JP4369500B2 - Rotating electrical machine equipment - Google Patents

Description

  The present invention mainly relates to a rotating electrical machine apparatus mounted on a vehicle, and particularly relates to stop control of a switching element of a power converter.

  In the rotating electrical machine apparatus, a large current flows through the armature winding during the power running operation, and when the power running operation is stopped, it is necessary to cut off the large current, and thus a large surge voltage is generated. For this reason, for example, in Patent Document 1, not all switching elements are turned off simultaneously by a stop command, but the surge voltage is generated by extending each switching element after turning it off until the timing (rotation position) at which it is originally turned off. Can be reduced. However, in the method of Patent Document 1, when the rotating electrical machine is low-speed or locked, the current flowing through the armature winding is limited only by the armature DC resistance component, There is a case where the generation of the induced current is small, and when a large current is cut off, the surge voltage may increase.

Japanese Patent Application No. 2005-366673 Specification

In general, when the current of a circuit through which a large current flows is sharply interrupted, a large surge voltage is generated, and the switching element breaks down withstand voltage. For this reason, the switching speed is usually adjusted so that the surge voltage can be reduced. However, if the switching speed is slowed, the switching loss in the switching element increases, and the switching element is overheated.
The present invention has been made in view of the above-described problems, and an object of the present invention is to obtain a rotating electrical machine apparatus that reduces a surge voltage when a current is interrupted.

  A rotating electrical machine apparatus according to the present invention includes a rotating electrical machine having a multi-phase armature winding, and an armature winding through a switching element of a first arm from a positive terminal of a power source for each phase of the armature winding. A power conversion unit connected to each phase of the armature winding from the armature winding through the switching element of the second arm to the negative terminal of the power supply, and the power conversion during the power running operation of the rotating electrical machine A gate control unit that controls a gate of each switching element of the unit and applies a rectangular wave voltage to the armature winding of the rotating electrical machine, and the gate control unit receives a stop command so as to stop the power running operation In order to cut off the current of the armature winding, the switching element on the arm side in which a plurality of phases are turned on in any one of the switching elements of the first and second arms is simultaneously turned off, and the current path The After switching off, the switching element of the opposite arm is turned off.

  According to the rotating electrical machine apparatus of the present invention, when the stop command is input to the gate control unit so as to stop the power running operation and the current interruption of the armature winding is performed, the switching elements of the first and second arms Since the switching element on the opposite arm is turned off after simultaneously turning off the switching element on the arm side where multiple phases are turned on in any of the above, the surge voltage at the time of current interruption Can be reduced.

Embodiment 1 FIG.
FIG. 1A is a configuration diagram showing a rotating electrical machine apparatus according to an embodiment of the present invention, and FIG. 1B is a waveform diagram showing a power running control signal thereof. As an example, a three-phase motor energized by a rectangular wave is shown. The rotating electrical machine mounted on the vehicle operates as a generator motor, a generator, or a motor. The rotating electric machine 400 has three-phase Y-type armature windings. The armature winding can be considered equivalently as an armature winding inductance component 401, 402, 403 and an armature DC resistance component 411, 412, 413. Although the armature winding side of the rotating electrical machine 400 is a stator (or rotor) and is not shown in the figure, the field winding type or permanent magnet type rotor (or facing the armature winding side of the rotating electrical machine 400) (or A stator).

  The power conversion unit 300 and the gate control unit 250 constitute a so-called three-phase inverter. The gate control unit 250 controls the gate of a switching element (described later) by the CPU. The power supply 100 which is a storage battery applies the voltage between the terminals to the DC terminal of the power conversion unit 300. Each phase of the armature winding is connected to the AC terminal of the power conversion unit 300 and is connected to two switching elements. For each phase of the armature winding, the positive side terminal (voltage Vp) of the power supply 100 is connected to the armature winding via the switching elements 301a, 302a, 303a of the first arm, and for each phase of the armature winding. The armature winding is connected to the negative terminal of the power supply through the switching elements 301b, 302b, and 303b of the second arm. A free-wheeling diode is connected to the switching element in the direction opposite to the conduction direction. If the switching element is a MOSFET, there is a parasitic diode, which normally serves as a free-wheeling diode.

  Each switching element of the power conversion unit 300 is controlled by a control signal from the gate control unit 250 based on information of the rotation sensor 200 that detects the rotor position of the rotating electrical machine 400. Energization command (UH) for switching element 301a of U-phase first arm, energization command (UL) for switching element 301b of U-phase second arm, energization command (VH) for switching element 302a of V-phase first arm, V-phase DC-AC conversion by energization command (VL) for switching element 302b of the second arm, energization command (WH) for switching element 303a of the W-phase first arm, and energization command (WL) for switching element 303b of the W-phase second arm Then, when the armature winding is energized, the power operation of the rotating electric machine 400 is performed.

