Regulator

Abstract

This regulator comprises: a fixed point detection unit (120) that detects a fixed point on the basis of a current of a phase for which the fixed point is to be detected among currents supplied from a three-phase AC generator; a line current measurement unit (125) that determines whether a current sign is positive or negative for a current of a reference target phase acquired according to a timing at which the fixed point is detected among the three phases; a pattern storage unit (130) that stores a correspondence relationship between the current sign of the reference target phase at the fixed point and the rotational position of the AC generator; and a drive pattern order determination unit (135) that reads, from the pattern storage unit, a rotational position corresponding to whether the current sign is positive or negative on the basis of the determination result of the line current measurement unit.

Description

Regulator

[0001] The present invention relates to a regulator that converts three-phase alternating current power into direct current power.

[0002] A phase control type regulator is a product that makes the charging voltage constant by advancing and retarding the phase. In order to control this phase, it is necessary to recognize the rotational position and rotational speed of a three-phase ACG (alternating current generator). As a method therefor, there is a first method of providing a position sensor (such as an electromagnetic pickup sensor) outside the ACG (for example, Patent Document 1). Further, instead of providing a position sensor outside the ACG, there is a second method of detecting the zero crossing of the line current of any one phase of the ACG and estimating the rotational position based on the detection result (for example, Patent Document 2).

[0003] Japanese Patent No. 6121624 Japanese Patent No. 4894417

[0004] However, in the first method, since it is necessary to provide a position sensor outside the ACG, wiring for connecting the external sensor and the control device becomes necessary. Further, in the second method, wiring for connecting the external sensor and the control device is unnecessary, but the combination of the three AC output terminals of the U phase, V phase, and W phase of the ACG and the three AC input terminals of the bridge circuit provided in the regulator needs to be connected in a specific combination. Therefore, connection management becomes necessary.

[0005] One aspect of the present invention is a regulator having a fixed point detection unit that detects a fixed point based on the current of a phase that is the object of detection of the fixed point among the currents supplied from a three-phase alternating current generator, a line current measurement unit that determines whether the current sign of the current of the reference target phase acquired according to the timing at which the fixed point is detected among the three phases is positive or negative, a pattern storage unit that stores the correspondence between the current sign of the reference target phase at the fixed point and the rotational position of the alternating current generator, and a drive pattern determination unit that reads out from the pattern storage unit a rotational position corresponding to whether the current sign is positive or negative based on the determination result of the line current measurement unit.

[0006] According to the present invention, a fixed point is detected based on the current of the phase to be detected among the current supplied from a three-phase AC generator, and it is determined whether the current sign of the reference phase current corresponding to the timing at which the fixed point was detected is positive or negative. By referring to data stored on the rotational position of the AC generator for each case where the current sign of the reference phase current is positive or negative, the rotational position corresponding to whether the current sign of the reference phase current obtained as a result of the determination is obtained. This makes it possible to determine the rotational position without installing an external sensor and without managing the connections between each terminal of the AC generator and each terminal of the bridge circuit.

[0007] This figure shows the configuration of a battery charging system 1 using a regulator 10 according to the first embodiment of the present invention. This figure shows an example of pattern data stored in the pattern storage unit 130. This is a flowchart explaining the operation of the regulator 10. This figure shows another example of pattern data stored in the pattern storage unit 130. This figure shows an example of switching pattern data. This figure explains the relationship between the current waveform in the connection state shown in item 1 and the drive pattern of the bridge circuit 115. This figure explains the relationship between the current waveform in the connection state shown in item 2 and the drive pattern of the bridge circuit 115. This figure explains the relationship between the current waveform in the connection state shown in item 3 and the drive pattern of the bridge circuit 115. This figure explains the relationship between the current waveform in the connection state shown in item 4 and the drive pattern of the bridge circuit 115. This figure explains the relationship between the current waveform in the connection state shown in item 5 and the drive pattern of the bridge circuit 115. This figure explains the relationship between the current waveform in the connection state shown in item 6 and the drive pattern of the bridge circuit 115. This figure shows the configuration of a battery charging system 1A using a regulator 10a. This diagram illustrates the relationship between the current waveform input to the regulator 10a, the zero-crossing signal, and the drive pattern of the bridge circuit 115. This diagram illustrates the relationship between the current waveform input to the regulator 10a, the zero-crossing signal, and the drive pattern of the bridge circuit 115. This diagram shows the configuration of a battery charging system 1B using a regulator 10b according to a second embodiment of the present invention. This diagram shows an example of pattern data stored in the pattern storage unit 130a. This diagram shows another example of pattern data stored in the pattern storage unit 130a. This is a flowchart illustrating the operation of the regulator 10. This diagram illustrates the relationship between the current waveform in the connection state shown in item 1 and the drive pattern of the bridge circuit 115. This diagram illustrates the relationship between the current waveform in the connection state shown in item 2 and the drive pattern of the bridge circuit 115. This diagram illustrates the relationship between the current waveform in the connection state shown in item 3 and the drive pattern of the bridge circuit 115. This diagram illustrates the relationship between the current waveform in the connection state shown in item 4 and the drive pattern of the bridge circuit 115.This figure illustrates the relationship between the current waveform in the connection state shown in item 5 and the drive pattern of the bridge circuit 115. This figure illustrates the relationship between the current waveform in the connection state shown in item 6 and the drive pattern of the bridge circuit 115. This figure shows the configuration of a battery charging system 1C using regulator 10c. This figure illustrates the relationship between the current waveform input to regulator 10c, the cross signal, and the drive pattern of the bridge circuit 115. This figure illustrates the relationship between the current waveform input to regulator 10c, the cross signal, and the drive pattern of the bridge circuit 115. This figure shows the configuration of a battery charging system 1D using regulator 10d according to the third embodiment of the present invention. This figure shows another example of pattern data stored in the pattern storage unit 130b. This is a flowchart illustrating the operation of regulator 10d to estimate the current value of current AC3. This is a flowchart illustrating the process by which regulator 10d determines the drive pattern sequence. This figure shows the configuration of a battery charging system 1E using regulator 10e. This figure illustrates the relationship between the current waveform in the connection state shown in item 4 and the drive pattern of the bridge circuit 115.

[0008] Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> Figure 1 is a diagram showing the configuration of a battery charging system 1 using a regulator 10 according to the first embodiment of the present invention. The battery charging system 1 includes an AC generator M, a regulator 10, a load 15, and a battery 20. The battery charging system 1 is mounted on a vehicle or the like, and the AC generator M, which is connected to the output shaft of an engine or the like, is driven in conjunction with the operation of the engine and generates three-phase AC power. The three-phase AC power generated by the AC generator M is supplied to the regulator 10, and is converted into DC power by the regulator 10, so that DC power is supplied to the load or battery 20. In this way, the battery 20 is charged using the power generated by the AC generator M.

[0009] The AC generator M is connected, for example, to the output shaft of an engine in a vehicle, and generates AC power by being driven in conjunction with the rotation of this output shaft. The AC generator M outputs the generated AC power to the regulator 10. This AC generator M is a three-phase AC generator. The combination of which of the three input terminals Tin1, Tin2, and Tin3 of the regulator 10 the three output terminals Mu, Mv, and Mw of the AC generator M are connected to is not particularly defined and may be arbitrary. In this embodiment, even if the combination of connected terminals is arbitrary, the rotational position of the AC generator M can be estimated. For example, the U-phase output terminal Mu of the AC generator M may be connected to the input terminal Tin1 of the regulator 10, the V-phase output terminal Mv of the AC generator M may be connected to the input terminal Tin2 of the regulator 10, and the W-phase output terminal Mw of the AC generator M may be connected to the input terminal Tin3 of the regulator 10. Alternatively, for example, the U-phase output terminal Mu of the AC generator M may be connected to the input terminal Tin2 of the regulator 10, the V-phase output terminal Mv of the AC generator M may be connected to the input terminal Tin3 of the regulator 10, and the W-phase output terminal Mw of the AC generator M may be connected to the input terminal Tin1 of the regulator 10.

[0010] In this embodiment, the phase current of the U phase is referred to as current AC1, the phase current of the V phase as current AC2, and the phase current of the W phase as current AC3. For example, when the output terminal Mu of the U phase of the AC generator M is connected to the input terminal Tin1 of the regulator 10, current AC1 is supplied to the input terminal Tin1. When the output terminal Mv of the V phase of the AC generator M is connected to the input terminal Tin2 of the regulator 10, current AC2 is supplied to the input terminal Tin2. When the output terminal Mw of the W phase of the AC generator M is connected to the input terminal Tin3 of the regulator 10, current AC3 is supplied to the input terminal Tin3.

[0011] The load 15 may be at least one of the following: lights, ignition devices, various actuators, etc. The first terminal of the load 15 is connected to the output terminal Tout1 of the regulator 10, and the second terminal of the load 15 is connected to the output terminal Tout2. The battery 20 can be charged by the power supplied from the regulator 10 and discharged to the load 15. The first terminal of the battery 20 is connected to the output terminal Tout1 of the regulator 10, and the second terminal of the battery 20 is connected to the output terminal Tout2. The battery 20 and the load 15 are connected in parallel.

[0012] The regulator 10 is a phase-controlled regulator. The output voltage of the AC generator M fluctuates depending on the engine speed. Even if the output voltage supplied from the AC generator M fluctuates, the regulator 10 can convert it into a constant DC voltage using the phase control method of the AC generator M and supply it to the load 15 and the battery 20.

[0013] The regulator 10 includes input terminal Tin1, input terminal Tin2, input terminal Tin3, output terminal Tout1, output terminal Tout2, current detection unit 110a, current detection unit 110b, bridge circuit 115, fixed point detection unit 120, line current measurement unit 125, pattern storage unit 130, drive pattern sequence determination unit 135, rotation position determination unit 140, rotation speed calculation unit 145, DC output voltage detection unit 150, angle retardation amount calculation unit 155, and switch command unit 160.

[0014] The current detection unit 110a is installed in the AC power supply path input from input terminal Tin1 and detects the current of the phase supplied to input terminal Tin1 among the three-phase AC power. The current detection unit 110b is installed in the AC power supply path input from input terminal Tin2 and detects the current of the phase supplied to input terminal Tin2 among the three-phase AC power. The current detection units 110a and 110b may each be, for example, shunt resistors.

