JPH09117159A - Gate drive circuit for power semiconductor bridge constitution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive drive control circuit for motor in which a current can be fed in one direction for a long time. SOLUTION: The power supply B2 for gate drive circuits 6, 8 of power semiconductors 2, 4 in an arm constituting the upper potential level part is provided independently from the power supply B1 for gate drive circuits 7, 9 of power semiconductors 3, 5 in an arm constituting the lower potential level part. The power supply B2 for gate drive circuits 6, 8 of power semiconductors 2, 4 in an arm constituting the upper potential level part can be constituted in tandem on the reference power supply B1. Furthermore, the power supply for gate drive circuits 6, 8 of power semiconductors 2, 4 in an arm constituting the upper potential level part may be provided with a constant current function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power semiconductor gate drive circuit having a bridge structure for supplying electric power to a load, and is particularly used for supplying electric power to a driving motor of a carrier truck and is used in forward and reverse directions. The present invention relates to an improvement of a gate drive circuit of a power semiconductor having a bridge structure which is optimum for supplying current.

[0002]

2. Description of the Related Art Recently, in industrial machines, an example using an electric motor driven by a bridge circuit is often seen. For example, in a battery-driven two-wheeled vehicle golf bag cart, the left and right wheels rotate at appropriate rotational speeds in response to turning commands, and travel in a predetermined direction in response to forward / backward commands. As described above, for example, the bridge circuit as shown in FIG. 4 is configured to supply and control the current to the DC motor. In FIG. 4, reference numeral 1 is a DC motor, and 2 to 5 are bridge-connected power semiconductor elements. The first power semiconductor element 2 and the second power semiconductor element 3 are connected in series, the connection point is connected to the first terminal 1a of the DC motor 1, and the first power semiconductor element 3 is connected in series.
The voltage of the battery B1 is applied to both ends of the power semiconductor element 2 and the second power semiconductor element 3. The third power semiconductor element 4 and the fourth power semiconductor element 5 are connected in series, the second terminal 1b of the DC motor 1 is connected to the connection point, and the third power semiconductor element 4 and the third power semiconductor element 4 connected in series are connected. The voltage of the battery B1 is applied to both ends of the power semiconductor element 5 of No. 4 in FIG. Therefore, when the first power semiconductor element 2 and the fourth semiconductor element 5 are turned on at the same time, the DC motor 1 rotates in the predetermined direction due to the current flowing in the direction of the arrow. When the third power semiconductor element 4 and the second semiconductor element 3 are turned on at the same time, a current flows in the DC motor 1 in the opposite direction of the arrow and rotates in the opposite direction.

The gate of the first power semiconductor element 2 is the first
Driven by the gate drive circuit element 6 of the second power semiconductor element 3 and the gate of the second power semiconductor element 3 is driven by the second gate drive circuit element 7
Driven by the third gate drive circuit element 8, and the gate of the third power semiconductor element 4 is driven by
The gate of the power semiconductor element 5 is driven by the fourth gate drive circuit element 9. Further, the diode 10, the resistor 11, and the capacitor 12 are connected in series to be connected to the battery B1, the first gate drive circuit element 6 is connected in parallel to the capacitor 12, and the constant voltage diode 1 is connected to the capacitor 12.
8 are connected in parallel. Therefore, when the second power semiconductor element 3 is turned on in this state, the battery B1 is applied across the series circuit of the diode 10, the resistor 11 and the capacitor 12.
Is applied to charge the capacitor 12, the second power semiconductor element 3 is turned off, and the capacitor 1 is also driven at the timing when the first power semiconductor element 2 is driven.
The first gate drive circuit element 6 operates by being supplied with the charged voltage of 2. The voltage of the battery B1 is applied to the second gate drive circuit element 7, and the capacitor 13 and the constant voltage diode 19 are connected in parallel. In addition, a circuit in which the diode 14, the resistor 15, and the capacitor 16 are connected in series is connected to the battery B1, and the third gate drive circuit element 8
Is connected in parallel to the capacitor 16, and the constant voltage diode 20 is connected in parallel to the capacitor 16. Therefore,
When the fourth power semiconductor element 5 is turned on in this state,
The voltage of the battery B1 is applied to both ends of the series circuit of the diode 14, the resistor 15, and the capacitor 16 so that the capacitor 16
Is charged, the fourth power semiconductor element 5 is turned off, and the voltage charged in the capacitor 16 is supplied to the third gate drive circuit element 8 even when the third power semiconductor element 4 is driven. Operate.

