JPH09247992A - Motor with controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a coil from being dewed with a very simple structure without requiring additional power supply or a heater. SOLUTION: An inverter device 10 drives an inverter main circuit 11 by means of a sinewave pulse duration modulating system through a base control circuit 15 for variable speed operation of a motor 1. At the coil 3 of the motor 1, a temperature sensor 12 for detecting its temperature is fitted. A base control circuit 15, when detected temperature by the temperature sensor 12 drops to the present temperature of less under a shutdown of the motor 1, conducts control of giving PWM signals of smaller number than those in ordinary operation to the bases of powder transistors Tr1 and Tr6 in the inverter main circuit 11, by which single-phase AC voltage of lower level than at the ordinary operation is applied between the power terminals Tu, Tw of the motor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor with a control device, which is made compact by integrating a motor and a control device which generates a variable voltage output as a power source of the motor.

[0002]

Generally, when dew condensation occurs on a motor coil, problems such as a decrease in dielectric strength and an increase in dielectric loss occur. Therefore, conventionally, for the purpose of preventing dew condensation on the motor coil, a heater for heating the atmosphere in the motor when the motor is stopped is provided, and in a three-phase motor, a heater for the motor is provided. A configuration in which a relatively low level of single-phase voltage is supplied to heat the motor coil in the stopped state may be adopted.

However, in the above-mentioned structure, since a heater and a power supply device are separately required, there is a problem that the structure becomes complicated and the size of the entire device is increased accordingly. It was an unsolved issue.

In view of the above circumstances, the present invention is directed to a motor integrally provided with a control device for variable voltage output as a power source, and an object thereof is to prevent dew condensation on a coil. It is to provide a motor with a control device that can be realized by.

[0005]

In order to achieve the above object, the invention according to claim 1 includes a motor having coils of a plurality of phases, and a controller for supplying a variable voltage output to each of the phase coils. In a motor with a control device integrally provided with, a single-phase AC voltage or a DC voltage having a lower level than usual is output from the control device between the two power supply terminals of the motor when the motor is stopped. In this configuration, an output control means for controlling the above is provided.

According to this structure, when the motor is not operating and the dew condensation occurs on the coil due to the temperature decrease, the output control means causes the control device to connect between the two power supply terminals of the motor. It is possible to output a single-phase AC voltage or DC voltage at a lower level than usual. When the controller outputs the single-phase AC voltage or DC voltage in this way, the coil heats up to prevent the occurrence of dew condensation. In this case, the motor is driven to rotate. There is no such thing.

Therefore, the prevention of dew condensation on the coil can be realized with an extremely simple structure which does not require a separate heater or power supply device, which may lead to a complicated structure and a large size of the entire device. Disappears.

In this case, as in the invention described in claim 2,
The output control means is provided with a temperature detection means for detecting the coil or the ambient temperature of the coil, and the output control means is set to a temperature lower than a normal level from a control device in a state where the temperature detected by the temperature detection means is equal to or lower than a set temperature. The control may be performed so that a single-phase AC voltage or a DC voltage is output.

According to this structure, when the coil or the ambient temperature of the coil is in a state where dew condensation occurs on the coil, the controller causes a single-phase AC voltage or DC voltage of a lower level than usual. Can be automatically output, so that the coil dew condensation prevention function can be reliably exerted.

Further, as in the invention described in claim 3, the control device is constituted by an inverter device having an inverter main circuit, and the output control means is provided with a predetermined switching element in the inverter main circuit. The ON / OFF control may be used to output a single-phase AC voltage or DC voltage at a lower level than in the normal state.

According to a fourth aspect of the present invention, the control device comprises a phase control device for generating a variable voltage output by controlling the conduction angle of the switching element, and the output control means is provided. The configuration may be such that a low-level single-phase AC voltage or DC voltage is output by making the conduction angle of the switching element smaller than in the normal state.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In FIG.
Motor case 2 of motor 1 (in this case, three-phase induction motor)
Has a structure in which bearing brackets 2b and 2c are fixed to both sides of the frame 2a, and a stator 4 having a three-phase coil 3 is fixed to the inner peripheral surface of the frame 2a. A rotor 5 is supported in the motor case 2 via bearings 6 and 7 provided on bearing brackets 2b and 2c.