[0015] The fixed point detection unit 120 is connected to the current detection unit 110a, the line current measurement unit 125, the rotation position determination unit 140, and the rotation speed calculation unit 145. The fixed point detection unit 120 detects a fixed point based on the current of the phase that is the target of detection among the currents supplied from the three-phase AC generator. The phase that is the target of detection is, for example, the first phase, and is the current obtained from the current detection unit 110a. More specifically, the fixed point detection unit 120 detects a fixed point based on the result of comparing the current value of the AC current output from the AC generator M and supplied to the input terminal Tin1 with a current threshold. In this embodiment, a fixed point is a point on the current waveform where the current value of the phase current to be detected is 0 (A). A fixed point on the phase current waveform can be any specific point on the phase current waveform that can be distinguished from other points. The fixed point on this waveform may be any of the following: the zero-crossing point when the phase current waveform transitions from a positive half-wave to a negative half-wave, the zero-crossing point when the phase current waveform transitions from a negative half-wave to a positive half-wave, or the point where the two phase current waveforms intersect. However, in this embodiment, we will describe the case where the fixed point is the zero-crossing point when the phase current waveform transitions from a negative half-wave to a positive half-wave. When the fixed point detection unit 120 detects a fixed point, it outputs to the line current measurement unit 125, the rotation position determination unit 140, and the rotation speed calculation unit 145 that a fixed point has been detected.

[0016] The line current measurement unit 125 is connected to the current detection unit 110b, the fixed point detection unit 120, and the drive pattern sequence determination unit 135. The line current measurement unit 125 determines whether the sign of the current of the reference phase, which is acquired according to the timing when a fixed point is detected among the three phases, is positive or negative. In the first embodiment, the current of the reference phase is the current of the second phase, which is different from the first phase. The current of the second phase is the current supplied to the current path to which the current detection unit 110b is attached. More specifically, when the line current measurement unit 125 acquires a signal from the fixed point detection unit 120 indicating that a fixed point has been detected, it acquires the detection result from the current detection unit 110b to acquire the current value of the phase current supplied to the input terminal Tin2, and determines whether the sign of the acquired current value is positive or negative. The line current measurement unit 125 outputs the determination result to the drive pattern sequence determination unit 135.

[0017] The pattern storage unit 130 stores pattern data representing the correspondence between the current code of the phase of the reference target at a fixed point and the rotational position of the AC generator. The pattern storage unit 130 is composed of a storage medium, such as flash memory, EEPROM (Electrically Erasable Programmable Read Only Memory), RAM (Random Access Read / Write Memory), ROM (Read Only Memory), or any combination of these storage media. For example, non-volatile memory can be used for this pattern storage unit 130.

[0018] Figure 2 shows an example of pattern data stored in the pattern storage unit 130. The pattern data is data that associates an item number, connection destination, current code at a fixed point, and the order of the drive pattern. The item number is a number assigned to a drive pattern to identify that drive pattern. The connection destination represents the connection relationship between the output terminals Mu, Mv, and Mw of the AC generator M and the input terminals Tin1, Tin2, and Tin3 of the bridge circuit 115. The current code at a fixed point represents whether the polarity of the current at that point is positive or negative. The drive pattern represents the combination of whether the drive signal supplied to each of the multiple switching elements included in the bridge circuit 115 is on or off. The order of the drive pattern represents the order of the drive signal patterns applied to each switching element of the bridge circuit 115 with respect to the fixed point. Here, there is a correlation between the current code at a fixed point and the rotational position of the AC generator M. Therefore, if the current code at a fixed point can be identified, the rotational position of the AC generator M at that time can be estimated. Therefore, if the current sign at a fixed point can be identified, a drive signal based on a drive pattern corresponding to the rotation position at that point in time can be supplied to the bridge circuit 115. This makes it possible to convert the AC power input to the regulator 10 into DC power of a constant voltage by the bridge circuit 115 and output it from the bridge circuit 115.

[0019] Such pattern data is determined in advance through experiments, etc., regarding the combinations of connecting the output terminals Mu, Mv, and Mw of the AC generator M to the input terminals Tin1, Tin2, and Tin3 of the regulator 10, the polarity of the current AC2 at the timing when a fixed point is reached, and the rotational position of the AC generator M, and is stored as pattern data in the pattern storage unit 130.

[0020] There are six possible combinations of connecting the output terminals Mu, Mv, and Mw of the AC generator M to the input terminals Tin1, Tin2, and Tin3 of the regulator 10. The connection of each output terminal of the AC generator M to each input terminal of the regulator 10 can be arbitrary. Therefore, during the assembly process, there is no need to manage the combinations when connecting the AC generator M and the regulator 10, resulting in efficient assembly.

[0021] Here, within the regulator 10, the current flowing through the path connected to input terminal Tin1 is referred to as current AC1, the current flowing through the path connected to input terminal Tin2 is referred to as current AC2, and the current flowing through the path connected to input terminal Tin3 is referred to as current AC3. When the combination of connecting each output terminal of the AC generator M to each input terminal of the regulator 10 is arbitrary, it is unknown at the time of assembly whether currents AC1, AC2, and AC3 in the regulator 10 correspond to the U-phase, V-phase, or W-phase supplied from the AC generator M. However, as described above, there are six such combinations, and each type will be explained as items 1 to 6.

[0022] Item 1 describes the case where output terminal Mu is connected to input terminal Tin1, output terminal Mv is connected to input terminal Tin2, and output terminal Mw is connected to input terminal Tin3, and the U phase is supplied as current AC1, the V phase as current AC2, and the W phase as current AC3. Item 2 describes the case where output terminal Mu is connected to input terminal Tin1, output terminal Mv is connected to input terminal Tin3, and output terminal Mw is connected to input terminal Tin2, and the U phase is supplied as current AC1, the V phase as current AC3, and the W phase as current AC2.

[0023] Item 3 is the case where output terminal Mu is connected to input terminal Tin3, output terminal Mv is connected to input terminal Tin1, and output terminal Mw is connected to input terminal Tin2, and the U phase is supplied as current AC3, the V phase as current AC1, and the W phase as current AC2. Item 4 is the case where output terminal Mu is connected to input terminal Tin2, output terminal Mv is connected to input terminal Tin1, and output terminal Mw is connected to input terminal Tin3, and the U phase is supplied as current AC2, the V phase as current AC1, and the W phase as current AC3.

[0024] Item 5 represents the case where output terminal Mu is connected to input terminal Tin2, output terminal Mv is connected to input terminal Tin3, and output terminal Mw is connected to input terminal Tin1, and the U phase is supplied as current AC2, the V phase as current AC3, and the W phase as current AC1. Item 6 represents the case where output terminal Mu is connected to input terminal Tin3, output terminal Mv is connected to input terminal Tin2, and output terminal Mw is connected to input terminal Tin1, and the U phase is supplied as current AC3, the V phase as current AC2, and the W phase as current AC1.

[0025] The current sign at a fixed point represents the current sign of each current AC1, AC2, and AC3 at the time the fixed point was detected. The current sign indicates whether the current value is positive or negative.

[0026] This section describes a case where the pattern data includes the connection destination, but the connection destination does not necessarily have to be included. In other words, the pattern storage unit 130 may not store the connection destination item, but instead store the item number, the current code at the fixed point, and the order of the drive pattern.

[0027] The drive pattern sequence determination unit 135 is connected to the line current measurement unit 125, the pattern storage unit 130, and the rotation position determination unit 140. The drive pattern sequence determination unit 135 is an example of the same pattern determination unit. Based on the determination result obtained from the line current measurement unit 125, the drive pattern sequence determination unit 135 reads the rotation position corresponding to whether the current sign is positive or negative from the pattern storage unit 130, and outputs the read result to the rotation position determination unit 140.

[0028] The rotation position determination unit 140 is connected to the drive pattern sequence determination unit 135, the fixed point detection unit 120, and the switch command unit 160. Based on the drive pattern identified by the drive pattern sequence determination unit 135 and the fixed points detected by the fixed point detection unit 120, the rotation position determination unit 140 determines which rotation position corresponds to the timing at which the fixed points were detected by the fixed point detection unit 120. The rotation position determination unit 140 outputs the determination result to the switch command unit 160.

[0029] The rotational speed calculation unit 145 stores the time when the fixed point detected by the fixed point detection unit 120 arrives, and calculates the rotational speed of the AC generator M from the time corresponding to one cycle of the phase current. For example, the rotational speed calculation unit 145 calculates the rotational speed of the AC generator M based on the time intervals in which the fixed points arrive periodically. The rotational speed calculation unit 145 outputs the calculated rotational speed to the retardation amount calculation unit 155.

[0030] The DC output voltage detection unit 150 is connected to the current path to which the output terminal Tout of the regulator 10 is connected, and is also connected to the angle retardation amount calculation unit 155. The DC output voltage detection unit 150 detects the voltage output from the bridge circuit 115 and outputs the detection result to the angle retardation amount calculation unit 155.

[0031] The angle retardation amount calculation unit 155 calculates the angle retardation amount, which is the angle retardation limit value such that the potential difference between the voltage of the battery 20 and the output voltage from the regulator 10 is the same. In doing so, the angle retardation amount calculation unit 155 refers to map data and calculates the angle retardation limit value corresponding to the rotor rotation speed detected by the rotation speed calculation unit 145. The map data is data in which the relationship between the angle retardation limit value, the rotor rotation speed, and the voltage of the battery 20 is predetermined. By calculating the angle retardation amount using the angle retardation amount calculation unit 155, it becomes possible to charge the battery 20 with a constant current without a decrease in charging current in response to the changing voltage of the battery 20, thereby suppressing the deterioration of the secondary battery while suppressing a decrease in charging efficiency.

[0032] The switch command unit 160 applies a control signal to the switching element to be controlled among the six switching elements (switching element Q1H, switching element Q1L, switching element Q2H, switching element Q2L, switching element Q3H, switching element Q3L) by advancing or retarding the phase of the gate signal of at least one of these six switching elements, based on the rotation position determined by the rotation position determination unit 140 and the retardation amount calculated by the retardation amount calculation unit 155. The switch command unit 160 drives the plurality of switching elements provided in the bridge circuit 115 according to the rotation position determined by the drive pattern order determination unit 135. The switch command unit 160 functions as a drive circuit for the bridge circuit 115.

[0033] The bridge circuit 115 is connected to the AC generator M and generates DC power from the AC power supplied by the AC generator M. The bridge circuit 115 includes six switching elements (switching element Q1H, switching element Q1L, switching element Q2H, switching element Q2L, switching element Q3H, and switching element Q3L) and converts the three-phase AC power input from input terminals Tin1, Tin2, and Tin3 into DC power. For example, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) are used as switching elements.

