KR20220033830A - Three phase variable induction motor for the air conditioner compressor drive of the diesel locomotive - Google Patents

Abstract

The present invention relates to a three-phase variable induction motor for driving an air conditioner compressor of a diesel locomotive and, more specifically, to a three-phase variable induction motor for driving an air conditioner compressor which is configured to drive an air conditioner compressor of a diesel locomotive in a variable voltage variable frequency (V.V.V.F) form, wherein the air conditioner compressor of the diesel locomotive generates an AC voltage of 3 Φ AC 45-215 V and 30-120 Hz according to a rotation frequency of an engine.

Description

Three phase variable induction motor for the air conditioner compressor drive of the diesel locomotive

The present invention relates to a three-phase variable induction motor for driving an air conditioner compressor of a diesel locomotive. It relates to an air conditioner compressor driving three-phase variable induction motor configured to be driven in the form of voltage variable frequency (VVVF).

There is no problem in adopting the air conditioner because the air conditioner supply power of general railroad vehicles is AC 110V, 220V, 380V and 440V. Since it has a range, there is an electrical obstacle to the adoption of air conditioner parts as a general 3-phase variable voltage variable frequency generator.

Therefore, in the conventional diesel locomotive, as a shunt generator, it rotates directly connected to the engine by a flexible coupling and an extension shaft. The speed is about 3.037 times the engine speed, but DC 74V±2V is generated using a DC auxiliary generator that generates a nearly constant voltage throughout the rotational speed, and then the DC voltage is inverted to 3Φ AC 55V 60Hz. It was composed of a compressor and a motor for evaporator and condenser driving.

In other words, the diesel locomotive generates a variable AC voltage and frequency of 3Φ AC 45-215V, 30-120Hz depending on the engine speed, so when driving the motor for the compressor, evaporator and condenser of the air conditioner using this changed AC voltage Since the desired driving power cannot be obtained, a DC auxiliary generator that always generates a constant DC voltage regardless of the engine rotation speed is separately installed, and the DC voltage generated by this generator is converted back into AC voltage. It was composed of a supply, etc.

Here, the inverter can be selected and used according to the used load or speed control method. That is, when controlling the speed, vector control, current control method, etc. are used, and the purpose of use can be achieved by distinguishing whether it is for a constant torque load or a reduced torque load. can

However, in all inverters, the voltage and frequency increase or decrease at almost the same rate, and the voltage/frequency is constantly changed to change the rotation speed of the motor.

In addition, the synchronous speed (N = (120 XF) χ P) of an induction motor changes the frequency (F) of the motor. Pole), the variable speed range of the motor is from 90RPM to 360RPM.

In the case of the inverter used above in general, the voltage/frequency may not be constant in the low-frequency region (about 60Hz or less), so it is difficult to select the precise rotation speed at 180 RPM or less, and the output waveform of the inverter is similar to that of general commercial power. Since it is a square wave, not a si wave, there is also a problem that a lot of heat is generated in the motor.

In addition, when a problem occurs in a certain part while driving the motor of each part of the air conditioner using the DC voltage generated from the DC auxiliary generator as described above, the manufacturer of each part asks for specific information (for example, AC 55V). It is difficult to procure parts for Korea, and the inverter that converts DC voltage of 74V±2V to AC voltage of 3Φ 60Hz 55V must be made to order, so the production cost of the product is set high and its size is very large, so the problem of securing mounting space arises. there is a situation.

Meanwhile, in the following prior art documents, the present invention only discloses the contents of an apparatus for controlling an air conditioner system installed in a vehicle, including a compressor and an evaporator driven by an electric motor whose rotational speed is controlled, but the technical gist of the present invention is not starting

Republic of Korea Patent Publication No. 10-2013-0129401

A three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention has the following object in order to solve the above-described problems.

The 3-phase variable induction motor for driving the compressor of the air conditioner installed in the diesel locomotive can be driven in the form of a variable voltage variable frequency (VVVF), so that the AC voltage of 3Φ AC 45-215V, 30-120Hz is applied according to the engine speed of the diesel locomotive. An object of the present invention is to provide a three-phase variable induction motor for driving an air conditioner compressor of a diesel locomotive that can be accommodated at the same time.

The problems to be solved of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

A three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention includes: a converter for full-wave rectification of a three-phase AC voltage output from an accompanying AC generator into a DC voltage; a smoothing circuit unit for removing the ripple voltage included in the output voltage of the converter; The DC voltage output through the smoothing circuit unit is turned on/off at a predetermined time so as to supply a voltage having the characteristics of a variable voltage variable frequency (VVVF) and a variable voltage constant frequency (VVCF). an inverter that converts an AC voltage of the rated frequency of the induction motor and applies it to each terminal (U, V, W) of a 3-phase induction motor for an air conditioner compressor; a brake circuit unit that regenerates power to a reversible converter or consumes regenerative power through a brake circuit when sudden braking of the three-phase induction motor is required to prevent an increase in DC voltage; and a control module for controlling at least one of the inverter and the brake circuit unit, wherein the control module controls at least one of the inverter and the brake circuit unit based on a detection result of a temperature sensor attached to the three-phase induction motor .

The control module includes: an inverter control unit for controlling on/off of a plurality of switching elements provided in the inverter; It is preferable to include a; a brake circuit control unit for controlling the on/off of the switch provided in the brake circuit unit.

