Drive circuit, method for controlling drive circuit

Abstract

Provided is a driving circuit which is for a voltage driven-type power semiconductor switching element and which is capable of performing switching control efficiently in accordance with a driving condition, while having a relatively simple configuration. The present invention is characterized by comprising a voltage driven-type switching element, an on-circuit for injecting electrical charges to the gate of the voltage driven-type switching element in accordance with a driving signal, and an off-circuit for extracting electrical charges from the gate of the voltage driven-type switching element in accordance with a driving signal, and also is characterized by performing injecting electrical charges to the gate of the voltage driven-type switching element or extracting electrical charges from the gate, and controlling switching time for the voltage driven-type switching element, by pulse driving of the on-circuit or the off-circuit.

Description

Technical Field

[0001] The present invention relates to a configuration of a drive circuit for a voltage-driven power semiconductor switching element and a control method thereof, and more particularly to a technique effective for application to a drive circuit for a voltage-driven power semiconductor switching element used in an in-vehicle power conversion device that requires power saving and high reliability.

Background Art

[0002] In voltage-driven power semiconductors used in power conversion devices, IGBTs, SiC MOSFETs, etc. are used, and in recent years, higher breakdown voltage and larger current have been achieved. These power conversion devices are also used in electric vehicles and are used for applications such as generating alternating current for driving a motor from direct current supplied from a battery.

[0003] In such fields, in order to improve the battery usage efficiency and suppress losses due to heat generation in the power conversion device, it is required to reduce switching losses. To solve such problems, for example, technologies such as that disclosed in Patent Document 1, which switches by switching the input resistance of an IGBT, have been developed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique of Patent Document 1, in order to switch the drive circuit to be operated, a plurality of resistors and switching elements must be prepared, resulting in problems such as an increase in their mounting area and the number of components.

[0006] In addition, the switching of the drive circuit can only be changed in the prepared drive circuit, and the switching timing is also fixed. Therefore, depending on the conditions, efficient switching cannot be performed, and in the worst case, there is a possibility of destroying the voltage-driven power semiconductor.

[0007] Therefore, an object of the present invention is to provide a drive circuit and a control method thereof that can perform efficient switching control according to drive conditions with a relatively simple configuration in a drive circuit for a voltage-driven power semiconductor switching element.

Means for Solving the Problems

[0008] To solve the above problems, the present invention includes a voltage-driven switching element, an on-circuit that injects charge into the gate of the voltage-driven switching element according to a drive signal, and an off-circuit that extracts charge from the gate of the voltage-driven switching element according to a drive signal. Another on-circuit and off-circuit different from the on-circuit and the off-circuit, And by pulse driving the on-circuit or the off-circuit, charge is injected into or extracted from the gate of the voltage-driven switching element, and the switching time of the voltage-driven switching element is controlled. A drive circuit that holds, as a table, a pattern of pulses for driving the on-circuit or the off-circuit, and the other on-circuit and off-circuit turn on and off only once in the switching period of the voltage-driven switching element It is characterized by this.

[0009] In addition, the present invention is a control method for a drive circuit that drives and controls a voltage-driven switching element. In By pulse driving the on-circuit or the off-circuit of the voltage-driven switching element, charge is injected into or extracted from the gate of the voltage-driven switching element, and the switching time of the voltage-driven switching element is controlled. A control method for a drive circuit that holds, as a table, a pattern of pulses for driving the on-circuit or the off-circuit, and the other on-circuit and off-circuit different from the on-circuit and the off-circuit turn on and off only once in the switching period of the voltage-driven switching element It is characterized by this.

Effects of the Invention

[0010] According to the present invention, in a drive circuit for a voltage-driven power semiconductor switching element, a drive circuit and a control method thereof that can perform efficient switching control according to drive conditions with a relatively simple configuration can be realized.

[0011] This makes it possible to reduce the switching loss of the voltage-driven power semiconductor switching element, contributing to higher efficiency and improved reliability of the power conversion device.

[0012] Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and detailed descriptions of overlapping parts are omitted.

Embodiment

[0015] Referring to FIGS. 1 to 6, the configuration of the drive circuit according to Embodiment 1 of the present invention and its control method will be described.

[0016] FIG. 1 is a schematic configuration diagram of a power conversion device between a battery and a motor generator configured using the drive circuit of this embodiment.

