JP2011035977A - Power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the versatility of a power supply device with an inverter mounted thereon. <P>SOLUTION: The power supply device includes a generator 2 and a VSCF converter 3. The VSCF converter 3 includes an AC-DC conversion circuit 13 which converts an AC voltage into a DC voltage, a DC-AC conversion circuit (inverter 14) which converts the DC voltage from the AC-DC conversion circuit into an AC voltage by performing a switching operation, and a controller 18 which controls the switching operation of the inverter 14. The controller 18 is configured to be mutually switchable between pulse-width modulation control based on a comparison results of a sine wave and a cosine wave, and fixed pattern control. In the fixed pattern control, the controller 18 performs the fixed pattern control following a pattern which is defined so as to lower a switching frequency of the inverter 14 more than that at the pulse-width modulation control. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power supply device, and more particularly to a power supply device including a DC / AC conversion circuit (hereinafter also referred to as an inverter) that converts DC power into AC power.

  Conventionally, a power supply device including an inverter that converts a DC voltage into an AC voltage is known. For example, Japanese Unexamined Patent Publication No. 2000-184798 (Patent Document 1) discloses a VSCF (Variable Speed Constant Frequency) converter and a VSCF power supply device. The VSCF converter and the VSCF power supply device described in this document include a DC / AC converter (inverter) that generates a periodic AC voltage composed of a pulse train of a fixed pattern from DC power, and the DC / AC converter. And a filter that removes and outputs a harmonic component contained in the obtained AC voltage. According to this configuration, an AC voltage having a constant frequency and a low harmonic content can be obtained without using a large-scale filter.

JP 2000-184798 A

  For example, when the load device connected to the power supply device is an inductive load such as a motor, there is a possibility that an inrush current may occur when the load is started. However, since the inverter control pattern is fixed in the power supply device described above, it is difficult to change the inverter control pattern in order to prevent an inrush current to the inductive load. For these reasons, it is conceivable to limit the types of loads that can be connected to the power supply device, but in that case, it becomes difficult to increase the versatility of the power supply device.

  An object of the present invention is to make it possible to increase the versatility of a power supply device equipped with an inverter.

  In summary, the present invention is a power supply device that converts an AC voltage into a DC voltage and converts the DC voltage from the AC / DC conversion circuit into an AC voltage by performing a switching operation. A first DC / AC conversion circuit; and a first control unit that controls a switching operation of the first DC / AC conversion circuit. The first control unit includes a pulse width modulation control unit that performs pulse width modulation control based on a comparison result between the sine wave and the carrier wave, and a lower switching frequency of the first DC / AC conversion circuit than the pulse width modulation control. A fixed pattern control unit that executes fixed pattern control according to a pattern determined to be performed, and a switching control unit configured to be able to switch between pulse width modulation control and fixed pattern control.

  According to this configuration, since two control patterns can be selected, the versatility of the power supply device can be improved. For example, the pulse width modulation control can be selected first, and then the control pattern can be switched from the PWM control pattern to the fixed control pattern, or the fixed control pattern can be selected first and then the PWM control pattern can be selected. In addition, when only one of fixed pattern control and pulse width modulation control is sufficient, the control pattern can be fixed.

  Preferably, the first control unit detects the zero cross of the AC voltage output from the power supply device, and controls the pulse width modulation control and the switching control unit based on the detection result of the zero cross detection unit. And an instruction unit for instructing switching from one of the fixed pattern controls to the other.

  According to this configuration, the control pattern is switched when the AC voltage is zero-crossed. This makes it possible to switch the control pattern while reducing the influence on the operation of the load device driven by the power supply device.

  Preferably, the power supply device includes a second DC / AC conversion circuit connected to the AC / DC conversion circuit in parallel with the first DC / AC conversion circuit, and a first DC / AC conversion by the first control unit. And a second control unit that controls the second DC / AC conversion circuit independently of the control of the circuit.

  According to this configuration, the power supply device has the first and second DC / AC conversion circuits (inverters). Thereby, a power supply voltage can be supplied from one power supply device to a plurality of load devices. Furthermore, according to the above configuration, the first and second DC / AC conversion circuits can be controlled independently from each other, so that the corresponding DC / AC conversion circuit can be used regardless of the operation status of the other DC / AC conversion circuits. The load device connected to the can be operated. Therefore, the versatility of the power supply device can be improved.

