JP2008182879A - Field-winding motor and control circuit for field-winding generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control circuit for a field-winding motor which maximally suppresses power loss that causes circuit heat generation since energy is consumed in an inverter circuit as power loss while the generation of the energy continues due to effects by a field-winding inductance even after interruption of a field current in a field-winding motor. <P>SOLUTION: The control circuit for a field-winding motor is configured as circuitry which connects both ends of the field winding to each electrode of a field power supply via each switching element, and includes a discharge circuit at both ends of the field winding so that a current direction during discharge is the same as that during conduction and potential at both ends of the field winding is reverse to that during conduction while the circuit is active for discharge. In a 4WD configuration, the drive of a field winding for a generator is stopped when a rapid increase of a power-supply voltage is detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a circuit for controlling the field current of a field winding type motor, and in particular, reduces the influence of an overvoltage that occurs transiently immediately after the supply of field current is stopped, and uses both engine drive and motor drive in combination. The present invention relates to a method of controlling a rotating electrical device drive circuit with respect to sudden load fluctuations in a four-wheel drive configuration (for example, a front wheel is driven by an engine and a rear wheel is driven by a motor, hereinafter referred to as 4WD).

  In the field current control circuit of a field winding type motor, if the weak field current cannot flow properly due to a circuit failure during high-speed operation, the power supply voltage of the inverter circuit rises due to the induced voltage caused by the field winding. May exceed the pressure resistance of the parts. In such a case, as means for preventing deterioration of circuit components due to excessive breakdown voltage, conventionally, for example, as disclosed in Patent Document 1 below, when the power supply voltage of the inverter circuit exceeds a predetermined threshold, Stops energization of the field winding and simultaneously turns on the switching elements in the arms on either the upstream side of the inverter circuit (high potential side of the inverter power supply) or the downstream side (low potential side of the inverter power supply) ( ON), and an overvoltage prevention means for preventing an increase in the power supply voltage due to the induced voltage by short-circuiting the windings between the rotor phases of the field winding type motor, that is, the windings of the armature, has been known.

Alternatively, as described in Patent Document 2 below, when the inverter power supply voltage is in an overvoltage state, a resistor is connected between the high potential side and the low potential side of the inverter power supply, and the inverter is bypassed with this resistor. A configuration for performing circuit protection is disclosed. Further, Patent Document 3 discloses a vehicle driving force control device that utilizes the fact that, when an acceleration slip occurs in a drive wheel, a surplus torque generated by the acceleration slip is converted into electric energy by a generator. ing.
JP 2002-10694 A JP 2001-352664 A JP 2002-218605 A

  In the prior art, the energy generated between the time when the field winding of the field winding motor is stopped and the time when the field current value actually becomes zero is consumed by the switching element of the inverter circuit. By doing so, it is configured to prevent the influence of overvoltage. For this reason, it is necessary to increase the allowable power loss of the inverter device and to design a sufficient heat dissipation so that the concentrated power loss can be allowed when the overvoltage prevention means operates. As a result, there is a problem that the field winding type motor control circuit is increased in size and cost.

  Further, in the case of the 4WD configuration, the field winding type motor drive power source is obtained from a field winding type generator driven by an engine, and simultaneously with the stop of energization of the field winding of the field winding type motor, A transient overvoltage occurs in the field winding on the field winding generator side. Since this overvoltage is also applied to the inverter circuit, it is necessary to increase the allowable amount of power loss in the inverter circuit.

  The present invention suppresses damage to circuit components due to overvoltage that occurs transiently when the field current flowing through the field winding in such a field winding type motor and field winding type generator is interrupted, thereby reducing the size of the device. An object of the present invention is to provide a field winding motor and a field winding generator control circuit that can reduce the cost.

  In the field winding type motor control circuit, switching elements are connected in series to the upstream terminal and the downstream terminal of the field winding connected to the field power supply, respectively, and both sides of the field winding are connected. The terminal has a discharge means for discharging the electric field generated in the field winding in the same direction as the current direction at the time of energization, and by reversing the potential level on both sides of the field winding. It is configured to reduce the time of the transient phenomenon when the current is interrupted. Specifically, current is supplied to the field winding via a switching element such as a MOSFET so that the forward direction is from the low potential side of the field power supply to the high potential side terminal of the field winding. A discharge means is realized with a configuration in which the first diode is connected to the second diode and the second diode is connected in the forward direction from the low potential side terminal of the field winding toward the high potential side of the field power supply. This constitutes a control circuit for the field winding type motor.

  In addition, the field winding generator is driven by an engine that drives one axle of the vehicle, and the field winding motor that drives the other axle is driven by the output power of the field winding generator. In the case of the configuration, it is detected from both sides of the hardware detection and the monitoring result by the computer of the system control that the power supply voltage fluctuation of the motor drive system that occurs transiently due to the sudden change of the load such as the road surface condition is overvoltage The driving state of the generator field winding is controlled by this detection signal.

  In the field winding type motor control circuit, the current flowing from the field power source to the field winding is controlled by the field current control circuit. The field current is configured by having a discharge means for discharging the energy generated in the field winding in the same direction as the above-described current and reversing the electric potential at both ends of the field winding when interrupted. The control response is improved, and in particular, when the increase of the motor induced voltage due to a circuit failure or the like is suppressed, the response (discharge) time can be shortened, which is also effective in suppressing heat generation due to power loss or the like. This effect is also applied to the generator side, which can shorten the period of the overvoltage state in the 4WD configuration, can prevent damage due to prolonged exposure of high voltage and high temperature to electrical components, This will lead to a reduction in size and cost.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 18 is a circuit diagram in which the switching element is replaced with a MOSFET in order to clarify the correspondence relationship between the control circuit of the field winding motor disclosed as the prior art and the circuit of the present invention. is there.

  FIG. 18 shows a conventional control circuit for the field winding motor 5 as an example of a three-phase synchronous motor. In the field winding type motor 5, the rotor rotates so as to follow a rotating magnetic field generated by a three-phase current flowing in the stator winding. The rotor is provided with a field winding 13. Is configured to generate a magnetic flux corresponding to the field current If flowing in the. The control of the motor torque generates a desired torque by appropriately controlling the amount and phase angle of the three-phase current flowing through the stator winding or the amount of the field current If flowing through the field winding 13. .

  Here, in order to pass the field current If to the field winding 13, the power supplied from the field power supply 6 is supplied to the switching element 15 connected in series with the field winding 13 as a field current command. The desired field current If is obtained by turning on / off according to the drive signal of the circuit 16. More specifically, when the switching element 15 is turned on (ON), a circuit is formed in which current flows from the field power supply 6 through the field winding 13 to the field power supply 6 through the switching element 15. Further, the field current If increases according to the ratio of the time constant determined by the inductive component (inductance) of the field winding 13 and the circuit resistance, and reaches a predetermined current value.