The fourth gate drive circuit element 9 has a battery B1.
Is applied, and the capacitor 17 and the constant voltage diode 21 are connected in parallel. That is, the first gate drive circuit element 6 and the third gate drive circuit element 8 are separated from each other on the ground side by the DC motor 1 and are independent from each other, as is apparent from the circuit shown in FIG. A higher voltage than the battery B1 is required. for that reason,
When the second power semiconductor element 3 is on, the capacitor 12
Are charged, the capacitors 16 are charged when the fourth power semiconductor element 5 is on, and the charging voltage of each capacitor is used for operating the first gate drive circuit element 6 and the third gate drive circuit element 8 respectively. Used as a power source. The above-mentioned constant voltage diode may not be connected depending on the withstand voltage condition of each gate drive circuit element.

FIG. 5 shows another structural example for driving a DC motor. In FIG. 5, the first terminal 30a of the DC motor 30 is connected to the connection point of the first power semiconductor element 31 and the second power semiconductor element 32 connected in series between the power supply circuit B30 and the ground level G. , Power supply circuit B3
The second terminal 30b of the DC motor 30 is connected to the connection point of the third power semiconductor element 33 and the fourth power semiconductor element 34, which are connected in series between 0 and the ground level G. In addition, each gate of the first power semiconductor element 31 and the second power semiconductor element 32 is a first gate drive IC.
The first auxiliary power supply circuit B30a supplies a predetermined voltage as a power supply for driving the first gate drive IC 35. Third power semiconductor element 33
And the gates of the fourth power semiconductor element 34 are driven by the second gate drive IC 36, and the second auxiliary power supply circuit B3 is used as a power supply for operating the second gate drive IC 36.
A predetermined voltage is supplied from 0b. With the configuration described above, the DC motor 30 rotates in the controlled direction at the controlled speed by appropriately driving the four power semiconductor elements as in the circuit example shown in FIG.

FIG. 6 shows an example of driving a three-phase electric motor. In FIG. 6, the power supply circuit B40 and the ground level G
At the connection point of the first power semiconductor element 41 and the second power semiconductor element 42 connected in series between
Of the third power semiconductor element 43 and the fourth power semiconductor element 44 connected in series between the power supply circuit B40 and the ground level G.
The second terminal 40b of the phase electric motor 40 is connected, and the connection point of the fifth power semiconductor element 45 and the sixth power semiconductor element 46 connected in series between the power supply circuit B40 and the ground level G is a three-phase electric motor. The third terminal 40c of 40 is connected. Further, each gate of the first power semiconductor element 41 and the second power semiconductor element 42 is driven by the first gate drive IC 47, and the first gate drive IC 47 is driven.
Is supplied with a predetermined voltage from the first auxiliary power supply circuit B40a as an operating power supply on the side of the first power semiconductor element 41, and a second auxiliary power supply circuit B40b as an operating power supply on the side of the second power semiconductor element 42. Is supplied with a predetermined voltage. The gates of the third power semiconductor element 43 and the fourth power semiconductor element 44 are respectively connected to the second gate drive IC 48.
Driven by the third gate drive IC 48
A predetermined voltage is supplied from the first auxiliary power supply circuit B40a as an operating power supply on the power semiconductor element 43 side, and a predetermined voltage is supplied from the second auxiliary power supply circuit B40b as an operating power supply on the fourth power semiconductor element 44 side. Is being supplied. Fifth power semiconductor element 45 and sixth power semiconductor element 4
Each gate of 6 is driven by a third gate drive IC 49, and a predetermined voltage is supplied to the third gate drive IC 49 from the first auxiliary power supply circuit B40a as an operating power supply on the fifth power semiconductor element 45 side. The second auxiliary power supply circuit B is used as an operating power supply on the side of the sixth power semiconductor element 46.
A predetermined voltage is supplied from 40b. By appropriately driving the six power semiconductor devices, the three-phase electric motor rotates in the controlled direction at the controlled speed.

[0007]

FIGS. 4 to 6 show an embodiment of the present invention.
As shown in the above example, when the electric motor is driven by the bridge coupling, it is originally necessary to separately provide the power supply for the gate drive circuit on the higher power supply side. In order to avoid providing an expensive power supply individually, a means for storing electricity in a capacitor and using the electric charge for control as shown in FIGS. 4 to 6 has also been used. However, for example, when a golf bag cart is run, it is necessary to supply current to the DC motor in the same direction for a relatively long time. Therefore, in the drive control circuit of the DC motor as shown in FIGS. 4 to 6, there is a limit to the capacity that can be stored in the capacitor, so that the traveling control may be disabled, and an expensive power source may be provided individually. It was needed. It is an object of the present invention to solve the above-mentioned problems (problems) of conventional ones and to provide an inexpensive power semiconductor gate drive circuit having a bridge structure capable of flowing a current in one direction for a long time.

