JP2002153094A - Field winding-type electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a field winding-type electric rotating machine wherein overvoltage is favorably prevented. SOLUTION: Alternating-current voltage outputted from an inverter circuit 3 is rectified and supplied to a field winding 9. If the generated voltage of the field winding-type electric rotating machine 2 becomes too high, the lower arm portion 32 of the inverter circuit 3 is short-circuited to prevent the generated power of the field winding-type electric rotating machine 2 from being outputted through the upper arm portion 31 of the inverter circuit 3. At the same time, supply of field current to the field winding 9 is suppressed by the short-circuiting of the lower arm portion 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a field winding type rotary electric machine.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional field winding type rotary electric machine.

[0003] 1 is a high-voltage main battery, 2 is a field winding type three-phase synchronous machine adopting, for example, a Landel pole type, 3 is a three-phase inverter, 5 is a switching element for interrupting field current, and 6 is a field magnet. A current control unit, 7 is a low-voltage auxiliary battery, 8 is a controller for intermittently controlling each switching element of the three-phase inverter 3, 9 is a field winding of the three-phase synchronous machine 2, 10 is a flywheel diode, and 11 is a smoothing wheel. Capacitor 12 is a low voltage electrical load. Switching element 5
Controls intermittently the field current supplied from the auxiliary battery 7 through the field winding 9 based on the control voltage of the field current control unit 6.

In this field winding type rotary electric machine, the three-phase synchronous machine can be operated not only by the power generation operation but also by the switching control of the inverter 3, so that it can be operated as a generator motor. In this case, in addition to power generation, engine start and torque assist can be performed.

In FIG. 2, power is supplied to the field current controller 6 from the auxiliary battery 7, but the main battery 1 may be omitted, and power may be exchanged between the inverter 3 and the auxiliary battery 7. Of course.

[0006]

However, in the above-described conventional field winding type rotary electric machine, the three-phase synchronous machine is used when the ground winding of the field winding 9 or the field current control is malfunctioning and at high speed rotation. 2 has a problem of generating an excessive power generation voltage.

Further, even if the switching element 5 for controlling the field current can be cut off, the large magnetic energy stored in the field winding is connected in antiparallel to the field winding as the field current. There is also a problem that it is difficult to immediately cut off or reduce the field current because it continues to flow through the field winding through the flywheel diode.

Although it is conceivable to restrict overvoltage output from the inverter unit by shutting off each switching element constituting the inverter unit interposed between the rotating electric machine and the DC power supply, Has flywheel diodes in anti-parallel with these switching elements, and this overvoltage generated in the armature winding of the rotating electric machine is applied to the DC power supply through these flywheel diodes and cannot be blocked by the inverter unit.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a field winding type rotary electric machine device capable of effectively preventing overvoltage.

[0010]

According to a first aspect of the present invention, there is provided a field winding type rotary electric machine including a field winding type rotary electric machine having a field winding, an upper arm and a lower arm each including a plurality of switching elements. An inverter circuit having an arm to exchange AC power with an armature winding of the field winding type rotating electric machine; a switching element for controlling a field current connected in series with the field winding; In a field winding type rotary electric machine device including a winding and a field current supply unit that supplies power to the switching element, and a field current control unit that controls the switching element intermittently, between a pair of DC terminals of the inverter circuit. When the voltage exceeds a predetermined value, the inverter circuit has lower arm short-circuit command means for short-circuiting a plurality of switching elements on the lower arm side, and the field current feed unit includes the inverter circuit and the inverter circuit. It is characterized in that it consists of rectifying circuit for rectifying the AC power fed from the connection point between the serial armature winding.

That is, in the present configuration, the AC voltage output from the inverter circuit is rectified and supplied to the field winding, and when the generated voltage of the field winding type rotating electric machine becomes excessive, the lower arm portion of the inverter circuit is used. To prevent the power generated by the field winding type rotating electric machine from being output through the upper arm portion of the inverter circuit, and to prevent the field current from being supplied to the field winding by short-circuiting the lower arm portion. Therefore, it is possible to reduce the generated voltage of the three-phase synchronous machine.

That is, in the present invention, the lower arm portion of the inverter circuit is short-circuited, so that the generated power can be converted to heat and the generated voltage can be reduced by reducing the field current at the same time. It is possible to prevent the excessive power generation voltage from damaging an external battery or the like. In particular, the present invention is effective for an interruption failure of a switching element for intermittent control of field current.