[0034] The current detection unit 110a, current detection unit 110b, bridge circuit 115, fixed point detection unit 120, line current measurement unit 125, pattern storage unit 130, drive pattern sequence determination unit 135, rotation position determination unit 140, rotation speed calculation unit 145, DC output voltage detection unit 150, angle retardation amount calculation unit 155, and switch command unit 160 may be composed of a processing unit such as a CPU (Central Processing Unit) or a dedicated electronic circuit.

[0035] Next, the operation of the regulator 10 described above will be explained. Figure 3 is a flowchart illustrating the operation of the regulator 10. During the assembly process, each output terminal of the AC generator M and each input terminal of the regulator 10 are connected in one of the following combinations. When the AC generator M is driven and AC power is supplied to the regulator 10, the fixed point detection unit 120 detects the current AC1 supplied to the input terminal Tin1 by the power generated by the AC generator M supplied to the regulator 10. Based on the detected current value of the current AC1 and the threshold (0(A)), the fixed point detection unit 120 determines whether the current AC1 is greater than or equal to the threshold (0(A)). If the current AC1 is greater than or equal to the threshold (0(A)), the fixed point detection unit 120 detects that a fixed point has arrived in the current waveform of the current AC1. When a fixed point is detected, the fixed point detection unit 120 outputs a detection result indicating that a fixed point has been detected to the line current measurement unit 125 and the rotation speed calculation unit 145.

[0036] When the line current measurement unit 125 receives a detection result from the fixed point detection unit 120 indicating that a fixed point has been detected, it detects the current AC2 supplied to the input terminal Tin2, determines whether the detected current value is 0 (A) or greater (step S101), and outputs the determination result to the drive pattern sequence determination unit 135. If the determination result obtained from the line current measurement unit 125 is 0 (A) or greater (step S101-YES), the drive pattern sequence determination unit 135 determines that the current AC2 is positive and reads the drive pattern for when the current AC2 is positive from the pattern storage unit 130 (step S102). If the current AC2 is positive, the drive pattern sequence determination unit 135 reads the drive pattern "starting from (3) in descending order" and outputs it to the rotation position determination unit 140.

[0037] The rotation position determination unit 140 outputs to the switch command unit 160 a drive pattern signal indicating the drive pattern "starting from (3) and descending order" obtained from the drive pattern sequence determination unit 135, and the timing at which a fixed point is detected by the fixed point detection unit 120. The switch command unit 160 applies a drive control signal to the bridge circuit 115 based on the drive pattern signal obtained from the rotation position determination unit 140 and the timing at which the fixed point is detected. The switch command unit 160 can estimate the rotation position of the AC generator M by aligning the starting position of the drive pattern indicated by the drive pattern signal with the timing at which the fixed point is detected. As a result, a drive control signal can be applied to the bridge circuit 115 based on the drive pattern corresponding to the rotation position of the AC generator M, and AC power can be converted to DC power and output. If the angle retardation amount is obtained from the angle retardation amount calculation unit 155, the switch command unit 160 applies the drive control signal to the bridge circuit 115 at a timing corresponding to the obtained angle retardation amount. On the other hand, if the determination result obtained from the line current measurement unit 125 is not 0 (A) or greater (step S101-NO), the drive pattern sequence determination unit 135 determines that the current AC2 is negative and reads the drive pattern for when the current AC2 is negative from the pattern storage unit 130 (step S103). If the current AC2 is negative, the drive pattern sequence determination unit 135 reads the drive pattern "starting from (1) in ascending order" and outputs it to the rotation position determination unit 140.

[0038] The rotation position determination unit 140 outputs to the switch command unit 160 a drive pattern signal indicating the drive pattern "starting from (1) and ascending order" output from the drive pattern sequence determination unit 135, and the timing at which a fixed point is detected by the fixed point detection unit 120. The switch command unit 160 applies a drive control signal to the bridge circuit 115 based on the drive pattern signal obtained from the rotation position determination unit 140 and the timing at which the fixed point is detected. If the angle retardation amount can be obtained from the angle retardation amount calculation unit 155, the switch command unit 160 applies the drive control signal to the bridge circuit 115 at a timing corresponding to the obtained angle retardation amount. This makes it possible to drive the bridge circuit 115 in a drive pattern corresponding to the rotation position of the AC generator M, and to convert AC power to DC power and output it.

[0039] Here, there are six patterns of data, numbered 1 through 6. For items 1, 3, and 5, the current sign at the fixed point and the order of the drive pattern are the same. For items 2, 4, and 6, the current sign at the fixed point and the order of the drive pattern are also the same. Therefore, the pattern data shown in Figure 2 only needs to store two combinations of the current sign of the target current (current AC2 in this case) measured by the line current measurement unit 125 and the order of the drive pattern, as shown in Figure 4. For this reason, it is not always necessary to identify which of items 1 through 6 it is. By determining whether the polarity of the monitored current (current AC2 in this case) is positive or negative at the timing when the fixed point is detected, the rotational position of the AC generator M can be estimated. By driving the bridge circuit 115 according to the drive pattern corresponding to this estimated rotational position, AC power can be converted to DC power.

[0040] Figure 5 shows an example of switching pattern data illustrating the relationship between the drive pattern and the logic applied to each element for driving the bridge circuit 115. The switching pattern data associates the item number representing the drive pattern with the logic applied to each switching element. For example, if the item number of the drive pattern is (1), it is specified that switching element Q1H of the bridge circuit 115 should be set to "High", switching element Q2H to "Low", and switching element Q3H to "High". Although not shown in Figure 5, the logic applied to switching elements Q1L, Q2L, and Q3L is different from the logic applied to switching elements connected in series. For example, if switching element Q1H is set to "High", switching element Q1L should be set to "Low". Similarly, if switching element Q2H is set to "Low", switching element Q2L should be set to "High". Furthermore, if switching element Q3H is given a "High" state, then switching element Q3L should be given a "Low" state.

[0041] If the drive pattern specified in item 1 is obtained as a result of the determination, the switch command unit 160 outputs "High" to switching element Q1H, "Low" to switching element Q1L, "Low" to switching element Q2H, "High" to switching element Q2L, "High" to switching element Q3H, and "Low" to switching element Q3L based on the switching pattern data. This allows the bridge circuit 115 to be driven in a manner corresponding to the rotational position of the AC generator M, and AC power can be converted to DC power and output. After this, the switch command unit 160 reads the logic combination corresponding to the drive pattern signal from the switching pattern data and applies a drive control signal to each switching element of the bridge circuit 115 based on the timing at which the fixed point is detected and the angle retardation amount obtained from the angle retardation amount calculation unit 155.

[0042] Figures 6 to 11 illustrate the relationship between the current waveform and the drive pattern supplied to the bridge circuit 115, depending on which of the states (1 to 6) the output terminal of the AC generator M and the input terminal of the regulator 10 are connected. Figure 6 illustrates the relationship between the current waveform in the connection state shown in item 1 and the drive pattern of the bridge circuit 115. Here, since a U-phase AC current is supplied to input terminal Tin1, the current monitored by the fixed point detection unit 120 is the U-phase current. Also, since a V-phase AC current is supplied to input terminal Tin2, the current monitored by the line current measurement unit 125 is the V-phase current. At the timing when a fixed point is detected for current AC1 (U-phase here), the current sign of current AC2 (V-phase here) is negative. Therefore, the drive pattern sequence determination unit 135 determines that the drive pattern is "starting from (1) in ascending order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on the sequence that ascends from the drive pattern (1) when a fixed point is detected.

[0043] Figure 7 illustrates the relationship between the current waveform in the connection state shown in item 2 and the drive pattern of the bridge circuit 115. Here, since a U-phase AC current is supplied to input terminal Tin1, the current monitored by the fixed point detection unit 120 is the U-phase current. Also, since a W-phase AC current is supplied to input terminal Tin2, the current monitored by the line current measurement unit 125 is the W-phase current. At the timing when a fixed point is detected for current AC1 (here, U-phase), the current sign of current AC2 (here, W-phase) is positive. Therefore, the drive pattern sequence determination unit 135 determines that the drive pattern is "starting from (3) in descending order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on the sequence that descends from drive pattern (3) at the timing when a fixed point is detected.

[0044] FIG. 8 is a diagram for explaining the relationship between the current waveform in the connection state shown in item number 3 and the drive pattern of the bridge circuit 115. Here, since an AC current of the V phase is supplied to the input terminal Tin1, the current monitored by the fixed-point detection unit 120 is the current of the V phase. Also, since an AC current of the W phase is supplied to the input terminal Tin2, the current monitored by the line current measurement unit 125 is the current of the W phase. At the timing when the fixed point is detected for the current AC1 (here, the V phase), the current sign of the current AC2 (here, the W phase) is negative. Therefore, the drive pattern order determination unit 135 determines that the drive pattern starts from "(1) and is in ascending order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on the order that starts from the drive pattern (1) and is in ascending order at the timing when the fixed point is detected.

[0045] FIG. 9 is a diagram for explaining the relationship between the current waveform in the connection state shown in item number 4 and the drive pattern of the bridge circuit 115. Here, since an AC current of the V phase is supplied to the input terminal Tin1, the current monitored by the fixed-point detection unit 120 is the current of the V phase. Also, since an AC current of the U phase is supplied to the input terminal Tin2, the current monitored by the line current measurement unit 125 is the current of the U phase. At the timing when the fixed point is detected for the current AC1 (here, the V phase), the current sign of the current AC2 (here, the U phase) is positive. Therefore, the drive pattern order determination unit 135 determines that the drive pattern starts from "(3) and is in descending order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on the order that starts from the drive pattern (3) and is in descending order at the timing when the fixed point is detected.

[0046] Figure 10 illustrates the relationship between the current waveform in the connection state shown in item 5 and the drive pattern of the bridge circuit 115. Here, since W-phase AC current is supplied to input terminal Tin1, the current monitored by the fixed point detection unit 120 is the W-phase current. Also, since U-phase AC current is supplied to input terminal Tin2, the current monitored by the line current measurement unit 125 is the U-phase current. At the timing when a fixed point is detected for current AC1 (W-phase in this case), the sign of current AC2 (U-phase in this case) is negative. Therefore, the drive pattern sequence determination unit 135 determines that the drive pattern is "starting from (1) in ascending order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on the sequence that ascends from drive pattern (1) at the timing when a fixed point is detected.