  On the contrary, when the switching element 15 is cut off (OFF), the energy stored in the field winding 13 is released when a current flows through the diode 14. That is, the field current If gradually decreases mainly by the time constant determined mainly by the inductive component of the field winding 13 and the circuit resistance, and reaches the state where the field current is interrupted. The field current command circuit 16 obtains a required field current If by appropriately turning ON / OFF the switching element 15 or performing DUTY control (or PWM control) so that the target field current If is obtained. Yes.

  Further, when a field current If is applied to the field winding 13, an induced voltage is generated in a stator coil (not shown) as the rotor rotates. This induced voltage increases as the rotor speed increases and may exceed the voltage of the inverter power supply line 18 connected to an inverter power supply (not shown). In such a case, the three-phase current command circuit 17 It operates so as to suppress the induced voltage by flowing a field weakening current according to the number of rotations. However, when a field weakening current cannot be applied due to a circuit failure or the like, the induced voltage generated in the stator winding at the time of high rotation exceeds the voltage of the inverter power supply line 18 and further the breakdown voltage of the components used in the inverter circuit 4. Overvoltage may occur.

  In the prior art, in order to provide a means for suppressing an unnecessary induced voltage generated in such a case, the voltage in the inverter power supply line 18 is monitored, and if the predetermined voltage is exceeded, the field winding 13 is energized. While stopping, all the switching elements of the upper (upstream side) side or lower (downstream side) side arm of the inverter circuit 4 are turned on (ON) so that the three-phase winding (armature winding) of the motor 5 is turned on. The occurrence of overvoltage is suppressed by short-circuiting each other. However, according to such a conventional technique, as described above, even if the energization to the field winding 13 is stopped, the energy (charge) stored in the field winding is determined by the time constant including the inductance. The field current If decreases only gradually at a certain rate.

  For this reason, even when the inverter circuit 4 is performing the short-circuit operation, the generation of electric energy due to the rotation of the rotor continues for a while, and the amount of power loss in the inverter circuit 4 due to the short-circuit of the armature windings. And cause deterioration of components such as heat generation in the inverter circuit 4. Therefore, for the overvoltage prevention operation according to the prior art, it is necessary to design the allowable loss of the inverter circuit 4 to be sufficiently larger than the allowable loss required for normal motor control, and the heat dissipation path also sufficiently reduces the thermal resistance. It is necessary to keep it. For this reason, there has been a problem that it becomes an obstacle to downsizing and cost reduction of the apparatus.

  Therefore, in the present invention, the configuration described with reference to FIG. 1 or FIG. 4 can be used to quickly reduce the field current If, and more reliably perform the overvoltage suppressing operation with the minimum performance of the inverter circuit necessary for motor control. It is configured to be implemented quickly. That is, an inverter circuit for controlling a current supplied to the stator of the field winding type motor, a field power source for supplying a current to the field winding of the field winding type motor, and a field flowing through the field winding A field current control circuit for controlling the magnetic current, and this field current control circuit is configured to store energy (charge) stored in the field winding when the current being supplied to the field winding is interrupted. ) Is a current in the same direction as the above current, and has a discharging means for discharging by reversing the potential at both ends of the field winding. Hereinafter, a case where the embodiment of the present invention is applied to a drive motor for an electric vehicle will be described as an example.

(Embodiment 1)
FIG. 1 is a circuit diagram showing a first embodiment of the present invention, and FIGS. 2 and 3 are timing diagrams for explaining the operation thereof. In the first embodiment, in addition to the configuration including the conventional inverter circuit 4 shown in FIG. 15, a switching element 23 is provided on the upstream side (high potential side) of the field winding 13 as shown in FIG. The downstream side (low potential side) diode 11 is connected so as to be forward from the ground side of the field power source 6 toward the connection point between the upstream side switching element 23 of the field winding 13 and the field winding 13. Provide. Thus, the control of the field current If is controlled by the motor field current control circuit 20. As shown in FIG. 1, the motor field current control circuit 20 uses the field power supply 6 and the energy generated in the field winding 13 when the current flowing through the field winding is cut off. Discharging means for discharging in the same direction as the current of the field winding 13 and with the potentials at both ends of the field winding 13 reversed.

  Specifically, the discharging means includes an upstream switching element 23 provided between one terminal of the field winding 13 and the high potential side terminal of the field power supply 6, and the other of the field winding 13. And the downstream switching element 21 provided between the terminal of the field power supply 6 and the low potential side terminal of the field power supply 6 having the same potential as the ground. These switching elements are in an OFF (cut-off) state during discharge. is there.

  The circuit through which the discharge current flows is a downstream diode 11 provided in a forward direction from the ground toward a connection point between the field winding 13 and the upstream switching element 23, and the field winding. 13 and the downstream switching element 21, the upstream diode 14 provided in the forward direction toward the high potential side of the field power supply 6, the upstream switching element 23, and the downstream side It comprises a field current command circuit 16 for driving the switching element 21. Further, the field current command circuit 16 has a function of setting one of the upstream side switching element 23 and the downstream side switching element 21 to a continuous energization state and turning the other ON / OFF at a predetermined timing or performing DUTY control. Is.

The operation of the circuit of FIG. 1 will be described below with reference to the timing chart of FIG.
First, the operation in normal field current control will be described. In the field winding type motor 5, the field current If only needs to be energized in one direction. Therefore, in normal operation, the upstream side switching element 23 and the downstream side switching element 21 are turned on (ON), and the field winding 13 and the downstream side switching are passed from the field power source 6 via the upstream side switching element 23. By forming a circuit from the element 21 to the low potential side of the field power supply 6, the field current If can be passed through the field winding 13 (j section in FIG. 2).

  At this time, either one of the upstream side switching element 23 or the downstream side switching element 21 is subjected to ON / OFF control at a predetermined ratio, or DUTY control is performed, and the other switching element is turned ON. Thus, it is possible to control the current to a value lower than the current that flows when both the upstream switching element 23 and the downstream switching element 21 are continuously turned on simultaneously (ON) (FIG. 2). k section). Note that the j ′ section, k ′ section, and k ″ section in FIG. 2 (e) indicate current supply to the field winding 13 when each of the switching elements 23 or 21 is in a conductive state or a cut-off state. It shows the situation of transient change.