According to a second aspect of the present invention, in the field winding type rotary electric machine according to the first aspect, the field current supply power supply circuit has an anode electrode connected to the connection point of each phase. Consists of a diode half bridge. Thereby, the rectifier circuit can be simplified.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described with reference to the following examples.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a field winding type rotary electric machine of this embodiment used for a vehicular generator motor will be described with reference to FIG.

(Circuit configuration) 1 is a high-voltage main battery,
Reference numeral 2 denotes a field winding type three-phase synchronous machine adopting a Landel pole type, 3 denotes a three-phase inverter, 4 denotes a diode half bridge, 5 denotes a switching element for interrupting and interrupting a field current, 6 denotes a field current control unit, 7 Is a low-voltage auxiliary battery, 8 is a controller for intermittently controlling each switching element of the three-phase inverter 3, 9 is a field winding of the three-phase synchronous machine 2, 10 is a flywheel diode, 11 is a smoothing capacitor, and 12 is a low voltage. An electric load 13 is a smoothing capacitor. Smoothing capacitor 1
3 may be omitted.

The inverter circuit 3 is a three-phase inverter circuit using six pairs of NMOS transistors and diodes connected in parallel, and includes an upper arm 31 and a lower arm 32.
Consists of 33 and 34 are DC terminals of the inverter circuit 3,
35 to 37 are AC terminals of the three-phase inverter circuit.
Since the inverter circuit 3 is well known, further description will be omitted.

The diode half bridge 4 has an anode electrode connected to the AC terminals 35 to 37 of the inverter circuit 3 and a cathode electrode connected to the high-order end of the field winding 9.
Consisting of two diodes.

The switching element 5 is connected in series with the field winding 9, the flywheel diode 10 is connected in parallel with the field winding 9, and the field current control unit 6 is supplied with power from the auxiliary battery 7 and Is controlling.

The field current controller 6 includes transistors 60 to
62, a constant voltage diode 63, and resistors 64-67. The resistors 64 and 65 are connected in series to form a resistor voltage dividing circuit, and divide the voltage of the main battery 1 supplied through the transistor 60. This voltage division is applied to the base electrode of the transistor 62 through the connection point between the constant voltage diode 63 and the resistor 66, and the transistor 62 controls the base electrode potential of the switching element 5. The base electrode of the switching element 5 is supplied with power from the auxiliary battery 7 through the transistor 61 and the resistor 67. The intermittent control of the field current by the field current control unit 6 and the switching element 5 is essentially the same as that of a conventional vehicle alternator (alternator).

(Engine Start Operation) The engine start operation of the three-phase synchronous machine 2 will be described first.

First, when an ignition switch (not shown) is turned on, the controller 8 turns on the transistor 61 and operates the inverter circuit 3 at the maximum duty ratio. The controller 8 keeps the transistor 60 off.

Thus, the inverter circuit 3 applies the three-phase AC voltage having the maximum amplitude to the armature winding of the three-phase synchronous machine 2,
The diode half bridge 4 rectifies the three-phase AC voltage output from the AC terminals 35 to 37 of the inverter circuit 3 and applies the rectified three-phase AC voltage to the high-order terminal of the field winding 9.

Since the transistor 60 is off and the transistor 61 is on, the transistor 62 is off regardless of the potential state of the main battery 1, and the switching element 5 is always on.

Thus, the three-phase synchronous machine 2 starts an engine (not shown) with the maximum torque. The three-phase synchronous machine 2 has a rotational position sensor (not shown) for detecting the rotational angle position of the rotor similarly to the ordinary three-phase synchronous machine, and the controller 8 controls the rotational angular position of the rotor detected by the rotational position sensor. To control the on / off of the six transistors of the inverter circuit 3 on the basis of.

The transistor 60 is connected to the transistor 6
It may be turned on simultaneously with 1. When the engine is started, the terminal voltage of the main battery 1 is sufficiently low and the transistor 6
Since the switching element 5 is hardly turned on when the switching element 2 is turned on, the same maximum torque engine starting operation as when the transistor 60 is turned off can be performed.

(Generation Operation) When the engine starts and the generated voltage of the three-phase synchronous machine 2 increases, the controller 2 changes the three-phase AC voltage output from the inverter circuit 3 from the electric phase range (maximum torque) to the power generation phase range. Change the controller 6
0 turns on the transistor 60. Thereby, only when the divided voltage of the terminal voltage of the main battery 1 exceeds the threshold voltage of the constant voltage diode 63, the transistor 62 is turned on to turn off the switching element 5, and the divided voltage of the terminal voltage of the main battery 1 is divided. Is converged to the threshold voltage of the constant voltage diode 63.