A fan 8 for cooling is attached to the end of the rotor shaft 5a on the side opposite to the load, and the bearing bracket 2b has a fan cover 9 having an intake port (not shown).
Are attached so as to cover the fan 8.
In addition, there is a predetermined ventilation gap 9a between the peripheral edge of the fan cover 9 and the peripheral edge of the bearing bracket 2b.

An inverter device 10 (corresponding to a control device in the present invention) for supplying a variable voltage / variable frequency output to the coil 3 is integrally attached to the outer surface of the frame 2a in a unitized state. Has been. The inverter device 10 includes a control circuit board 10 in a case 10a.
b and a power unit including an inverter main circuit (indicated by reference numeral 11 in FIG. 1) are housed.

A temperature sensor 12 (corresponding to the temperature detecting means in the present invention) for detecting the temperature of the coil 3 is attached to the coil end portion of the coil 3 by heat transfer. The pulled-out signal lead wire 12a is connected to the control circuit board 10a while penetrating the frame 2a. As the temperature sensor 12, various types such as a temperature sensitive resistance element such as a thermistor, a semiconductor such as a diode or a transistor, a thermoelectromotive force element such as a thermocouple, or the like can be used.

FIG. 1 schematically shows an electrical structure. 1, in addition to the inverter main circuit 11, an inverter device 10 includes a power supply circuit 14 for rectifying and smoothing an output of an AC power supply 13, and power transistors Tr1 to Tr6 in the inverter main circuit 11 (the present invention). The base control circuit 15 (corresponding to the output control means in the present invention) for controlling on / off of the switching element (1) is provided.

In this case, the inverter main circuit 11 is
Power transistors Tr1 to Tr6 are configured by three-phase bridge connection, and output terminals Pu, Pv for each phase,
Pw is the U, V, W phase input terminals Tu, T of the motor 1.
v and Tw, respectively. Although not shown, a known flywheel diode is connected between the collector and the emitter of each of the power transistors Tr1 to Tr6.

The base control circuit 15 includes the temperature sensor 1
The second output signal is received via the signal lead wire 12a. The base control circuit 15 is provided on the control circuit board 10a (see FIG. 4), and uses the sine wave pulse width modulation method for the inverter main circuit 11 based on a speed command from an operation circuit (not shown). By driving the motor 1, a variable speed operation of the motor 1 is performed. In FIG. 3A, the voltages Vu, Vv output from the phase output terminals Pu, Pv, Pw of the inverter main circuit 11 in the state where the variable speed operation of the motor 1 is performed,
An example of the waveform of Vw is schematically shown.

The base control circuit 15 is composed of a CPU and has power transistors Tr1 to Tr6 based on pulsed PWM (sine wave pulse width modulation) signals.
ON / OFF control of the speed command, the temperature sensor 12
It is configured to be performed on the basis of an output signal from the computer and a program stored in advance.

FIG. 2 shows the contents of the temperature monitoring routine related to the gist of the present invention among the control contents of the base control circuit 15, which will be described below together with the operation of the related parts. That is, in FIG. 2, in the temperature monitoring routine, it is determined whether the detected temperature ΔT (corresponding to the temperature of the coil 3) indicated by the output signal from the temperature sensor 12 is equal to or lower than the preset temperature stored in advance (step S1), if the set temperature is exceeded, the process directly returns to the main program. The set temperature is set to, for example, an upper limit value of a temperature range in which dew condensation occurs on the coil 3.

On the other hand, when the temperature ΔT detected by the temperature sensor 12 is below the set temperature, that is, the coil 3
In the case where the dew condensation occurs due to the temperature decrease, it is determined whether the operation of the motor 1 is stopped (step S2), and if the operation is not stopped, the process directly returns.