[0008]

In order to solve the above-mentioned problems, in a bridged power semiconductor gate drive circuit according to the present invention, a power semiconductor gate drive circuit power supply of an arm forming an upper potential level portion is provided. Is configured separately from the power supply for the gate drive circuit of the power semiconductor of the arm that constitutes the lower potential level section.
In this case, the power supply for the gate drive circuit of the power semiconductor of the arm forming the higher potential level portion can be configured in tandem on the reference power supply. Further, the power supply for the gate drive circuit of the power semiconductor of the arm constituting the above-mentioned higher potential level section may be obtained from the power supply higher than the reference voltage. With such a configuration, as a power supply for the gate drive circuit, conventionally, it was necessary to add two power supplies for a single phase and three power supplies for a three phase, but since the gate drive circuit does not require a large load power, it is inexpensive. Only one power supply is needed. Therefore, the intended purpose of providing an inexpensive control circuit for driving an electric motor capable of flowing current in one direction for a long time is achieved, and the electric motor can be driven in one direction for a long time at a low cost. If a constant current function is provided in the power supply for the gate drive circuit of the power semiconductor of the arm forming the higher potential level section, there is no risk of overcurrent flowing in the gate drive circuit, and there is no risk of damage.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Three embodiments of a bridge structure power semiconductor gate drive circuit according to the present invention will be described in detail with reference to FIGS. In FIGS. 1 to 3, the same components as those described in the related art are designated by the same reference numerals as those in FIG. 4, and detailed description thereof will be omitted.

First Embodiment: In FIG. 1, 1 is a DC motor, and 2 to 5 are bridge-connected power semiconductor elements. The first power semiconductor element 2 and the second power semiconductor element 3 are connected in series, the connection point is connected to the first terminal 1a of the DC motor 1, and the first power semiconductor element 3 is connected in series.
The voltage of the first battery B1 is applied to both ends of the power semiconductor element 2 and the second power semiconductor element 3. Third
Power semiconductor element 4 and the fourth power semiconductor element 5 are connected in series, the second terminal 1b of the DC motor 1 is connected to the connection point, and the third power semiconductor element 4 and the fourth power semiconductor element 4 connected in series are connected. The voltage of the first battery B1 is applied to both ends of the power semiconductor element 5. Therefore, when the first power semiconductor element 2 and the fourth semiconductor element 5 are turned on at the same time, the DC motor 1 rotates in the predetermined direction due to the current flowing in the direction of the arrow. When the third power semiconductor element 4 and the second semiconductor element 3 are turned on at the same time, the DC electric motor 1 causes a current to flow in the opposite direction of the arrow, and rotates in the opposite direction.

The gate of the first power semiconductor element 2 is driven by the first gate drive circuit element 6. In the first gate drive circuit element 6, a first battery B in which a diode 10M and a resistor 11M are connected in series and connected in tandem
The summed voltage of 1 and the second battery B2 is applied, the ground side is connected to the same level as the first power semiconductor element 2, and the smoothing capacitor 12N and the constant voltage diode 18 are connected in parallel. ing. The input circuit of the first gate drive circuit element 6 is not shown. The gate of the second power semiconductor element 3 is connected to the second gate drive circuit element 7
Driven by A voltage is applied to the second gate drive circuit element 7 by the first battery B1, the ground side is connected to the same ground level as the second power semiconductor element 3, and the noise prevention capacitor 13 is used. Are connected. The input circuit of the second gate drive circuit element 7 is not shown. Third power semiconductor element 4
The gate of is driven by the third gate drive circuit element 8. A voltage obtained by adding the first battery B1 and the second battery B2, in which the diode 14M and the resistor 15M are connected in series and connected in tandem, is applied to the third gate drive circuit element 8, and the ground side has the first voltage. 3 is connected to the same level as the power semiconductor element 4 and the smoothing capacitor 16N and the constant voltage diode 20 are connected in parallel. The input circuit of the third gate drive circuit element 8 is not shown. The gate of the fourth power semiconductor element 5 is driven by the fourth gate drive circuit element 9. A voltage is applied to the fourth gate drive circuit element 9 by the first battery B1, the ground side is connected to the same ground level as the fourth power semiconductor element 5, and the noise prevention capacitor 17 is provided. Are connected. The input circuit of the fourth gate drive circuit element 9 is not shown. 2 mentioned above
The individual capacitors 13 and 17 may be removed if there is no risk of noise depending on the circuit conditions. In addition, the two constant voltage diodes 18 and 20 described above may not be connected depending on the breakdown voltage condition of each gate drive circuit element.