  FIG. 1B shows a case where the switching element 301a, 302a, 303a, 301b, 302b, 303b of each phase is controlled to be turned on / off and the rotating electrical machine 400 is subjected to power running control. The signal (energization command) output to the gate is shown. When each signal UH, UL, VH, VL, WH, WL is +, the corresponding switching elements 301a, 302a, 303a, 301b, 302b, 303b are turned on.

Next, the case where the rotating electrical machine performs stop control during the power running operation will be described. When the rotating electric machine has a low rotation speed, the current that constantly flows in the armature winding is limited only by the armature DC resistance component. For example, when a stop command is input at the timing as shown in FIG. 2 and all the switching elements are turned off at the same time, currents flowing as shown in FIG. 3 are cut off, so that I ₁₁ , I ₁₂ , and I ₁₃ are as follows: It becomes like this.
I ₁₁ = (2/3) (Vp / R) (1)
I ₁₂ = I ₁₃ = (1/3) (Vp / R) (2)
All the switching elements are simultaneously turned off at this time (UH, VL, at the same time off the WL) Then, in the switching element 301a in the worst U-phase first arm including variations of each switching element to cut off the current amount of I ₁₁ Become.

Next, when the rotating electrical machine is running at a low speed, when the switching element that is in the on state is extended to the timing of turning off by the stop command as shown in FIG. The steady currents I ₂₁ and I ₂₃ are as follows.
I ₂₁ = I ₂₃ = (1/2) (Vp / R) (3)
At this time, when the switching element of the U-phase first arm is turned off at the current interruption timing, the current amount of I ₂₁ is interrupted.

In order to reduce the amount of current to be interrupted compared to the case described with reference to FIGS. 2 and 3 and FIGS. 4 and 5, in the present invention, when the rotating electrical machine is at a low speed, the stop command is significant as shown in FIG. (When a stop command is input), the switching element on the arm side in which the two phases are turned on (in the case of FIG. 6, the switching element (VL control) of the V phase second arm and the W When the two phases of the switching element (WL control) of the phase second arm are turned on at the same time and then one phase of the opposite arm is turned off, the current that the switching element cuts off is I _12, next _{I 13,} as compared with the case must be cut off the _{I 11} and _{I 21, I 23,} it is possible to reduce the burden on the switching device during current interruption.

That is, in FIG. 3, when the switching elements 302b and 303b on the second arm side in which the two phases are turned on are simultaneously turned off, the current to be cut off is I ₁₂ = I ₁₃ = (1/3) (Vp / R ) When the current is cut off, the current flowing through the armature winding (current flowing through the armature DC resistor 411 in FIG. 3) is turned on from the armature DC resistors 412 and 413 and the parasitic diodes of the switching elements 302a and 303a. It flows as a reflux current through the switching element 301a, and attenuates with time. Thereafter, the switching element 301a of the opposite arm in the attenuated state is turned off.

  As described above, when a stop command is input to stop the power running operation and current interruption of the armature winding is performed, a plurality of phases are turned on in one of the switching elements of the first and second arms. Since the switching element on the opposite arm side is turned off at the same time to cut off the current path, the switching element on the opposite arm is turned off, so that the current interruption when a large current flows is shared by multiple phase switching elements. Thus, the burden on each switching element can be reduced, the switching speed can be further reduced, and the surge voltage at the time of interrupting a large current can be reduced. In addition, the surge voltage can be reduced and inevitably the surge voltage of the switching operation during normal powering can be reduced, which is effective as a noise countermeasure.

  Next, in order for the currents of the values of the expressions (1) to (3) to actually flow, after switching on, the switching state is changed by the armature winding inductance component L and the armature DC resistance component R, and then constant. Delayed period. In other words, in order for the current flowing through the switching element on the arm side in which the two phases are turned on to be equal, after switching on, the current is delayed for a certain period, but when the current becomes equal, the current of the armature winding is cut off It is desirable.

As for the current I flowing through the armature winding, if the voltage applied to the armature winding at the time of switching on is E and the elapsed time after switching on is t, the following relational expression is established.

  Therefore, when a stop command is input so as to stop the power running operation, the timing of actually cutting off the current of the armature winding is such that the armature winding inductance component L and the armature DC resistance component R are known values. In this case, the obtained I can be predicted by the elapsed time t that is substantially equal to the elapsed time t from the switching-on of each arm-side switching element in which the two phases are in the ON state.

  In addition, the timing of actually cutting off the current of the armature winding is the timing at which the currents flowing through the switching elements on the arm side where the two phases are on are equalized, This can also be known by detecting the current flowing through the line.