[0017] Reference numeral 100 denotes a battery, which supplies a DC voltage that is the source of power in the power conversion device, or stores the power generated by the motor generator 400 described later.

[0018] Reference numeral 110 denotes a capacitor, which supplies power in the case of an instantaneous voltage drop when the motor generator 400 is driven, and stores power when the motor generator 400 generates electricity. Further, noise generated during the switching of the voltage-driven switching elements 200 to 205 described later is reduced by the charge and discharge of the capacitor.

[0019] Reference numerals 200 to 205 denote voltage-driven switching elements, which are, for example, IGBTs (Insulated Gate Bipolar Transistors) or SiC MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), but are not limited thereto. The voltage-driven switching elements 200 to 205 perform a switching operation by charging and discharging a charge to the control terminals thereof, and perform power conversion.

[0020] Reference numerals 210 to 215 denote diodes connected in anti-parallel to the voltage-driven switching elements 200 to 205, and are used to cause the current to flow back. They may be used alone, or may be configured based on the parasitic elements of the voltage-driven switching elements 200 to 205.

[0021] Symbols 220 to 225 are temperature sensors, which acquire the temperature information of the voltage-driven switching elements 200 to 205 and output it to the control circuit 600 described later. For example, a constant current is passed through the diodes 210 to 215, and the measurement is performed based on the amount of voltage drop.

[0022] In FIG. 1, a configuration is shown in which one temperature sensor 220 to 225 is arranged for each of the voltage-driven switching elements 200 to 205. However, for example, for the voltage-driven switching elements 200 and 203, the voltage-driven switching elements 201 and 204, and the voltage-driven switching elements 202 and 205, if there is no difference in temperature, such as two voltage-driven switching elements being packaged together as one for the upper arm and the lower arm, there is no problem in arranging one temperature sensor for each combination. Furthermore, if there is no temperature bias, a configuration in which one temperature sensor is arranged for the voltage-driven switching elements 200 to 205 may be adopted.

[0023] Symbols 230 to 232 are current sensors, which acquire the information of the current amount flowing through each of the three-phase (U, V, W) lines connected to the motor generator 400 and output it to the control circuit 600. For the current sensors 230 to 232, a method of detecting using a magnetic field by a Hall element may be used, a method of detecting using a shunt resistor may be adopted, or other methods may be used.

[0024] Symbol 240 is a voltage sensor, which acquires the voltage information of the battery 100 and the capacitor 110 and outputs it to the control circuit 600.

[0025] Symbols 300 to 305 are resistors, which limit the amount of current injected into or withdrawn from the control terminals of the voltage-driven switching elements 200 to 205. In FIG. 1, the resistors 300 to 305 are configured such that one resistor is arranged for each of the voltage-driven switching elements 200 to 205, but a configuration in which a plurality of resistors are arranged is also possible.

[0026] Reference numeral 400 is a motor generator, such as a synchronous machine or an induction machine, which operates as a motor when power is supplied and as a generator when a rotational force is applied to the rotating shaft. Since its operation changes depending on the operating method, it will be described as a motor generator in the present invention.

[0027] In FIG. 1, a three-phase power conversion device driven by using six voltage-driven switching elements 200 to 205 and six diodes 210 to 215 respectively is taken as an example, but it is not limited thereto, and the quantity may be increased or decreased according to the configuration.

[0028] Reference numeral 500 is a driver circuit that drives the voltage-driven switching elements 200 to 205 via resistors 300 to 305.

[0029] Reference numeral 600 is a control circuit that controls the driver circuit 500 by using information from temperature sensors 220 to 225, current sensors 230 to 232, voltage sensor 240, and operation instruction information for the motor generator 400 from a higher-level control unit (not shown).

[0030] The operations of the driver circuit 500 and the control circuit 600 will be described in detail with reference to FIG. 2. FIG. 2 is a diagram showing a control system for one system that drives the voltage-driven switching element 200.

[0031] The driver circuit 500 includes a gate control pulse generation unit 510, a drive circuit 530 that injects charge into the control terminal of the voltage-driven switching element 200 via the resistor 300, and a drive circuit 531 that extracts charge from the control terminal of the voltage-driven switching element 200 via the resistor 300.

[0032] The gate control pulse generation unit 510 stores in advance, as a gate control pulse table 520 for charge injection and a gate control pulse table 521 for charge extraction, a table for setting what kind of pulse (Pulse) is to be generated at the time of switching of the voltage-driven switching element 200 to perform charge injection or extraction.

