transistor, the first output of the second resistor and the first output of the fifth capacitor, the emitter of the first transistor RA and the second terminal of the fifth capacitor are connected to the second terminal, the base of the first transistor is connected to the second terminal of the second key through the fourth resistor and to the second terminal through the sixth capacitor, the second terminal of the second resistor is connected to the sixth terminal, the first input of the first element And is connected to the first terminal of the fourth capacitor, through a third resistor with a collector of the second transistor and with the sixth clamp through a variable resistor, the emitter of the second transistor and the second output of the fourth capacitor is connected to the second clamp, base and the second transistor is connected to the fifth terminal through the third capacitor, between the sixth and second terminals the first capacitor and a zener diode (anode to the second terminal) and the first and second terminals for connecting the power source of the starter are connected, the fifth terminal is connected to the inverter input and through the first resistor with a sixth clamp, the output of the inverter is connected to the first input of the second element AND, the output of the starting device is connected to the second input of the first element I.  2. The bridge inverter and its control circuit according to claim 1, characterized in that the first element And is equipped with an additional third input connected to the output of the inverter.  3. The bridge inverter and its control circuit according to claims 1 and 2, characterized in that the second element And is equipped with an additional third input connected to the first input of the first element I.  4. The bridge inverter and its control circuit according to claims 1 to 3, characterized in that the circuit is equipped with a fifth resistor connected between the control and the second terminal of the first key, and a sixth resistor connected between the control terminal of the second key and the second terminal.  5. The bridge inverter and its control circuit according to claims 1 to 4, characterized in that the circuit is equipped with a seventh resistor connected between the third input of the control device and the second clamp, and a thermistor connected between the third input of the control device and the sixth clamp, and the thermistor is attached to one of the heating surfaces in the product.  6. The bridge inverter and its control circuit according to claims 1 to 5, characterized in that the circuit is equipped with an eighth resistor connected between the base of the second transistor and the second clamp.  7. The bridge inverter and its control circuit according to claims 1 to 6, characterized in that the circuit is equipped with a ninth resistor connected between the first and sixth clamps.  8. The bridge inverter and its control circuit according to claims 1 to 7, characterized in that the circuit is equipped with a seventh and eighth terminals for connecting to an external AC voltage source, a rectifier having two inputs connected to the seventh and eighth terminals, and two outputs, connected to the first and second terminals, respectively, the seventh capacitor included between the first and second terminals, as well as the tenth and eleventh resistors connected between the sixth terminal and the seventh and eighth terminals, respectively.