It is naturally possible to control the generated voltage by controlling the phase of the inverter circuit 3. For example,
At the time of regenerative braking, the transistor 60 is turned off and the switching element 5 is always turned on, so that a required amount of power generation (regenerative braking) torque can be generated by controlling the phase of the three-phase AC voltage output from the inverter circuit 3. However, in order to avoid overcharging of the engine, the controller 8 needs to stop the power generation by turning on the transistor 60 or controlling the phase when the terminal voltage of the main battery 1 reaches a predetermined value.

(Torque assist operation) At the time of large acceleration or uphill, the controller 2 changes the three-phase AC voltage output from the inverter circuit 3 from the power generation phase range to the motorized phase range, turns off the transistor 60, and turns off the motorized phase. The required electric torque is generated by performing phase control within the range.

(Lower Arm Short-Circuit Operation) In the above-described power generation operation, a protection operation when the generated voltage becomes excessive will be described below.

Reference numeral 14 denotes a comparator, which includes resistors 64 and 6
The controller 5 compares the divided voltage of the main battery 1 output from the connection point 5 with a predetermined reference voltage Vref, and outputs the comparison result to the controller 8. When the divided voltage of the main battery 1 exceeds the predetermined reference voltage Vref, the controller 8 immediately changes the potential of the AC terminals 35 to 37 of the inverter circuit 3 to three NMOS transistors forming the lower arm 32 of the inverter circuit 3. Drop and turn on all.

As a result, the inverter circuit 3 does not output an excessively high power generation voltage to the main battery 1, and furthermore, the field current supplied to the field winding 9 through the diode half bridge 4 is blocked. The generated voltage can be suppressed well.

(Modification 1) In the above embodiment, the inverter circuit 3 was normally operated prior to the application of the field current to enable the power supply to the field winding 9 when the engine was started.
Since the inductance of the field winding 9 is large and it takes time for the field current to reach a predetermined value, the three NMOSs in the upper arm of the inverter circuit 3 are first used when starting the engine.
Turning on all the transistors, turning off all three transistors in the lower arm, turning off the transistor 60 (the transistor 60 can be omitted), a large field current is passed through each diode of the diode half bridge 4. A current is applied to the field winding 9 to quickly raise the field current.
The OS transistor may be normally intermittently controlled to generate a three-phase AC voltage.

(Modification 2) The comparator 14 can be replaced with a circuit having the same configuration as the constant voltage diode 63 and the resistor 66. However, the threshold voltage Vref of the constant voltage diode needs to be set higher than that of the constant voltage diode 63.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a field winding type rotary electric machine according to an embodiment.

FIG. 2 is a circuit diagram of a conventional field winding type rotary electric machine device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main battery 2 Three-phase synchronous machine (field winding type rotary electric machine) 3 Three-phase inverter circuit (inverter circuit) 4 Diode half bridge (rectifier circuit, field current feed part) 5 Switching element 6 Field current control part 7 Supplement Machine battery 8 controller 9 field winding 14 comparator (lower arm short-circuit command means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H115 PA08 PC06 PG04 PI16 PI29 PI30 PO02 PO06 PO17 PU10 PU25 PV09 QE04 QE08 QE10 QI04 SE04 SE10 TO13 TR04 TU05 TU16 5H590 AB04 CA07 CA23 CC01 CC18 CC24 CC28 CD01 CD03 CE05 EA01 EA05 EA05 FA06 FA08 FB01 FB03 FB05 FC12 FC17 FC21 FC22 HA02 HA11 HB06 JB09

Claims (2)

[Claims] 1. A field winding type rotary electric machine having a field winding, and an armature winding of the field winding type rotary electric machine having an upper arm and a lower arm each including a plurality of switching elements. An inverter circuit for transmitting and receiving AC power; a switching element for controlling a field current connected in series with the field winding; a field current supply unit for supplying power to the field winding and the switching element; And a field current control unit that controls the intermittent operation of the elements. In the field winding type rotary electric machine device, when a voltage between a pair of DC terminals of the inverter circuit exceeds a predetermined value, a plurality of lower arm sides of the inverter circuit are provided. And a lower-arm short-circuit instructing means for short-circuiting the switching element. The field current feeder regulates AC power fed from a connection point between the inverter circuit and the armature winding. A field winding type rotary electric machine device comprising a flowing rectifier circuit. 2. The field winding type rotary electric machine device according to claim 1, wherein said power supply circuit for supplying field current comprises a diode half bridge having an anode electrode connected to said connection point of each phase. Field winding type rotary electric machine device.