  In such a control mode, when the switching element performing the DUTY control (the upstream side switching element 23 in the case of FIG. 2) is cut off (OFF), the diode connected to the switching element The return current from the field winding is allowed to flow transiently. In this way, since a continuous current flows through the field winding 13 (FIG. 2 (e)), the duration of the OFF period of the DUTY control is mainly energized with the inductance of the field winding 13. If the time length determined by the time constant determined from the resistance of the circuit is set to be sufficiently shorter than the time length, it can be considered that a substantially constant current flows through the field winding 13 even during DUTY control. it can. The field current command circuit 16 performs the above-described series of DUTY control operations based on a request value for the field current If from a host system (or an external system) (not shown).

Next, a protection operation (hereinafter referred to as overvoltage protection) when the voltage in the inverter power supply line 18 rises in a state where field-weakening control is not performed by motor control will be described.
When the voltage in the inverter power supply line 18 is in an overvoltage state and exceeds a first threshold value Vth1 indicating that the field current If is suddenly reduced [time t _{1 in} FIG. The operation of both the side switching element 23 and the downstream side switching element 21 is stopped [time t ₁ in FIGS. 3C and 3D] and both are turned off (OFF) [time in FIG. 3A] t ₁ after].

  As a result, the field current If that was flowing in the field winding 13 at that time is that the downstream diode 11 and the upstream diode 14 are in a conductive state (ON), and these diodes, the field winding 13 and the field winding A circuit including the power supply 6 is configured and flows in the forward direction of the diode 11 and the diode 14. Therefore, the polarity of the voltage Vf at both ends of the field winding 13 is reversed. That is, during normal control, the field winding 13 has a polarity in which the upstream side switching element 23 is positive (high potential side) and the downstream side switching element 21 is negative (low potential side). 23 and the downstream switching element 21 are both cut off, and a circuit passing through the diode 11 and the diode 14 is formed to reverse the polarity.

In this way, the current direction is the same, and the potentials at both ends of the field winding 13 are opposite in polarity when energized, so that the switching element on one side is turned off (OFF) as described in the prior art. The time until the field current If becomes zero is shortened. [V section at the bottom of FIG. 3]. The voltage Vf continues to reverse positive and negative until the voltage on the power supply line 18 of the inverter 4 reaches an overvoltage state until the field current If reaches a value that can be regarded as 0 from [t _{1 in} FIG. [Lower section v section of FIG. 3 (f)].

  Further, the voltage of the inverter power supply line 18 exceeds the withstand voltage of the parts used in the inverter circuit 4 and peripheral circuits, and the switching elements of either the upper or lower arm of the inverter circuit 4 are turned on all at once. When the second threshold value (Vth2) is exceeded, the inverter command circuit 17 immediately stops the power generation operation of the generator 1 and stops the normal three-phase current control switching operation. All the switching elements of the lower arm are simultaneously turned on (ON).

  As a result, the three-phase wires of the motor 5 are short-circuited with each other, and are generated by the field winding 13 due to the inductance component of the winding of the motor 5, and the loss of the resistance of the switching element and circuit wiring of the inverter circuit 4. The energy caused by the induced voltage caused by the magnetic field generated and the induced current generated in the stator winding of the motor 5 is consumed. At this time, if the field current If described above is quickly stopped, the consumed power loss can be reduced, and the allowable loss can be reduced as compared with the prior art. Thereby, the specification regarding the performance improvement of the inverter circuit 4 and the heat dissipation structure is relaxed, and it becomes possible to prevent an increase in size and cost of the device accompanying the overvoltage protection operation.

  In addition, since the transient response time at the time of interrupting the current of the field winding can be shortened by adopting the configuration as shown in FIG. 1, the control response of the field current If in normal motor control is improved. Needless to say, in addition to the ON / OFF combinations for the upstream side switching element 23 and the downstream side switching element 21 described above, any ON / OFF combination is possible. For example, as shown in the section w of FIG. 3, only the downstream switching element 21 is subjected to DUTY control during the period in which both the upstream switching element 23 and the downstream switching element 21 are cut off (OFF) [FIG. (D)] During the period in which the downstream side switching element 21 is in the conducting state (ON), a circuit is formed by the downstream side switching element 15 → the field winding 13 → the downstream diode 11, and both ends of the field winding 13 are formed. The voltage Vf of can be made substantially zero although a potential difference corresponding to the voltage drop due to the diode remains.

  As a result, the field current If can be reduced more slowly than the current reduction rate when both the switching elements 23 and 21 are turned off (OFF). In the actual operation of the field current command circuit 16, the above-described arbitrary switching pattern may be selected in consideration of the situation of the system in which current increase / decrease is required and the restrictions of hardware and software. Further, in the first embodiment, since the power supply voltage fluctuation occurs due to the switching operation, an appropriate value determined by the allowable value of the power supply voltage fluctuation of other connected devices, the allowable amount of radiation noise, and the like. It is more preferable that a smoothing capacitor 9 having a large capacity is placed at the position shown in FIG.

(Embodiment 2)
Next, a second embodiment will be described. FIG. 4 is a circuit configuration diagram of the second embodiment, and FIG. 5 is a timing diagram for explaining the operation thereof. In the second embodiment as well, as in the first embodiment, an inverter circuit that controls a current to be supplied to the stator of the motor 5 is included. FIG. 4 shows a case where MOSFETs 10 and 15 are used as switching elements for the switching elements 23 and 21 in FIG. 1, respectively. In the second embodiment, as shown in FIG. 4, an inverter circuit 4 that controls a current to be supplied to the stator of the motor 5 and a field current control circuit that controls a current to be supplied to the field winding 13 of the motor. The field current control circuit 22 includes a field power source 6 that supplies power to the field winding 13, one terminal of the field winding 13, and a high potential side of the field power source 6. Between the upstream side switching element (MOSFET) 10 provided between the terminal and the other terminal of the field winding and the low potential side terminal of the field power source 6 having the same potential as the ground. A downstream switching element (MOSFET) 15; a downstream diode 11 provided in a forward direction from the ground toward a connection point between the field winding 13 and the upstream switching element 10; and a field winding. Line 13 and downstream switching element 15 Drive the upstream diode 14, the upstream switching element 10, and the downstream switching element 15 provided in the forward direction from the connection point to the high potential side power line 18 of the inverter circuit 4. The field power supply 6 is formed by the diodes 8 and 7 from both the inverter power supply line 18 and the field power supply 6, respectively. The field current command circuit 16 is configured to selectively operate, and the upstream side switching element 10 and the downstream side switching element 15 can be turned on / off at a predetermined timing or can be DUTY controlled. is there.