[0047] Figure 11 illustrates the relationship between the current waveform in the connection state shown in item 6 and the drive pattern of the bridge circuit 115. Here, since a W-phase AC current is supplied to input terminal Tin1, the current monitored by the fixed point detection unit 120 is the W-phase current. Also, since a V-phase AC current is supplied to input terminal Tin2, the current monitored by the line current measurement unit 125 is the V-phase current. At the timing when a fixed point is detected for current AC1 (W-phase in this case), the current sign of current AC2 (V-phase in this case) is positive. Therefore, the drive pattern sequence determination unit 135 determines that the drive pattern is "starting from (3) in descending order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on the sequence that descends from drive pattern (3) at the timing when a fixed point is detected.

[0048] FIG. 12 is a diagram showing the configuration of a battery charging system 1A in which a regulator 10a is used. The regulator 10a is an example of a case where a part of the regulator 10 is configured by hardware. In FIG. 12, mainly the points different from the configuration of FIG. 1 will be described, and the same components or corresponding components as those in the configuration of FIG. 1 may be denoted by the same reference numerals and their description may be omitted. The regulator 10a is connected to the alternator M. The current detection units 110a and 110b may use, for example, shunt resistors. The line current zero-cross detection unit 121 is an example of a case where a part of the function of the fixed-point detection unit 120 is configured using hardware. The line current zero-cross detection unit 121 includes an amplifier 121a, a comparator 121b, and an edge detection unit 121c.

[0049] The amplifier 121a amplifies the current detected by the shunt resistor that constitutes the current detection unit 110a. The output of the amplifier 121a is connected to the first input terminal of the comparator 121b, and the intermediate potential of the amplifier 121a is supplied as a reference potential to the second input terminal of the comparator 121b. This intermediate potential is given, for example, a potential for detecting a value at which the current detected by the current detection unit 110a becomes 0 A. The comparator 121b compares the output of the amplifier 121a with the intermediate potential of the amplifier 121a and outputs the comparison result to the edge detection unit 121c. The output of the comparator 121b represents a zero-cross signal at which the output of the amplifier 121a and the intermediate potential of the amplifier 121a cross each other. The edge detection unit 121c detects the timing at which the output signal output as the comparison result of the comparator 121b changes from the low level to the high level, and outputs the detection result as an edge signal to the drive pattern sequence determination unit 136.

[0050] The line current measurement unit 126 is an example of a case where a part of the line current measurement unit 125 is represented by hardware. The line current measurement unit 126 includes an amplifier 126a and an A / D converter 126b. The amplifier 126a amplifies the current detected by the shunt resistor that constitutes the current detection unit 110b. The A / D converter 126b converts an analog signal indicating the current value supplied from the amplifier 126a into a digital signal and outputs it to the drive pattern sequence determination unit 136.

[0051] The drive pattern sequence determination unit 136 has a configuration corresponding to the drive pattern sequence determination unit 135, but some functions differ. The drive pattern sequence determination unit 136 determines whether the current sign of the current AC2 is positive or negative based on the output signal output from the edge detection unit 121c and the output signal output from the A / D converter 126b. The drive pattern sequence determination unit 136 outputs a drive pattern signal indicating the drive pattern according to the current sign determination result to the switching element drive circuit 160a. The edge detection unit 121c, the A / D converter 125b, and the drive pattern sequence determination unit 136 may be incorporated into a microcontroller (MCU) 137.

[0052] The switching element drive circuit 160a controls the on / off state of each element in the bridge circuit 115 by applying a drive control signal to the bridge circuit 115 based on the drive pattern signal output from the drive pattern sequence determination unit 136. The switching element drive circuit 160a functions as a drive circuit that drives the multiple switching elements provided in the bridge circuit 115.

[0053] Figure 13 illustrates the relationship between the current waveform input to the regulator 10a, the zero-crossing signal, and the drive pattern of the bridge circuit 115. The upper part of Figure 13 shows the waveforms when the U phase is supplied as current AC1, the V phase as current AC2, and the W phase as current AC3. Here, the AC generator M and the regulator 10a are wired in a combination such that current AC2 is negative at a fixed point. The zero-crossing signal Z1 is an output signal representing the result of current AC1 detected by the current detection unit 110a being amplified by the amplifier 121a and compared with the midpoint potential of the amplifier 121a by the comparator 121b.

[0054] At time T1, the current AC1 has reached a fixed point and is in a downward phase, so the output of comparator 121b (zero-crossing signal Z1) falls to a low level. No fixed point is detected here. At time T2, the current AC1 has reached the zero-crossing point from a negative value and is in a upward phase, so the zero-crossing signal Z1 rises to a high level. At time T3, the current AC1 has reached the zero-crossing point from a positive value and is in a downward phase, so the zero-crossing signal Z1 falls to a low level. No fixed point is detected here. In this example, the timing for detecting a fixed point is when the current AC1 reaches the zero-crossing point when it changes from a negative value to a positive value.

[0055] Similarly, in the intervals where the current AC1 is positive, the zero-crossing signal Z1 becomes high level, and in the intervals where the current AC1 is negative, the output of the zero-crossing signal Z1 becomes low level. This zero-crossing signal Z1 is then supplied to the edge detection unit 121c. The edge detection unit 121c detects the timing at which the zero-crossing signal Z1 changes from low level to high level and outputs an edge signal representing the detected timing to the drive pattern sequence determination unit 136.

[0056] Meanwhile, the current AC2 detected by the current detection unit 110b is amplified by the amplifier 126a and output to the A / D converter 126b. The A / D converter 126b converts the analog signal output from the amplifier 126a into a digital signal and outputs it to the drive pattern sequence determination unit 136.

[0057] The drive pattern sequence determination unit 136 acquires the output of the A / D converter 126b at the timing when an edge signal is supplied from the edge detection unit 121c. This allows the value of current AC2 at the timing when current AC1 crosses zero from a negative value. The drive pattern sequence determination unit 136 then determines whether the sign of the acquired current AC2 is positive or negative. For example, at time T2, when current AC1 crosses zero, the sign of current AC2 is negative, so the drive pattern sequence determination unit 136 determines that the drive pattern is "starting from (1) in ascending order".

[0058] The drive pattern sequence determination unit 136 then supplies drive pattern signals to the switching element drive circuit 160a in ascending order, starting from the timing when the edge signal is obtained, beginning with drive pattern (1). The switching element drive circuit 160a applies a drive control signal to the bridge circuit 115 based on the drive pattern signal. For example, in the interval from time T2 to time T3, the drive patterns are in the order of (1), (2), and (3), and in the interval from time T3 to time T4, the drive patterns are in the order of (4), (5), and (6). In the interval where the drive pattern is (1), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "High", switching element Q2H is "Low", and switching element Q3H is "High". In section of the drive pattern (2), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "High", switching element Q2H is "Low", and switching element Q3H is "Low". In section of the drive pattern (3), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "High", switching element Q2H is "High", and switching element Q3H is "Low". In section of the drive pattern (4), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "Low", switching element Q2H is "High", and switching element Q3H is "Low". In section of the drive pattern (5), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "Low", switching element Q2H is "High", and switching element Q3H is "High". In the section of the drive pattern (6), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "Low", switching element Q2H is "Low", and switching element Q3H is "High".

[0059] The timing for switching the drive pattern may be allocated such that the six drive patterns (1) to (6) fit within one cycle of the zero-crossing signal, or it may be allocated such that three drive patterns fit in the high-level section of the zero-crossing signal and three drive patterns fit in the low-level section.

[0060] Figure 14 illustrates the relationship between the current waveform input to the regulator 10a, the zero-crossing signal, and the drive pattern of the bridge circuit 115. While Figure 13 described the case where the AC generator M and regulator 10a are wired in a combination such that the current AC2 is negative at a fixed point, Figure 14 describes the case where the AC generator M and regulator 10a are wired in a combination such that the current AC2 is positive.

[0061] The upper part of Figure 14 shows the waveforms when the U phase is supplied as current AC1, the V phase as current AC3, and the W phase as current AC2. In this example, the timing for detecting a fixed point is when current AC1 reaches the zero-crossing point when it changes from a negative value to a positive value. At time T2, the drive pattern sequence determination unit 136 detects that a fixed point has arrived when the zero-crossing signal Z1 rises to a high level, and obtains an edge signal, then takes the output of the A / D converter 126b. This allows the unit to obtain the value of current AC2 at the timing when current AC1 crosses zero, and to determine whether the sign of current AC2 is positive or not. In Figure 14, since the sign of current AC2 at the timing when current AC1 crosses zero is positive, the drive pattern sequence determination unit 136 determines that the drive pattern is "starting from (3) in descending order". For example, in the interval from time T2 to time T3, the drive pattern is in the order of (3), (2), (1), and in the interval from time T3 to time T4, the drive pattern is in the order of (6), (5), (4). The drive pattern sequence determination unit 136 supplies the drive pattern signal to the switching element drive circuit 160a according to this drive pattern sequence. As a result, the switching element drive circuit 160a applies a drive control signal corresponding to the drive pattern signal to the bridge circuit 115.

[0062] Next, a second embodiment will be described. Figure 15 shows the configuration of a battery charging system 1B using the regulator 10b according to the second embodiment of the present invention. In the battery charging system 1B of the second embodiment, the same reference numerals are used for the same functions as in the battery charging system 1 shown in Figure 1, and their descriptions may be omitted. Different functions will be described using different reference numerals. In the regulator 10 of the first embodiment, the case in which the fixed point detection unit 120 detects a zero crossing was described, but in this second embodiment, the regulator 10b differs in that the fixed point detection unit 120a detects a line current crossing where two phases cross.

[0063] The fixed point detection unit 120a is connected to the current detection unit 110a, the current detection unit 110b, the line current measurement unit 125a, the rotation position determination unit 140a, and the rotation speed calculation unit 145. The fixed point detection unit 120a detects fixed points based on the relationship where the current of the first phase and the current of a second phase, which is different from the first phase, intersect among the currents supplied from the three-phase AC generator. The first phase that the fixed point detection unit 120a detects is, for example, the current supplied to the input terminal Tin1 (current AC1). The second phase that the fixed point detection unit 120a detects is, for example, the current supplied to the input terminal Tin2 (current AC2).

[0064] More specifically, the fixed point detection unit 120a detects a fixed point based on a comparison between the current value of the AC current output from the AC generator M and supplied to input terminal Tin1 and the current value of the AC current supplied to input terminal Tin2. In this second embodiment, the fixed point is a point where the waveforms of the two phase currents to be detected intersect. As an example, the fixed point on the phase current waveform is described as a point where the current of the first phase intersects with the current of the second phase in a section where the current value of the first phase rises, but it may also be a point where the current of the first phase intersects with the current of the second phase in a section where the current value of the first phase falls. When the fixed point detection unit 120a detects a fixed point, it outputs to the line current measurement unit 125a, the rotation position determination unit 140a, and the rotation speed calculation unit 145 that a fixed point has been detected.