When the temperature ΔT detected by the temperature sensor 12 is equal to or lower than the set temperature and the operation of the motor 1 is stopped (“YES” in step S2), the signal output step S3 is executed and then the process returns to step S1. . Therefore, the signal output step S3 is performed until it is determined to be "NO" in steps S1 and S2, that is, the state in which the temperature ΔT detected by the temperature sensor 12 exceeds the set temperature or the operation of the motor 1 is started. It will be repeatedly executed until.

Specifically, in the signal output step S3, control is performed so that a smaller number of PWM signals than in normal operation are applied to the bases of, for example, the power transistors Tr1 and Tr6 in the inverter main circuit 11. As a result, between the output terminals Pu and Pw of the inverter main circuit 11, the voltages Vu ′ and Vw ′ having the waveforms shown in FIG. 3B are output. Therefore, when the temperature ΔT detected by the temperature sensor 12 is equal to or lower than the set temperature and the operation of the motor 1 is stopped, the U-phase and the W-phase of the coil 3 are applied with a single-phase AC voltage having a lower level than usual. Will be done.

In short, according to the configuration of this embodiment described above, the temperature sensor 12 can be operated when the motor 1 is not operating.
When the detected temperature ΔT is lower than the set temperature, that is, when the dew condensation occurs on the coil 3 due to the temperature decrease, the inverter main circuit 11 connects the power supply terminals Tu and Tw of the motor 1 to each other. The single-phase AC voltage having a lower level than usual is applied.

In such a state, the coil 3 heats up without being driven to rotate the motor 1, so that the coil 3 and the inside of the motor case 2 are heated and the occurrence of dew condensation is prevented. . Therefore, the prevention of dew condensation on the coil 3 and other parts can be realized with an extremely simple configuration that does not require a separate heater or power supply device, which complicates the structure and increases the overall size of the device. Will not be invited.

A second embodiment of the present invention is shown in FIGS. 5 and 6, and only parts different from the above embodiment will be described below. The present embodiment is characterized in that the phase controller 16 configured as shown in FIG. 5 is used as a controller for supplying a variable voltage output to the coil 3 of the motor 1. This phase control device 16 is provided for the frame 2 of the motor 1.
It is integrally attached to the outer surface of a (see FIG. 4) in a unitized state.

In FIG. 5, a phase controller 16 controls a phase control circuit 17 having six thyristors SR1 to SR6 (corresponding to switching elements in the present invention) and a conduction phase of the thyristors SR1 to SR6. And a gate control circuit 18 (corresponding to the output control means in the present invention) for the purpose.

In this case, the phase control circuit 17 includes the thyristors SR1 and SR2 for the U phase and the thyristor S for the V phase.
Each pair of R3 / SR4 and W-phase thyristors SR5 / SR6 are connected in anti-parallel, and the output terminals Qu, Qv, Qw for each phase are the input terminals for each phase of U, V, W of the motor 1. It is connected to Tu, Tv, and Tw, respectively.

The gate control circuit 18 receives the output signal of the temperature sensor 12 via the signal lead wire 12a. The gate control circuit 18 controls the thyristors SR1 to SR based on a voltage command from an operation circuit (not shown).
By controlling the conduction angle of R6, a variable speed operation of the motor 1 is performed. Incidentally, FIG. 6A shows the phase control circuit 1 in the state where the variable speed operation of the motor 1 is performed.
7 schematically shows an example of the waveforms of the voltages Vu, Vv, and Vw output from the output terminals Qu, Qv, and Qw of the seven phases.

The gate control circuit 18 is configured to include a CPU, and controls the conduction angles of the thyristors SR1 to SR6 based on the voltage command, the output signal from the temperature sensor 12 and a prestored program. It is configured to do.

In particular, in the gate control circuit 18, when the temperature detected by the temperature sensor 12 becomes lower than a preset temperature stored in advance when the motor 1 is not operating,
By making the conduction angles of the thyristors SR1, SR2, SR5, and SR6 smaller than usual, the output terminals Qu, Q
Control is performed so that the voltages Vu ′ and Vw ′ having the waveforms shown in FIG. 6B are obtained from w. As a result, when the temperature detected by the temperature sensor 12 is equal to or lower than the set temperature and the operation of the motor 1 is stopped, the U-phase and the W-phase of the coil 3 are applied with a single-phase AC voltage having a lower level than in the normal state. Will be done.

