Regenerative power consumption device and inverter device

Abstract

To provide a regenerative power consumption device or the like capable of effectively consuming a regenerative electric power while preventing an increase of a size of a regenerative resistor.SOLUTION: A regenerative power consumption device 14 comprises: a smooth capacitor 12 that can be charged by a regenerative electric power generated in a motor 20; a regenerative resistance 142 that is connected in parallel to the smooth capacitor 12, and can consume at least one part of the regenerative electric power; a transistor 141 that is connected to the regenerative resistance 142 in serial, and can be transmitted between an on-state that a regenerative power consumption path is conducted and an off-state that the regenerative power consumption path is disconnected; and a driver 143 for controlling a state of the transistor 141, where the driver 143 can apply an intermediate signal between an on signal and an off signal as a control signal to the transistor 141 in order to add the on signal of the transistor 141 and the off signal of the transistor 141, and control the transistor 141 to an intermediate state where at least one part of the regenerative electric power is consumed by sharing it with the regenerative resistance 142.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a regenerative power consumption device and the like. [Background technology]

[0002] Patent Document 1 discloses an inverter device that uses a regenerative resistor to consume excess regenerative power generated by a motor. A switching element that can be turned on and off is connected in series to the regenerative resistor. When the voltage of a smoothing capacitor charged with regenerative power becomes excessive, the switching element is switched to the on state, and the excess regenerative power is consumed by the regenerative resistor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-166954 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the excess regenerative power is substantially consumed only by the regenerative resistor. Therefore, in applications where a large amount of regenerative power needs to be consumed, the regenerative resistor needs to be made larger, which leads to an increase in the size of the entire inverter device.

[0005] The present disclosure has been made in consideration of these circumstances, and has an object to provide a regenerative power consumption device etc. that can efficiently consume regenerative power while preventing an increase in the size of a regenerative resistor. [Means for solving the problem]

[0006] In order to solve the above problems, a regenerative power consumption device of one embodiment of the present disclosure includes a capacitor that can be charged with regenerative power generated by a motor, a regenerative resistor connected in parallel with the capacitor and capable of consuming at least a portion of the regenerative power, a transistor connected in series with the regenerative resistor and capable of transitioning between an on state that connects a regenerative power consumption path between the regenerative resistor and at least one of the motor and the capacitor, and an off state that blocks the regenerative power consumption path, and a driver for controlling the state of the transistor, which in addition to an on signal for controlling the transistor to the on state and an off signal for controlling the transistor to the off state, is capable of applying an intermediate signal between the on signal and the off signal as a control signal to the transistor to control the transistor to an intermediate state in which at least a portion of the regenerative power is shared with the regenerative resistor and consumed.

[0007] In this embodiment, the transistor can be controlled to an intermediate state between the conventional on and off states (for example, the switching element in Patent Document 1). In this intermediate state, the transistor is not in a substantially completely conductive state like the on state, but is in a partially conductive state, and functions like a resistor. At this time, the regenerative power that should be consumed is also consumed by the transistor functioning like a resistor, so that the regenerative power consumed by the regenerative resistor connected in series with it can be reduced. In this way, even in applications where the regenerative power that should be consumed is large, the amount of consumption shared by the regenerative resistor can be suppressed by actively having the transistor functioning like a resistor share the consumption of the regenerative power, and therefore the regenerative resistor can be prevented from becoming large.

[0008] Another aspect of the present disclosure is an inverter device, which includes a smoothing capacitor that smoothes direct current and is chargeable with regenerative power generated by a motor, a DC / AC converter that converts the direct current smoothed by the smoothing capacitor into alternating current and applies the alternating current to the motor, a regenerative resistor that is connected in parallel with the smoothing capacitor and is capable of consuming at least a portion of the regenerative power, a transistor that is connected in series with the regenerative resistor and is capable of transitioning between an on state that conducts a regenerative power consumption path between at least one of the motor and the smoothing capacitor and the regenerative resistor and an off state that blocks the regenerative power consumption path, and a driver that controls the state of the transistor and is capable of applying an intermediate signal between the on signal and the off signal as a control signal to the transistor in order to control the transistor to an intermediate state in which at least a portion of the regenerative power is shared and consumed by the regenerative resistor in addition to an on signal for controlling the transistor to an on state and an off signal for controlling the transistor to an off state.