  Preferably, the power supply device is connected to the AC / DC conversion circuit in parallel with the first DC / AC conversion circuit, and converts the DC voltage from the AC / DC conversion circuit into a predetermined DC voltage. And a third control unit for controlling the direct current / direct current conversion circuit.

  According to this configuration, since not only an AC voltage but also a DC voltage can be output from one power supply device, the versatility of the power supply device can be enhanced.

  Preferably, the power supply device further includes a generator that supplies an AC voltage to the AC / DC conversion circuit.

  According to this configuration, since the generator supplies an AC voltage to the AC / DC conversion circuit, the power supply device can be operated (output the AC voltage from the power supply device) regardless of the installation location of the power supply device. Therefore, the versatility of the power supply device can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the versatility of the power supply device carrying an inverter can be improved.

It is a block diagram of the power supply device which concerns on Embodiment 1 of this invention. It is a functional block diagram explaining the structure of the controller 18 shown in FIG. FIG. 3 is a functional block diagram illustrating a configuration of an inverter control unit 26 illustrated in FIG. 2. FIG. 4 is a circuit diagram showing a specific configuration of an inverter control unit 26 shown in FIG. 3. It is a wave form diagram explaining control of the inverter by a fixed pattern control system. It is a figure for demonstrating control of the inverter by a PWM control system. 5 is a timing chart for explaining a gate pattern switching operation by the inverter control unit 26 having the configuration shown in FIG. 4. It is a block diagram of the power supply device which concerns on Embodiment 2 of this invention. It is a functional block diagram explaining the structure of the controller 18A shown in FIG. It is a block diagram of the power supply device which concerns on Embodiment 3 of this invention. It is a functional block diagram explaining the structure of the controller 18B shown in FIG.

  Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a configuration diagram of a power supply device according to Embodiment 1 of the present invention. Referring to FIG. 1, the power supply device includes a generator 2 and a VSCF converter 3. The generator 2 generates an alternating voltage by being driven by an engine 1 mounted on an aircraft, an automobile, a ship, or the like. The generator 2 includes an armature winding 2a and a field winding 2b.

  The VSCF converter 3 is a device for converting an AC voltage obtained from the generator 2 into an AC voltage having a constant frequency (for example, 50 Hz or 60 Hz) and outputting the AC voltage. The VSCF converter 3 includes an AVR (automatic voltage regulator) 11, a transformer 12, an AC / DC converter circuit 13, an inverter 14 that is a DC / AC converter circuit, a filter 15, an output terminal 16, and a current transformer. 17, a controller 18, a controller power supply 19, and a switch 20.

  The AVR 11 controls the field current supplied to the generator 2 so that the AC voltage output from the generator 2 is kept constant regardless of the rotational speed of the engine 1 or the magnitude of the load. The transformer 12 converts the AC voltage output from the generator 2 into a voltage having a predetermined magnitude. One of the two outputs of the transformer 12 is supplied to the AVR 11 as a power supply voltage, and the other is input to the controller 18 as a monitor voltage for monitoring the output voltage of the generator 2.

  The AC / DC conversion circuit 13 includes a rectifier circuit 21 and a capacitor 22. The rectifier circuit 21 converts the AC voltage from the generator 2 into a DC voltage. Specifically, the rectifier circuit 21 is a diode bridge circuit. The capacitor 22 is a smoothing capacitor that reduces fluctuations in the DC voltage output from the rectifier circuit 21.

  The inverter 14 is controlled by the controller 18 to convert the DC voltage output from the AC / DC conversion circuit 13 into an AC voltage. The control of the inverter 14 will be described in detail later. Since a known configuration can be applied as the configuration of the inverter 14, detailed description will not be repeated here, but the inverter 14 includes a semiconductor switching element (not shown) such as an IGBT or a MOSFET.

  The filter 15 removes harmonic components contained in the AC voltage output from the inverter 14. Specifically, the filter 15 is an LC filter including an inductor 23 and a capacitor 24. The AC voltage that has passed through the filter 15 is output from the output terminal 16 and supplied to a load device (AC load) (not shown).

