JPS622959Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a commutatorless motor with measures against instantaneous power outages.

Non-commutator motors require some kind of countermeasure to continue operation without any problems even if a momentary power outage occurs. In particular, loss of power supply voltage during regenerative operation will lead to a sudden increase in overcurrent, and It is inevitable that commutation failure will occur and accidents such as element damage will occur. For this reason, various methods have been implemented in the past, but as mentioned above, there is a high possibility that a momentary power outage during regenerative operation will develop into a serious accident. a special device that detects that
A logical arithmetic circuit is required to receive the detection signal and quickly implement overcurrent protection, which complicates the circuit configuration and increases costs.

In view of the above, the object of the present invention is to provide a completely new non-commutator motor that can implement all measures against instantaneous power outages by simply detecting power outages, regardless of whether regeneration or drive is being performed.

The present invention will be explained in detail below based on the illustrated embodiments. Although the embodiments will be described with reference to an AC non-commutator motor, there is of course no problem in applying the present invention to a DC non-commutator motor as well.

In the drawings, Fig. 1 is a main circuit diagram of the AC non-commutator motor, Fig. 2 is a block diagram of its control circuit,
Further, FIG. 3 is a diagram showing an example of an instantaneous logic circuit. In Fig. 1, 1 is a synchronous motor type electric motor,
Although not shown, a position detector is connected to the rotor side to detect the relative position between the stator windings and the rotor, and generates a driving torque so that the magnetomotive force between them is always in a perpendicular relationship, that is, to maintain rotation. Each thyristor group on the stator side UP, VP, WP,
Give ignition signals to UN, VN, and WN, and as the rotor rotates, the above thyristor groups UP to WN
are sequentially switched to generate a rotating magnetomotive force. Thyristor groups UP to WN are three thyristors corresponding to each phase R, S, and T of a commercial frequency three-phase AC power supply, for example, for the UP group, URP,
Consisting of USP and UTP, while the motor speed is lower than the power supply frequency, the power supply commutation period is shorter than the period due to motor back emf commutation, and commutation within the same group, that is, from URP to USP or from USP Translocation to UTP is relatively frequent. However, as the motor speed increases and becomes greater than the power supply frequency, commutation within the thyristor group can only occur by chance since the power supply commutation period is longer than the motor commutation period. In this way, an AC non-commutator motor generates a rotational emf that is synchronized with a DC field rotor through two commutation operations: power commutation and motor back emf commutation from a commercial frequency three-phase AC power supply via a cycloconverter. It obtains magnetic force and continues to rotate.

FIG. 2 shows a control circuit for the AC non-commutator motor, in which the instantaneous power failure countermeasure according to the present invention is implemented. That is, the block diagram shown is a typical control circuit consisting of an α control system and a β control system, except for the momentary power failure countermeasure circuit, and the set control advance angle β ₀ is switched depending on the position signal F, at low speeds such as starting, and at other speeds. Torque direction discrimination signal T detects the torque direction to perform four-quadrant operation by shifting the speed discrimination signals N _L and N _H β ₀ by 180 degrees.
A position signal converter 2 that takes three signals _F and T _R as input signals and outputs a position signal according to each operation mode, a speed discrimination circuit 3 that outputs the speed discrimination signals N _L and N _H mentioned above, and a torque direction a β control system consisting of a torque direction discrimination circuit 4 that detects the torque direction, a speed setter, and a speed regulator _PIN 6 that amplifies and adjusts speed deviation;
Current regulator PI _I 7 of the current minor loop, thyristor phase shifter TD8 controlling the thyristor firing phase shift,
Since it is an AC system, it further comprises an αβ synthesis logic circuit 9 for synthesizing the α and β signals.

The present invention uses a general non-commutator motor control circuit consisting of the α and β control systems described above, and includes a power failure detection circuit 10 that detects a power failure, an electronic switch X11 that operates based on the output thereof, and a rotation When a power outage occurs between the direction discrimination circuit 12, the torque direction discrimination circuit 4, and the position signal converter 2, normal torque is generated if the rotation is in the forward direction, and normal torque is generated if the rotation is in the reverse direction, regardless of the normal torque commands TF and TR. It is constructed by connecting an instantaneous power failure logic circuit 13 that fixes the torque command to the reverse torque. In addition, in FIG. 2, the current discrimination circuit 14 shown by a broken line is provided as necessary.