[0033] Based on these tables, the drive circuit 530 and the drive circuit 531 operate, and charge is injected as a pulse to the control terminal of the voltage-driven switching element 200 via the resistor 300 according to the gate control pulse table 520, and similarly, charge is extracted as a pulse according to the gate control pulse table 521.

[0034] The gate control pulse tables 520 and 521 each hold a plurality of pulse patterns for switching the voltage-driven switching element 200, and which pulse pattern to use is selected by a signal instructed from the control circuit 600.

[0035] These gate control pulse tables may hold the frequency of the pulse, the time of the pulse, and the delay time from the switching instruction of the voltage-driven switching element 200 from the control circuit 600 to the generation of the first pulse, or may hold the pulse waveform itself to be generated. Also, there is no reason why the generated pulses must be uniform, and non-uniformly spaced pulses are also acceptable.

[0036] FIG. 3 shows the losses in the voltage-driven switching element. Also, FIG. 4 shows the relationship between the slew rate and the surge in the voltage-driven switching element.

[0037] Generally, the losses in a voltage-driven switching element used in a power conversion device are divided into an on-loss and a switching loss as shown in FIG. 3.

[0038] Regarding losses, since they are determined by the characteristics of voltage-driven switching elements, losses cannot be reduced unless the characteristics are improved.

[0039] On the other hand, regarding switching losses, it is possible to shorten the time required for switching by increasing the amount of charge injected into or withdrawn from the control terminal of the voltage-driven switching element, or by increasing the switching slew rate of the voltage-driven switching element, and accordingly, the switching losses can be reduced.

[0040] However, as shown in FIG. 4, when the slew rate is increased, the surge amount also increases at the same time, and ultimately, there is a risk of destroying the switching element by exceeding the rated voltage that can be applied to the voltage-driven switching element.

[0041] Therefore, in the conventional method, within the range of operating conditions used, the resistance value of the resistance corresponding to resistors 300 to 305 is determined as a fixed value so that the slew rate is such that the surge does not exceed the voltage that can be applied to the voltage-driven switching element.

[0042] However, in this method, even though there is a margin with respect to the rated voltage that can be applied to the voltage-driven switching element depending on the environmental conditions, the slew rate cannot be changed.

[0043] Therefore, in this embodiment, as shown in FIG. 5, the slew rate is controlled by changing the number of pulses for injecting charge into the control terminal of the voltage-driven switching element 200 via resistor 300. During the switching of the voltage-driven switching element 200, if the number of times of injecting charge into the control terminal by the pulse is increased, the slew rate becomes steep, and if the number is decreased, it becomes gentle. This is selected and implemented from the waveforms registered in the gate control pulse tables 520 and 521.

[0044] Further, instead of the PFM (Pulse Frequency Modulation) method of controlling the switching slew rate of the voltage-driven switching element 200 by the number of pulses as shown in FIG. 5, a PWM (Pulse Width Modulation) method of controlling the slew rate by the width of the pulses as shown in FIG. 6 may be used. In this case, the wider the pulse width, the higher the switching slew rate of the voltage-driven switching element 200 becomes.

[0045] In the conventional method, in order to perform such slew rate control, it was necessary to arrange a plurality of elements corresponding to the drive circuits 530 and 531 and the element corresponding to the resistor 300 in parallel, and switch the driving circuit or change the number of driving circuits.

[0046] However, even when arranged in n lines, the slew rate can be changed by a maximum of 2 n -1 step, and each has a large physical size, and it is not practical to arrange a large number of lines.

[0047] On the other hand, in this embodiment, it is possible to control the slew rate for the stages of PFM or PWM with only one line of the drive circuits corresponding to the drive circuits 530 and 531 and the resistor 300, and the slew rate can be changed more efficiently.

[0048] As a result, it becomes possible to reduce the switching loss of the voltage-driven switching element 200, and it becomes possible to more efficiently convert the DC power charged in the battery 100 into three-phase AC power.

[0049] The waveforms registered in the gate control pulse tables 520 and 521 do not have to be equally spaced pulses.