In the above circuit configuration, the first gate drive circuit element 6 is applied with the voltage obtained by adding the first battery B1 and the second battery B2, but the first power semiconductor element 2 is used. Is turned on or off, and the second power semiconductor element 3
At the timing of turning off the first gate drive circuit element 6, the first gate drive circuit element 6 is substantially connected to the first battery B1 and the second battery B1.
The voltage obtained by subtracting the potential of the first terminal 1a of the electric motor 1 from the added voltage of 2 is applied, and the series resistance value of the diode 10M and the resistor 11M and the internal resistance value of the first gate drive circuit element 6 are applied. And the voltage determined by the constant voltage diode 18 is used. The first power semiconductor element 2 is turned off, and the second power semiconductor element 3 is turned off.
At the timing of turning on, the first gate drive circuit element 6 is applied with a voltage obtained by adding the first battery B1 and the second battery B2, and the series resistance value of the diode 10M and the resistor 11M is applied. And the internal resistance value of the first gate drive circuit element 6 and the voltage determined by the constant voltage diode 18. Therefore, the first power semiconductor element 2 is turned on or off. The voltage of the first battery B1 is applied to the second gate drive circuit element 7, and according to a signal input from an input circuit (not shown),
The second power semiconductor element 3 is turned on or off.

The voltage obtained by adding the first battery B1 and the second battery B2 is applied to the third gate drive circuit element 8, but the third power semiconductor element 8 is turned on or off,
At the timing when the fourth power semiconductor element 9 is turned off, the third gate drive circuit element 8 is substantially
The voltage obtained by subtracting the potential of the second terminal 1b of the electric motor 1 from the added voltage of the battery B1 and the second battery B2 is applied, and the series resistance value of the diode 14M and the resistor 15M and the third gate drive are applied. It is determined by the ratio with the internal resistance value of the circuit element 8, and further operates at a voltage determined by the constant voltage diode 20. Turning off the third power semiconductor element 4,
At the timing of turning on the fourth power semiconductor element 5, the voltage obtained by adding the first battery B1 and the second battery B2 is applied to the third gate drive circuit element 8, and the diode 14M is applied. And the series resistance value of the resistor 15M and the internal resistance value of the third gate drive circuit element 8 are determined, and the voltage is determined by the constant voltage diode 20. Therefore, the third power semiconductor element 8 is turned on or off. The voltage of the first battery B1 is applied to the fourth gate drive circuit element 9, and the fourth power semiconductor element 5 is driven according to a signal input from an input circuit (not shown).
Is turned on or off. Therefore, when the first power semiconductor element 2 and the fourth power semiconductor element 5 are turned on and the second power semiconductor element 3 and the third power semiconductor element 4 are turned off, the electric motor 1 rotates in the direction of the arrow, When the second power semiconductor element 3 and the third power semiconductor element 4 are turned on and the first power semiconductor element 2 and the fourth power semiconductor element 5 are turned off, the electric motor 1 rotates in the direction opposite to the arrow.

The following is a comparison and arrangement of the configuration of this embodiment and the configuration of the conventional technique described with reference to FIG. (1) The power supply for the first gate drive circuit element 6 and the third gate drive circuit element 8 is constituted by a power supply circuit in which a battery B2 of low power consumption and low voltage is added to the power supply circuit B1. (2) The power supply circuits for the second gate drive circuit element 7 and the fourth gate drive circuit element 9 are the same as the conventional ones.

Second Embodiment: In the circuit of FIG. 1, in the power semiconductor circuit of the bridge structure for supplying electric power to the load, the gate drive circuit of the power semiconductor of the arm constituting the upper potential level section has The second battery is connected in tandem to the power supply for the gate drive circuit of the power semiconductor of the arm constituting the potential level section, but in the present embodiment, the power of the arm constituting the higher potential level section is supplied. The power supply for the semiconductor gate drive circuit is configured separately from the power supply for the gate semiconductor drive circuit for the power of the arm forming the lower potential level portion. That is, as shown in FIG. 2, the first gate drive circuit element 6 and the third gate drive circuit which form the gate drive circuit of the power semiconductor of the arm which constitutes the higher potential level part from the battery B3 different from the battery B1. The element 8 is supplied to the element 8. The configuration other than the power source is the same as that of the first embodiment shown in FIG. 1, and thus detailed description thereof will be omitted.