[0009] Any combination of the above components, or any conversion of these components into a method, device, system, recording medium, computer program, or the like, is also encompassed by the present disclosure. Effect of the Invention

[0010] According to the present disclosure, regenerative power can be consumed efficiently while preventing an increase in the size of the regenerative resistor. [Brief description of the drawings]

[0011] [Figure 1] 1 shows a schematic configuration of an inverter device. [Diagram 2] 3 is a schematic diagram showing an example of a regenerative power consumption process performed by a regenerative power consumption device; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] In the following, a form for carrying out the present disclosure (hereinafter also referred to as an embodiment) will be described in detail with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc. will be given the same reference numerals, and duplicated descriptions will be omitted. The scale and shape of each part shown in the drawings are set for convenience in order to simplify the description, and are not to be interpreted as being limiting unless otherwise specified. The embodiment is an example, and does not limit the scope of the present disclosure in any way. All features and their combinations presented in the embodiment are not necessarily essential to the present disclosure. The embodiment is presented for convenience, decomposed into components for each function and / or each functional group that realizes it. However, one component in the embodiment may actually be realized by a combination of multiple components as separate entities, and multiple components in the embodiment may actually be realized by one component as an integrated entity.

[0013] 1 is a schematic diagram showing a configuration of an inverter device 10 according to an embodiment of the present disclosure. The inverter device 10 includes a rectifier unit 11 that rectifies and converts multi-phase AC having different phases input from an AC power source 1 into DC, a smoothing capacitor 12 such as an electrolytic capacitor that smoothes the DC rectified by the rectifier unit 11 to shape the waveform, and a DC-AC converter unit 13 that converts the DC smoothed by the smoothing capacitor 12 into AC.

[0014] The rectifier unit 11 includes at least six diodes (not shown) connected in a bridge shape, which rectify the three-phase (R, S, T) AC input from the AC power supply 1 in a certain direction (from bottom to top in FIG. 1). The diode on the positive side of the R phase (upper side in FIG. 1) passes current when the R phase AC is positive, the diode on the negative side of the R phase (lower side in FIG. 1) passes current when the R phase AC is negative, the diode on the positive side of the S phase passes current when the S phase AC is positive, the diode on the negative side of the S phase passes current when the S phase AC is negative, the diode on the positive side of the T phase passes current when the T phase AC is positive, and the diode on the negative side of the T phase passes current when the T phase AC is negative. Due to these diodes connected in a bridge configuration, a pulsating current with a constant direction and fluctuating magnitude appears between the high potential line 10H to which the high potential output terminal 11H of the rectifier unit 11 is connected, and the low potential line 10L to which the low potential output terminal 11L is connected.

[0015] The smoothing capacitor 12 smoothes the pulsating current obtained by the rectifier 11 to generate a direct current with a regular waveform.

[0016] The DC / AC converter 13 converts the DC between the high potential line 10H and the low potential line 10L smoothed by the smoothing capacitor 12 into three-phase (U, V, W) AC by at least six transistors (not shown) connected in a bridge shape. Specifically, a U-phase DC / AC converter having high potential transistors and low potential transistors that generate U-phase AC based on the DC, a V-phase DC / AC converter having high potential transistors and low potential transistors that generate V-phase AC based on the DC, and a W-phase DC / AC converter having high potential transistors and low potential transistors that generate W-phase AC based on the DC are provided in parallel. Since the DC / AC converters of each phase have the same configuration, the U-phase DC / AC converter will be representatively described below.

[0017] The U-phase DC / AC conversion unit is provided between a high potential line 10H to which a high DC potential is supplied and a low potential line 10L to which a low DC potential is supplied, and includes an output terminal 13U for outputting a U-phase AC current fluctuating between the high DC potential and the low DC potential. A high potential transistor (not shown) is connected between the high potential line 10H and the output terminal 13U, and a low potential transistor (not shown) is connected between the low potential line 10L and the output terminal 13U. The high potential transistor has its conduction state switched in response to a control signal from a high potential driver (not shown) connected to its control electrode. The low potential transistor has its conduction state switched in response to a control signal from a low potential driver (not shown) connected to its control electrode.