[0050] For example, at the initial stage of starting the switching of the voltage-driven switching element 200, a waveform is registered in which the amount of pulses is increased, or the duty ratio of the pulses is increased to increase the slew rate, and in the latter half of the switching, the amount of pulses is decreased, or the duty ratio of the pulses is decreased to decrease the slew rate. By controlling the switching waveform, the switching time can be shortened to suppress the loss of the voltage-driven switching element 200, and a configuration may be adopted to suppress the surge generated during switching.

[0051] Furthermore, a configuration may be adopted in which both the set of the gate control pulse table 520 and the drive circuit 530 and the set of the gate control pulse table 521 and the drive circuit 531 are operated during one switching from On to Off or from Off to On of the voltage-driven switching element 200.

[0052] For example, during the switching from Off to On of the voltage-driven switching element 200, at the initial stage of switching, the gate control pulse table 520 and the drive circuit 530 are used to inject charge into the control terminal of the voltage-driven switching element 200 via the resistor 300 to perform switching. In the latter half of the switching, the gate control pulse table 521 and the drive circuit 531 are used to draw out a part of the charge from the control terminal of the voltage-driven switching element 200 via the resistor 300 to decrease the slew rate of the switching and suppress the surge. After the switching is completed, a process may be performed to turn on and fix the drive circuit 530 again.

[0053] By performing such processing, it becomes possible to control the switching waveform with higher degrees of freedom, shorten the switching time, reduce the loss of the voltage-driven switching element 200, and suppress the surge generated during switching.

[0054] The control circuit 600 includes a gate control selection unit 601. The gate control selection unit 601 outputs a signal for selecting a waveform to be used in the gate control pulse tables 520 and 521 by using the information of the temperature sensors 220 to 225, the current sensors 230 to 232, and the voltage sensor 240.

[0055] For example, regarding the voltage sensor 240, the higher the voltage, the smaller the amount of surge allowed within the rated voltage that can be applied to the voltage-driven switching element 200, so a table with a lower On ratio (in the case of PFM, a smaller number of pulses; in the case of PWM, a lower Duty) is selected.

[0056] Regarding the temperature sensors 220 to 225, for example, when an IGBT is used as the voltage-driven switching element 200, the influence of the surge becomes significant at low temperatures. Therefore, it may be determined that the one with the lowest temperature among the temperature sensors 220 to 225 becomes critical, and a configuration may be adopted to select the waveform to be used in the gate control pulse tables 520 and 521 based on that information.

[0057] Similarly, regarding the current sensors 230 to 232, it is also possible to adopt a configuration to select the waveform to be used in the gate control pulse tables 520 and 521 based on the information from the current sensors 230 to 232.

[0058] Also, although not shown, a signal for selecting the waveform to be used in the gate control pulse tables 520 and 521 may be generated by using information such as the output required torque and rotational speed at the motor generator 400 from a higher-level control unit, and the voltage applied to each phase of the motor generator 400.

[0059] For example, when the output required torque in the motor generator 400 is large, since an increase in temperature is expected, when selecting the waveforms used in the gate control pulse tables 520 and 521, it is possible to adopt a configuration such as using a table with a higher On ratio. Similarly, when the rotational speed is high, since a further increase in temperature is expected, when selecting the waveforms used in the gate control pulse tables 520 and 521, it is possible to adopt a configuration such as using a table with a higher On ratio.

[0060] When the signal for selecting the waveforms used in the gate control pulse tables 520 and 521 is changed during the switching operation of the voltage-driven switching element 200, an unexpected pulse pattern will occur, exceeding the breakdown voltage of the voltage-driven switching element 200 and possibly leading to breakdown. Therefore, it is desirable to control so that the voltage-driven switching element 200 does not reach breakdown by switching the signal for selecting the waveforms used in the gate control pulse tables 520 and 521 at a timing when switching does not occur in synchronization with the On / Off switching period of the voltage-driven switching element 200.

[0061] Also, although the driver circuit 500 drives the voltage-driven switching elements 200 to 205 via the resistors 300 to 305, if the signals for selecting the waveforms used in the respective gate control pulse tables 520 and 521 for these do not switch simultaneously, a difference in switching may occur between the voltage-driven switching elements 200 to 205, and it is conceivable that the motor generator 400 cannot be controlled as expected.

[0062] To prevent this, it is desirable to control so that the selection signals of the respective gate control pulse tables 520 and 521 are updated synchronously for the total of 6 phases of the upper and lower arms of the voltage-driven switching elements 200 to 205.