  That is, both power supplies of the field power supply 6 and the inverter power supply line 18 are connected by a diode OR by the diodes 7 and 8, and either the field power supply 6 or the inverter power supply line 18 is connected to the high voltage side. In this configuration, electric power is supplied to the field winding 13. As a result, the voltage of the power supply that can be used for supplying the field current If can be increased, and the control response time of the field current If can be further reduced as compared with the first embodiment.

  Furthermore, the upstream diode 14 connected to the high potential side of the field power supply 6 in the first embodiment is connected to the inverter power supply line 18 in the second embodiment. Thereby, the return current when the upstream MOSFET element 10 and the downstream MOSFET element 15 are simultaneously cut off (OFF) flows to the inverter power supply line 18 via the upstream diode 14, and smoothes the inverter circuit 4. The capacitor 3 is charged. The smoothing capacitor 3 of the inverter circuit 4 is normally a sufficiently large value as compared with the smoothing capacitor 9 on the field current control side, and therefore the voltage rise due to the return current is small. Therefore, it is possible to configure the capacitor 3 at a low cost without particularly increasing the capacity of the capacitor 3.

  In the second embodiment, the power supply to the field winding control circuit 22 for driving the field winding 13 is constituted by two OR-connected diodes 7 and 8, and the field winding as a load is provided. When energy is generated on the power supply side, no current flows toward the power supply 6 or the power supply line 18 side. Therefore, a rise in power supply voltage may not be negligible with a small-capacitance capacitor such as a power supply circuit on the field winding side. However, with the configuration of the second embodiment, the smoothing capacitor 3 having a sufficiently larger capacity than the capacitor 9 normally used in the field winding braking circuit 22 can be used. Therefore, it is possible to simultaneously improve the normal control response by the high voltage selection type power source and shorten the stop speed of the field current If.

  Further, in the second embodiment, during normal field current control, while the upstream MOSFET element 10 is performing DUTY control, the downstream MOSFET (switching) element 15 is always ON as shown in FIG. To do. Thereby, when the upstream side MOSFET element 10 is in a conductive state (ON) and the downstream side MOSFET element 15 is in a cut-off state (OFF), it is possible to prevent the return current from flowing into an unintended circuit.

  In the above two embodiments, the threshold voltage (Vth1) at which the field current starts to be reduced is different from the threshold voltage (Vth2) that makes all the switching elements of one arm in the inverter circuit 4 conductive. However, it is also possible to set the same voltage. In this case, it is possible to provide a larger margin between the normal operation voltage and the threshold voltage at which overvoltage protection is started. The degree is improved. In such a case, it goes without saying that the field current control response improvement technique according to the present invention is more effective.

In addition, it is possible to connect only a plurality of switching elements in either the upper or lower arm of the inverter circuit 4. As a result, it is possible not only to suppress an increase in the power supply voltage of the inverter circuit, but also to realize a rapid decrease in the field current according to the present invention, thereby burdening the inverter circuit 4 when performing a short-circuit operation. Therefore, it is possible to prevent the inverter circuit from having an excessively large allowable loss, and to simplify the heat dissipation structure. As a result, the apparatus can be reduced in size and cost.
(Embodiment 3)
As described above, overvoltage countermeasures in the inverter circuit for driving the motor can be implemented. In this configuration, the front wheel (or rear wheel) in the vehicle is used as the engine driving wheel, and the rear wheel (or front wheel) is used as the motor driving wheel. It is also possible to apply to the case of the 4WD configuration. FIG. 6 shows this basic configuration. The engine 30 drives the front axle and simultaneously drives the generator 1 serving as a driving power source for the motor 5 (where the term “motor” is simply referred to as a field winding type motor) by a belt. It has become. Here, when the accelerator is depressed, a signal for instructing the power generation of the generator 1 (the one that is simply referred to as a generator in the text indicates a field winding generator) is sent to an electronic control unit (ECU) 27 described later. Generated. As a result, the generated current of the generator 1 flows to the motor 5 as a motor current, and a driving force is generated on the rear axle simultaneously with the front axle by the engine. Here, forward and reverse are discriminated by a shift position switch (shift position SW) 39, and the polarity of the motor field current is changed. Further, the clutch 31 is assumed to be connected in advance, but when the 4WD switch (4WD · SW) 38 is OFF, that is, when 4WD is not required, the clutch 31 is in the disconnected state. In the case of such a 4WD configuration, the following problems may occur.

  That is, generally, a method of increasing the number of turns of the generator field winding is used as a means for improving the power generation function. However, as a result, the inductance of the generator field winding increases, which increases the time constant of the power generation control system, delays the control result, disrupts the balance between power generation and discharge, and causes a transient overvoltage state. May be. For this reason, although not shown in FIG. 6, it is necessary to strengthen the protection function of the inverter circuit for driving the motor at the time of overvoltage. Such a problem occurs when the road surface condition changes and the engine and motor loads change suddenly. For example, there is a discrepancy in the rotational speed between the front wheels and the rear wheels due to wheel locking or slipping, and as a result, the power generation amount of the generator 1 and the power consumption amount of the motor 5 are transiently unbalanced. To correct this, the current in the generator field winding is controlled. Due to the delay in the power generation control system, the DC voltage that is the inverter power supply cannot be suppressed suddenly and the DC voltage is excessively exceeded (overvoltage condition). As a result, the circuit component is damaged, or the fail-safe function for avoiding this damage is activated, and the motor control function is stopped or the output is restricted, resulting in a decrease in 4WD running performance.

  Further, even if the output of the generator 1 serving as the power source of the inverter circuit 4 for driving the motor 5 is detected to be in an overvoltage state, and even if the generator field drive circuit is stopped, the generator field winding The generator output gradually decreases due to an increase in inductance due to an increase in the number of turns. During this gradual decrease period, an excessive voltage is applied to the motor drive system such as an inverter although it is transient. For this reason, the motor 5 and the motor drive system and related circuits need to have a large margin for overvoltage, and accordingly, the scale of the protection circuit becomes large. Therefore, even if the component mounting property inside the inverter and the protection circuit for this purpose are externally mounted, a large installation space is required anyway, and the vehicle mounting property is deteriorated. Along with this, there is a problem that the cost of parts increases and it becomes impossible to provide an inexpensive control system. Conversely, as will be described later (FIGS. 14 and 15), when a sudden increase in the number of rotations of the motor occurs, that is, when a torque increase is required on the field winding type motor side, It becomes necessary to increase the output on the electric side. For this reason, the first point in the present invention is to control to stop, increase or decrease the field current of the field winding generator. Thus, in the third embodiment, unlike the first or second embodiment, the generator is driven by an engine that drives either the front axle or the rear axle of the vehicle, and the field winding type motor is In a 4WD configuration for driving the rear wheel or front wheel of a vehicle, the field winding of the field winding generator is connected in place of the field winding of the field winding motor shown in FIG. The field drive circuit is configured to control the output stop or increase / decrease of the field winding generator according to the fluctuation of the load. That is, the basic configuration of the third embodiment is that the field current of the field winding generator is controlled by the field drive circuit in accordance with the fluctuation of the load of the field winding motor. Here, as shown in FIG. 11, for the motor field winding, the motor field current value is detected by a current sensor and fed back to the motor control calculation unit 56 for controlling the rotation of the motor to drive the motor. After setting the conditions, the basic configuration is that the PWM unit 61 controls the rotation of the motor via a three-phase inverter circuit by DUTY control.