[0018] A driver pair consisting of a high-potential driver and a low-potential driver converts direct current into alternating current of the U phase by performing switching control to complementarily switch the conductive state of a transistor pair consisting of a high-potential transistor and a low-potential transistor. Here, "complementarily switching" means controlling so that the transistor pairs of each phase are not simultaneously turned on. In other words, when one transistor of each phase is turned on, the other transistor of the phase is controlled to be turned off. However, it is permitted that the transistor pairs of each phase are simultaneously turned off. Specifically, when the high-potential transistor is turned on, the paired low-potential transistor is controlled to be turned off, and when the low-potential transistor is turned on, the paired high-potential transistor is controlled to be turned off. Therefore, when the U-phase high-potential transistor is turned on, a high potential appears at the output terminal 13U, and when the U-phase low-potential transistor is turned on, a low potential appears at the output terminal 13U. By periodically repeating such switching control, high and low potentials appear alternately at the output terminal 13U, generating an alternating current (U phase).

[0019] The DC / AC converter 13 supplies the motor 20 with three-phase AC converted from DC. The motor 20 is, for example, a three-phase brushless motor having coils (not shown) of three phases, namely, U-phase, V-phase, and W-phase. A U-phase voltage from the U-phase DC / AC converter is applied to the U-phase coil, causing a U-phase current to flow, a V-phase voltage from the V-phase DC / AC converter is applied to the V-phase coil, causing a V-phase current to flow, and a W-phase voltage from the W-phase DC / AC converter is applied to the W-phase coil, causing a W-phase current to flow. The DC / AC converters of each phase apply AC currents of different phases to the coils of each phase based on the rotational position of a rotor (not shown) detected by a Hall element (not shown) of the motor 20. The AC applied to the coils of each phase in this way generates a rotating magnetic field, which rotates a rotor equipped with a magnet or the like, thereby obtaining a desired rotational power. The motor 20 may be another type of motor driven by AC. The number of phases of the motor 20 is not limited to three, and may be any natural number. Similarly, the number of phases of the AC input to the rectifier unit 11 is not limited to three and may be any natural number.

[0020] The inverter device 10 further includes a regenerative power consumption device 14 that consumes regenerative power generated by the motor 20. The regenerative power consumption device 14 is a group of circuits provided in parallel between the smoothing capacitor 12 and the DC / AC conversion unit 13 / motor 20.

[0021] When the motor 20 is operating and decelerating, the motor 20 functions as a generator to generate regenerative power. The regenerative power from the motor 20 is normally supplied to the smoothing capacitor 12 (for example, when the regenerative power consumption device 14 is not substantially operating, as described later). In this manner, the smoothing capacitor 12 can be charged with the regenerative power generated by the motor 20. On the other hand, although details will be described later, when the charge amount of the smoothing capacitor 12 reaches a predetermined upper limit value and the voltage increases to a predetermined threshold value (a first voltage threshold value, described later), the regenerative power consumption device 14 starts to consume the excess regenerative power.

[0022] The regenerative power consumption device 14 includes a transistor 141, a regenerative resistor 142, a driver 143, a voltage detection unit 144, a current sensor 145, a current detection unit 146, a threshold setting unit 147, and an operational amplifier 148. As long as the regenerative power consumption device 14 can achieve at least some of the functions and / or effects described below, some of these components may be omitted, and their arrangement may be arbitrary.

[0023] The transistor 141 is controlled to at least a partial conductive state when the regenerative power consumption device 14 operates, and is controlled to a cut-off state or non-conductive state when the regenerative power consumption device 14 does not operate. In other words, when the transistor 141 is controlled to at least a partial conductive state, the regenerative power consumption device 14 operates, and when the transistor 141 is controlled to a cut-off state or non-conductive state, the regenerative power consumption device 14 does not operate. Note that the transistor 141 may be any transistor or switching element such as an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), other FETs (Field-Effect Transistors), or a bipolar transistor.