  The current transformer 17 monitors the current output from the filter 15 to the outside (load device) of the power supply device via the output terminal 16 and sends the result to the controller 18. The controller 18 receives the power supply voltage from the controller power supply 19 when the switch 20 is on, thereby controlling the AVR 11 and the inverter 14.

  FIG. 2 is a functional block diagram for explaining the configuration of the controller 18 shown in FIG. Referring to FIG. 2, the controller 18 includes an AVR control unit 25 and an inverter control unit 26.

  The AVR control unit 25 receives the monitor voltage from the transformer 12 and the monitor current from the current transformer 17. The AVR control unit 25 generates a control signal for controlling the AVR 11 based on the input voltage and current, and outputs the control signal to the AVR 11.

  The inverter control unit 26 generates a gate pattern signal (hereinafter simply referred to as “gate pattern”) for controlling the semiconductor switching elements included in the inverter 14, and sends the gate pattern to the inverter 14. The inverter 14 (switching element) converts the DC voltage from the AC / DC conversion circuit 13 into an AC voltage by performing a switching operation according to the gate pattern from the inverter control unit 26.

  FIG. 3 is a functional block diagram illustrating the configuration of inverter control unit 26 shown in FIG. Referring to FIG. 3, inverter control unit 26 includes fixed pattern generation unit 31, PWM (pulse width modulation) pattern generation unit 32, pattern designation unit 33, switching signal generation unit 34, and zero cross detection unit 35. The AND circuit 36 and the selection control unit 37 are provided.

  The fixed pattern generator 31 generates a pulse train according to the fixed pattern as a gate pattern. The fixed pattern is stored in a ROM (Read Only Memory) (not shown), for example. The fixed pattern generation unit 31 generates a pulse train based on the pattern stored in the ROM and outputs the pulse train to the selection control unit 37.

  The PWM pattern generation unit 32 generates a control pattern (PWM pattern) for controlling the inverter 14 according to the PWM method, and outputs the control pattern to the selection control unit 37.

  The pattern designating unit 33 designates which one of the fixed pattern and the PWM pattern input to the selection control unit 37 is output from the selection control unit 37 to the selection control unit. The selection control unit 37 selects one of the fixed pattern and the PWM pattern in accordance with an instruction from the pattern designating unit 33, and outputs the selected gate pattern.

  The switching signal generator 34 generates a signal for switching the control pattern to the selection controller 37. The zero-cross detector 35 detects a zero-cross of the AC voltage output from the power supply device shown in FIG. The AND circuit 36 receives the switching signal generated by the switching signal generator 34 and the detection result of the zero cross detector 35. When the zero cross of the AC voltage output from the power supply device is detected by the zero cross detector 35, the AND circuit 36 sends the switching signal generated by the switching signal generator 34 to the selection controller 37.

  When receiving a switching signal from the AND circuit 36, the selection control unit 37 switches the control pattern from the current pattern to the pattern selected by the pattern designating unit 33. Therefore, the control pattern (gate pattern) of the inverter 14 is switched at the zero-cross timing of the AC voltage output from the power supply device.

  The fixed pattern generator 31 corresponds to the “fixed pattern controller” of the present invention, and the PWM pattern generator 32 corresponds to the “pulse width modulation controller” of the present invention. Further, the selection control unit 37 corresponds to the “switching control unit” of the present invention. Further, the pattern designating unit 33, the switching signal generating unit 34, and the AND circuit 36, based on the detection result of the zero cross detecting unit 35, have one of a fixed pattern control and a pulse width modulation control unit for the selection control unit 37. This corresponds to an instruction unit for instructing switching from one to the other.

  The configuration and each block illustrated in FIG. 3 may be realized by a combination of electronic circuits (hardware), or may be realized by a program (software) executed by the controller 18. Below, one form of the concrete structure of the inverter control part 26 is demonstrated.

