Power conversion device, battery charging device, and power conversion method

Abstract

To reduce heat generation.SOLUTION: A power conversion device comprises: a rectification unit for outputting DC power that is derived by rectifying three phases of AC power according to electrical continuity to switch elements connected to respective signal wires of three-phase AC power outputted by a generator is established in accordance with rotation of a rotor; a control unit for outputting a stop signal to stop electrical continuity to the switch elements when a voltage of the DC power outputted by the rectification unit increases to or above a prescribed voltage; and an adjustment processing unit for adjusting the control signal for the switch element for each phase on the basis of the stop signal outputted by the control unit, so that the switch elements are not stuck to a constant state of electrical continuity in any of the three phases.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power conversion device, a battery charging device, and a power conversion method.

Background Art

[0002] In recent years, power conversion devices used for charging batteries and the like are known (see, for example, Patent Document 1). Such a conventional power conversion device rectifies three-phase AC power output from a generator using a switching element such as a thyristor and converts it into DC power for charging a battery.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, since the power output by the generator varies according to the rotational speed, in a conventional power conversion device, the rectification operation is adjusted by controlling the period during which the switching element is in the on state, and it is controlled to obtain an optimal charging voltage. However, when the generator rotates at a high speed, the output power from the generator increases, so the period during which the switching element is in the on state becomes short, causing variations in the three-phase rectification period and resulting in current bias where rectification concentrates on a specific phase. When this current bias occurs, current flows concentratedly in a specific phase and generates heat. Therefore, in a conventional power conversion device, for example, elements and configurations for reducing heat generation are required, and there is a problem that the device becomes large-sized.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a power conversion device, a battery charging device, and a power conversion method capable of reducing heat generation.

Means for Solving the Problems

[0006] To solve the above problems, one aspect of the present invention includes: a rectifier unit that outputs DC power rectified from the three-phase AC power output by a generator by the conduction of switch elements connected to each signal line of the three-phase AC power output by a generator in accordance with the rotation of a rotor; a control unit that outputs a stop signal to stop the conduction of the switch elements when the voltage of the DC power output by the rectifier unit exceeds a predetermined voltage; and an adjustment processing unit that adjusts the control signals of the switch elements in each of the three phases based on the stop signal output by the control unit, so that the switch elements in each of the three phases are in an even conduction state, not fixed in a constant conduction state where a rectification period biased to a particular phase of the three phases occurs, at timings that are staggered for each phase and at timings that are synchronized with the cycle of the three phases so that the non-conduction period of the switch elements is not fixed. The adjustment processing unit includes a signal output unit that outputs an output signal to adjust the non-conductive period of the switch element in each of the three phases so that the switch element is not fixed in a constant conductive state, and which prohibits conduction of the switch element corresponding to that phase for the period from the zero-crossing timing of each phase to the next zero-crossing timing of the other phase; and a logic circuit unit that generates the control signal by performing a logic operation on the stop signal output by the control unit and the output signal output by the signal output unit. This is a power conversion device characterized by the following features.

[0007] Furthermore, in one aspect of the present invention, the power conversion device described above is characterized in that the adjustment processing unit performs an adjustment process to adjust the control signals of the switch elements of each phase when the rotational speed of the rotor is equal to or greater than a threshold.

[0008] Furthermore, in one aspect of the present invention, the power conversion device described above is characterized in that the switching element is a thyristor, and the adjustment processing unit generates a control signal that causes the thyristor to become non-conductive so that the conduction period of the thyristor is not fixed in a constant conduction state for each phase.

[0009] Furthermore, in one aspect of the present invention, the power conversion device described above is characterized in that the adjustment processing unit comprises a signal output unit that outputs an output signal to adjust the non-conductive period of the switch elements in each of the three phases so that the switch elements are not fixed in a constant conductive state, and a logic circuit unit that generates the control signal by performing a logic operation on the stop signal output by the control unit and the output signal output by the signal output unit.

[0010] Furthermore, one aspect of the present invention is characterized in that the logic circuit section of the power conversion device described above is an OR circuit.

[0011] Furthermore, one aspect of the present invention is a battery charging device comprising the power conversion device described above, wherein the rectifier unit supplies DC power, obtained by rectifying the three-phase AC power, to the battery as charging power.

[0012] Furthermore, one aspect of the present invention is a power conversion method for a power conversion device that outputs DC power rectified from three-phase AC power by the conduction of switch elements connected to each signal line of the three-phase AC power output by a generator in accordance with the rotation of a rotor, the method comprising: a control step in which a control unit outputs a stop signal to stop the conduction of the switch elements when the voltage of the DC power output by the rectifier unit exceeds a predetermined voltage; and an adjustment step in which an adjustment processing unit adjusts the control signal of the switch elements for each of the three phases based on the stop signal output by the control step, so that the switch elements in each of the three phases are in an even conduction state, not fixed in a constant conduction state where a rectification period biased to a particular phase of the three phases occurs, at timings that are staggered for each phase and at timings that are synchronized with the period of the three phases so that the non-conduction period of the switch elements is not fixed. The adjustment processing unit comprises a signal output unit and a logic circuit unit, and the adjustment step includes: the signal output unit outputting an output signal that adjusts the non-conductive period of the switch element in each of the three phases so that the switch element is not fixed in a constant conductive state in each phase, and the output signal prohibits conduction of the switch element corresponding to that phase for the period from the zero-crossing timing of each phase to the next zero-crossing timing of the other phase; and the logic circuit unit generating the control signal by performing a logic operation on the stop signal output by the control unit and the output signal output by the signal output unit. This is a power conversion method characterized by the following features. [Effects of the Invention]