[0024] The regenerative resistor 142 is connected in series with the transistor 141 between the high potential line 10H and the low potential line 10L that provide direct current. The regenerative resistor 142 is also connected in parallel with the smoothing capacitor 12 and the DC / AC conversion unit 13 / motor 20. When the transistor 141 is controlled to at least a partial conductive state in order to consume excess regenerative power generated in the motor 20 and / or excess regenerative power that overcharges the smoothing capacitor 12, a current corresponding to the excess regenerative power flows through the regenerative resistor 142. Here, if the resistance value of the regenerative resistor 142 is R and the current that flows is I, then the regenerative resistor 142 will have a current I 2The regenerative power of R is dissipated. Thus, the regenerative resistor 142 is capable of dissipating excess regenerative power when the transistor 141 is in at least a partially conductive state.

[0025] The path in which the transistor 141 and the regenerative resistor 142 are connected in series is a current path for consuming excess regenerative power, and may be expressed as a regenerative power consumption path. The regenerative power consumption path may be understood as a path connecting the motor 20 and / or the smoothing capacitor 12 to the regenerative resistor 142. When the transistor 141 is in an on state, which is a substantially complete conductive state, the regenerative power consumption path between the high potential line 10H and the low potential line 10L is conductive, and when the transistor 141 is in an off state, which is a cut-off state, the regenerative power consumption path between the high potential line 10H and the low potential line 10L is cut off. In this way, the transistor 141 can transition between an on state that makes the regenerative power consumption path conductive and an off state that cuts off the regenerative power consumption path.

[0026] The driver 143 applies a control signal to a control electrode of the transistor 141 (for example, a gate in an IGBT or a MOSFET, or a base in a bipolar transistor), thereby controlling the state of the transistor 141. For example, the driver 143 can apply, as a control signal, an on signal for controlling the transistor 141 to an on state and an off signal for controlling the transistor 141 to an off state, to the control electrode of the transistor 141. As will be described later, in this embodiment, in addition to the on signal and the off signal, the driver 143 can apply, as a control signal, an intermediate signal between the on signal and the off signal to the control electrode of the transistor 141 in order to control the transistor 141 to an intermediate state in which at least a portion of the regenerative power is consumed in sharing with the regenerative resistor 142.

[0027] The voltage detection unit 144 is provided between the high potential line 10H and the low potential line 10L in parallel with the smoothing capacitor 12. The voltage detection unit 144 detects the voltage of the smoothing capacitor 12, i.e., the DC voltage between the high potential line 10H and the low potential line 10L. Although details will be described later, the driver 143 changes the control signal for the transistor 141 mainly between an on signal, an intermediate signal, and an off signal in response to the DC voltage detected by the voltage detection unit 144.

[0028] Current sensor 145 is provided in series with transistor 141 and regenerative resistor 142 on the regenerative power consumption path, and measures the current flowing through the regenerative power consumption path when transistor 141 is in the on state or intermediate state. Current detection unit 146 detects the current in the regenerative power consumption path measured by current sensor 145. In this way, current detection unit 146 detects the current flowing through the regenerative power consumption path when transistor 141 is in the on state or intermediate state.

[0029] The voltage detection unit 144 detects the voltage at both ends of the regenerative power consumption path (the upper and lower ends in FIG. 1), and the current detection unit 146 detects the current flowing through the regenerative power consumption path, so that the total regenerative power consumed in the regenerative power consumption path can be calculated by multiplying the two. In addition, since the resistance value of the regenerative resistor 142 is typically known, the regenerative power consumed in the regenerative resistor 142 can also be calculated, as described above. Furthermore, based on these values ​​and the known characteristics of the transistor 141, the regenerative power consumed in the transistor 141 can also be calculated. For example, the regenerative power consumed in the transistor 141 can be calculated by subtracting the regenerative power consumed in the regenerative resistor 142 from the total regenerative power consumed in the regenerative power consumption path.

[0030] Although details will be described later, threshold setting unit 147 sets a predetermined current threshold for the current of the regenerative power consumption path detected by current detection unit 146. Operational amplifier 148 provides driver 143 with a drive signal according to a comparison result between the current of the regenerative power consumption path detected by current detection unit 146 and the current threshold set by threshold setting unit 147. Although details will be described later, driver 143 changes a control signal for transistor 141 mainly between an on signal and an intermediate signal according to the drive signal provided from operational amplifier 148.