  FIG. 4 is a circuit diagram showing a specific configuration of inverter control unit 26 shown in FIG. Referring to FIG. 4, pattern designating unit 33 includes a switch 33a and a resistor 33b. The switch 33a is connected between a node N to which a high voltage is applied and one end of the resistor 33b. The other end of the resistor 33b is grounded. “High voltage” means a voltage higher than the ground voltage, and the magnitude of the voltage is not particularly limited.

  The switch 33a may be operated manually or may be controlled by the controller 18. A high voltage is applied to the selection control unit 37 by turning on the switch 33a. On the other hand, when the switch 33a is turned off, a ground voltage is applied to the selection control unit 37. That is, the pattern designating unit 33 generates a signal whose voltage level is switched between an H (logic high) level and an L (logic low) level. Here, the “H level” is a level corresponding to the voltage of the node N, and the “L level” is a level corresponding to the ground voltage.

  In the present embodiment, the fixed pattern is specified when the level of the signal from the pattern specifying unit 33 is H level, while the PWM pattern is specified when the level of the signal is L level. However, the correspondence relationship between the level of the signal from the pattern designating unit 33 and the control pattern may be opposite to the above relationship.

  The switching signal generator 34 includes a switch 34a and a resistor 34b. The switch 34a is connected between a node N to which a high voltage is applied and one end of the resistor 34b. The other end of the resistor 34b is grounded. The switch 34a may be operated manually or may be controlled by the controller 18.

  When the switch 34a is operated, the switching signal generator 34 generates a signal for switching the voltage level between the H level and the L level. The correspondence between the logic level of the signal and the voltage (high voltage or ground voltage) is the same as the correspondence in the pattern designating unit 33.

  When the switch 34 a is turned on, an H level signal is applied to the AND circuit 36. This state corresponds to the state where the switching signal is generated. When the switch 34 a is turned off, an L level signal is applied to the AND circuit 36. This state corresponds to the state where the generation of the switching signal is stopped.

  The zero cross detection unit 35 detects the zero cross of the AC voltage based on the sine wave signal given from the PWM pattern generation unit 32 and sends an H level signal to the AND circuit 36 as the detection result. The PWM pattern generation unit 32 generates a sine wave signal that serves as a reference for the waveform of the AC voltage so that the waveform of the AC voltage output from the power supply device becomes a sine wave. Therefore, the zero cross of the sine wave signal corresponds to the zero cross of the AC voltage output from the power supply device.

  The zero cross detector 35 detects the zero cross of the sine wave signal as the zero cross of the AC voltage. The zero cross detector 35 may directly detect the zero cross of the AC voltage output from the power supply device.

  The selection control unit 37 includes a D flip-flop 41, an inverter 42, and NAND circuits 43, 44, and 45.

  The D flip-flop 41 has terminals D, CK, and Q. A signal output from the pattern designating unit 33 is input to the terminal D. A signal output from the AND circuit 36 is input to the terminal CK. A signal is output from the AND circuit 36 at the timing when the zero cross of the AC voltage output from the power supply device is detected.

  The inverter 42 inverts the logic level of the signal output from the terminal Q of the D flip-flop 41 and outputs the inverted signal to the NAND circuit 44. The NAND circuit 43 receives the pulse train (fixed pattern) from the fixed pattern generation unit 31 and the signal from the terminal Q of the D flip-flop 41 and outputs the calculation result to the NAND circuit 45. The NAND circuit 44 receives the pulse train (PWM pattern) generated by the PWM pattern generator 32 and the output of the inverter 42, and outputs the calculation result to the NAND circuit 45. The NAND circuit 45 receives the outputs of the NAND circuits 43 and 44 and outputs the calculation result.

  Each of the NAND circuits 43 to 45 outputs an L level signal only when both of the two input signals are at an H level, and outputs an H level signal in the other cases. As a result, the selection control unit 37 outputs a gate pattern selected from the fixed pattern and the PWM pattern.

  Next, the control patterns generated by the fixed pattern generator 31 and the PWM pattern generator 32 will be described in detail.

  FIG. 5 is a waveform diagram for explaining the control of the inverter by the fixed pattern control method. Referring to FIG. 5, a control pattern for controlling the switching operation of inverter 14 is output as a pulse train from fixed pattern generation unit 31. The voltage output from the inverter 14 to the filter 15 is an AC voltage having a waveform corresponding to this fixed pattern.