[0013] According to the present invention, the power converter has an adjustment processing unit that adjusts the control signals for the switch elements of each phase of the three phases based on the stop signals output by the control unit, so that the switch elements are not fixed in a constant conductive state in each phase. This reduces the occurrence of current bias where rectification is concentrated in a particular phase. As a result, the power converter can reduce heat generation, and since there is no need to add elements or configurations for heat reduction, the device can be made smaller. [Brief explanation of the drawing]

[0014] [Figure 1]This block shows an example of a battery charging device and a power conversion device according to this embodiment. [Figure 2] This flowchart shows an example of the operation of the control unit of the power converter according to this embodiment. [Figure 3] This flowchart shows an example of the operation of the adjustment processing unit of the power conversion device according to this embodiment. [Figure 4] This figure shows an example of the operation of the power converter according to this embodiment in the high-speed range. [Figure 5] This figure shows an example of the operation of the power converter according to this embodiment in the low rotation range. [Figure 6] This figure shows an example of the operation of the power converter according to this embodiment in the medium rotation range. [Figure 7] This figure shows an example of operation in the high-speed range using conventional technology. [Modes for carrying out the invention]

[0015] Hereinafter, a power conversion device, a battery charging device, and a power conversion method according to one embodiment of the present invention will be described with reference to the drawings. Figure 1 is a block diagram showing an example of a battery charging device 100 and a power conversion device 1 according to this embodiment.

[0016] As shown in Figure 1, the battery charging device 100 is connected to the generator 2 and the battery 3 and includes a power converter 1. The battery charging device 100 is mounted on a vehicle such as a motorcycle and rectifies the AC power generated by the generator 2 to charge the battery 3. A load unit (not shown) is connected to the battery charging device 100, and the power generated by the generator 2 or the output power of the battery 3 is supplied to the load unit.

[0017] Generator 2 is, for example, a three-phase AC generator that generates electricity in accordance with the rotation of a rotor (not shown) and outputs three-phase AC power (three-phase AC signals) corresponding to the generated power. Here, the rotor is, for example, a crankshaft connected to the rotating shaft of an internal combustion engine of a motorcycle. The three-phase AC power here is, for example, AC signals of the U-phase, V-phase, and W-phase.

[0018] Here, the signal line for the U-phase AC power generated by generator 2 is connected to node N1, and the signal line for the V-phase AC power generated by generator 2 is connected to node N2. In addition, the signal line for the W-phase AC power generated by generator 2 is connected to node N3.

[0019] Furthermore, the generator 2 is equipped with a rotation speed sensor 21. The rotation speed sensor 21 outputs a signal indicating the rotation speed. In this embodiment, "rotation speed" refers to the number of rotations per unit time, or rotational speed. The generator 2 is designed so that as the rotation speed increases, the amount of electricity generated (generated electricity) increases in proportion to the rotation speed.

[0020] Battery 3 is, for example, a lead-acid battery and is connected between the signal line L1, which outputs the output voltage Vout of the power converter 1, and the GND line L2 (ground line). The positive electrode (+) of battery 3 is connected to the signal line L1 of the output voltage Vout, and the negative electrode (-) is connected to the GND line L2. Battery 3 is charged by the power generated by the generator 2 supplied via the signal line L1, and the charged power is supplied to the load section (not shown) via the signal line L1.

[0021] The power converter 1 is, for example, a three-phase thyristor open-type regulator that converts the three-phase (U-phase, V-phase, W-phase) AC power output by the generator 2 into a predetermined constant voltage. The power converter 1 comprises a rectifier unit 10, a U-phase driver unit 13, a V-phase driver unit 14, a W-phase driver unit 15, an adjustment processing unit 30, and a control unit 40.

[0022] The rectifier unit 10 outputs DC power by rectifying the three-phase AC power through the conduction of thyristors (11, 12) connected to the respective signal lines of the three-phase AC power output by the generator 2. The rectifier unit 10 comprises upper thyristors 11 (11-1 to 11-3) and lower thyristors 12 (12-1 to 12-3). Thyristors 11 and 12 are examples of switching elements.

[0023] In this embodiment, thyristors 11-1, 11-2, and 11-3 each refer to the upper thyristor (upper switching element), and when referring to any upper thyristor provided in the power converter 1, or when not making a distinction, they are referred to as thyristor 11.

[0024] Furthermore, thyristors 12-1, 12-2, and 12-3 each refer to the lower thyristor (upper switching element), and when referring to any lower thyristor provided in the power converter 1, or when no particular distinction is made, they are referred to as thyristor 12.

[0025] Thyristor 11-1 is the upper switching element for the U phase, with its anode terminal connected to node N1, its cathode terminal connected to signal line L1, and its control terminal (gate terminal) connected to the signal line of the upper control signal of the U phase driver unit 13.

[0026] Furthermore, the thyristor 11-2 is an upper switching element for the V phase, with its anode terminal connected to node N2, its cathode terminal connected to signal line L1, and its control terminal connected to the signal line of the upper control signal of the V phase driver unit 14.