[0031] 2 is a schematic diagram showing an example of a regenerative power consumption process performed by the regenerative power consumption device 14 having the above-mentioned configuration. In this diagram, time progresses from left to right. In addition, in this diagram, from the top, the direct current voltage (DC voltage) between the high potential line 10H and the low potential line 10L or the voltage of the smoothing capacitor 12 detected by the voltage detection unit 144, the current (discharge current) flowing through the regenerative power consumption path or the current sensor 145 detected by the current detection unit 146, the control signal or control voltage (FET gate voltage) applied by the driver 143 to the gate of the transistor 141 as an FET, the regenerative power consumed by the regenerative resistor 142 (regenerative resistor loss), and the regenerative power consumed by the transistor 141 as an FET (FET loss) are shown side by side.

[0032] In the illustrated example, the "FET gate voltage" as a control signal is controlled to three main values. The off-voltage V off turns the transistor 141 to the off state S off The on-voltage V on turns the transistor 141 to the on state S on The absolute value is the off-voltage V off and on-state voltage V on The intermediate voltage V mid puts the transistor 141 into an intermediate state S mid This is an intermediate signal for controlling the

[0033] The transistor 141 has a threshold voltage Vth In this embodiment, the threshold voltage V th is between "3V" and "5V". Here, the off-state voltage V off is the threshold voltage V th is sufficiently smaller than, for example, 0 V, and the on-voltage V on is the threshold voltage V th The intermediate voltage V mid is the threshold voltage V th It is preferable to set the intermediate voltage V mid is the threshold voltage V th It may be larger or smaller, but at least the off-state voltage V off On-state voltage V on Less than.

[0034] Off-state voltage V of approximately "0V" off is applied to the gate (or no voltage is applied) off Since no current flows through transistor 141, the “discharge current” detected by current detection unit 146 is “0”, and both the “regenerative resistor loss” in regenerative resistor 142 and the “FET loss” in transistor 141 are “0”.

[0035] On-state voltage V of about 10V on is applied to the gate, on Since a current flows through the transistor 141, the "discharge current" detected by the current detection unit 146 rises from "0", and both the "regenerative resistor loss" in the regenerative resistor 142 and the "FET loss" in the transistor 141 occur. on In the case of the regenerative resistor 142, since the resistance value of the transistor 141, which is almost completely conductive, is small, most of the loss occurs in the regenerative resistor 142. In other words, most of the regenerative power is consumed in the regenerative resistor 142.

[0036] Intermediate voltage V of about 3V to 5V mid (≒ threshold voltage V th ) is applied to the gate, midThe transistor 141 is in the on state S on Although it is not completely conductive like the threshold voltage V th The intermediate voltage V mid Therefore, in the intermediate state S mid The transistor 141 in the on state S on As with the transistor 141, a "discharge current" flows.

[0037] Here, the intermediate state S, which is only partially conductive, mid The transistor 141 is in the on state S on Therefore, the intermediate state S mid The “FET losses” in transistor 141 in the on-state S on The "FET loss" in the regenerative resistor 142 is larger than the "FET loss" in the regenerative resistor 142. By adding the transistor 141, which functions like a resistor, to the regenerative resistor 142, the total resistance or total series resistance in the regenerative power consumption path increases, so that the decrease in the "DC voltage" (i.e., the voltage drop due to the total series resistance) continues without weakening from the "response time". Also, since the "discharge current" decreases due to the increase in the total series resistance and / or the decrease in the "DC voltage", the "regenerative resistor loss" in the regenerative resistor 142 becomes smaller. Furthermore, when the transistor 141 is in the intermediate state S mid In this case, the transistor 141, which functions like a resistor, shares and consumes the regenerative power that should be consumed in the regenerative power consumption path, thereby reducing the amount of consumption shared by the regenerative resistor 142. As a result, it is possible to prevent the regenerative resistor 142 and the entire inverter device 10 from becoming large.