  FIG. 7 shows a configuration of an inverter system having a function of protecting the overvoltage as described above. In the third embodiment, the overvoltage detection circuit 24 detects whether or not the output of the generator 1 is in an overvoltage state, and when the overvoltage state is detected, the switching MOSFET 26 is turned on and the overvoltage is detected. At the same time as the extraction of energy due to the generator excess voltage via the protective resistor 25, the generator field winding drive is also stopped. In the case of the above description, power generation by the field winding generator 1 is interrupted. However, depending on the load condition of the field winding motor, it may be necessary to increase the power supply to the motor. For this reason, the output signal when the overvoltage detection circuit 24 detects the overvoltage state is input to the field drive circuit 32 of the field winding generator as the first field control signal. The operation of the field drive circuit 32 is controlled by stopping or increasing / decreasing the field current. Here, the overvoltage detection circuit 24 directly measures the DC voltage of the inverter power supply line 18 by hardware, or monitors it in software in a control computer.

  In other words, the present invention is characterized in that the output of the overvoltage detection circuit 24 not only performs an energy extraction operation based on the overvoltage, but also simultaneously controls the discharge process in the field drive circuit of the generator 1. . The field drive circuit 29 controls the stop or increase / decrease of the field current by a field control signal corresponding to the first and each control function. Thereby, the responsiveness of the generator 1 with respect to the rapid fluctuation | variation of a load can be improved, the rise time of the DC voltage which arises transiently by the responsiveness improvement part can be suppressed, and it is consumed with a load after all. Since electric power can be reduced, the drawing circuit 37 on the load side of the generator 1 can be small and light.

Hereinafter, each control function of the 4WD control, the motor control, and the power generation control will be described.
FIG. 8 shows a 4WD system configuration. In FIG. 8, the generator 1 output is connected to the inverter circuit 4 via a relay BOX 42 as a motor drive current. This relay BOX 42 is installed in the middle of the inverter power supply line 18, and ON / OFF is controlled by a relay current from the 4WD control unit 41. The output of the engine 30 is transmitted as the driving force of the front axle 43 and the generator 1, and the output of the motor 5 is transmitted as the driving force to the rear axle 44 through the clutch 31 after being decelerated at a predetermined rotation ratio by the speed reducer. . The operations of these components are controlled by a microcomputer built in the 4WD control unit 41.

  FIG. 9 shows a processing block diagram of the 4WD control function. The 4WD control function is basically composed of three parts: a “motor driving force target value calculation unit”, an “output unit”, and a “front wheel traction control control unit”. In the “motor driving force target value calculation unit”, the target value of the motor driving force is calculated from each parameter of the accelerator opening, the engine rotation speed, and the wheel speed of each wheel, and at the same time from the engine rotation speed and the wheel speed of each wheel. Control rear wheel traction control. In response to the calculation result, the “output unit” uses the motor rotation speed, the actual torque value, the DC voltage of the inverter power supply line 18, the output of the shift position sensor, etc. as parameters, and the motor torque command value, clutch control signal, and generator consumption. Torque is calculated, thereby outputting a motor torque command value and a current for clutch control. Furthermore, the generator consumption torque is calculated, and the engine torque demand command value and the transmission gear shift command value are set by the front wheel traction control control unit based on this result and the above-mentioned engine rotation speed and wheel speed. Set.

  Here, when the overvoltage detection circuit 24 in FIG. 7 reaches an overvoltage state, an overvoltage detection signal is sent to the output unit in FIG. 9, and after the overvoltage state is recognized by this output unit, the generator field cutoff signal is field driven. The signal is sent to the circuit 29 to stop its operation. Further, since it is necessary to stop the field drive circuit even when a failure occurs in the generator field drive system, the process for stopping the field drive circuit in the 4WD control function is summarized as shown in FIG. Will be executed. As described above, when the power supply voltage of the field winding type motor is in an overvoltage state, the electronic control unit 27 generates various control signals required when the vehicle travels, and when the overvoltage state occurs, A second field control signal for controlling the field current of the field winding generator is generated by the 4WD control function of the control unit, and the operation of the field drive circuit is controlled by the second field control signal. It is configured.

  10, (1) means for directly measuring in hardware either the generator 1 output or the DC voltage of the inverter power supply line 18 indicated by the overvoltage detection circuit 24 in FIG. 7 or (2) the ECU 27. An overvoltage condition was detected from the result of either or both of the means for softly monitoring an excess of the threshold voltage corresponding to the preset overvoltage in the system, and at the same time, the control system failed. It is determined whether or not the torque command value has become zero. When the torque command value becomes zero, it is determined that an overvoltage has occurred, a generator field drive circuit stop signal is sent, and the series of processing programs is terminated (RTS / Return To Subroutine).

  Next, the motor control function will be described. FIG. 11 shows a configuration of main parts of the motor 5 control function and the generator 1 control system. In FIG. 11, the output of the generator 1 driven by an engine (not shown) is rectified by the three-phase full-wave rectifier circuit 50, smoothed by the smoothing capacitor 3 through the inverter power supply line 18, and then in the inverter circuit 4. The motor 5 is driven after being converted into three-phase power for driving the motor. Control of the motor 5 uses the rotor rotation angle information detected by the resolver 55 to perform coordinate control on the dq axes in the motor control calculation unit 56 to perform current control for driving the motor 5, and further to the three-phase voltage. A general control method can be applied in which the PWM unit 61 performs PWM control of the motor 5 by re-conversion. Here, the voltage of the inverter power supply line 18 is monitored by software inside the microcomputer that performs arithmetic processing in the motor control calculation unit 56, although not shown in the figure, and when the voltage of the inverter power supply line 18 indicates an overvoltage state, motor field control is performed. The current of the field winding unit 46 (M field) including the motor drive circuit is cut off by the switch 58 formed of a MOSFET or the like using the output of the unit 57. As described above, when the power supply voltage of the field winding type motor becomes an overvoltage state, the field current of the field winding type generator is controlled by stopping or increasing / decreasing by the motor control function of the electronic control unit 27. The third field control signal is generated, and the operation of the field drive circuit is controlled by the third field control signal.