[0027] Furthermore, the thyristor 11-3 is the upper switching element for the W phase, with its anode terminal connected to node N3, its cathode terminal connected to signal line L1, and its control terminal connected to the signal line of the upper control signal of the W phase driver unit 15.

[0028] Furthermore, the thyristor 12-1 is the lower switching element for the U phase, with its anode terminal connected to the GND line L2, its cathode terminal connected to node N1, and its control terminal connected to the signal line of the lower control signal of the U phase driver unit 13.

[0029] Furthermore, the thyristor 12-2 is the lower switching element for the V phase, with its anode terminal connected to the GND line L2, its cathode terminal connected to node N2, and its control terminal connected to the signal line of the lower control signal of the V phase driver unit 14.

[0030] Furthermore, the thyristor 12-3 is the lower switching element for the W phase, with its anode terminal connected to the GND line L2, its cathode terminal connected to node N3, and its control terminal connected to the signal line of the lower control signal of the W phase driver unit 15.

[0031] The U-phase driver unit 13 is a driver that generates control signals for thyristors 11-1 and 12-1. The U-phase driver unit 13 generates the U-phase control signal S output from the adjustment processing unit 30, which will be described later. off1 Based on this, control signals for thyristor 11-1 and thyristor 12-1 are generated.

[0032] The V-phase driver unit 14 is a driver that generates control signals for thyristors 11-2 and 12-2. The V-phase driver unit 14 generates the V-phase control signal S output from the adjustment processing unit 30, which will be described later. off2 Based on this, control signals for thyristor 11-2 and thyristor 12-2 are generated.

[0033] The W-phase driver unit 15 is a driver that generates control signals for thyristors 11-3 and 12-3. The W-phase driver unit 15 generates the W-phase control signal S output from the adjustment processing unit 30, which will be described later. off3 Based on this, control signals for thyristor 11-3 and thyristor 12-3 are generated.

[0034] The control unit 40 is, for example, a processor including a CPU (Central Processing Unit), and controls the power converter 1. When the voltage of the DC power output by the rectifier unit 10 (output voltage Vout) exceeds a predetermined voltage (above the threshold voltage), the control unit 40 outputs an OFF signal (stop signal) that stops the conduction of the thyristors (11, 12). Here, the OFF signal (stop signal) is the output signal S off0 This indicates the state where the signal is in the H state (high logic state). Furthermore, the predetermined voltage (above the threshold voltage) is, for example, a voltage value that prevents battery 3 from overcharging.

[0035] The control unit 40 controls the conduction of the thyristors (11, 12) of the rectifier unit 10 so that the output voltage Vout is less than a predetermined voltage. Here, the output signal S off0 When the state is L (low logic state), the control unit 40 controls the thyristors (11, 12) to the ON state (conducting state), and when the state is H (OFF signal output state), it controls the thyristors (11, 12) to the OFF state. For example, when the output voltage Vout is less than a predetermined voltage (less than threshold voltage), the control unit 40 controls the output signal S off0 When the voltage is set to L, and the output voltage Vout is greater than or equal to a predetermined voltage, the output signal S off0 Set it to the H state and output an OFF signal.

[0036] The adjustment processing unit 30 receives the OFF signal (or output signal S) output by the control unit 40. off0 Based on this, the control signals for the thyristors (11, 12) in each of the three phases (U phase, V phase, W phase) are adjusted so that the thyristors (11, 12) in each phase are not fixed in a constant conductive state. The adjustment processing unit 30 performs an adjustment process to adjust the control signals for the thyristors (11, 12) in each phase when the rotational speed of the rotor is above a threshold. Here, the threshold is, for example, the upper limit of rotational speed at which heat generation is to be tolerated even if there is an imbalance in the current of each phase.

[0037] Furthermore, the adjustment processing unit 30 controls the thyristors (11, 12) to an off state (non-conductive state) so that the conduction period of the thyristors (11, 12) is not fixed in a constant conduction state for each phase (Soff1 , S off2 , S off3 ) is generated. Further, the adjustment processing unit 30 includes a rotation speed detection unit 31, a signal output unit 32, and a logic circuit unit 33.

[0038] The rotation speed detection unit 31 detects the rotation speed of the generator 2 (rotor) based on the output of the rotation speed sensor 21. The rotation speed detection unit 31 detects the rotation speed of the generator 2 based on, for example, a signal indicating the rotation speed output by the rotation speed sensor 21.

[0039] When the rotation speed detected by the rotation speed detection unit 31 is equal to or higher than the threshold value (in the high rotation speed range), the signal output unit 32 outputs output signals (S1, S2, S3) that adjust the OFF periods (non-conducting periods) of the thyristors (11, 12) in each of the three phases (U phase, V phase, W phase) so that the thyristors (11, 12) are not fixed in a certain conduction state. Here, the output signal S1 is the output signal of the U phase, the output signal S2 is the output signal of the V phase, and the output signal S3 is the output signal of the W phase.

[0040] The signal output unit 32 outputs the output signals (S1, S2, S3) of each phase, for example, at shifted timings in each phase and at timings where the OFF periods are not fixed in synchronization with the periods of the three phases. Further, when the rotation speed is less than the threshold value (in the medium rotation speed range or the low rotation speed range), the signal output unit 32 does not output the output signals (S1, S2, S3).