  FIG. 5 shows an example of the waveform of the AC voltage output from the inverter 14. The waveform of one cycle of the AC voltage is determined by the fixed pattern described above. The harmonic component contained in the AC voltage from the inverter 14 is removed by the filter 15. As a result, an AC voltage consisting of a sine wave is output from the filter 15.

  FIG. 6 is a diagram for explaining control of the inverter by the PWM control method. Referring to FIG. 6, in PWM control, a gate pattern for controlling the switching operation of inverter 14 is generated based on a voltage comparison between a carrier wave (for example, a triangular wave) and a sine wave that is an AC voltage command. When the switching element of the inverter 14 performs a switching operation according to the gate pattern, the DC voltage is converted into an AC voltage having a waveform corresponding to the PWM control pattern.

  The harmonic component contained in the AC voltage from the inverter 14 is removed by the filter 15. As a result, an AC voltage consisting of a sine wave is output from the filter 15.

  As described above, the inverter 14 repeats the switching operation (switching element on / off) in order to convert the DC voltage into the AC voltage. The switching frequency in PWM control is set to about 1 to 10 kHz, for example. The switching frequency in the fixed pattern control is set to a predetermined frequency lower than 1 kHz, for example.

  The inverter 14 generates a loss due to the switching operation. The higher the switching frequency, the greater the inverter loss.

  In the fixed pattern control, the switching operation of the inverter is controlled according to a fixed pattern determined so as to lower the switching frequency of the inverter 14 than in the pulse width modulation control.

  In the fixed pattern control, the inverter loss can be reduced by lowering the switching frequency than when the PWM control is executed. However, in the fixed pattern control, the amplitude of the AC voltage output from the power supply device is fixed.

  On the other hand, in the PWM control, it is possible to change the amplitude of the voltage output from the inverter 14 by changing the amplitude of the sine wave that is the AC voltage command. That is, according to the PWM control, it is possible to change the magnitude of the AC voltage output from the power supply device.

  When the load device connected to the power supply device is operating in a substantially steady state, it is preferable that the loss of the power supply device be as small as possible. Therefore, in the present embodiment, the fixed pattern control is basically selected. However, for example, when the load device is an inductive load such as a motor, an inrush current may flow when the load device is activated. In order to suppress the inrush current, it is necessary to control the AC voltage by the inverter 14 so that the AC voltage supplied to the load device becomes small. However, in the fixed pattern control, it is difficult to change the magnitude of the AC voltage.

  According to the first embodiment, the control pattern can be set to the PWM control pattern when the PWM control is preferable, for example, at the time of starting the inductive load. Then, if necessary, the PWM control pattern can be switched to the fixed control pattern. As described above, according to the first embodiment, since the control pattern can be switched, the versatility of the power supply device can be improved.

  Furthermore, according to the present embodiment, the control pattern is switched during the zero crossing of the AC voltage. This makes it possible to switch the control pattern while reducing the influence on the operation of the load device.

  FIG. 7 is a timing chart for explaining the gate pattern switching operation by the inverter control unit 26 having the configuration shown in FIG. Referring to FIG. 7, at time t0, the level of the signal input to terminal D of D flip-flop (that is, the signal output from pattern designating unit 33) changes from L level to H level.

  At time t0, the switch 34a of the switching signal generator 34 is in the OFF state, so that the signal input to the terminal CK is at the L level. For this reason, the signal output from the terminal Q of the D flip-flop 41 is also at the L level.

  The fixed pattern generator 31 and the PWM pattern generator 32 periodically output gate patterns regardless of the state of the D flip-flop 41. Note that the fixed pattern and the PWM pattern are different from each other. In order to facilitate understanding of this point, each pattern is schematically shown in FIG.

  Since the level of the signal output from the terminal Q of the D flip-flop 41 is L level, the NAND circuit 43 outputs an H level signal. On the other hand, the NAND circuit 44 outputs a signal whose level is inverted from that of the signal output from the PWM pattern generator 32. As a result, the NAND circuit 45 outputs the same pattern as the gate pattern output from the PWM pattern generator 32. That is, the selection control unit 37 selectively outputs the gate pattern (PWM pattern) generated by the PWM pattern generation unit 32.