The field current of the motor 5 is supplied by a battery (V _M ) 48 and measured by a current sensor 59. Further, the output control of the motor 5 is performed by calculating the required electric energy as the product of the motor torque command value (abbreviated as torque command value in FIG. 11) obtained from the 4WD control unit (output unit in FIG. The required power amount is obtained in the unit 51, the power generation target value is obtained from the required power amount and the engine speed by the power generation limiter unit 52, the power generation target value is branched, and one power generation target value is supplied from the 4WD control system. The torque command value correction unit 60 performs correction, and the correction value is input to the motor control calculation unit 56 as a motor drive actual torque command value. The motor control calculation unit 56 calculates the motor control by including the resolver 55 output value and the motor field current value which is the output of the current sensor 59 in the motor drive actual torque command value and the motor speed. The result is subjected to pulse width modulation by the PWM unit 61, whereby the rotation of the motor 5 is controlled.

The power generation control function will be described with reference to the configuration of FIG. 11 since the third embodiment uses a common microcomputer for motor control and power generation control. The other one of the branched power generation target values is input to the generator field control unit 53, and in the generator field control unit 53, the branched power generation target value, the rotational speed of the generator 1 (the product of the engine speed and the pulley ratio). ) And the DC voltage (V _DC ) value in the inverter power supply line 18, the current of the generator field winding 131 is controlled at the same time as not shown in FIG. 11. Here, as an overvoltage protection measure, the overvoltage detection circuit 24 and the overvoltage protection circuit 37 shown in FIG. 7 are built in the field winding portion (G field) 54 of the generator in FIG. The overvoltage protection circuit 37 extracts the electrical energy stored in the generator output system at the time, but at the same time, the current path of the field winding circuit is controlled as described below to make a transient due to load fluctuations. This makes it possible to shorten the feedback in the overvoltage state.

  In FIG. 11, it is assumed that the motor control system and the generator control system use a common computer. However, the present invention is not limited to this, and each is configured using dedicated logic. There is no problem. As described above, when the power supply voltage of the field winding type motor becomes an overvoltage state, the power generation control function of the electronic control unit 27 controls the stop or increase / decrease of the field current of the field winding type generator. 4 field control signals are generated, and the operation of stopping or increasing / decreasing the field drive circuit current of the field winding generator is controlled by the fourth field control signal.

  In addition, with respect to the signal indicating the overvoltage state from the overvoltage detection circuit 24 described above, at least one control function of each control function in the electronic control unit generates the second and subsequent field control signals.

Hereinafter, the current path at the time of charging / discharging with respect to the generator field winding in the present invention will be described using the circuit in the second embodiment of the present invention shown in FIG.
12 and 13 show the path of the field current when the discharge current of the generator field winding 131 is reduced. Since these drawings are common, the path of the overvoltage protection circuit (extraction circuit) 37 by the resistor 25 is omitted. FIG. 12 shows a configuration in which the discharge current amount is controlled, and the reduction rate of the discharge current is controlled by driving the downstream MOSFET 15 on / off with a PWM signal. Here, the field current command circuit 16 shown in FIG. 18 is omitted for easy understanding of the current path, but generates a PWM signal for performing ON / OFF control of the switching element.

  In FIG. 12, when performing discharge current control, the upstream side MOSFET 10 is always OFF, and the downstream side MOSFET 15 is controlled by a PWM signal to control the average discharge current from the field winding 131 of the field winding generator. is doing. That is, when the PWM signal is turned OFF, the electrical energy stored in the generator field winding 131 passes through the upstream diode 14 (see FIG. 4) from one terminal of the generator field winding 131 to the diode. 8 is divided into two parts on the anode side, one is a loop (bold line / broken line) flowing from the capacitor 3 on the input side of the inverter circuit 4 to the other terminal of the generator field winding 131 via the ground system, and a diode 8 forms a loop which passes through the capacitor 9 in the forward direction and returns to the other terminal of the generator field winding 131.

  FIG. 13 shows the case of discharging so as to decrease rapidly, which corresponds to the case where the PWM signal in FIG. 12 is logic “0”. This is because the energy accumulated in the generator field winding 131 is consumed by the loss of the field winding and wiring resistance, and the energy in the field winding 131 is transferred to the smoothing capacitors 3 and 9. It is configured to reduce energy rapidly by pulling out. With this configuration, it has been obtained that the field current can be reduced from 6 A to 0 A in the order of several ms, whereby the generator output current is also rapidly attenuated, and the inductance and resistance 25 of the generator field winding 131 are reduced. There is also a trial calculation result that the time constant of the generator output system including the one that was about 300 ms when the present invention is not applied can be reduced to 50 to 100 ms or less by the application of the present invention. In the above, the generator field current is measured by the current sensor 62.

  The above is a description of the case where the electric energy accumulated in the generator output system is extracted. Increase or rapid increase. In this case, it is performed as follows. That is, in FIG. 14, when electric energy is injected into the generator output system, the downstream MOSFET 15 is always turned on, and the upstream MOSFET 10 is controlled by the PWM signal. When the PWM signal is logic “1”, both the upstream side MOSFET 10 and the downstream side MOSFET 15 are in the ON state. Therefore, the generator field winding 131 is directly connected to the battery 6 which is the power source for driving the generator field winding. When the current flows in the field winding 131 and the PWM signal is logic “0”, the upstream MOSFET 10 is in the OFF state and the downstream MOSFET 15 is in the ON state, so there is no power supply from the battery 6. The energy in the generator field winding circulates in a closed loop (closed loop shown by a broken line in FIG. 14) including the generator field winding 131 and the downstream MOSFET 15 to be in a discharge state. It attenuates at.

  Further, in order to rapidly energize the generator field winding 131, as shown in FIG. 14, the generator field winding 131 may be directly connected to the battery 6 serving as a power source. The path indicated by the solid line arrow in FIG. 15, that is, both the upstream and downstream MOSFETs 10 and 15 may be turned on.

  In FIG. 7, when the overvoltage detection circuit 24 detects that the DC voltage of the inverter power supply line 18 has risen to an overvoltage state, the operation of each control function in the ECU 27 is stopped. The supply of the field current is stopped, and at the same time, the MOSFET 26 is turned on, and the energy stored in the generator output system is extracted via the resistor 25.