[0041] The logic circuit unit 33 logically operates the output signal S off0 output by the control unit 40 and the output signals (S1, S2, S3) output by the signal output unit 32 to generate control signals (S off1 , S off2 , S off3 ). The logic circuit unit 33 includes an OR circuit 331, an OR circuit 332, and an OR circuit 333. That is, the logic circuit unit 33 is composed of three OR circuits (331, 332, 331).

[0042] The OR circuit 331 is, for example, a logical OR operation circuit, and the output signal S off0 The result of the logical OR operation with the output signal S1 is then used to control the U-phase signal S off1 The signal is output to the U-phase driver unit 13. off1 When the state is L, thyristors 11-1 and 12-1 are turned ON, and when the state is H, thyristors 11-1 and 12-1 are turned OFF.

[0043] Furthermore, the OR circuit 332 is, for example, a logical OR operation circuit, and the output signal S off0 The result of the OR operation with the output signal S2 is then used as the V-phase control signal S off2 The V-phase driver unit 14 outputs the signal. off2 When the device is in the L state, thyristors 11-2 and 12-2 are turned ON, and when it is in the H state, thyristors 11-2 and 12-2 are turned OFF.

[0044] Furthermore, the OR circuit 333 is, for example, a logical OR operation circuit, and the output signal S off0 The result of the OR operation with the output signal S3 is then used as the W-phase control signal S off3 The W-phase driver unit 15 outputs the signal. off3 When the state is L, thyristors 11-3 and 12-3 are turned ON, and when the state is H, thyristors 11-3 and 12-3 are turned OFF.

[0045] Next, the operation of the power converter 1 according to this embodiment will be described with reference to the drawings. Figure 2 is a flowchart showing an example of the operation of the control unit 40 of the power converter 1 according to this embodiment.

[0046] As shown in Figure 2, the control unit 40 of the power converter 1 first determines whether the output voltage Vout is equal to or greater than the threshold voltage (step S101). If the output voltage Vout is equal to or greater than the threshold voltage (step S101: YES), the control unit 40 proceeds to step S102. If the output voltage Vout is less than the threshold voltage (step S101: NO), the control unit 40 proceeds to step S103.

[0047] In step S102, the control unit 40 outputs an OFF signal (stop signal). The control unit 40 outputs, for example, the output signal S as the OFF signal. off0 Set to the H state. After the processing in step S102, the control unit 40 returns the process to step S101.

[0048] In step S103, the control unit 40, for example, outputs the signal S off0 Set to the L state. After the processing in step S103, the control unit 40 returns the process to step S101.

[0049] Next, with reference to Figure 3, the operation of the adjustment processing unit 30 of the power conversion device 1 according to this embodiment will be described. Figure 3 is a flowchart showing an example of the operation of the adjustment processing unit 30 of the power conversion device 1 according to this embodiment.

[0050] As shown in Figure 3, the adjustment processing unit 30 of the power converter 1 first determines whether the rotational speed is above a threshold (step S201). The signal output unit 32 of the adjustment processing unit 30 determines whether the rotational speed detected by the rotational speed detection unit 31 is above a threshold (whether it is in the high rotational speed range). If the rotational speed is above the threshold (high rotational speed range) (step S201: YES), the signal output unit 32 proceeds to step S202. If the rotational speed is below the threshold (medium rotational speed range or low rotational speed range) (step S201: NO), the signal output unit 32 proceeds to step S203.

[0051] In step S202, the signal output unit 32 performs an adjustment process. That is, the signal output unit 32 outputs output signals (S1, S2, S3) to adjust the off period (non-conductive period) of each phase thyristor (11, 12) so that each phase thyristor (11, 12) is not fixed in a constant conductive state. Then, the OR circuit 331 outputs the output signal S off0 The output signal S1 is then ORed to obtain the U-phase control signal S off1 The output signal S is sent to the U-phase driver unit 13. Additionally, the OR circuit 332 outputs the output signal S. off0 The output signal S2 is ORed to obtain the V-phase control signal S off2 The output signal S is sent to the V-phase driver unit 14. Additionally, the OR circuit 333 outputs the output signal S. off0 The output signal S3 is ORed to obtain the W-phase control signal S off3 The signal is output to the W-phase driver unit 15. After the processing in step S202, the signal output unit 32 returns to the processing in step S201.

[0052] Furthermore, in step S203, the signal output unit 32 stops the adjustment process. In this case, the signal output unit 32 fixes the output signals (S1, S2, S3) to the L state. As a result, OR circuits 331, 332, and 333 adjust the output signal S off0 The U-phase control signal S remains as is. off1 , V-phase control signal S off2 , and the W-phase control signal S off3 The signals are then output to the U-phase driver unit 13, the V-phase driver unit 14, and the W-phase driver unit 15, respectively. After the processing in step S203, the signal output unit 32 returns to the processing in step S201.

[0053] Next, referring to Figure 4, we will explain in detail the process in the case of high rotational speed, which is the process in step S202 of Figure 3 described above. Figure 4 shows an example of the operation of the power converter 1 according to this embodiment in the high-speed range.