That is, in the present invention, when the power supply is normal, the power failure detection circuit 10 does not operate, and the electronic switch
As is, the input and output of the speed regulator 6 and current regulator 7 of the α control system are not short-circuited and operate steadily.
In addition, the output of the instantaneous power failure logic circuit 13 matches the normal torque command from the torque direction discrimination circuit 4, and if the forward rotation drive or reverse regeneration operation is in progress, the forward torque command T'F
However, if the reverse rotation drive or normal rotation regeneration operation is in progress, a reverse torque command T'R is applied to the position signal converter 2, respectively. However, when a power outage occurs, the power outage detection circuit 1
0 is activated, and therefore the electronic switch , On the other hand, in the β control system, the instantaneous power failure logic circuit 13 receives the output from the power failure detection circuit 10 and drives the motor.
Regardless of regeneration, if normal rotation is in progress, forward torque command is given.
TF′, if it is reversing, issues a reverse torque command TR′,
Therefore, regardless of whether the drive is in forward or reverse direction, the torque command will not change during drive operation, and conversely, if regenerative operation is in progress, the torque command will be reversed. During reverse regeneration, the forward torque command TF is switched to the instantaneous power failure reverse torque command TR'. As a result, the β control system, which corresponds to the thyristor commutator of the thyristor device on the motor side, always performs reverse conversion operation during a momentary power failure, regardless of the operating state of forward rotation, reverse rotation, drive, or regeneration, and the motor back electromotive force acts to attenuate the current flowing in the main circuit, and the above-mentioned phase shift control effect on the kick pulse position of the α control system is superimposed, and the main circuit current immediately becomes zero. In addition,
A current discrimination circuit 14 shown by a broken line is inserted, and when the motor is operated with no load or light load, and the current is in an intermittent state, but a momentary power failure occurs in the current interruption section, the current "no" signal is detected. As input signals to the torque direction determination circuit 4 and the instantaneous power failure logic circuit 10, countermeasures against instantaneous power failure may not be taken at that time. Further, if only one-way operation is required without the need for four-quadrant operation, the illustrated rotational direction determination circuit 12 is not necessary.

Although FIG. 3 shows an example of the instantaneous power failure logic circuit 13, it may be a very simple one that combines an inverter and an AND gate, and the normal reverse torque command TR during forward regenerative operation is changed to the instantaneous power failure forward torque command TF'. To explain how the power outage signal "H" and the forward rotation signal "HF" in the rotation direction become the input signals of the AND gate 14, the output is inverted to "H" level, and that signal is directly used for instantaneous power outage. In addition to being output as a forward torque command TF', the output of the inverter 15 is set to "H" level, which is converted to "L" level via the next stage inverter 16, and the reverse torque command TR' for instantaneous power failure is set to zero. As long as a power failure signal does not occur, the normal reverse torque command TR maintains the H level through the two inverters 15 and 16, and even if it passes through the instantaneous power failure logic circuit 13, it is output as the instantaneous power failure reverse torque command TR', and the torque command is not converted. do not have. The same thing can be said during reverse regenerative operation. The reason why the normal forward torque command TF is converted into the reverse torque command TR' during a power outage is due to the functions of the AND gate 17 and the inverter 19. In addition, in the case of one-way drive operation, even if an instantaneous power failure occurs, the same torque command is given regardless of whether the rotation is forward or reverse.
If TF' is in reverse operation, a reverse torque command TR' can be obtained respectively. The output signal becomes "H", that is, the positive torque command TF' for instantaneous power failure becomes H level, and matches the signal obtained from the normal torque command TF via the two inverters 18 and 19, regardless of whether a power outage has occurred. For forward rotation drive operation, a forward torque command is generated, and for reverse rotation drive operation, a reverse torque command is generated.

That is, as mentioned earlier, the instantaneous power failure logic circuit according to the present invention issues a forward torque command if the motor is rotating in the forward direction, regardless of drive or regeneration during a power outage, and a reverse torque command if it is in the reverse direction. As a result,
During driving, the torque command does not change, but during regeneration, the torque command is changed from positive to reverse or from reverse to positive, respectively, causing the β control system to perform reverse conversion operation and attenuating the main circuit current. Eggplant.

As mentioned above, the present invention provides a special device for detecting motor operating conditions, especially regenerative operation, which conventional devices of this kind are indispensable, and instantaneously changes the phase shift of the α and β control systems in response to the regenerative operation detection signal. Countermeasures against instantaneous power outages are achieved with an extremely simple configuration that includes a power outage detection circuit that detects power outages without the need for any devices such as logical operation circuits, and an instantaneous power outage logic circuit that fixes the torque command based on the rotation direction signal at the time of power outage. It has the excellent feature that it can be realized, and it greatly contributes to significant cost reduction and reliability improvement.

[Brief explanation of the drawing]

Figure 1 shows the AC non-commutator motor main circuit;
FIG. 2 shows an example of a control circuit implementing the instantaneous power failure countermeasure according to the present invention, and FIG. 3 shows an example of the instantaneous power failure logic circuit. 2...Position signal converter, 3...Speed discrimination circuit,
4...Torque direction discrimination circuit, 10...Power failure detection circuit, 11...Electronic switch, 12...Rotation direction discrimination circuit, 13...Momentary power failure logic circuit.

Claims (1)

[Scope of utility model registration request] In a non-commutator motor, the input signals are the forward and reverse torque commands, the output signal from the power failure detection circuit that detects a power failure, and the output signal from the rotation direction discrimination circuit that determines the rotation direction if necessary. Equipped with an instantaneous power failure logic circuit that issues the same torque command as the above-mentioned forward and reverse torque commands when the power goes out, and issues a forward torque command if the power is running in the forward direction and a reverse torque command if the motor is running in the reverse direction. , setting the control advance angle β ₀ of the β control system in accordance with the torque command from the instantaneous power failure logic circuit, and in the α control system, actuating the electronic switch at the time of power failure to set the phase shifter input to zero; A commutatorless motor characterized in that a control delay angle α is set at a tight position.