[0065] The line current measurement unit 125a is connected to the current detection unit 110b, the fixed point detection unit 120a, and the drive pattern sequence determination unit 135a. The line current measurement unit 125a determines whether the sign of the current of the reference phase, which is acquired according to the timing at which a fixed point is detected by the fixed point detection unit 120a among the three phases, is positive or negative. The current of the reference phase can be either the current of the first phase or the second phase. In the second embodiment, the case where the current of the reference phase is the second phase will be described as an example. The current of the second phase is the current supplied to the current path to which the current detection unit 110b is attached. More specifically, when the line current measurement unit 125a acquires a signal from the fixed point detection unit 120a indicating that a fixed point has been detected, it acquires the detection result of the current detection unit 110b to acquire the current value of the phase current supplied to the input terminal Tin2, and determines whether the sign of the acquired current value is positive or negative. The line current measurement unit 125a outputs the determination result to the drive pattern sequence determination unit 135a.

[0066] The pattern storage unit 130a stores pattern data representing the correspondence between the current sign of the phase of the reference target at a fixed point and the rotational position of the AC generator. Figure 16 shows an example of pattern data stored in the pattern storage unit 130a. Such pattern data is determined in advance by conducting experiments, etc., regarding the combination of connections between the output terminals Mu, Mv, and Mw of the AC generator M and the input terminals Tin1, Tin2, and Tin3 of the regulator 10, the polarity of the current AC2 at the timing when the fixed point arrives, and the rotational position of the AC generator M, and is stored as pattern data in the pattern storage unit 130a.

[0067] The pattern data shown in Figure 16 is the same as the pattern data shown in Figure 2 in terms of item numbering and connection destinations. Regarding the current sign at the fixed point, currents AC2 and AC3 are the same as in Figure 2, but current AC1 is "negative" in items 1, 3, and 5, and "positive" in items 2, 4, and 6. Also, the order of the drive patterns relative to the fixed point is "starting from (1) and ascending after an electrical angle of 30°" for items 1, 3, and 5, and "starting from (2) and descending after an electrical angle of 30°" for items 2, 4, and 6. Here, based on the timing of the arrival of the fixed point, the drive pattern is either "starting from (1) and ascending after an electrical angle of 30° has elapsed" or "starting from (2) and descending after an electrical angle of 30° has elapsed". Therefore, the timing of the arrival of the fixed point and the timing of switching the drive signal applied to the switching element are different due to the difference of 30° in electrical angle.

[0068] Figure 16 describes a case where the pattern data includes the connection destination, but the connection destination does not necessarily have to be included. That is, the pattern storage unit 130 may not store the connection destination item, but instead store the item number, the current code at the fixed point, and the order of the drive pattern.

[0069] Here, there are six possible patterns for the pattern data, numbered 1 through 6. For items 1, 3, and 5, the current sign at the fixed point and the order of the drive pattern are the same. For items 2, 4, and 6, the current sign at the fixed point and the order of the drive pattern are the same. Therefore, the pattern data shown in Figure 16 may be stored in two ways, as shown in Figure 17. These two ways may be (A) and (B) below. (A) When the current sign of the first phase and the current sign of the second phase are both "negative" at the time the fixed point based on the first and second phases is detected. (B) When the current sign of the first phase and the current sign of the second phase are both "positive" at the time the fixed point based on the first and second phases is detected.

[0070] Therefore, it is not always necessary to identify which of items 1 through 6 applies. By determining whether the current sign of the first and second phases being monitored is positive or negative at the time the fixed point is detected, the rotational position of the AC generator M can be estimated. By driving the bridge circuit 115 according to the drive pattern corresponding to this estimated rotational position, the AC power can be converted to DC power.

[0071] Next, the operation of the regulator 10b described above will be explained. Figure 18 is a flowchart illustrating the operation of the regulator 10. During the assembly process, each output terminal of the AC generator M and the input terminal of the regulator 10b are connected in one of the following combinations. When the AC generator M is driven and AC power is supplied to the regulator 10b, the fixed point detection unit 120a detects the current value of the current AC1 supplied from the AC generator M to input terminal Tin1 and the current AC2 supplied to input terminal Tin2, respectively, and detects a fixed point where currents AC1 and AC2 intersect. When a fixed point is detected, the fixed point detection unit 120a outputs a detection result indicating that a fixed point has been detected to the line current measurement unit 125a and the rotational speed calculation unit 145.

[0072] When the line current measurement unit 125a receives a detection result from the fixed point detection unit 120a indicating that a fixed point has been detected, it detects the current AC2 supplied to the input terminal Tin2, determines whether the detected current value is 0 (A) or greater (step S201), and outputs the determination result to the drive pattern sequence determination unit 135. If the determination result obtained from the line current measurement unit 125a is 0 (A) or greater (step S201-YES), the drive pattern sequence determination unit 135a determines that the current AC2 is positive and reads the drive pattern for when the current AC2 is positive from the pattern storage unit 130a (step S202). If the current AC2 is positive, the drive pattern sequence determination unit 135 reads the drive pattern "after an electrical angle of 30°, starting from (2) and in descending order" and outputs it to the rotation position determination unit 140a.

[0073] The rotation position determination unit 140a outputs to the switch command unit 160 the drive pattern signal output from the drive pattern sequence determination unit 135a, which indicates a drive pattern "starting from (2) and descending after an electrical angle of 30°", and the timing at which a fixed point was detected by the fixed point detection unit 120a. Based on the drive pattern signal obtained from the rotation position determination unit 140a and the timing at which the fixed point was detected, the switch command unit 160 applies a drive control signal to the bridge circuit 115. The switch command unit 160 can estimate that the rotation position of the AC generator M is such that the drive pattern starts from (2) and descends from the point after an electrical angle of 30° has elapsed, using the timing at which the fixed point was detected as a reference. As a result, the bridge circuit 115 can be driven to produce a drive pattern corresponding to the rotation position of the AC generator M, and AC power can be converted to DC power and output. Furthermore, if the switch command unit 160 can obtain an angle retardation amount from the angle retardation amount calculation unit 155, it applies a drive control signal to the bridge circuit 115 at a timing corresponding to the obtained angle retardation amount.

[0074] On the other hand, if the determination result obtained from the line current measurement unit 125a is not 0 (A) or greater (step S201-NO), the drive pattern sequence determination unit 135a determines that the current AC2 is negative and reads the drive pattern for when the current AC2 is negative from the pattern storage unit 130a (step S203). If the current AC2 is negative, the drive pattern sequence determination unit 135a reads the drive pattern "after an electrical angle of 30°, starting from (1) and in ascending order" and outputs it to the rotation position determination unit 140a.

[0075] The rotation position determination unit 140a outputs to the switch command unit 160 the drive pattern signal output from the drive pattern sequence determination unit 135a, which indicates a drive pattern "starting from (1) and ascending after an electrical angle of 30°", and the timing at which a fixed point was detected by the fixed point detection unit 120a. Based on the drive pattern signal obtained from the rotation position determination unit 140a and the timing at which the fixed point was detected, the switch command unit 160 applies a drive control signal to the bridge circuit 115. The switch command unit 160 can estimate that the rotation position of the AC generator M is such that the drive pattern starts from (1) and ascends from the point after an electrical angle of 30° has elapsed, using the timing at which the fixed point was detected as a reference. As a result, the bridge circuit 115 can be driven to produce a drive pattern corresponding to the rotation position of the AC generator M, and AC power can be converted to DC power and output. Furthermore, if the switch command unit 160 can obtain an angle retardation amount from the angle retardation amount calculation unit 155, it applies a drive control signal to the bridge circuit 115 at a timing corresponding to the obtained angle retardation amount.

[0076] According to the regulator 10b described above, control can be initiated in descending order starting from drive pattern (2), or ascending order starting from drive pattern (1), after 30° of electrical angle has elapsed since the detection of the fixed point. Therefore, it is possible to allow a 30° electrical angle buffer between the detection of the fixed point and the actual start of control. This also makes it possible to secure sufficient time for control.

[0077] Figures 19 to 24 illustrate the relationship between the current waveform and the drive pattern of the bridge circuit 115 when the output terminal of the AC generator M and the input terminal of the regulator 10b are connected in any of the states shown in items 1 to 6 in Figure 16. Figure 19 illustrates the relationship between the current waveform in the connection state shown in item 1 and the drive pattern of the bridge circuit 115. Here, it is shown that a U-phase AC current is supplied to input terminal Tin1 and a V-phase AC current is supplied to input terminal Tin2. In this case, the currents monitored by the fixed point detection unit 120a are the U-phase and V-phase currents. In the section where current AC1 (here, U-phase) is rising, at the fixed point where current AC1 (here, U-phase) and current AC2 (here, V-phase) intersect, the sign of current AC2 (here, V-phase) is negative. Therefore, the drive pattern sequence determination unit 135a determines that the drive pattern is "after an electrical angle of 30°, starting from (1) and ascending in order". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on an ascending sequence starting from drive pattern (1), with the starting point being 30° after the electrical angle has elapsed since the fixed point was detected. In this second embodiment, the section in which the fixed point is to be detected is the section in which the current AC1 increases.

[0078] Figure 20 illustrates the relationship between the current waveform in the connection state shown in item 2 and the drive pattern of the bridge circuit 115. Here, a case is shown where a U-phase AC current is supplied to input terminal Tin1 and a W-phase AC current is supplied to input terminal Tin2. In this case, the currents monitored by the fixed point detection unit 120a are the U-phase and W-phase currents. In the section where current AC1 (here, U-phase) is rising, at the fixed point where current AC1 (here, U-phase) and current AC2 (here, W-phase) intersect, the sign of current AC2 (here, W-phase) is positive. Therefore, the drive pattern sequence determination unit 135a determines that the drive pattern is "after an electrical angle of 30°, starting from (2) and in descending order". As a result, the rotation position determination unit 140, at the timing when the fixed point is detected, drives the bridge circuit 115 based on a sequence that starts from drive pattern (2) and descends, with the timing after an electrical angle of 30° having elapsed as the starting point.