[0054] In Figure 4, waveforms W1 to W10 are, from top to bottom, the output signal S off0U-phase output signal S1, V-phase output signal S2, W-phase output signal S2, U-phase control signal S off1 , V-phase control signal S off2 W-phase control signal S off3 The waveforms of the U-phase current Iu, V-phase current Iv, and W-phase current Iw are shown. The horizontal axis represents time, and the vertical axis shows the logic state for waveforms W1 to W7 and the current value for waveforms W8 to W10.

[0055] As shown in waveforms W2 to W4 in Figure 4, the signal output unit 32 outputs the U-phase output signal S1, the V-phase output signal S2, and the W-phase output signal S3 when the rotation speed is above a threshold in the high rotation range. Then, as shown in waveforms W5 to W7, the adjustment processing unit 30 (logic circuit unit 33) outputs the output signal S2, which is output by the control unit 40. off0 And the U-phase control signal S obtained by ORing output signals S1 to S3. off1 , V-phase control signal S off2 , and the W-phase control signal S off3 Outputs.

[0056] For example, at time T1, the U-phase control signal S off1 As a result, the U-phase thyristor 11-1 turns ON, and the U-phase current Iu flows (see waveform W8). Also, the W-phase control signal S off3 As a result, the W-phase thyristor 12-3 turns on, and the W-phase current Iw flows (see waveform W10). Note that thyristor 11-1 turns off when the U-phase current Iu is "0" (zero point), and thyristor 12-3 turns off when the W-phase current Iw is "0".

[0057] Also, at time T2, the V-phase control signal S off2 As a result, the V-phase thyristor 11-2 turns ON, and the V-phase current Iv flows (see waveform W9). Also, the W-phase control signal S off3 As a result, the W-phase thyristor 11-3 turns on, and the W-phase current Iw flows (see waveform W10). Note that thyristor 11-2 turns off when the V-phase current Iv is "0", and thyristor 11-3 turns off when the W-phase current Iw is "0".

[0058] Furthermore, at time T3, the U-phase control signal S off1 As a result, the U-phase thyristor 12-1 turns ON, and the U-phase current Iu flows (see waveform W8). Also, the V-phase control signal S off2 As a result, the V-phase thyristor 12-2 turns on, and a V-phase current Iv flows (see waveform W9). Note that thyristor 12-1 turns off when the U-phase current Iu is "0", and thyristor 12-2 turns off when the V-phase current Iv is "0".

[0059] Furthermore, the operation of power converter 1 at time T4 is the same as in the case of time T1 described above, and the operation of power converter 1 at time T5 is the same as in the case of time T2 described above. Also, the operation of power converter 1 at time T6 is the same as in the case of time T3 described above.

[0060] Thus, in the power converter 1, the adjustment processing unit 30 adjusts the conduction timing of the thyristors (11, 12) of each phase so that the three phases (U phase, V phase, W phase) are not fixed in a constant conduction state, as shown in waveforms W8 to W10, but rather have a nearly uniform conduction state.

[0061] Next, with reference to Figures 5 and 6, the processing in the low and medium rotation ranges, which is the process in step S203 of Figure 3 described above, will be explained in detail. Figure 5 shows an example of the operation of the power converter 1 according to this embodiment in the low rotation range.

[0062] In Figure 5, waveforms W11 to W20 are, from top to bottom, the output signal S off0 U-phase output signal S1, V-phase output signal S2, W-phase output signal S3, U-phase control signal S off1 , V-phase control signal S off2 W-phase control signal S off3 The waveforms of the U-phase current Iu, V-phase current Iv, and W-phase current Iw are shown. The horizontal axis represents time, and the vertical axis shows the logic state for waveforms W11 to W17 and the current value for waveforms W18 to W20.

[0063] In the low rotation range shown in Figure 5, the output voltage Vout is always below a predetermined voltage (below the threshold voltage), so the control unit 40 keeps the output signal Soff0 in the L state, as shown in waveform W11.

[0064] Furthermore, as shown in waveforms W12 to W14, the signal output unit 32 stops outputting the U-phase output signal S1, the V-phase output signal S2, and the W-phase output signal S3 because the rotation speed is below the threshold, and fixes them in the L state. Therefore, the adjustment processing unit 30 (logic circuit unit 33) controls the U-phase control signal S as shown in waveforms W15 to W17. off1 , V-phase control signal S off2 , and the W-phase control signal S off3 Outputs an L state.

[0065] As a result, in the low rotation range, as shown in waveforms W18 to W20, the U-phase current Iu, V-phase current Iv, and W-phase current Iw have current waveforms that are the same as the AC power output by the generator 2.

[0066] For example, at time T11, the U-phase control signal S off1 This causes the U-phase thyristor 11-1 to turn ON. Furthermore, at time T12, the V-phase thyristor 12-2 turns off when the V-phase current Iv is "0", and the V-phase control signal S off2 This causes the V-phase thyristor 11-2 to turn on.

[0067] Furthermore, at time T13, the W-phase thyristor 12-3 turns off when the W-phase current Iw is "0", and the W-phase control signal S off3 This causes the W-phase thyristor 11-3 to turn on.

[0068] Furthermore, at time T14, the U-phase thyristor 11-1 turns off when the U-phase current Iu is "0", and the U-phase control signal S off1 This causes the U-phase thyristor 12-1 to turn on.

[0069] Furthermore, at time T15, the V-phase thyristor 11-2 turns off when the V-phase current Iv is "0", and the V-phase control signal S off2 This causes the V-phase thyristor 12-2 to turn on.