[0063] According to the configuration of the drive circuit and its control method of the present embodiment described above, efficient switching control of the voltage-driven power semiconductor switching element is possible under various environmental conditions, and a highly efficient power conversion device can be provided.

Embodiment

[0064] With reference to FIGS. 7 and 8, the configuration of the drive circuit and its control method according to Embodiment 2 of the present invention will be described.

[0065] FIG. 7 is a configuration diagram of the driver circuit of this embodiment. Similar to FIG. 2, it shows a control system for one system of the voltage-driven switching element.

[0066] The configuration as a power conversion device is substantially the same as that of Embodiment 1 (FIG. 1), except that the driver circuit 500 is replaced by the driver circuit 501, and each of the resistors 300 to 305 is replaced by four resistors 306 to 309. Four resistors 306 to 309 are connected to the control terminal of the voltage-driven switching element 200. Hereinafter, the configurations and functions already described in Embodiment 1 will be omitted.

[0067] The driver circuit 501 includes a gate control pulse generation unit 511 and incorporates gate control pulse tables 522 and 523.

[0068] In addition, the driver circuit 501 has drive circuits 532 and 534 in addition to the drive circuits 533 and 535 controlled by the gate control pulse tables 522 and 523. Different from the drive circuits 533 and 535, the drive circuits 532 and 534 are not controlled by the gate control pulse table but are directly controlled by the gate control pulse generation unit 511.

[0069] Using FIG. 8, the operations of the control circuit 600, the gate control pulse generation unit 511, the resistors 306 to 309, and the voltage-driven switching element 200 will be described. FIG. 8 is a diagram showing the relationship between the control terminal signal pattern, the slew rate, and the surge in FIG. 7.

[0070] When a control instruction for switching the voltage-driven switching element 200 from the off state to the on state is issued from the control circuit 600, the gate control pulse generation unit 511 first turns off the control signal of the drive circuit 534 to control so that no through current flows.

[0071] Thereafter, the control signal of the drive circuit 532 is turned on to inject charge into the control terminal of the voltage-driven switching element 200. This becomes the basic (the lowest slew rate) state when performing the switching of the voltage-driven switching element 200 from the off state to the on state.

[0072] In addition to this, when the control signal of the drive circuit 532 is turned on, the gate control pulse generation unit 511 drives the drive circuit 533 according to the waveform of the gate control pulse table 522 selected according to the gate control selection unit 602 of the control circuit 600, and additional charge is injected into the control terminal of the voltage-driven switching element 200 via the resistor 307, and the slew rate is controlled.

[0073] The waveform selection of the gate control selection unit 602 is performed based on information such as a temperature sensor, a voltage sensor, and a current sensor in the same manner as in the first embodiment, and is controlled so that the slew rate is high within the withstand voltage range of the voltage-driven switching element 200, the loss of the voltage-driven switching element 200 is reduced, and efficient power conversion processing is performed.

[0074] On the other hand, in the case of a control instruction for switching the voltage-driven switching element 200 from the on state to the off state, the operations of the drive circuit 532 and the drive circuit 534 are reversed, the charge of the control terminal of the voltage-driven switching element 200 is withdrawn via the resistor 308, and instead of the drive circuit 533, the drive circuit 535 operates according to the waveform of the gate control pulse table 523, and the charge of the control terminal of the voltage-driven switching element 200 is additionally withdrawn via the resistor 309, and the switching slew rate is controlled. Thereby, efficient power conversion processing is implemented.

[0075] Unlike in the first embodiment, in this embodiment, two sets of drive circuits for injecting charge and for extracting charge are prepared. Even if one of the drive circuits malfunctions, it is possible to continue switching the voltage-driven switching element 200.

[0076] For example, when the drive circuit 533 malfunctions, the drive circuit 532 can inject charge via the resistor 306 to switch the voltage-driven switching element 200. Also, for example, when the drive circuit 534 malfunctions, a waveform of the gate control pulse table 523 with a high duty ratio or a large number of pulses is selected to drive the drive circuit 535, and charge is extracted via the resistor 309, so that it is also possible to switch the voltage-driven switching element 200 at a throughput rate close to that when there is no problem. This makes it possible to provide a highly robust power conversion device.