[0079] Figure 21 is a diagram illustrating the relationship between the current waveform in the connection state shown in item 3 and the drive pattern of the bridge circuit 115. Here, it is shown that a V-phase AC current is supplied to input terminal Tin1 and a W-phase AC current is supplied to input terminal Tin2. In this case, the currents monitored by the fixed point detection unit 120a are the V-phase and W-phase currents. In the section where current AC1 (V-phase in this case) is rising, at the fixed point where current AC1 (V-phase in this case) and current AC2 (W-phase in this case) intersect, the sign of current AC2 (W-phase in this case) is negative. Therefore, the drive pattern sequence determination unit 135a determines that the drive pattern is "starting from (1) in ascending order after an electrical angle of 30°". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on an ascending order starting from drive pattern (1), with the timing after an electrical angle of 30° has elapsed from the timing when the fixed point is detected as the starting point.

[0080] Figure 22 illustrates the relationship between the current waveform in the connection state shown in item 4 and the drive pattern of the bridge circuit 115. Here, a V-phase AC current is supplied to input terminal Tin1, and a U-phase AC current is supplied to input terminal Tin2. In this case, the currents monitored by the fixed point detection unit 120a are the V-phase and U-phase currents. In the section where current AC1 (V-phase in this case) is rising, at the fixed point where current AC1 (V-phase in this case) and current AC2 (U-phase in this case) intersect, the sign of current AC2 (V-phase in this case) is positive. Therefore, the drive pattern sequence determination unit 135a determines that the drive pattern is "starting from (2) in descending order after an electrical angle of 30°". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on a sequence that starts from drive pattern (2) in descending order, with the starting point being the timing after an electrical angle of 30° has elapsed since the fixed point was detected.

[0081] Figure 23 illustrates the relationship between the current waveform in the connection state shown in item 5 and the drive pattern of the bridge circuit 115. Here, a W-phase AC current is supplied to input terminal Tin1, and a U-phase AC current is supplied to input terminal Tin2. In this case, the currents monitored by the fixed point detection unit 120a are the W-phase and U-phase currents. In the section where current AC1 (W-phase in this case) is rising, at the fixed point where current AC1 (W-phase in this case) and current AC2 (U-phase in this case) intersect, the sign of current AC2 (U-phase in this case) is negative. Therefore, the drive pattern sequence determination unit 135a determines that the drive pattern is "starting from (1) in ascending order after an electrical angle of 30°". As a result, the rotation position determination unit 140 drives the bridge circuit 115 based on an ascending order starting from drive pattern (1), with the timing after an electrical angle of 30° has elapsed from the timing when the fixed point is detected as the starting point.

[0082] Figure 24 illustrates the relationship between the current waveform in the connection state shown in item 6 and the drive pattern of the bridge circuit 115. Here, a W-phase AC current is supplied to input terminal Tin1, and a V-phase AC current is supplied to input terminal Tin2. In this case, the currents monitored by the fixed point detection unit 120a are the W-phase and V-phase currents. In the section where current AC1 (W-phase in this case) is rising, at the fixed point where current AC1 (W-phase in this case) and current AC2 (V-phase in this case) intersect, the sign of current AC2 (V-phase in this case) is positive. Therefore, the drive pattern sequence determination unit 135a determines that the drive pattern is "after an electrical angle of 30°, starting from (2) and in descending order". As a result, the rotation position determination unit 140, at the timing when the fixed point is detected, drives the bridge circuit 115 based on a sequence that starts from drive pattern (2) and descends, with the timing after an electrical angle of 30° having elapsed as the starting point.

[0083] Figure 25 shows the configuration of a battery charging system 1C using regulator 10c. Regulator 10c is an example of a case where part of regulator 10b is configured by hardware. In Figure 25, the differences from the configuration in Figure 15 will be mainly explained, and the same reference numerals are used for components that are the same as or corresponding to the configuration in Figure 15, and their explanations may be omitted. The line current zero-crossing detection unit 122 is an example of a case where part of the function of the fixed-point detection unit 120 is configured by hardware. The line current zero-crossing detection unit 122 includes an amplifier 122a, a comparator 122b, and an edge detection unit 122c.

[0084] Amplifier 122a amplifies the current detected by the shunt resistor constituting the current detection unit 110a. The output terminal of amplifier 122a is connected to the first input terminal of comparator 122b, and the output terminal of amplifier 127a is connected to the second input terminal of comparator 122b. The output terminal of comparator 122b is connected to the input terminal of edge detection unit 122c. Comparator 122b compares the output of amplifier 122a and the output of amplifier 127a, and outputs the comparison result to edge detection unit 122c. The output of comparator 122b represents the zero-crossing signal where the output of amplifier 122a and the output of amplifier 127a intersect. Edge detection unit 122c detects the timing at which the output signal output as a comparison result of comparator 122b changes from a low level to a high level, and outputs the detection result as an edge signal to drive pattern sequence determination unit 136a.

[0085] The drive pattern sequence determination unit 136a has a configuration corresponding to the drive pattern sequence determination unit 136a, but some functions are different. The drive pattern sequence determination unit 136a determines whether the current sign of the current AC2 is positive or negative based on the output signal output from the edge detection unit 122c and the output signal output from the A / D converter 127b. The drive pattern sequence determination unit 136a outputs a drive pattern signal indicating the drive pattern according to the determination result of the current sign to the switching element drive circuit 160a. The edge detection unit 122c, A / D converter 127b, and drive pattern sequence determination unit 136a may be incorporated into the microcontroller 137a.

[0086] The switching element drive circuit 160a controls the on / off state of each element of the bridge circuit 115 by applying a drive control signal to the bridge circuit 115 based on the drive pattern signal output from the drive pattern sequence determination unit 136a.

[0087] Figure 26 illustrates the relationship between the current waveform input to the regulator 10c, the crossover signal, and the drive pattern of the bridge circuit 115. The upper part of Figure 26 shows the waveforms when the U phase is supplied as current AC1, the V phase as current AC2, and the W phase as current AC3. Here, the AC generator M and the regulator 10c are wired in a combination such that current AC2 is negative at a fixed point. The crossover signal Z2 is an output signal representing the result of current AC1 detected by the current detection unit 110a being amplified by the amplifier 122a and compared with the output of amplifier 127a by the comparator 122b.

[0088] At time T1, currents AC1 and AC2 intersect, and since current AC1 is in a downward phase, the output of comparator 122b (cross signal Z2) falls to a low level. No fixed point is detected here. At time T2, currents AC1 and AC2 intersect, and since current AC1 is in an upward phase, the cross signal Z2 rises to a high level. At time T3, currents AC1 and AC2 intersect, and since current AC1 is in a downward phase, the cross signal Z2 falls to a low level. No fixed point is detected here.

[0089] Similarly, in the subsequent sections where current AC1 rises, the cross signal Z2 becomes high at the point where current AC1 and current AC2 intersect. Also, in the section where current AC1 falls at the point where current AC1 and current AC2 intersect, the cross signal Z2 becomes low. This cross signal Z2 is then supplied to the edge detection unit 122c. The edge detection unit 122c detects the timing when the cross signal Z2 changes from a low level to a high level and outputs an edge signal representing the detected timing to the drive pattern sequence determination unit 136a.

[0090] Meanwhile, the current AC2 detected by the current detection unit 110b is amplified by the amplifier 127a and output to the A / D converter 127b. The A / D converter 127b converts the analog signal output from the amplifier 127a into a digital signal and outputs it to the drive pattern sequence determination unit 136a.

[0091] The drive pattern sequence determination unit 136a acquires the output of the A / D converter 127b at the timing when an edge signal is supplied from the edge detection unit 122c. This allows the value of current AC2 at the timing when current AC1 and current AC intersect. The drive pattern sequence determination unit 136a then determines whether the sign of the acquired current AC2 is positive or negative. For example, at time T2, when current AC1 and current AC2 intersect, the sign of current AC2 is negative, so the drive pattern sequence determination unit 136a determines that the drive pattern is "after an electrical angle of 30°, starting from (1) and proceeding in ascending order".

[0092] The drive pattern sequence determination unit 136 then supplies drive pattern signals to the switching element drive circuit 160a in ascending order from drive pattern (1), starting from the point when an electrical angle of 30° has elapsed since the edge signal was obtained. As a result, the switching element drive circuit 160a applies a drive control signal corresponding to the drive pattern signal to the bridge circuit 115. For example, in the section from time T2 to time T3 that is shifted back by an electrical angle of 30°, the drive patterns are in the order of (1), (2), and (3). In the section where the drive pattern is (1), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "High", switching element Q2H is "Low", and switching element Q3H is "High". In section of the drive pattern (2), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "High", switching element Q2H is "Low", and switching element Q3H is "Low". In section of the drive pattern (3), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "High", switching element Q2H is "High", and switching element Q3H is "Low".

[0093] In the interval between time T3 and time T4, shifted back by an electrical angle of 30°, the drive patterns are in the order of (4), (5), and (6). In the interval of drive pattern (4), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "Low", switching element Q2H is "High", and switching element Q3H is "Low". In the interval of drive pattern (5), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "Low", switching element Q2H is "High", and switching element Q3H is "High". In the interval of drive pattern (6), a drive signal is supplied to the bridge circuit 115 such that switching element Q1H is "Low", switching element Q2H is "Low", and switching element Q3H is "High".

[0094] The timing for switching the drive pattern may be allocated such that six drive patterns (1) to (6) fit within one cycle of the cross signal, or it may be allocated such that three drive patterns fit in the high-level section of the zero-cross signal and three drive patterns fit in the low-level section.

[0095] Figure 27 illustrates the relationship between the current waveform input to the regulator 10c, the crossover signal, and the drive pattern of the bridge circuit 115. While Figure 26 described the case where the AC generator M and regulator 10c are wired in a combination such that the current AC2 is negative at a fixed point, Figure 27 describes the case where the AC generator M and regulator 10c are wired in a combination such that the current AC2 is positive.

[0096] In the upper part of Figure 27, the waveforms are shown when the U phase is supplied as current AC1, the V phase as current AC3, and the W phase as current AC2. At time T2, the drive pattern sequence determination unit 136a detects that a fixed point has arrived when the cross signal Z2 rises to a high level, and obtains an edge signal, then takes the output of the A / D converter 127b. This allows it to obtain the value of current AC2 at the timing when current AC1 and current AC2 cross, and to determine whether the sign of current AC2 is positive or not. In Figure 27, since the sign of current AC2 at the timing when current AC1 and current AC2 cross is positive, the drive pattern sequence determination unit 136a determines that the drive pattern is "after an electrical angle of 30°, starting from (2) and in descending order".

[0097] For example, in the interval from time T2 to time T3, shifted backward by an electrical angle of 30°, the drive patterns are in the order of (2), (1), and (6). In the interval from time T3 to time T4, shifted backward by an electrical angle of 30°, the drive patterns are in the order of (5), (4), and (3). In each drive pattern, the drive control signals supplied to the bridge circuit 115 are the same as those described in Figure 26.