FIG. 16 compares the discharge characteristic (c) of the third embodiment with that of the conventional example (a) and the case of the conventional semi-H bridge configuration (b). The horizontal axis represents the time axis, and the vertical axis represents the generator field. The change of the DC discharge current discharged from the magnetic winding is shown. Here, as the time axis origin, an overvoltage occurrence is detected by the overvoltage detection circuit 24 due to a sudden change in the road surface state, that is, the DC voltage of the generator 1 output exceeds a predetermined threshold voltage, and the generator field drive circuit 29 is the time when the operation was stopped. That, MOSFET 26 is a reference time _{t d} to ON and the resistor 25 is the time axis origin point of a connected state.

  A curve (a) in FIG. 16 is a conventional example, and shows a transient discharge current change that is attenuated only by a loss due to resistance in the field winding itself and the discharge current path. Curve (b) shows a case of a generator field drive circuit having a conventional semi-H bridge configuration. A generator field winding, a loss due to resistance in a discharge current path, and a smoothing capacitor 9 with a built-in field winding drive circuit are shown. The case where the power consumption by charging is performed is shown. A curve (c) shows the case of the configuration according to the third embodiment. The loss due to the resistance in the generator field winding and the discharge path, the smoothing capacitor 9 of the generator drive circuit 29, and the inverter circuit 4 for driving the motor. Discharge is performed through charging of the smoothing capacitor 3 connected to the power input side of the.

FIG. 17 illustrates this situation, and it is assumed that the electric power initially required by the motor 5 is given by a curve m1 indicated by a broken line, and the operating point at this time is the isomagnetic field of the generator 1 indicated by a solid curve n1. It is assumed that it is at the intersection a with the output characteristic curve. Now, when the road surface condition changes suddenly and the electric power required by the motor is suddenly reduced due to, for example, wheel lock or wheel slip, the power control is delayed if the time constant of the generator field winding drive system is large. At this time, the operating point at the point a tries to move to the curve n2 (black arrow A), but if the time constant of the power source is large, it cannot immediately move to the intersection b with the curve m2 (black arrow B). Then, it moves in the direction of the hollow arrow along the curve n1 and moves to the intersection c with the curve m2, and at this time, the output voltage may exceed the overvoltage detection threshold _Vth . If the operating point can be moved quickly, in other words, if the transient voltage rise can be discharged at high speed, power generation control can be performed without exceeding the overvoltage detection threshold _Vth .

  According to the third embodiment, since the discharge time of the electric energy accumulated in the generator output system can be shortened, the burden due to the overvoltage on the circuit components at the time of discharge is reduced. As a result, the amount of energy absorbed is reduced and the temperature rise can be suppressed, so that the conditions for the thermal design of the circuit components and the circuit are relaxed.

FIG. 3 is a circuit configuration diagram according to the first embodiment. FIG. 3 is a timing chart in the first embodiment. FIG. 3 is a timing chart in the first embodiment. FIG. 4 is a circuit configuration diagram of a second embodiment. FIG. 6 is a timing chart in the second embodiment. The basic block diagram of 4WD vehicle electric system. The system block diagram of the inverter with an overvoltage protection apparatus. FIG. 6 is a circuit configuration diagram according to a third embodiment. The processing block diagram of 4WD control system. The flowchart of the electric field drive circuit stop process by overvoltage detection. The processing system figure of a motor control system and a generator control system. The current path figure at the time of the discharge control by PWM in a generator field circuit. The current path figure at the time of rapid discharge in a generator field circuit. Current path diagram when the generator field current increases. The current path figure at the time of the rapid increase of a generator field current. Comparison chart of energy loss during power generation. The comparison figure of the generated voltage with respect to the sudden reduction of motor electric power demand. The circuit diagram of the motor control system by a prior art.

Explanation of symbols

1: Generator 2: Rectifier 3: Smoothing capacitor 4: Inverter circuit 5: Field winding motor 6: Field power supply 9: Smoothing capacitor 10: Upstream MOSFET element 11: Diode 13: Field winding 14: Diode 15: Downstream MOSFET element 16: Field current command circuit 17: Three-phase current command circuit 18: Inverter power line 20: Motor field current control circuit 21: Downstream switching element 22: Motor field current control circuit 23: Upstream Side switching element 24: overvoltage detection circuit 25: resistor 26: MOSFET
27: Electronic control unit (ECU) 29: Field winding drive circuit 30: Engine 31: Clutch unit 32: Generator field drive circuit 36: Field current control circuit 131: Generator field winding 38: 4WD switch 39: Shift position switch 40: Warning lamp 41: 4WD control unit 42: Relay BOX
43: Front axle 44: Rear axle 45: Accelerator opening sensor 46: Motor field winding 47: Current sensor 48: Battery 50: Three-phase full-wave rectifier circuit 51: Required power amount calculation unit 52: Power generation amount limiter unit 53 : Generator field control unit 54: Generator field winding unit 55: Resolver 56: Motor control calculation unit 57: Motor field control unit 58: Switch 59: Current sensor 60: Torque command value correction unit 61: PWM unit 62: Generator Field current sensor

Claims (15)