[0070] Furthermore, at time T16, the W-phase thyristor 11-3 turns off when the W-phase current Iw is "0", and the W-phase control signal S off3 This causes the W-phase thyristor 12-3 to turn on.

[0071] Next, with reference to Figure 6, the operation of the power converter 1 in the medium rotation range according to this embodiment will be described. Figure 6 shows an example of the operation of the power converter 1 in the medium rotation range according to this embodiment.

[0072] In Figure 6, waveforms W21 to W30 are, from top to bottom, the output signal S off0 U-phase output signal S1, V-phase output signal S2, W-phase output signal S3, U-phase control signal S off1 , V-phase control signal S off2 W-phase control signal S off3 The waveforms of the U-phase current Iu, V-phase current Iv, and W-phase current Iw are shown. The horizontal axis represents time, and the vertical axis shows the logic state for waveforms W21 to W27 and the current value for waveforms W28 to W30.

[0073] In the mid-speed range shown in Figure 6, there is a period during which the output voltage Vout is above a predetermined voltage (above the threshold voltage), so the control unit 40 outputs the output signal Soff0 as shown in waveform W21.

[0074] Furthermore, as shown in waveforms W22 to W24, the signal output unit 32 stops outputting the U-phase output signal S1, the V-phase output signal S2, and the W-phase output signal S3 because the rotation speed is below the threshold, and fixes them in the L state. Therefore, the adjustment processing unit 30 (logic circuit unit 33) outputs the U-phase control signal S as shown in waveforms W25 to W27. off1 , V-phase control signal S off2 , and the W-phase control signal S off3Outputs.

[0075] For example, at time T21, the U-phase control signal S off1 As a result, the U-phase thyristor 11-1 turns ON, and the U-phase current Iu flows (see waveform W28). Also, the V-phase control signal S off2 As a result, the V-phase thyristor 12-2 turns on, and the W-phase current Iw flows (see waveform W29). Also, the W-phase control signal S off3 As a result, the W-phase thyristor 12-3 turns on, and the W-phase current Iw flows (see waveform W30).

[0076] At time T22, the V-phase thyristor 12-2 turns off when the V-phase current Iv is "0", and the V-phase control signal S off2 This causes the V-phase thyristor 11-2 to turn on.

[0077] Furthermore, at time T23, the W-phase thyristor 12-3 turns off when the W-phase current Iw is "0", and the W-phase control signal S off3 This causes the W-phase thyristor 11-3 to turn on.

[0078] Furthermore, at time T24, the U-phase thyristor 11-1 turns off when the U-phase current Iu is "0", and the U-phase control signal S off1 This causes the U-phase thyristor 12-1 to turn on.

[0079] Furthermore, at time T25, the V-phase thyristor 11-2 turns off when the V-phase current Iv is "0", and the V-phase control signal S off2 This keeps the V-phase thyristor 12-2 in the off state.

[0080] Furthermore, at time T26, the W-phase thyristor 11-3 turns off when the W-phase current Iw is "0", and the W-phase control signal S off3 This causes the W-phase thyristor 12-3 to remain in the off state.

[0081] Furthermore, at time T27, the U-phase thyristor 12-1 turns off when the U-phase current Iu is "0", and the U-phase control signal S off1 This causes the U-phase thyristor 11-1 to turn on (see waveform W28). Also, the V-phase control signal S off2 This causes the V-phase thyristor 12-2 to turn on (see waveform W29). Also, the W-phase control signal S off3 This causes the W-phase thyristor 12-3 to turn on (see waveform W30).

[0082] Thus, in the medium rotation range, as shown in waveforms W28 to W30, the U-phase current Iu, V-phase current Iv, and W-phase current Iw are not fixed to conduction in a specific phase, although there are periods of inactivity in some parts.

[0083] As described above, the power conversion device 1 according to this embodiment comprises a rectifier unit 10, a control unit 40, and an adjustment processing unit 30. The rectifier unit 10 outputs DC power rectified from the three-phase AC power (U-phase, V-phase, W-phase) output by the conduction of switch elements (thyristors (11, 12)) connected to the respective signal lines of the AC power output by the generator 2, in accordance with the rotation of the rotor. The control unit 40 outputs an OFF signal (stop signal) to stop the conduction of the switch elements (thyristors (11, 12)) when the voltage (output voltage Vout) of the DC power output by the rectifier unit 10 exceeds a predetermined voltage (above a threshold voltage). Based on the OFF signal output by the control unit 40, the adjustment processing unit 30 controls the control signals (S) of the switch elements (thyristors (11, 12)) in each of the three phases so that the switch elements (thyristors (11, 12)) are not fixed in a constant conduction state. off1 S off2 S off3 Adjust ).

[0084] As a result, in the power converter 1 according to this embodiment, the adjustment processing unit 30 adjusts the control signals of the switch elements (thyristors (11, 12)) in each of the three phases (U phase, V phase, W phase) so that the switch elements are not fixed in a constant conductive state, thereby reducing the occurrence of current bias where rectification is concentrated in a particular phase. Therefore, the power converter 1 according to this embodiment can reduce heat generation, and since there is no need to add elements or configurations for heat reduction, the device can be made smaller.