[0038] In conventional inverter devices where excessive regenerative power was consumed essentially only by regenerative resistors, so-called cement resistors are often used as regenerative resistors when the regenerative power to be consumed is large. The cement resistors themselves have a large area and volume, and are hardened with cement, so that they have low heat dissipation. According to the present embodiment, the amount of power consumed by the regenerative resistor 142 can be suppressed, so that even if cement resistors are used as in the past, the number and size of the cement resistors can be reduced. Alternatively, by using a surface mount resistor or the like that is more compact and has excellent heat dissipation properties instead of the cement resistor, the mounting space for the regenerative resistor 142 can be significantly reduced.

[0039] In addition, in this embodiment, since the amount of heat generated by the transistor 141 increases, a heat sink for dissipating heat may be provided for the transistor 141. Since the transistor 141 has a higher heat dissipation property than a cement resistor, a relatively small heat sink can be used. For example, if the number of cement resistors used as the regenerative resistor 142, which was conventionally two, can be reduced to one by the present embodiment, space saving can be achieved even if one heat sink is additionally provided for the transistor 141 (that is, the mounting area of ​​one cement resistor that can be reduced is larger than the mounting area of ​​one heat sink that is added). In addition, if a large heat sink is originally provided for dissipating heat from the entire inverter device 10, it is only necessary to mount the transistor 141 on the heat sink, and therefore there is no need to provide an additional heat sink.

[0040] As described above, the transistor 141 is in the intermediate state S mid When the transistor 141 is in the on state S on As in the case where the regenerative resistor 142 is in the on-state S, both the "regenerative resistor loss" in the regenerative resistor 142 and the "FET loss" in the transistor 141 occur. However, when the transistor 141 is in the on-state S on In contrast to the case where most of the regenerative power is consumed in the regenerative resistor 142 when in the intermediate state S mid The transistor 141 in the ON state S consumes a significant portion of the regenerative power that should be consumed in the regenerative power consumption path in cooperation with the regenerative resistor 142. For example,on When the transistor 141 in the intermediate state S consumes less than “10%” of the regenerative power that should be consumed in the regenerative power consumption path, mid The transistor 141 in the regenerative power consuming path may consume 20% to 50% or more of the regenerative power that should be consumed in the regenerative power consuming path.

[0041] The intermediate state S mid The share of the regenerative power consumed by the transistor 141 is determined by the intermediate voltage V applied to the gate of the transistor 141 by the driver 143. mid For example, the intermediate voltage V mid is the threshold voltage V th By increasing the resistance of the transistor 141 from mid is the threshold voltage V th By decreasing the intermediate voltage V mid Although only one value is shown for the intermediate voltage V, the driver 143 adjusts the intermediate voltage V according to the "DC voltage" detected by the voltage detection unit 144 and the "discharge current" detected by the current detection unit 146. mid may be varied continuously or discretely between multiple values.

[0042] Next, the example shown in FIG. 2 will be explained in chronological order (ie, from left to right in FIG. 2).

[0043] In the first "normal state," the motor 20 operates normally, but when the "DC voltage" detected by the voltage detection unit 144 reaches a first voltage threshold V DC1 Since the control voltage from the driver 143, the FET gate voltage, is lower than the off voltage V off , and the transistor 141 is turned off S offTherefore, in this "normal state", the regenerative power consumption device 14 is not substantially operating. In other words, no "discharge current" flows through the regenerative resistor 142 and the transistor 141 provided on the regenerative power consumption path, and neither "regenerative resistor loss" in the regenerative resistor 142 nor "FET loss" in the transistor 141 occurs.

[0044] In the subsequent "regenerative charging" period, the motor 20 continues to operate normally from the "normal" period, but the "DC voltage" detected by the voltage detection unit 144 exceeds the first voltage threshold V DC1 Since the control voltage from the driver 143, the FET gate voltage, is lower than the off voltage V off , and the transistor 141 is turned off S off Therefore, even during this "regenerative charging", the regenerative power consumption device 14 is not actually operating. However, during this "regenerative charging", excess regenerative power generated when the motor 20 decelerates is charged to the smoothing capacitor 12. For this reason, the "DC voltage" detected by the voltage detection unit 144, which is also the inter-terminal voltage of the smoothing capacitor 12, increases.