[0077] In this embodiment, a configuration is adopted in which one resistor 306 to 309 is arranged for each of the drive circuits 532 to 535. However, even if a configuration is adopted in which one resistor is shared between the drive circuits 532 and 535 and one resistor is shared between the drive circuits 533 and 534, an equivalent effect can be obtained. Also, it is possible to adopt a configuration in which one resistor is shared by the drive circuits 532 to 535.

Embodiment

[0078] With reference to FIG. 9, the configuration of the drive circuit and its control method according to Embodiment 3 of the present invention will be described.

[0079] FIG. 9 is a configuration diagram of the driver circuit of this embodiment, and similar to FIGS. 2 and 7, shows a control system for one set of voltage-driven switching elements.

[0080] The configuration as a power conversion device is substantially the same as that in the first embodiment (FIG. 1), and the driver circuit 500 is replaced by the driver circuit 502. However, the voltage of the control terminal of the voltage-driven switching element 200 is input to the driver circuit 502. Hereinafter, the configurations and functions already described in the first embodiment will be omitted from the description.

[0081] The gate control pulse generation unit 512 includes gate control pulse generation units 540 and 541. The gate control pulse generation units 540 and 541 hold the relationship between the target voltage and time of the control terminal during the switching of the voltage-driven switching element 200.

[0082] This information can be rewritten by the gate control selection unit 603 of the control circuit 600 based on information such as a temperature sensor, a voltage sensor, and a current sensor. Also, it is possible to output a waveform for controlling the drive circuits 530 and 531 by PWM or PFM, and the voltage of the control terminal of the voltage-driven switching element 200 is input.

[0083] For example, in the case of switching the voltage-driven switching element 200 from the off state to the on state, the target voltage at the time from the switching control instruction from the off state to the on state from the control circuit 600 is compared with the voltage of the control terminal of the voltage-driven switching element 200. If it is low, the duty ratio of PWM is increased, or the number of pulses of PFM is increased to increase the charge injection amount through the resistor 300. Conversely, if it is high, the duty ratio of PWM is decreased, or the number of pulses of PFM is decreased to decrease the charge injection amount and adjust the slew rate of the voltage-driven switching element 200.

[0084] In this embodiment, control is performed using the voltage of the control terminal of the voltage-driven switching element 200. This makes it possible to more accurately control the slew rate of the switching of the voltage-driven switching element 200, shorten the switching time, reduce the loss of the voltage-driven switching element 200, and suppress the surge generated during switching.

[0085] Also, the gate control pulse generation units 540 and 541 are made to hold the threshold value when the voltage fluctuates excessively from the target voltage. In that case, among the drive circuits 530 and 531, the drive circuit on the side opposite to the one related to the switching of the voltage-driven switching element 200 (for example, in the case of switching from Off to On, the drive circuit 530 is related to the switching, and the opposite side is the drive circuit 531) may perform control to approach the target voltage by injecting or extracting charge from the control terminal of the voltage-driven switching element 200, in the same manner as in the first embodiment.

[0086] In each of the above embodiments, the drive circuit has been described by taking the power conversion device that drives the motor generator 400 as an example. However, the present invention is not limited to this, and it can also be applied to in-vehicle inverter circuits, uninterruptible power supply devices, power conversion devices for trains and ships, industrial power conversion devices such as electric motors in factory facilities, power conversion devices for solar power generation systems, power conversion devices for household electric motors, and the like.

[0087] Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can also be added to the configuration of one embodiment. Further, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible.

Description of Reference Numerals

[0088] 100… Battery 110… Capacitor 200~205… Voltage-driven switching element 210~215… Diode 220~225… Temperature sensor 230~232… Current sensor 240… Voltage sensor 300~309… Resistor 400… Motor generator 500~502… Driver circuit 510~512… Gate control pulse generation unit 520~523… Gate control pulse table 530~535… Drive circuit 540,541… Gate control pulse generation unit 600… Control circuit 601~603… Gate control selection unit

Claims

1. A voltage-driven switching element, an on-circuit that injects charge into the gate of the voltage-driven switching element in response to a drive signal, an off-circuit that extracts charge from the gate of the voltage-driven switching element in response to a drive signal, and another on-circuit and off-circuit different from the on-circuit and the off-circuit, and a drive circuit that performs injection of charge into or extraction of charge from the gate of the voltage-driven switching element by pulse driving of the on-circuit or the off-circuit to control the switching time of the voltage-driven switching element, wherein a pattern of pulses for driving the on-circuit or the off-circuit is held as a table, and the other on-circuit and off-circuit are drive circuits that turn on and off only once in the switching period of the voltage-driven switching element.