[0085] Here, for comparison with the power conversion device 1 according to this embodiment, the operation of a conventional technology that does not include an adjustment processing unit 30 will be described. Figure 7 shows an example of operation in the high-speed range using the conventional technology.

[0086] In Figure 7, waveforms W31 to W34, from top to bottom, represent the output signal S. off0 The waveforms of the U-phase current Iu, V-phase current Iv, and W-phase current Iw are shown. The horizontal axis represents time, and the vertical axis shows the logic state for waveform W31 and the current values ​​for waveforms W32 to W34. In the conventional technology, the output signal S of the control unit 40 off0 This will be used directly as the control signal for the thyristors (11, 12).

[0087] As shown in Figure 7, in the conventional technology, at high rotational speeds, variations occur in the conduction state of each phase, with the U phase of waveform W32 being the main conduction phase, while the V phase of waveform W33 and the W phase of waveform W34 are hardly conduction at all. Thus, in the conventional technology, a bias occurs in the current of each phase, causing a fixed conduction state in a specific phase, which leads to the problem of overheating of the switching elements (thyristors (11, 12)) of that specific phase and the windings of the generator 2.

[0088] In contrast, in the power converter 1 according to this embodiment, the adjustment processing unit 30 adjusts the conduction timing of each phase, so that, for example, as shown in waveforms W8 to W10 in Figure 4, each phase can conduct almost equally. In other words, the power converter 1 according to this embodiment can equalize the heat generated by the windings of the generator 2 by reducing the current imbalance. As a result, the power converter 1 according to this embodiment does not require consideration of adding an external system necessary for cooling.

[0089] Furthermore, the power converter 1 according to this embodiment equalizes the heat generated by the switching elements (e.g., thyristors (11, 12)), eliminating the need for additional elements or configurations to reduce heat generation. Moreover, the power converter 1 according to this embodiment reduces the possibility of overcharging caused by heat generated by the switching elements (e.g., thyristors (11, 12)) in the high rotation range, thereby improving quality and reliability.

[0090] Furthermore, in this embodiment, the adjustment processing unit 30 performs an adjustment process to adjust the control signals of the thyristors (11, 12) of each phase when the rotational speed of the rotor is equal to or greater than a threshold. As a result, the power converter 1 according to this embodiment performs the adjustment process and stops it based solely on a rotational speed threshold, which makes the implementation of this control easier compared to methods that acquire the AC waveforms of each of the three phases (U phase, V phase, and W phase). Furthermore, the power converter 1 according to this embodiment can be made more streamlined in its configuration.

[0091] Furthermore, in this embodiment, the switch element is a thyristor (11, 12), and the adjustment processing unit 30 controls a control signal (S) to de-conduct the thyristor (11, 12) so that the conduction period of the thyristor (11, 12) is not fixed in a constant conduction state for each phase. off1 S off2 S off3 ) generates.

[0092] As a result, the power conversion device 1 according to this embodiment can reduce heat generation with a simple configuration using thyristors (11, 12).

[0093] Further, in the present embodiment, the adjustment processing unit 30 includes a signal output unit 32 and a logic circuit unit 33. The signal output unit 32 outputs output signals (S1, S2, S3) for adjusting the non-conduction periods of the thyristors (11, 12) in each phase so that the thyristors (11, 12) in each of the three phases are not fixed in a certain conduction state. The logic circuit unit 33 logically operates the OFF signal (output signal S off0 ) output by the control unit 40 and the output signals (S1, S2, S3) output by the signal output unit 32 to generate control signals (S off1 , S off2 , S off3 ).

[0094] Thereby, the power conversion device 1 according to the present embodiment can adjust and equalize the conduction bias of the thyristors (11, 12) in each phase with a simple configuration using the signal output unit 32 and the logic circuit unit 33.

[0095] Also, in the present embodiment, the logic circuit unit 33 is an OR circuit (331, 332, 333). Thereby, the power conversion device 1 according to the present embodiment can further simplify and miniaturize the configuration without requiring a complex logic circuit by using the OR circuit (331, 332, 333).

[0096] Further, the battery charging device 100 according to the present embodiment includes the above-described power conversion device 1, and the rectifying unit 10 supplies the DC power obtained by rectifying the three-phase AC power to the battery 3 as charging power. Thereby, the battery charging device 100 according to the present embodiment exhibits the same effects as the above-described power conversion device 1, can reduce heat generation, and can miniaturize the device.

[0097] Furthermore, the power conversion method according to this embodiment is a power conversion method for a power converter 1 that includes a rectifier unit 10 that outputs DC power rectified from three-phase AC power by the conduction of thyristors (11, 12) connected to each signal line of the three-phase AC power output by the generator 2 in accordance with the rotation of the rotor, and includes a control step and an adjustment step. In the control step, the control unit 40 outputs an OFF signal (stop signal) to stop the conduction of the thyristors (11, 12) when the voltage of the DC power output by the rectifier unit 10 (output voltage Vout) becomes above a predetermined voltage. In the adjustment step, the adjustment processing unit 30 adjusts the control signals of the thyristors (11, 12) of each phase so that the thyristors (11, 12) are not fixed in a constant conduction state in each of the three phases, based on the OFF signal (stop signal) output in the control step.

[0098] As a result, the power conversion method according to this embodiment achieves the same effects as the power conversion device 1 and battery charging device 100 described above, reducing heat generation and allowing for miniaturization of the device.