[0045] When the smoothing capacitor 12 is charged by excessive regenerative power, the “DC voltage” detected by the voltage detection unit 144 exceeds the first voltage threshold V DC1 When the control voltage is increased to the off voltage V off to on-voltage V on Then, the on-state voltage V on is applied to the off state S off From on state S on The regenerative power consumption device 14 starts to operate due to the transistor 141 transitioning to the on state S. In other words, a "discharge current" starts to flow through the regenerative resistor 142 and the transistor 141 provided on the regenerative power consumption path, and both a "regenerative resistor loss" in the regenerative resistor 142 and an "FET loss" in the transistor 141 occur. onIn this example, since the resistance value of the transistor 141, which is almost completely conductive, is small, most of the loss occurs in the regenerative resistor 142 (regenerative resistor loss). In other words, the “FET loss” in the transistor 141 is significantly smaller than the “regenerative resistor loss” in the regenerative resistor 142.

[0046] At this "discharge start time", the regenerative power charged in the smoothing capacitor 12 is discharged, so that the "DC voltage" detected by the voltage detection unit 144 becomes equal to or lower than the first voltage threshold value V DC1 On the other hand, the "discharge current" flowing through the regenerative power consumption path increases mainly due to the consumption of regenerative power in the regenerative resistor 142. Accordingly, the "regenerative resistance loss" in the regenerative resistor 142 also increases. In this embodiment, in order to prevent the regenerative resistor 142 from becoming large, a certain upper limit is set on the "regenerative resistance loss" in the regenerative resistor 142. The upper limit on this "regenerative resistance loss" is set by the current threshold I set by the threshold setting unit 147. th Corresponds to.

[0047] Specifically, the “discharge current” detected by the current detection unit 146 is equal to or lower than the current threshold I th When this voltage is reached, the operational amplifier 148 operates and sets the "FET gate voltage" of the driver 143 to the on-voltage V on to intermediate voltage V mid That is, the driver 143 generates a drive signal to change the "discharge current" detected by the current detection unit 146 to the current threshold I th When the control voltage reaches the on-voltage V on to intermediate voltage V mid Due to the response or delay of the operational amplifier 148, the “discharge current” detected by the current detection unit 146 is caused to transition to the current threshold I th After exceeding the intermediate voltage V of the "FET gate voltage" of the driver 143 mid It will take some "response time" for the changes to be completed.

[0048] In the "Response Time" section, the "FET Gate Voltage" of the driver 143 is on to intermediate voltage Vmid The "FET gate voltage" decreases linearly or nonlinearly until the "FET gate voltage" decreases. As described above, the "resistance value" of the transistor 141 increases with the decrease in the "FET gate voltage", and the ratio or share of the "FET loss" in the transistor 141 to the "regenerative resistance loss" in the regenerative resistance 142 increases. As a result, the "FET loss" in the transistor 141 increases rapidly, while the "regenerative resistance loss" in the regenerative resistance 142 decreases rapidly. This effectively prevents the regenerative resistance 142 from falling into an overload state due to excessive "regenerative resistance loss". Note that even during this "response time", the smoothing capacitor 12 continues to discharge, so the "DC voltage" detected by the voltage detection unit 144 continues to decrease. However, due to the increase in the "resistance value" of the transistor 141 in the regenerative power consumption path, the "discharge current" becomes less likely to flow (it starts to decrease during the "response time"), and the speed at which the "DC voltage" decreases slightly decreases.

[0049] In the next “threshold loss” period, the “FET gate voltage” of the driver 143 is set to the intermediate voltage V mid In the illustrated example, the threshold voltage V th The intermediate voltage V is approximately equal to mid is applied to the intermediate state S mid Since the transistor 141, which is maintained at a constant current, functions like a resistor, the "FET loss" in the transistor 141 increases. As shown in the figure, during this "threshold loss period", the "FET loss" in the transistor 141 and the "regenerative resistor loss" in the regenerative resistor 142 may each be maintained approximately constant. In this case, the "discharge current" detected by the current detection unit 146 is equal to or greater than the threshold current I th The "DC voltage" detected by the voltage detection unit 144 decreases linearly.