Third Embodiment: In the first and second embodiments shown in the circuits of FIGS. 1 and 2, the voltage is supplied to the gate drive circuit of the power semiconductor of the arm which constitutes the higher potential level section. Although the power supply has been described as being directly supplied to the diode 10M and the diode 14M, in the present embodiment, a constant current function is provided to the power supply supplied to the gate drive circuit of the power semiconductor of the arm forming the higher potential level section. It is a thing. That is, in FIG. 3, reference numeral 22 denotes an element having a constant current characteristic, which is a constant current element having a constant current characteristic determined by a current allowable value of a gate drive circuit element forming a gate drive circuit. The configuration other than the connection of the constant current element is the same as that of the first embodiment shown in FIG. 1, and therefore detailed description will be omitted. In the present embodiment, an example in which the constant current function 22 is coupled to FIG. 1 has been described, but it goes without saying that the constant current function 22 is coupled to the battery B3 shown in FIG. Further, although the constant current element is described as being coupled to the power supply circuit, a constant current control function may be coupled instead of the constant current element.

The above description shows an example in which the technical idea based on the present invention is applied, and as described in each embodiment, the power semiconductor element to which the upper voltage of the bridge structure is applied is driven. Naturally, the peripheral circuits may be appropriately configured in accordance with the detailed circuit configuration and functional characteristics of each gate drive circuit element. That is, it is obvious that the above technical idea can be applied to a circuit for driving a multi-phase electric motor such as the three-phase electric motor shown in FIG. 6 in the related art. The circuits shown in FIGS. 1 to 3 are basic circuits to which the present invention is applied.
In order to prevent each semiconductor element from high-voltage noise components and to prevent malfunction due to noise, capacitors, diodes, etc. may be properly connected or may be omitted from the figure. It goes without saying that the circuit may be modified. In each embodiment, each power source is
Although the third to third batteries have been described above, it goes without saying that any of them may have a power source function of converting from an AC power source to obtain a predetermined voltage. The second power source shown may connect the low potential side of the secondary side of the transformer to a predetermined portion of the circuit. In addition, in the third embodiment, it goes without saying that the power supply circuit itself may be provided with a constant current function.

[0018]

EFFECTS OF THE INVENTION Since the present invention has the above-described method and is configured as a system, it has the following excellent effects. According to this gate drive circuit, the electric motor can be driven in one direction for a long time. Since a large load current is not required for the gate drive circuit (gate drive circuit element), it is only necessary to add an inexpensive power supply, so that the configuration is inexpensive. When the constant current function is provided in the power supply for the gate drive circuit of the power semiconductor of the arm that constitutes the higher potential level section, there is no risk of overcurrent flowing in the gate drive circuit, so there is no risk of damage.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a first embodiment for explaining a gate drive circuit of a power semiconductor having a bridge configuration according to the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a second embodiment for explaining a gate drive circuit of a power semiconductor having a bridge configuration according to the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a third embodiment for explaining a gate drive circuit of a power semiconductor having a bridge configuration according to the present invention.

FIG. 4 is a schematic block diagram illustrating a conventional power semiconductor gate drive circuit having a bridge configuration.

FIG. 5 is a schematic block diagram different from FIG. 4 for explaining a conventional power semiconductor gate drive circuit having a bridge configuration.

FIG. 6 is a schematic block diagram different from FIGS. 4 and 5 for explaining a conventional power semiconductor gate drive circuit having a bridge structure.

[Explanation of symbols]

 1: DC motor 2, 3, 4, 5: Power semiconductor element 6, 7, 8, 9: Gate drive circuit element 12N, 13, 16N, 17: Capacitor 10M, 14M: Diode 11M, 15M: Fixed resistor 18, 20: Constant voltage diode 22: Constant current element B1, B2, B3: Battery (DC power supply)

Claims (2)

[Claims] 1. A power semiconductor circuit having a bridge structure for supplying power to a load, wherein a power supply for a gate drive circuit of a power semiconductor of an arm constituting an upper potential level section is tandemly arranged on a reference power supply. The gate drive circuit of the power semiconductor of the bridge structure characterized by the above. 2. A power semiconductor circuit having a bridge structure for supplying power to a load, wherein a power supply for a gate drive circuit of a power semiconductor of an arm constituting an upper potential level section is obtained from a power supply higher than a reference voltage. A gate drive circuit of a power semiconductor with a bridge configuration.