As described above, when a stop command is input so as to stop the power running operation, the timing of cutting off the current of the armature winding flows to the switching element on the arm side in which a plurality of phases are turned on. When the currents are substantially equal, the current path is cut off at the same time to cut off the current path, and then the switching elements on the opposite arm are turned off to reduce (minimize) the burden on both switching elements when the current is cut off. be able to.
The above is an example in which the armature winding of the rotating electric machine has a three-phase Y connection. However, even if it is a three-phase Δ connection or a six-phase connection, the same applies if the present invention is applied. The current to be cut off can be reduced.

Embodiment 2. FIG.
FIG. 7 is a diagram showing a control signal waveform, an on / off state of each switching element, and a current flow when the energization pattern is switched in the second embodiment. Here, a state in which the rotor (armature) is locked when powering with a 120-degree conduction pattern as shown in FIG. 7A is shown. The state of the switching element at this time is such that the switching element (UH control) of the U-phase first arm is on and the switching element (WL control) of the W-phase second arm is on, respectively. Since only one phase is turned on, when the current is cut off with the switching element turned off from this state,
I ₃₁ = I ₃₃ = (1/2) (Vp / R) (5)
It becomes.

Therefore, in the present invention, as shown in FIG. 7B, by switching to the 180-degree conduction pattern once, that is, the energization angle range of each switching element is expanded (from 120 degrees to 180 degrees), the first arm side Alternatively, when either of the second arms is turned on for two phases, the current is shunted, and the switching elements on the arm side where the two phases are turned on {in the case of FIG. The two phases of the arm switching element (VL control) and the W-phase second arm switching element (WL control) are turned on simultaneously}, and then one phase of the opposite arm (FIG. 7B) ), The current that the switching element actually cuts off by turning off the switching element (UH control) of the U-phase first arm is
I ₄₂ = I ₄₃ = (1/3) (Vp / R) (6)
Therefore, it becomes smaller than when I ₃₁ and I ₃₃ are cut off.

Embodiment 3 FIG.
FIG. 8 is a flowchart showing a stop process switching operation based on the rotational speed in the third embodiment. When a stop command is input so as to stop the power running operation and the current interruption of the armature winding is performed, that is, when the power running stop command becomes significant, first, in step S1, the rotor (armature) flows. The displacement per unit time obtained from the rotational position detector of the rotor is used to determine whether the current is limited only by the armature DC resistance component or whether the induced current of the rotating electrical machine is low. Judging from the amount (number of rotations). Here, the determination value in step S1 is set to 500 r / min, but an appropriate value varies depending on the characteristics of the rotating electrical machine, the current interruption capability of the switching element, and the like. Here, the determination of whether or not a sufficient induced current is generated is determined by the number of rotations of the rotor, but in addition, the magnitude of the current flowing through the switching element and the magnitude of the current supplied to the rotating electrical machine , U, V, and W phase voltages can also be used for determination.

  If the condition is not satisfied in step S1, the gate control unit 250 executes step S5 which is a normal stop process, and performs the stop process of the first embodiment or the second embodiment when the condition is satisfied. If the condition is not satisfied in step S1, that is, if the rotational speed of the rotor is 500 r / min or more, there is much generation of an induced current in the rotating electrical machine. As shown, all the switching elements that are in the on state, which is a normal stop process, are immediately turned off simultaneously to interrupt the current path.

  At this time, as shown in FIG. 4, at step 5, the gate control unit 250 extends the switching element that is in the ON state to the original OFF timing and stops the energization current as shown in FIG. You may make it turn off. That is, the UH control switching element of FIG. 4 extended to the original turn-off timing may be turned off, and then the WL control switching element of the opposite arm may be turned off. In other words, if the switching element in the off state is maintained in the off state and the energizing current of the switching element in the on state is turned off at a timing that becomes zero, the current path is cut off. Good.

If the condition is satisfied in step S1, the gate control unit 250 first determines that, in step S2, if none of the first and second arm side switching elements are in the two-phase ON state, In this case, the energization angle range of each switching element is expanded, for example, the energization is expanded to 180 degrees, and either of the switching elements on the first and second arm sides is turned on in a two-phase ON state to divert current. In Step 3, after simultaneously turning off the switching elements on the arm side in which these two phases are turned on to cut off the current path, in Step 4, by turning off the one-phase switching elements in the opposite arm, The output is stopped.
In this way, it is possible to reduce the burden on the switching element in the case of interrupting a large current at the time of low rotation or locking in the rotating electric machine.

  As described above, when a stop command is input to stop the power running operation and the armature winding is interrupted, the rotational speed of the rotating electrical machine during the power running operation is medium to high speed (for example, 500 r / min or more). When the current flowing through the armature winding is limited by the winding inductance component, or when there is a large amount of induced current in the rotating electrical machine, the normal power running operation is stopped. Surge voltage can be reduced.