In the control circuit of the field winding type motor,
An inverter circuit for controlling a current supplied to the stator of the motor;
A field power supply for energizing the field winding of the motor, and a field current control circuit for controlling the field current flowing in the field winding,
The field current control circuit is configured to transmit energy generated in the field winding in the same direction as the current of the field winding and the field winding when the current being supplied to the field winding is interrupted. A control circuit for a field winding motor, characterized by having discharge means for discharging electric potential by reversing the electric potential at both ends of the wire. In the control circuit of the field winding type motor,
An inverter circuit for controlling a current to be supplied to the stator of the motor, and a field current control circuit for controlling a current to be supplied to a field winding of the motor,
The field current control circuit includes a field power supply for supplying power to the field winding,
An upstream switching element provided between one terminal of the field winding and a high potential side terminal of the field power supply;
A downstream switching element provided between the other terminal of the field winding and the low potential side terminal of the field power supply having the same potential as the ground;
From the ground, a downstream diode provided in a forward direction toward a connection point between the field winding and the upstream switching element,
From the connection point of the field winding and the downstream switching element, an upstream diode provided to be in a forward direction toward the high potential side of the field power supply,
It is composed of a field current command circuit for driving the upstream switching element and the downstream switching element,
The field current command circuit is characterized in that either the upstream side switching element or the downstream side switching element is in a continuous energization state and the other is in a conduction / cutoff state at a predetermined timing, or DUTY-controlled. A control circuit for a field winding motor. In the control circuit of the field winding type motor,
An inverter circuit for controlling a current to be supplied to the stator of the motor, and a field current control circuit for controlling a current to be supplied to a field winding of the motor,
The field current control circuit includes a field power supply for supplying power to the field winding,
The upstream switching element provided between one terminal of the field winding and the high potential side terminal of the field power supply, and the other terminal of the field winding and the ground have the same potential A downstream switching element provided between the low-potential side terminal of the field power supply;
From the ground, a downstream diode provided in a forward direction toward a connection point between the field winding and the upstream switching element,
From the connection point between the field winding and the downstream switching element, an upstream diode provided so as to be in the forward direction toward the high potential power supply line of the inverter circuit;
It is composed of a field current command circuit for driving the upstream switching element and the downstream switching element,
A power supply for supplying current to the field winding is configured to select a higher voltage from the power supply line of the inverter circuit and the field power supply via a wired OR circuit using a diode, and the field current The command circuit sets the upstream side switching element and the downstream side switching element to a conductive / shut-off state at a predetermined timing, or performs a DUTY control. In the control circuit of the field winding type motor according to claim 3,
The field current command circuit controls the downstream switching element to maintain a conductive state when the upstream switching element is DUTY controlled. . In the control circuit of the field winding type motor according to claim 3 or 4,
A power supply line of the inverter circuit includes a smoothing capacitor having a capacity large enough to absorb a voltage rise in a smoothing capacitor connected to the field power supply side. Control circuit. In the field winding type motor control circuit according to any one of claims 2 to 5,
The field current command circuit is configured to turn off both the upstream switching element and the downstream switching element when the voltage of the inverter power supply exceeds a predetermined voltage. Motor control circuit. In the control circuit of the field winding type motor according to claim 6,
When the voltage of the inverter power supply line exceeds a predetermined voltage value, a plurality of switching elements are temporally overlapped on either side of the upper arm or the lower arm of the inverter circuit to be in a conductive state. A control circuit for a field winding type motor, characterized by short-circuiting a stator conducting wire of the field winding type motor. In the field winding type motor control circuit according to any one of claims 2 to 5,
The first threshold voltage for connecting a plurality of switching elements in the upper or lower arm of the inverter circuit and the second threshold voltage for starting reduction of the field current are set to the same voltage. Control circuit for field winding motor. A field winding generator driven by an engine that drives either the front axle or the rear axle, and power is supplied by the output of the field winding generator, and the other axle is driven. In a control circuit for a field winding generator of a vehicle having a 4WD configuration having a field winding motor that
A field winding generator comprising a field drive circuit for controlling a field current flowing in a field winding of the field winding generator according to a change in a load of the field winding motor. Control circuit. In the control circuit of the field winding generator according to claim 9,
An overvoltage detection circuit that detects that a power supply voltage of an inverter that drives the field winding type motor exceeds a predetermined allowable voltage in accordance with a change in a load of the field winding type motor; An output signal when the overvoltage detection circuit detects an overvoltage state is input as a first field control signal to the field drive circuit of the field winding generator to control the operation of the field drive circuit. Control circuit for field winding generator. In the control circuit of the field winding generator according to claim 9 or 10,
An overvoltage protection circuit that bypasses the output of the field winding generator to a ground potential via a resistor in response to a signal that the overvoltage detection circuit detects an overvoltage state; and A first field control signal for controlling a field current flowing in the field winding; and a field drive circuit for the field winding generator, and an electronic control unit for setting a vehicle running condition. Have
The electronic control unit generates various control signals required when the vehicle travels, and the field current of the field winding generator is generated by a 4WD control function of the electronic control unit when the overvoltage state occurs. A field winding type generator control circuit, characterized in that a second field control signal for controlling the field drive signal is generated and the operation of the field drive circuit is controlled by the second field control signal. In the control circuit of the field winding generator according to claim 9 or 10,
An overvoltage protection circuit that bypasses the output of the field winding generator to a ground potential via a resistor in response to a signal that the overvoltage detection circuit detects an overvoltage state; and A first field control signal for controlling a field current flowing in the winding; and a field drive circuit for the field winding generator; and an electronic control unit for setting a vehicle running condition. And
The electronic control unit generates various control signals required when the vehicle travels, and the field winding of the field winding generator is generated by a motor control function of the electronic control unit when the overvoltage state occurs. Field winding type power generation characterized in that a third field control signal for controlling a field current flowing in the wire is generated, and the operation of the field drive circuit is controlled by the third field control signal. Machine control circuit. In the control circuit of the field winding generator according to claim 9 or 10,
An overvoltage protection circuit that bypasses the output of the field winding generator to a ground potential via a resistor in response to a signal that the overvoltage detection circuit detects an overvoltage state; and A first field control signal for controlling a field current flowing in the field winding; and a field drive circuit for the field winding generator, and an electronic control unit for setting a vehicle running condition. Have
The electronic control unit generates various control signals required when the vehicle travels, and the field current of the field winding generator is generated by the power generation control function of the electronic control unit when the overvoltage state occurs. A field winding generator control circuit, characterized in that a fourth field control signal for controlling the field drive signal is generated and the operation of the field drive circuit is controlled by the fourth field control signal. In the control circuit of the field winding generator according to any one of claims 11 to 13,
A control circuit for a field winding generator, wherein operation of a field drive circuit is controlled by a combination of at least any two of the second to fourth field control signals. In the control circuit of the field winding generator according to any one of claims 9 to 14,
The overvoltage detection circuit;
The overvoltage protection circuit,
A field winding power source that supplies power to the field winding of the field winding generator and has a smoothing capacitor connected to the output end thereof;
The upstream side switching element connected between one terminal of the field winding and the high potential side terminal of the field winding power supply, and the other terminal of the field winding and the ground potential A downstream switching element connected between a low potential side terminal of the field winding power supply and the ground to a connection point between the one terminal of the field winding and the upstream switching element. From the connection point between the downstream diode provided in the forward direction and the other terminal of the field winding and the downstream switching element, the power supply for the field winding is directed to the high potential side. A field winding type generator composed of an upstream diode provided in the forward direction, a field current command circuit for driving the upstream switching element, and the downstream switching element. Field current control circuit
The field current command circuit uses the two or more of the first field control signal from the overvoltage detection circuit and the second to fourth field control signals from the electronic control unit to perform the upstream side and the downstream side. A control circuit for a field winding generator, which generates a control signal for controlling a switching element.

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