  At time t1, the switch 34a of the switching signal generator 34 is turned on. As a result, an H level signal is input from the switching signal generator 34 to the AND circuit 36. As described above, the switch 34 a may be operated manually or may be controlled by the controller 18. When the controller 18 controls the switch 34a, for example, the controller 18 turns on the switch 34a after a predetermined time (for example, 1 minute) has elapsed since the power supply to the load device was turned on.

  At time t2, the zero cross detector 35 detects the zero cross of the sine wave signal sent from the PWM pattern generator 32 and outputs a pulse signal (not shown) indicating the detection of the zero cross. The AND circuit 36 outputs a pulse signal in synchronization with the input of the pulse signal from the zero cross detector 35. The pulse signal from the AND circuit 36 is input to the terminal CK of the D flip-flop 41.

  In response to the rise of the signal input to the terminal CK of the D flip-flop 41, the D flip-flop 41 outputs a signal having the same level as the level (H level) of the signal input to the terminal D from the terminal Q. Therefore, at time t2, the level of the signal output from terminal Q changes from L level to H level. By outputting an H level signal from the terminal Q, the NAND circuit 43 outputs a signal whose logic level is inverted from that of the pulse train generated by the fixed pattern generator 31. On the other hand, the output of the NAND circuit 44 is at the H level while the output from the terminal Q of the D flip-flop 41 is at the H level. Therefore, the NAND circuit 45 outputs the same pattern as the gate pattern generated by the fixed pattern generator 31. That is, at time t2, the gate pattern output from the selection control unit 37 is switched from the PWM control pattern to the fixed pattern.

  After the gate pattern is switched from the PWM pattern to the fixed pattern, the switch 34a of the switching signal generator 34 is turned off at time t3. Therefore, no pulse signal is input to the terminal CK of the D flip-flop 41, but the level of the signal output from the terminal Q is maintained at the H level even after time t3. Therefore, the output of the fixed pattern is continued from the NAND circuit 45.

  When the gate pattern is switched from the fixed pattern to the PWM control pattern, the operation described below is executed. At time t4, the switch 33a of the pattern designating unit 33 is turned off. As a result, the level of the signal input to the terminal D of the D flip-flop 41 is switched from the H level to the L level. Further, at time t5, the switch 34a of the switching signal generator 34 is turned on. Thereafter, at time t <b> 6, the zero cross detection unit 35 detects the zero cross in the sine wave signal from the PWM pattern generation unit 32. As a result, the level of the signal output from the terminal Q of the D flip-flop 41 is switched from the H level to the L level.

  In this case, as before time t2, the output of the NAND circuit 43 becomes H level. On the other hand, the output of the NAND circuit 44 is a pattern in which the logic level is inverted from the PWM pattern. Therefore, the output of the NAND circuit 45 is the same pattern as the PWM pattern. That is, at time t6, the gate pattern output from the selection control unit 37 is switched from the fixed pattern to the PWM pattern.

  As described above, according to the first embodiment, the gate pattern (control pattern) of the inverter (14) that converts the DC voltage into the AC voltage can be switched between the fixed pattern and the PWM pattern. That is, the control of the inverter 14 can be switched between fixed pattern control and PWM control.

  As a result, the inverter 14 can be controlled in accordance with the PWM method when an inductive load such as a motor is started. In this case, by gradually increasing the amplitude of the AC voltage command (sine wave signal), the AC voltage supplied from the power supply device to the load device can be gradually increased. Can be suppressed. Furthermore, since the PWM control can be switched to the fixed pattern control, the inverter can be controlled according to the fixed pattern control when the operation of the load device is stable. In this case, since the loss of the inverter can be reduced, the efficiency of the power supply device can be increased. As described above, according to the first embodiment, during the operation of the load device, it is possible to appropriately select the control of the inverter according to the characteristics of the load device.

  Furthermore, according to the first embodiment, when only fixed pattern control or PWM control is sufficient, it is possible to operate the load device with the control pattern fixed to one of them. As described above, according to the first embodiment, since control of inverter 14 can be selected according to the load device, versatility of the power supply device including the inverter can be enhanced.