[0098] Next, a third embodiment will be described. Figure 28 shows the configuration of a battery charging system 1D using the regulator 10d according to the third embodiment of the present invention. In the third embodiment, the battery charging system 1D may use the same reference numerals as the battery charging system 1B shown in Figure 15 for functions that are described in the same way, and different functions will be described using different reference numerals.

[0099] Furthermore, while the second embodiment described a case in which the drive pattern sequence determination unit 135a in the regulator 10c refers to the current code of current AC2, this third embodiment describes a case in which the current code of current AC3 is referred to.

[0100] The line current measurement unit 128 is connected to the current detection unit 110a, the current detection unit 110b, the fixed point detection unit 120a, and the AC3 line current value estimation unit 134. Depending on the timing when a fixed point is detected by the fixed point detection unit 120a, the line current measurement unit 128 acquires the detected value of current AC1 detected by the current detection unit 110a and the detected value of current AC2 detected by the current detection unit 110b.

[0101] The AC3 line current value estimation unit 134 estimates the current value of the third phase based on the current value of the first phase (e.g., current AC1) and the current value of the second phase (e.g., current AC2) detected by the line current measurement unit 128, and outputs the estimation result to the drive pattern sequence determination unit 135b. For example, the AC3 line current value estimation unit 134 estimates current AC3 by finding the sum of the current value of the first phase and the current value of the second phase and inverting the sign of the current. Here, the current output from the AC generator M is a three-phase alternating current, and the phases of the U, V, and W phases are shifted by 120 degrees. Therefore, it is possible to estimate current AC3 by finding the sum of the current value of the first phase and the current value of the second phase and inverting the sign of the current. The AC3 line current value estimation unit 134 may also determine whether the estimated sign of the third phase current is positive or negative. The AC 3-line current value estimation unit 134 is an example of an estimation unit.

[0102] The pattern storage unit 130b stores pattern data representing the correspondence between the current sign of the reference phase at a fixed point and the rotational position of the AC generator. The pattern storage unit 130b may store pattern data as shown in Figure 16 described above, or it may store pattern data as shown in Figure 29. Figure 29 shows an example of the pattern data to be stored when two cases included in the pattern data shown in Figure 16 are stored. These two cases may be (C) and (D) below. (C) When the current sign of the third phase is "positive" at the time the fixed point based on the first and second phases is detected. (D) When the current sign of the third phase is "negative" at the time the fixed point based on the first and second phases is detected.

[0103] In the case of (C) above, the order of the drive patterns is "starting from (1) after an electrical angle of 30° and proceeding in ascending order". In the case of (D) above, the order of the drive patterns is "starting from (2) after an electrical angle of 30° and proceeding in descending order".

[0104] Therefore, it is not always necessary to identify which of items 1 through 6 applies. By determining whether the sign of the third current being monitored is positive or negative at the time the fixed point is detected, the rotational position of the AC generator M can be estimated. Then, by driving the bridge circuit 115 according to the drive pattern corresponding to this estimated rotational position, the AC power can be converted to DC power.

[0105] The drive pattern sequence determination unit 135b is connected to the AC3 line current value estimation unit 134, the pattern storage unit 130b, and the rotation position determination unit 140a. The drive pattern sequence determination unit 135b reads the rotation position from the pattern storage unit 130b according to whether the current sign of the third phase (for example, current AC3), which is the estimation result estimated by the AC3 line current value estimation unit 134, is positive or negative, and outputs the read result to the rotation position determination unit 140a.

[0106] The rotation position determination unit 140a determines which rotation position corresponds to the timing at which a fixed point was detected by the fixed point detection unit 120a, based on the drive pattern sequence determination unit 135b.

[0107] Next, the operation of the regulator 10d to estimate the current value of current AC3 will be explained. Figure 30 is a flowchart illustrating the operation of the regulator 10d to estimate the current value of current AC3. When a fixed point is detected by the fixed point detection unit 120a, the line current measurement unit 128 obtains the detected value of current AC1 detected by the current detection unit 110a and the detected value of current AC2 detected by the current detection unit 110b. The AC3 line current value estimation unit 134 calculates the sum of the current values ​​of current AC1 and current AC2, and estimates current AC3 by inverting the sign of the current (step S301). The AC3 line current value estimation unit 134 then outputs the estimated current value of current AC3 to the drive pattern sequence determination unit 135b.

[0108] Next, the process by which the regulator 10d determines the drive pattern sequence will be explained. Figure 31 is a flowchart illustrating the process by which the regulator 10d determines the drive pattern sequence. When the AC generator M is driven and a fixed point is detected by the fixed point detection unit 120a, the line current measurement unit 128 detects currents AC1 and AC2 and outputs the detection results to the AC3 line current value estimation unit 134. The AC3 line current value estimation unit 134 estimates the current value of current AC3 from currents AC1 and AC2, determines whether the estimation result is 0 (A) or greater (step S401), and outputs the determination result to the drive pattern sequence determination unit 135b. Here, the determination result indicates that if the estimation result is 0 (A) or greater, the current sign of current AC3 is positive. If the drive pattern sequence determination unit 135b determines that the current value of current AC3 is 0 (A) or greater (step S401-YES), it determines that current AC3 is positive and reads the drive pattern for when current AC3 is positive from the pattern storage unit 130b (step S402). If current AC3 is positive, the drive pattern sequence determination unit 135b reads the drive pattern "after an electrical angle of 30°, starting from (1) and in ascending order" and outputs it to the rotation position determination unit 140a.

[0109] The rotation position determination unit 140a outputs to the switch command unit 160 the drive pattern signal output from the drive pattern sequence determination unit 135a indicating the drive pattern "after an electrical angle of 30°, starting from (1) and proceeding in ascending order," and the timing at which a fixed point is detected by the fixed point detection unit 120a.

[0110] On the other hand, if the current value of current AC3 is not 0 (A) or greater (step S401-NO), the drive pattern sequence determination unit 135b determines that current AC3 is negative and reads the drive pattern for when current AC3 is negative from the pattern storage unit 130a (step S403). If current AC3 is negative, the drive pattern sequence determination unit 135b reads the drive pattern "after an electrical angle of 30°, starting from (2) and in descending order" and outputs it to the rotation position determination unit 140a. The rotation position determination unit 140a outputs the drive pattern "after an electrical angle of 30°, starting from (2) and in descending order" output from the drive pattern sequence determination unit 135a to the switch command unit 160.

[0111] After step S402 or step S403, the switch command unit 160 applies a drive control signal to the bridge circuit 115 based on the drive pattern signal obtained from the rotation position determination unit 140a and the timing at which the fixed point is detected. If the angle retardation amount is obtained from the angle retardation amount calculation unit 155, the switch command unit 160 applies the drive control signal to the bridge circuit 115 at a timing corresponding to the obtained angle retardation amount.

[0112] Figure 32 shows the configuration of a battery charging system 1E using regulator 10e. Regulator 10e is an example of a case where a part of regulator 10d shown in Figure 28 is configured by hardware. In Figure 32, the differences from the configuration in Figure 28 will be mainly explained, and the same reference numerals are used for components that are the same as or corresponding to the configuration in Figure 28, and their explanations may be omitted.

[0113] The line current measurement unit 129 is an example of a part of the line current measurement unit 128 being represented by hardware. The line current measurement unit 129 includes an amplifier 129a, an amplifier 129b, an A / D converter 129c, and an A / D converter 129d. Amplifier 129a amplifies the current detected by the shunt resistor constituting the current detection unit 110a and supplies the amplified current to the comparator 123b and the A / D converter 129c. Amplifier 129b amplifies the current detected by the shunt resistor constituting the current detection unit 110b and supplies the amplified current to the comparator 123b and the A / D converter 129d.

[0114] When the A / D converter 129c receives a command from the microcontroller 137b to acquire a current value, it acquires an analog signal indicating the current supplied from the amplifier 129a. The A / D converter 129c converts the analog signal indicating the current supplied from the amplifier 129a into a digital signal and supplies it to the AC 3-line current value estimation unit 134a.

[0115] When the A / D converter 129d receives a command from the microcontroller 137b to acquire a current value, it acquires an analog signal indicating the current supplied from the amplifier 129b. The A / D converter 129d converts the analog signal indicating the current supplied from the amplifier 129b into a digital signal and supplies it to the AC 3-line current value estimation unit 134a.

[0116] The line current zero-cross detection unit 123 includes a comparator 123b and an edge detection unit 123c. The first input terminal of the comparator 123b is connected to the output terminal of the amplifier 129a, and the second input terminal is connected to the output terminal of the amplifier 129b. The output terminal of the comparator 123b is connected to the input terminal of the edge detection unit 123c. The comparator 123b compares the output signal of the amplifier 129a and the output signal of the amplifier 129b, and outputs the comparison result to the edge detection unit 123c. The output of the comparator 123b represents the cross signal (line current cross signal) where the output of the amplifier 129a (current AC1) and the output of the amplifier 129b (current AC2) intersect. The comparator 123b raises its output signal to a high level when current AC1 and current AC2 intersect while current AC1 is increasing, and lowers its output signal to a low level when current AC1 and current AC2 intersect while current AC1 is decreasing.

[0117] The edge detection unit 123c detects the timing at which the output signal output as a comparison result of the comparator 123b changes from a low level to a high level, and based on the detection result, outputs an edge signal representing the timing at which the level became high to the drive pattern sequence determination unit 136b.

[0118] The first input terminal of the AC3-wire current value estimation unit 134a is connected to the output terminal of the A / D converter 129c, and the second input terminal is connected to the output terminal of the A / D converter 129d. The output terminal of the AC3-wire current value estimation unit 134a is connected to the drive pattern sequence determination unit 136b. The AC3-wire current value estimation unit 134a estimates the current value of current AC3 based on the current value obtained from the A / D converter 129c (current value of current AC1) and the current value obtained from the A / D converter 129d (current value of current AC2), and outputs the estimated current value to the drive pattern sequence determination unit 136b.

[0119] The drive pattern sequence determination unit 136b determines whether the sign of current AC3 is positive or negative based on the current value of current AC3 output from the AC3 line current value estimation unit 134a when the edge signal supplied from the edge detection unit 123c becomes high level. The drive pattern sequence determination unit 136b outputs a drive pattern signal indicating a drive pattern corresponding to the result of determining whether the sign of current AC3 is positive or negative to the switching element drive circuit 160b.