[0099] It should be noted that the present invention is not limited to the embodiments described above, and can be modified without departing from the spirit of the invention. For example, in the above embodiment, an example was described in which the power converter 1 is used in a battery charging device 100, but the invention is not limited to this, and the power converter 1 may be applied to other devices (other uses).

[0100] Furthermore, although the above embodiment describes an example in which the power converter 1 is a three-phase thyristor open-type regulator, it is not limited to this, and any other power converter that rectifies a three-phase AC signal (AC power) may be used.

[0101] Furthermore, although the above embodiment describes an example where the switching element is a thyristor (11, 12), it is not limited to this, and other switching elements such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) may also be used.

[0102] Furthermore, although the above embodiment describes an example in which the logic circuit section 33 is an OR circuit (331, 332, 333), it is not limited to this, and other logic circuits may be used.

[0103] Furthermore, in the above embodiment, the adjustment processing unit 30 and the control unit 40 may be implemented by circuit means, or by software processing that causes a CPU (Central Processing Unit) to execute a program.

[0104] Furthermore, some or all of the functions of the adjustment processing unit 30 and the control unit 40 described above may be implemented as an integrated circuit such as an LSI (Large Scale Integration). Each of the above functions may be individually implemented as a processor, or some or all of them may be integrated into a single processor. In addition, the method of implementing the integrated circuit is not limited to LSIs; it may also be implemented using dedicated circuits or general-purpose processors. Furthermore, if an integrated circuit technology that can replace LSIs emerges due to advances in semiconductor technology, an integrated circuit using that technology may be used. [Explanation of symbols]

[0105] 1. Power converter 2 generators 3 Batteries 10 Rectifier 11, 11-1, 11-2, 11-3, 12, 12-1, 12-2, 12-3 thyristors 13 U-phase driver section 14 V-phase driver section 15 W-phase driver unit 21. Rotation speed sensor 30 Adjustment Processing Unit 31. Rotation speed detection unit 32 Signal Output Section 33 Logic Circuit Section 40 Control Unit 100 Battery Charging Device 331, 332, 333 OR circuits

Claims

1. A rectifier unit outputs DC power by rectifying the three-phase AC power, which is generated by the conduction of switch elements connected to each signal line of the three-phase AC power output by the generator in accordance with the rotation of the rotor. A control unit that outputs a stop signal to stop the conduction of the switch element when the voltage of the DC power output by the rectifier unit exceeds a predetermined voltage, Based on the stop signal output by the control unit, an adjustment processing unit adjusts the control signal of the switch element in each of the three phases at a staggered timing for each phase, and at a timing synchronized with the period of the three phases so that the switch element does not become fixed in a constant conduction state where a biased rectification period occurs in a particular phase of the three phases, so that the switch element is in an even conduction state. Equipped with, The adjustment processing unit is, A signal output unit that outputs an output signal to adjust the non-conductive period of the switch element in each of the three phases so that the switch element is not fixed in a constant conductive state, wherein the output signal outputs a signal that prohibits conduction of the switch element corresponding to the phase for the period from the zero-crossing timing of each phase to the next zero-crossing timing of the other phase, A logic circuit unit generates the control signal by performing a logic operation on the stop signal output by the control unit and the output signal output by the signal output unit. A power conversion device characterized by comprising the following features.

2. The adjustment processing unit performs an adjustment process to adjust the control signals of the switch elements of each phase when the rotational speed of the rotor is equal to or greater than a threshold. The power conversion device according to feature 1.

3. The aforementioned switching element is a thyristor, The adjustment processing unit generates the control signal to de-conduct the thyristor so that the conduction period of the thyristor is not fixed in a constant conduction state for each phase. A power conversion device according to claim 1 or 2.

4. The power conversion device according to claim 1, characterized in that the logic circuit section is an OR circuit.

5. A power conversion device according to any one of claims 1 to 4, The rectifier unit supplies the DC power obtained by rectifying the three-phase AC power to the battery as charging power. A battery charging device characterized by the following features.

6. A power conversion method for a power conversion device comprising a rectifier that outputs DC power by rectifying the three-phase AC power according to the rotation of a rotor, by conducting switch elements connected to each signal line of the three-phase AC power output by a generator, A control step in which the control unit outputs a stop signal to stop the conduction of the switch element when the voltage of the DC power output by the rectifier unit exceeds a predetermined voltage, An adjustment step in which the adjustment processing unit adjusts the control signal of the switch element in each of the three phases, based on the stop signal output by the control step, so that the switch element is in an even conduction state, not fixed in a constant conduction state where a biased rectification period occurs in a particular phase of the three phases, at a timing that is staggered for each phase and synchronized with the period of the three phases so that the non-conduction period of the switch element is not fixed; Includes, The adjustment processing unit comprises a signal output unit and a logic circuit unit. The adjustment step described above is: The signal output unit outputs an output signal that adjusts the non-conductive period of the switch element in each of the three phases so that the switch element is not fixed in a constant conductive state, and the output signal prohibits conduction of the switch element corresponding to that phase for the period from the zero-crossing timing of each phase to the next zero-crossing timing of the other phase. The logic circuit unit performs a logical operation on the stop signal output by the control unit and the output signal output by the signal output unit to generate the control signal. A power conversion method characterized by including [a certain component].

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