  Furthermore, according to Embodiment 1, the control pattern is switched at the zero-cross point of the AC voltage output from the power supply device. This makes it possible to switch the control pattern while suppressing the influence on the operation of the load device during operation of the load device.

[Embodiment 2]
FIG. 8 is a configuration diagram of a power supply device according to Embodiment 2 of the present invention. Referring to FIG. 8, the power supply device according to the second embodiment is different from the power supply device according to the first embodiment in that VSCF converter 3 </ b> A is provided instead of VSCF converter 3. The VSCF converter 3A is different from the VSCF converter 3 in that it further includes inverters 14A and 14B, filters 15A and 15B, output terminals 16A and 16B, and current transformers 17A and 17B. Furthermore, the VSCF converter 3A is different from the VSCF converter 3 in that a controller 18A is provided instead of the controller 18. Each of inverters 14A and 14B has the same configuration as inverter 14.

  FIG. 9 is a functional block diagram illustrating a configuration of the controller 18A illustrated in FIG. Referring to FIG. 9, controller 18A is different from controller 18 in that inverter controllers 26A and 26B are further provided. The inverter control unit 26A generates a gate pattern for controlling the switching operation of the inverter 14A, and outputs the gate pattern to the inverter 14A. Similarly, the inverter control unit 26B generates a gate pattern for controlling the switching operation of the inverter 14B, and outputs the gate pattern to the inverter 14B. The AVR control unit 25 generates an AVR control signal based on the monitor voltage from the transformer 12 and the monitor current from the current transformers 17, 17 A, and 17 B, and outputs the signal to the AVR 11.

  Each of inverter control units 26A and 26B has the same configuration as inverter control unit 26 (see FIGS. 3 and 4), for example. In this case, each of the inverters 14A and 14B can be controlled while switching the control pattern between the fixed pattern and the PWM pattern. However, the functions of the inverter control units 26A and 26B are not limited in this way. For example, one or both of the inverter control units 26A and 26B may be configured to control the corresponding inverter (14A, 14B) by only one control pattern (which may be either a fixed pattern or a PWM control pattern).

  According to the second embodiment, the power supply device has a plurality of inverters. Thereby, a power supply voltage can be supplied from one power supply device to a plurality of load devices. Furthermore, according to Embodiment 2, a plurality of inverters can be controlled independently of each other. Thereby, the load device connected to the corresponding inverter can be operated regardless of the operation status of the other inverters.

  For example, if a malfunction occurs in the operation of any one of a plurality of inverters, it may be necessary to stop the operation of the inverter. When a plurality of inverters cannot be controlled independently from each other, only one inverter cannot be stopped, so that all inverters must be stopped. On the other hand, according to the second embodiment, even if any one of the plurality of inverters needs to be stopped, the operation of the other inverters can be continued.

  For the above reasons, according to the second embodiment, the versatility of the power supply device can be improved.

  In FIG. 8, the number of inverters included in the VSCF converter 3B is three. However, in the second embodiment, the number of inverters is not particularly limited as long as it is two or more.

[Embodiment 3]
FIG. 10 is a configuration diagram of a power supply device according to Embodiment 3 of the present invention. Referring to FIG. 10, the power supply device according to the third embodiment is different from the power supply device according to the first embodiment in that VSCF converter 3 </ b> B is provided instead of VSCF converter 3. The VSCF converter 3B is different from the VSCF converter 3 in that it includes an inverter 14A, a filter 15A, output terminals 16A and 16C, a current transformer 17A, and a DC / DC converter 14C. Furthermore, the VSCF converter 3B is different from the VSCF converter 3 in that a controller 18B is provided instead of the controller 18.

  Inverter 14 </ b> A has the same configuration as inverter 14. The DC / DC converter 14C converts the input DC voltage into a desired DC voltage (for example, DC 24V) by a switching operation.