  However, when a stop command is input to stop the power running operation and the armature winding current is cut off, the rotating electrical machine during the power running operation is at a low speed or locked (for example, at 500 r / min or less). If so, the current that flows through the armature is limited only by the armature DC resistance component, or the induction current of the rotating electrical machine is low, so that multiple phases are turned on. By simultaneously turning off the switching elements on the arm side and cutting off the current path, the switching element on the opposite arm is turned off, so that the surge voltage can be reduced over the entire rotational speed of the rotating electrical machine.

  In the present invention, since the electric current to be interrupted at the time of stopping power running becomes the maximum when the rotating electric machine is in a low rotation or locked state, the current to be interrupted is smaller than that in the conventional method, so that soft switching can be performed. The voltage can also be reduced, which is effective as a noise countermeasure.

In relation to the embodiment of the present invention, (a) is a configuration diagram showing a rotating electrical machine apparatus, and (b) is a waveform diagram showing its power running control signal. It is a wave form diagram which shows the control timing when stop control is carried out during a power running operation, and all the switching elements are turned off simultaneously. FIG. 3 is a diagram showing an on / off state of each switching element and a current flow immediately before switching off in FIG. 2. It is a wave form diagram which shows the control timing when extending to the timing which turns off originally at the time of stop control, and turning off a switching element. FIG. 5 is a diagram showing an on / off state of each switching element and a current flow immediately before switching off in FIG. 4. In Embodiment 1, it is a wave form diagram which shows the control timing when the switching element of the arm on the opposite side is turned off after simultaneously turning off the switching element on the arm side where the two phases are turned on. It is a figure which shows the ON / OFF state of each switching element, and the flow of an electric current when the energization pattern is switched in Embodiment 2. 10 is a flowchart showing the operation of the rotating electrical machine apparatus in the third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Power supply 200 Rotation sensor 250 Gate control part 300 Power conversion part 301a Switching element of U phase 1st arm 302a Switching element of V phase 1st arm 303a Switching element of W phase 1st arm 301b Switching element of U phase 2nd arm 302b V-phase second arm switching element 303b W-phase second arm switching element 400 Rotating electric machine 401 U-phase armature winding inductance component 402 V-phase armature winding inductance component 403 W-phase armature winding inductance component 411 U-phase Armature DC resistance component 412 V-phase armature DC resistance component 413 W-phase armature DC resistance component

Claims (6)

A rotating electric machine having a multi-phase armature winding;
Each phase of the armature winding is connected from the positive terminal of the power source to the armature winding via the switching element of the first arm, and switching from the armature winding to the second arm for each phase of the armature winding. A power converter connected to the negative terminal of the power source through an element;
A gate control unit that controls a gate of each switching element of the power conversion unit during powering operation of the rotating electrical machine and applies a rectangular wave voltage to an armature winding of the rotating electrical machine,
When the gate control unit receives a stop command to stop the power running operation and cuts off the current of the armature winding, a plurality of phases are turned on in one of the switching elements of the first and second arms. A rotating electrical machine apparatus configured to turn off a switching element of an opposite arm after simultaneously switching off an arm-side switching element in a state to interrupt a current path. When none of the switching elements on the first and second arm sides is turned on for a plurality of phases, the energization angle range of each switching element is expanded, and either of the switching elements on the first and second arm sides is Multi-phase ON state to shunt current,
The switching element of the opposite arm is turned off after the switching elements on the arm side in which the plurality of phases are turned on are simultaneously turned off to interrupt the current path. The rotating electrical machine apparatus according to 1.   When the currents flowing through the switching elements on the arm side in which the plurality of phases are on are substantially equal, the switching elements on the arm side in which the plurality of phases are on are simultaneously turned off to interrupt the current path The rotating electrical machine apparatus according to claim 1 or 2, wherein the switching element of the opposite arm is turned off later. When the rotating electric machine during power running is below a predetermined number of revolutions,
2. The structure according to claim 1, wherein the switching elements on the opposite arm are turned off after the switching elements on the arm side in which a plurality of phases are turned on are simultaneously turned off to interrupt the current path. The rotating electrical machine apparatus according to any one of claims 3 to 4. When the rotating electric machine during the power running operation is equal to or higher than a predetermined rotational speed,
5. The rotating electrical machine apparatus according to claim 4, wherein all of the switching elements in an on state are simultaneously turned off to interrupt a current path. When the rotating electric machine during the power running operation is equal to or higher than a predetermined rotational speed,
Maintaining the off state of the switching element in the off state;
5. The rotating electrical machine apparatus according to claim 4, wherein the rotating electrical machine apparatus is configured to be turned off at a timing when an energization current of the switching element in an on state becomes zero to interrupt a current path.

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