2. A voltage-driven switching element, an on-circuit that injects charge into the gate of the voltage-driven switching element in response to a drive signal, an off-circuit that extracts charge from the gate of the voltage-driven switching element in response to a drive signal, and a drive circuit that performs injection of charge into or extraction of charge from the gate of the voltage-driven switching element by pulse driving of the on-circuit or the off-circuit to control the switching time of the voltage-driven switching element, wherein a pattern of pulses for driving the on-circuit or the off-circuit is held as a table, and a drive circuit that selects the pattern of the pulses based on the torque output by a synchronous machine or an induction machine driven by the drive circuit.

3. A voltage-driven switching element, an on-circuit that injects charge into the gate of the voltage-driven switching element in response to a drive signal, an off-circuit that extracts charge from the gate of the voltage-driven switching element in response to a drive signal, and a drive circuit that performs injection of charge into or extraction of charge from the gate of the voltage-driven switching element by pulse driving of the on-circuit or the off-circuit to control the switching time of the voltage-driven switching element, wherein a pattern of pulses for driving the on-circuit or the off-circuit is held as a table, and a drive circuit that selects the pattern of the pulses based on the rotational speed of a synchronous machine or an induction machine driven by the drive circuit.

4. A drive circuit according to any one of claims 1 to 3, a drive circuit that selects a pattern of the pulse based on at least one of the temperature of the voltage-driven switching element, the amount of current flowing through the voltage-driven switching element, the DC voltage supplied to the voltage-driven switching element, and the voltage of a terminal of the voltage-driven switching element.

5. A drive circuit according to any one of claims 1 to 3, a drive circuit that updates the pattern of the pulse in synchronization with the switching period of the voltage-driven switching element.

6. A drive circuit according to claim 5, a drive circuit used in a circuit that generates alternating current having three or more phases.

7. A drive circuit according to any one of claims 1 to 3, a drive circuit in which a pattern of a pulse for driving the on-circuit and a pattern of a pulse for driving the off-circuit both exist during a switching operation of the voltage-driven switching element.

8. A drive circuit according to any one of claims 1 to 3, a drive circuit that changes a switching time of the voltage-driven switching element by changing the pattern of the pulse.

9. A drive circuit according to any one of claims 1 to 3, a drive circuit that drives and controls the voltage-driven switching element mounted on a power conversion device.

10. In a control method of a drive circuit that drives and controls a voltage-driven switching element, a control method of a drive circuit that controls a switching time of the voltage-driven switching element by injecting charge into or extracting charge from a gate of the voltage-driven switching element by pulse driving of an on-circuit or an off-circuit of the voltage-driven switching element, wherein a pattern of a pulse for driving the on-circuit or the off-circuit is held as a table, a control method of a drive circuit in which another on-circuit and off-circuit different from the on-circuit and the off-circuit are turned on and off only once in a switching period of the voltage-driven switching element.

11. In a control method of a drive circuit that drives and controls a voltage-driven switching element, A control method for a drive circuit that controls the switching time of a voltage-driven switching element by injecting charge into or extracting charge from the gate of the voltage-driven switching element by pulse driving of the on-circuit or off-circuit of the voltage-driven switching element, comprising: The pattern of the pulse for driving the on-circuit or the off-circuit is held as a table, A control method for a drive circuit that selects the pattern of the pulse based on the torque output by a synchronous machine or an induction machine driven by the drive circuit.

12. In a control method for a drive circuit that drives and controls a voltage-driven switching element, A control method for a drive circuit that controls the switching time of a voltage-driven switching element by injecting charge into or extracting charge from the gate of the voltage-driven switching element by pulse driving of the on-circuit or off-circuit of the voltage-driven switching element, comprising: The pattern of the pulse for driving the on-circuit or the off-circuit is held as a table, A control method for a drive circuit that selects the pattern of the pulse based on the rotational speed of a synchronous machine or an induction machine driven by the drive circuit.

13. A control method for a drive circuit according to any one of claims 10 to 12, comprising: A control method for a drive circuit that selects the pattern of the pulse based on at least one of the temperature of the voltage-driven switching element, the amount of current flowing through the voltage-driven switching element, the DC voltage supplied to the voltage-driven switching element, and the voltage of the terminals of the voltage-driven switching element.

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