  FIG. 11 is a functional block diagram for explaining the configuration of the controller 18B shown in FIG. Referring to FIG. 11, controller 18 </ b> B is different from controller 18 in that inverter controller 26 </ b> A and DC / DC converter controller 27 are further provided. Inverter control unit 26A generates a gate pattern for controlling the switching operation of inverter 14A, and outputs the gate pattern to inverter 14A. The DC / DC converter control unit 27 receives the voltage value input to the DC / DC converter 14C and the voltage value output from the DC / DC converter 14C. These voltage values are detected by a voltage sensor (not shown).

  The DC / DC converter control unit 27 generates a control signal for controlling the switching operation of the DC / DC converter 14C based on the values of the input voltage and output voltage of the DC / DC converter 14C, and outputs the control signal to the DC / DC converter. Output to the DC converter 14C.

  Similarly to the second embodiment, the inverter control unit 26A may have the same configuration as the inverter control unit 26, or controls the inverter 14A only by one control pattern (either a fixed pattern or a PWM control pattern). May be configured.

  Furthermore, in FIG. 10, the number of inverters included in the VSCF converter 3B is two. However, in the third embodiment, the number of inverters is not particularly limited as long as the number is one or more. However, in the third embodiment, at least one inverter control unit has a configuration similar to that of the inverter control unit 26 (see FIGS. 3 and 4). That is, the inverter control unit is configured to be able to switch between fixed pattern control and PWM control.

  According to the third embodiment, not only an AC voltage but also a DC voltage can be output from one power supply device. Thereby, according to Embodiment 3, the versatility of a power supply device can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 engine, 2 generator, 2a armature winding, 2b field winding, 3, 3A, 3B VSCF converter, 12 transformer, 13 AC / DC conversion circuit, 14, 14A, 14B inverter (DC / AC conversion circuit) , 14C DC / DC converter, 15, 15A, 15B filter, 16, 16A, 16B, 16C output terminal, 17, 17A, 17B current transformer, 18, 18A, 18B controller, 19 controller power supply, 20 switch, 21 rectification Circuit, 22, 24 Capacitor, 23 Inductor, 25 AVR Control Unit, 26, 26A, 26B Inverter Control Unit, 27 DC / DC Converter Control Unit, 31 Fixed Pattern Generation Unit, 32 PWM Pattern Generation Unit, 33 Pattern Designation Unit, 33a , 34a switch, 33b, 34b resistance, 34 Switching signal generation unit, 35 Zero cross detection unit, 36 AND circuit, 37 Selection control unit, 41 D flip-flop, 42 Inverter (selection control unit), 43 to 45 NAND circuit, N node.

Claims (5)

An AC / DC conversion circuit for converting AC voltage to DC voltage;
A first DC / AC conversion circuit that converts a DC voltage from the AC / DC conversion circuit into an AC voltage by performing a switching operation;
A first control unit that controls the switching operation of the first DC / AC conversion circuit,
The first controller is
A pulse width modulation control unit that executes pulse width modulation control based on a comparison result between the sine wave and the carrier wave;
A fixed pattern control unit that executes fixed pattern control according to a pattern determined to lower the switching frequency of the first DC / AC converter circuit than the pulse width modulation control;
A power supply apparatus comprising: a switching control unit configured to be able to switch between the pulse width modulation control and the fixed pattern control. The first controller is
A zero-cross detection unit for detecting a zero-cross of an AC voltage output from the power supply device;
The apparatus further includes an instruction unit that instructs the switching control unit to switch from one of the pulse width modulation control and the fixed pattern control to the other based on a detection result of the zero-cross detection unit. The power supply device according to 1. The power supply device
A second DC / AC conversion circuit connected to the AC / DC conversion circuit in parallel with the first DC / AC conversion circuit;
The control apparatus according to claim 1, further comprising: a second control unit that controls the second DC / AC conversion circuit independently of the control of the first DC / AC conversion circuit by the first control unit. 2. The power supply device according to 2. The power supply device
A DC / DC conversion circuit that is connected to the AC / DC conversion circuit in parallel with the first DC / AC conversion circuit and converts a DC voltage from the AC / DC conversion circuit to a predetermined DC voltage;
The power supply device according to claim 1, further comprising a third control unit that controls the DC / DC conversion circuit. The power supply device
The power supply device according to any one of claims 1 to 4, further comprising a generator for supplying an AC voltage to the AC / DC conversion circuit.

Images