[0120] The switching element drive circuit 160b controls the on / off state of each element in the bridge circuit 115 by applying a drive control signal to the bridge circuit 115 based on the drive pattern signal output from the drive pattern sequence determination unit 136b. The switching element drive circuit 160b functions as a drive circuit that drives the multiple switching elements provided in the bridge circuit 115.

[0121] With the regulators 10d and 10e described above, instead of determining whether the current sign of current AC1 or current AC2 is positive or negative, the current sign of current AC3, estimated from currents AC1 and AC2, is determined to be positive or negative. Here, the period from the arrival of the fixed point to the timing when the current sign of the third phase (current AC3) switches is longer than the period from the fixed point to the timing when the current value of either the first phase (current AC1) or the second phase (current AC2) switches. As a result, by referring to the current sign of current AC3, it is possible to create a margin in the timing for current detection by the current detection unit 110a or current detection unit 110b to take in the current, compared to the case where the current sign of current AC1 or current AC2 is referred to.

[0122] Here, the effect of estimating current AC3 will be explained using the current waveform in the connection state shown in item 4 as an example. Figure 33 is a diagram illustrating the relationship between the current waveform in the connection state shown in item 4 and the drive pattern of the bridge circuit 115. When a V-phase AC current is supplied to input terminal Tin1, a U-phase AC current is supplied to input terminal Tin2, and a W-phase AC current is supplied to input terminal Tin3, a fixed point is detected at time T1. At time T1, when the fixed point is detected, the current signs of both current AC1 and current AC2 are positive. As time T2 is reached from time T1, the current value of current AC1 has increased compared to time T1, and its current sign remains positive. On the other hand, the current value of current AC2 has decreased compared to time T1, reaching 0 (A). Furthermore, as time T3 is reached from time T2, the current sign of current AC1 remains positive, but the current sign of current AC2 has remained negative since time T2.

[0123] When a fixed point is detected at time T1 and a cross signal is supplied from comparator 123b, the microcontroller 137b causes A / D converters 129c and 129d to perform the process of acquiring current values. Here, if the process of detecting the cross signal and having A / D converters 129c or 129d acquire current values ​​is completed during the period from time T1 when the fixed point is detected until time T2, the drive pattern can be determined according to the current code of the acquired current AC1 or AC2. However, there are cases where the timing of A / D converters 129c and 129d acquiring current values ​​is delayed. For example, the process of A / D converters 129c and 129d acquiring current values ​​is performed in response to receiving an acquisition control signal from the microcontroller 137b to perform the acquisition of current values. Therefore, if the microcontroller 137b receives an interrupt related to another process that takes priority over outputting the acquisition control signal, it may output the acquisition control signal to the A / D converters 129c and 129d only after the interrupt-related process has been completed. In such cases, the timing at which the A / D converters 129c and 129d acquire the current value may be significantly delayed from the timing at which the crossover signal is detected.

[0124] For example, if the current values ​​of A / D converters 129c and 129d are acquired between time T1 and before time T2, the current codes of current AC1 and current AC2 will be the same as the current codes at the time the fixed point was detected. In this case, the drive pattern can be accurately identified.

[0125] On the other hand, if the timing of acquiring the current values ​​of A / D converters 129c and 129d is delayed and performed between time T2 and time T3, the current sign of current AC2 will have switched from positive to negative. That is, the current sign of current AC1 will be the same even if it is performed between time T2 and time T3. On the other hand, the current sign of current AC2 is positive when the fixed point is detected, but it will have switched to negative by the time the acquisition is performed. If the acquisition of current values ​​of A / D converters 129c and 129d is performed between time T2 and time T3 in this manner, the acquisition will occur in a state not specified in the pattern data stored in the pattern storage unit 130a (or storage unit 103b), which may result in the inability to accurately identify the drive pattern.

[0126] In contrast, according to the third embodiment described above, current AC3 is estimated from currents AC1 and AC2, and it is determined whether the sign of the estimated current AC3 is positive or negative. If it is current AC3, the sign of the current does not change not only during the period from time T1 to time T2, but also during the period from time T2 to time T3. Therefore, even if the current value is acquired not only during the period from time T1 to time T2, but also during the period from time T2 to time T3, the drive pattern can be accurately identified. This expands the period during which current values ​​can be acquired. Therefore, it is possible to have more leeway in the timing of acquiring current values.

[0127] Furthermore, comparing the regulator 10e shown in Figure 32 with the regulator 10c shown in Figure 25, the required electronic components and the number of components are the same. Although one additional A / D converter is required in the microcontroller, the only difference in each component is the wiring. In terms of processing, the regulator 10e has an additional process for estimating the third phase current value, as shown in Figure 30, compared to the regulator 10c. However, the calculation of this estimated value is a basic arithmetic operation, and the other processing is basically the same as that of the regulator 10c. Therefore, the regulator 10e can be implemented with a very simple configuration and processing.

[0128] According to the first to third embodiments described above, the rotational position of the AC generator can be determined without providing external sensors and without managing the connections between each terminal of the AC generator and each terminal of the bridge circuit. Furthermore, according to the first to third embodiments described above, it is possible to estimate the rotational position of the AC generator in real time regardless of the combination of wiring to which the AC generator and the regulator are connected. Moreover, according to the first to third embodiments described above, it is possible to implement these without using high-performance electronic components or processors. Furthermore, according to the regulator 10a in the first embodiment, the regulator 10c in the second embodiment, and the regulator 10e in the third embodiment described above, a shunt resistor and an amplifier can be used for line current detection, and an amplifier and a comparator can be used for fixed-point detection, so they can be constructed using common and inexpensive components.

[0129] Furthermore, while the first to third embodiments described above explain the case where the fixed point is a zero crossing or a phase crossing, any point other than a zero crossing or phase crossing may be used as long as it is distinguishable from other points on the current waveform. In this case, by using the point designated as a fixed point as a reference, the current sign of the current to be referenced and the drive pattern can be determined in advance through experiments or simulations, and the pattern data can be stored in the memory unit to estimate the rotational position of the AC motor.

[0130] Furthermore, according to the second and third embodiments described above, phase crossovers are detected for the two phases. Since the relationship between the crossover points of the two phases is unlikely to be disrupted, the possibility of false phase detection due to the intrusion of external noise can be reduced, and there is an advantage that it is less susceptible to noise.

[0131] In the above-described embodiment, all or part of the regulators 10, 10a, 10b, 10c, 10d, and 10e may be implemented using a computer. Alternatively, a program for implementing the functions of the processing unit shown in Figure 1 may be recorded on a computer-readable recording medium, and construction management may be performed by loading this program recorded on the recording medium into a computer system and executing it. The term "computer system" here includes hardware such as an operating system and peripheral devices.

[0132] Furthermore, "computer system" includes the homepage provisioning environment (or display environment) if a WWW system is being used. "Computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and storage devices such as hard disks built into computer systems. "Computer-readable recording medium" also includes volatile memory within server and client computer systems that retain programs for a certain period of time. The above program may only implement a part of the aforementioned functions, and may also be implemented in combination with programs already recorded in the computer system. The above program may also be stored on a designated server and distributed (downloaded, etc.) via a communication line in response to requests from other devices.

[0133] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs and the like that do not depart from the spirit of this invention.

[0134] 1, 1A, 1B, 1C, 1D, 1E Battery charging system 10, 10a, 10b, 10c, 10d, 10e Regulator 15 Load 20 Battery 103b Memory unit 110a, 110b Current detection unit 115 Bridge circuit 120, 120a Fixed point detection unit 121, 122, 123 Line current zero-crossing detection unit 121a, 122a, 126a, 127a, 129a, 129b Amplifier 121b, 122b, 123b Comparator 121c, 122c, 123c Edge detection unit 125, 125a, 126, 128, 129 Line current measurement unit 125b, 126b, 127b A / D converter 129c, 129d A / D converter 130, 130a, 130b Pattern memory unit 134, 134a Line current value estimation unit 135, 135a, 135b, 136, 136a, 136b Drive pattern sequence determination unit 137a, 137b Microcontroller 140, 140a Rotation position determination unit 145 Rotation speed calculation unit 150 DC output voltage detection unit 155 Timing retardation amount calculation unit 160 Switch command unit 160a, 160b Switching element drive circuit M AC generator Mu, Mv, Mw, Tout, Tout1, Tout2 Output terminals Q1H, Q1L, Q2H, Q2L, Q3H, Q3L Switching element Tin1, Tin2, Tin3 Input terminals

Claims

1. A regulator comprising: a fixed point detection unit that detects a fixed point based on the current of the phase to be detected among the currents supplied from a three-phase AC generator; a line current measurement unit that determines whether the current sign is positive or negative for the current of a reference phase among the three phases, which is acquired according to the timing at which the fixed point is detected; a pattern storage unit that stores the correspondence between the current sign of the reference phase at the fixed point and the rotation position of the AC generator; and a drive pattern determination unit that reads the rotation position corresponding to whether the current sign is positive or negative from the pattern storage unit based on the determination result of the line current measurement unit.

2. The regulator according to claim 1, wherein the fixed point detection unit detects a fixed point based on the current of the first phase among the currents supplied from the three-phase AC generator, and the line current measurement unit determines whether the current sign of the second phase current, which is different from the first phase, is positive or negative.

3. The regulator according to claim 1, wherein the fixed point detection unit detects a fixed point based on the relationship where the current of the first phase and the current of a second phase different from the first phase intersect among the currents supplied from the three-phase AC generator, and the line current measurement unit determines whether the current sign of the first phase or the second phase is positive or negative.

4. The regulator according to claim 3, comprising: a bridge circuit connected to the AC generator and generating DC power from AC power supplied from the AC generator; and a drive circuit that drives a plurality of switching elements provided in the bridge circuit according to the rotational position determined by the drive pattern determination unit, wherein the timing at which a fixed point based on the current of the first phase and the current of the second phase arrives is different from the timing at which the drive signal applied to the switching elements is switched.

5. The regulator according to claim 1, wherein the fixed point detection unit detects a fixed point based on the current of the first phase and the current of a second phase different from the first phase among the currents supplied from the three-phase AC generator, and the regulator has an estimation unit that estimates the current value of the third phase based on the current value of the first phase and the current value of the second phase, and the estimation unit determines whether the sign of the estimated third phase current is positive or negative.

6. The regulator according to claim 5, wherein the period from the timing when the fixed point arrives until the timing when the current sign of the third phase switches is longer than the period from the fixed point until the timing when the current sign switches, wherein the current value of either the first phase or the second phase.

Images