[0050] During the “threshold loss” period, the “DC voltage” that decreases linearly in the example of Figure 2 reaches the first voltage threshold V DC1 The second voltage threshold V DC2 At this time, the driver 143 changes the control voltage to the intermediate voltage V mid to off voltage V off The off-state voltage Voff is applied to the off state S off With the transistor 141 having transitioned to the high state, the regenerative power consuming device 14 returns to the "normal state" or "regenerative charging state" in which it does not substantially operate.

[0051] The present disclosure has been described above based on the embodiments. Various modifications are possible to the combinations of the components and processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included within the scope of the present disclosure.

[0052] The configuration, action, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. For example, a processor, ROM, RAM, and various integrated circuits can be used as hardware resources. For example, programs such as an operating system and applications can be used as software resources. [Explanation of symbols]

[0053] 10 inverter device, 10H high potential line, 10L low potential line, 11 rectifier section, 12 smoothing capacitor, 13 DC / AC conversion section, 14 regenerative power consumption device, 20 motor, 141 transistor, 142 regenerative resistor, 143 driver, 144 voltage detection section, 145 current sensor, 146 current detection section, 147 threshold setting section, 148 operational amplifier.

Claims

1. A capacitor that can be charged using regenerative power generated by the motor. a regenerative resistor connected in parallel with the capacitor and capable of consuming at least a portion of the regenerative power; a transistor connected in series with the regenerative resistor and capable of transitioning between an on state that connects a regenerative power consumption path between the regenerative resistor and at least one of the motor and the capacitor and an off state that cuts off the regenerative power consumption path; a driver for controlling a state of the transistor, the driver being capable of applying to the transistor, as a control signal, an intermediate signal between the on signal and the off signal in order to control the transistor to an intermediate state in which at least a portion of the regenerative power is consumed in a shared manner with the regenerative resistance, in addition to an on signal for controlling the transistor to the on state and an off signal for controlling the transistor to the off state; A regenerative power consumption device comprising:

2. the on-signal is an on-voltage greater than a threshold voltage of the transistor; the off signal is an off voltage less than the threshold voltage, the intermediate signal is an intermediate voltage that is smaller than the on-voltage and larger than the off-voltage; The regenerative power consumption device according to claim 1 .

3. a voltage detection unit that detects a voltage of the capacitor, the driver transitions the control signal from the off signal to the on signal when the voltage detected by the voltage detection unit increases to a first voltage threshold while the transistor is in the off state; The regenerative power consumption device according to claim 2 .

4. 4. The regenerative power consumption device of claim 3, wherein the driver transitions the control signal from the intermediate signal to the off signal when the voltage detected by the voltage detection unit decreases to a second voltage threshold lower than the first voltage threshold while the transistor is in the intermediate state.

5. a current detection unit that detects a current flowing through the regenerative power consumption path when the transistor is in the on state; the driver transitions the control signal from the on signal to the intermediate signal when the current detected by the current detection unit reaches a current threshold. The regenerative power consumption device according to claim 2 .

6. 6. The regenerative power consumption device according to claim 1, wherein the driver controls, by the intermediate signal, a share of the transistor and the regenerative resistance in consuming at least a portion of the regenerative power in the intermediate state.

7. The capacitor is a smoothing capacitor that smoothes direct current, a DC / AC converter that converts the DC smoothed by the smoothing capacitor into AC and applies the AC to the motor, 6. A regenerative power consumption device according to claim 1.

8. a smoothing capacitor that smoothes direct current and that can be charged with regenerative power generated by the motor; a DC / AC converter that converts the DC smoothed by the smoothing capacitor into AC and applies the AC to the motor; a regenerative resistor connected in parallel with the smoothing capacitor and capable of consuming at least a portion of the regenerative power; a transistor connected in series with the regenerative resistor and capable of transitioning between an on state that connects a regenerative power consumption path between the regenerative resistor and at least one of the motor and the smoothing capacitor and an off state that cuts off the regenerative power consumption path; a driver for controlling a state of the transistor, the driver being capable of applying to the transistor, as a control signal, an intermediate signal between the on signal and the off signal in order to control the transistor to an intermediate state in which at least a portion of the regenerative power is consumed in a shared manner with the regenerative resistance, in addition to an on signal for controlling the transistor to the on state and an off signal for controlling the transistor to the off state; An inverter device comprising:

Images