Therefore, also in the present embodiment, when the motor 3 is in the operation stopped state and the dew condensation occurs due to the temperature decrease in the coil 3, the phase control circuit 17 causes the power supply terminal of the motor 1 to operate. Between Tu and Tw, a single-phase AC voltage having a lower level than usual is applied, so that the same dew condensation prevention effect as in the first embodiment can be obtained.

The present invention is not limited to the above embodiment, and the following modifications and expansions are possible.
Although the PWM control inverter device 10 and the phase control device 16 are given as examples of the control device, a PAM control inverter device or a cycloconverter may be used. Although the temperature of the coil 3 is detected by the temperature sensor 12, the temperature around the coil 3 (ambient temperature in the frame 2a, outside air temperature, etc.) may be detected. Further, it is also possible to use temperature detecting means configured to detect the temperature based on the electric resistance of the coil 3.

Further, the inverter device 10 or the phase control device 16 outputs a low-level single-phase AC voltage when the temperature detected by the temperature sensor 12 is below the set temperature. May be output. That is, a configuration may be adopted in which only the positive half-waves or the negative half-waves of the U-phase and W-phase voltages Vu ′ and Vw ′ shown in FIG. 3B or 6B are output.

[0035]

According to the first aspect of the present invention, when the motor is not in operation, a single-phase alternating current having a lower level than usual between the two power supply terminals of the motor and the control device provided in the motor. Since the output control means capable of outputting the voltage or the DC voltage is provided, it is possible to prevent the dew condensation of the coil with an extremely simple configuration, and there is no fear of complicating the structure or increasing the size of the entire device. is there.

According to the second aspect of the invention, when the coil or the ambient temperature of the coil exceeds the set temperature,
Since the operation for preventing the dew condensation of the coil as described above is automatically performed, the dew condensation preventing function of the coil can be surely exhibited.

[Brief description of drawings]

FIG. 1 is an electrical configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing the control contents of the main part.

FIG. 3 is a timing chart schematically showing a voltage waveform applied to a coil.

FIG. 4 is a side view showing the motor in an upper half sectional state.

FIG. 5 is an electrical configuration diagram showing a second embodiment of the present invention.

FIG. 6 is a timing chart schematically showing a voltage waveform applied to a coil.

[Explanation of symbols]

1 is a motor, 3 is a coil, 10 is an inverter device (control device), 11 is an inverter main circuit, TR1 to TR6 are transistors (switching elements), 12 is a temperature sensor (temperature detecting means), and 15 is a base control circuit (output). Control means), 16 is a phase control device (control device), 17 is a phase control circuit, SR1 to SR6 are thyristors (switching elements), and 18 is a gate control circuit (output control means).

Claims (4)

[Claims] 1. A motor with a control device integrally provided with a motor having a plurality of phase coils and a control device for supplying a variable voltage output to each of the phase coils. A motor with a control device comprising: output control means for controlling so that a single-phase AC voltage or a DC voltage of a lower level than usual is output from the control device between two power supply terminals of the motor. 2. A temperature detecting means for detecting the temperature of the coil or the surrounding temperature of the coil, wherein the output control means is lower than a normal temperature from a control device when the temperature detected by the temperature detecting means is below a set temperature. 2. The motor with a control device according to claim 1, wherein the motor is controlled so that a single-phase AC voltage or a DC voltage of a level is output. 3. The control device is composed of an inverter device having an inverter main circuit, and the output control means is a single phase having a lower level than usual by on / off control of a predetermined switching element in the inverter main circuit. The motor with a control device according to claim 1 or 2, wherein the motor is configured to output an AC voltage or a DC voltage. 4. The phase controller controls the conduction angle of the switching element to generate a variable voltage output, and the output control means makes the conduction angle of the switching element smaller than usual. The motor with a control device according to claim 1 or 2, wherein the motor is configured to output a low-level single-phase AC voltage or a DC voltage.