When the temperature of the three-phase induction motor detected by the temperature sensor reaches a preset temperature A, the inverter control unit preferably controls the plurality of switching elements in a direction to reduce the rotational speed of the three-phase induction motor Do.

When the temperature of the three-phase induction motor detected by the temperature sensor reaches a preset temperature B, the brake circuit unit control unit controls the brake circuit unit switch to stop driving the three-phase induction motor, and the B The temperature is preferably higher than the temperature A.

Preferably, the temperature sensor is configured to include a plurality of temperature detection devices, and the control module further includes a specific resistance value correcting unit for correcting specific resistance values of the plurality of temperature detection devices.

A three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention simultaneously accommodates a variable AC voltage of 3Φ AC 45-215V and a variable frequency of 30-120Hz generated from an auxiliary alternator of a diesel locomotive. As it can drive the 3-phase AC motor of the air conditioner compressor, it is possible to reduce the production cost of the product, as well as advantageous for maintenance work, and has the effect of securing the installation space easily.

Effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

1 is a circuit diagram of a three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention.
2 is a block diagram illustrating a detailed configuration of a control module of a three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention.
3 is a block diagram illustrating a detailed configuration of the resistivity correction unit of FIG. 2 .

A preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings, but the same or similar components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

In addition, in the description of the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easy understanding of the spirit of the present invention, and should not be construed as limiting the spirit of the present invention by the accompanying drawings.

1 is a block diagram of the present invention. According to this, two diodes D1-D6 are connected in parallel to each phase R, S, T, and the three-phase AC voltage output from the auxiliary alternator 100 is a converter 200 for half-wave rectification to a DC voltage, respectively; The coil L and the capacitor C are connected in parallel to the output part of the converter 200, and the ripple voltage included in the output voltage of the converter 200 and the ripple voltage (current) generated in the inverter 400 ) to remove the smoothing circuit unit 300 and; The smoothing circuit unit 300 is configured to supply a voltage having the characteristics of a variable voltage variable frequency (VVVF) and a variable voltage constant frequency (VVCF) and turns on/off six switching elements at a predetermined time through the smoothing circuit unit 300 an inverter 400 that converts the output DC voltage into an AC voltage of a desired frequency and applies it to each terminal (U, V, W) of the three-phase induction motor 6 for an air conditioner compressor; It is installed between the output terminal of the smoothing circuit unit 300 and the input terminal of the inverter 400 to regenerate power with a reversible converter or consume regenerative power through a brake circuit when you want to suddenly brake the three-phase induction motor 600 It is characterized in that it is composed of a brake circuit unit 500 to prevent the rise of the DC voltage.

The operation and effect of the circuit of the present invention configured as described above will be described as follows.

First, the auxiliary alternator 100 used to provide power for auxiliary devices such as an engine cooling fan motor, an inertial filter blower motor and a traction motor blower motor in a diesel locomotive is installed to be mechanically connected to the main generator of the diesel locomotive. , installed to be electrically independent.

Such an auxiliary alternator 100 is a rotating field type, and the stator is fixed to the main generator frame with bolts, and the rotor assembly is directly connected to the crankshaft of the diesel locomotive together with the main generator rotor by a disk-type flexible coupling, and the engine's Different power generation voltages and frequencies are indicated depending on the number of revolutions. For example, in the idle state where the speed of the locomotive is 0, AC 45V at 32Hz is generated, at 60KM/H, AC 100V at 60Hz is generated, and at 140KM/H, 120Hz is generated. of AC 215V will be generated.

The variable frequency variable AC voltage output from the auxiliary alternator 100 is half-wave rectified into a DC voltage through the converter 200 composed of two diodes D1-D6 corresponding to each phase, respectively, and then the smoothing circuit unit 300, the converter 200 is configured as a reversible converter using two sets of thyristor converters, so that the direction of power is reversible, thereby enabling regenerative operation.

On the other hand, the half-wave rectified DC voltage through the converter 200 includes a ripple voltage of 6 times frequency, and also the ripple voltage in the inverter 400 that applies the AC voltage to the three-phase induction motor 600 for the air conditioner compressor. Since a current is generated and the DC voltage fluctuates, in the present invention, a smoothing circuit unit 300 having a configuration in which a coil (L) and a capacitor (C) are connected in parallel between the converter 200 and the inverter 400 is installed. After removing the ripple voltage included in the output voltage of the converter 200 and the ripple voltage (current) generated in the inverter 400 , only a pure DC voltage can be applied to the inverter 400 and the brake circuit unit 500 .

Such a smoothing circuit unit 300 may simplify the smoothing circuit itself by omitting the coil if the power supply or main circuit component is given a margin when the capacity of the device is small.

In addition, it is installed between the output terminal of the smoothing circuit unit 300 and each power terminal (U, V, W) of the three-phase induction motor 600 , opposite to the converter 200 , the direct current output through the smoothing circuit unit 300 . The inverter 400, which converts the voltage into an AC voltage of a desired frequency, consists of six switching elements, but turns on/off each switching element at a predetermined time, thereby compressing the air conditioner regardless of the engine speed of the diesel locomotive. It is possible to obtain AC voltage of desired frequency from 3-phase induction motor for machine use.

On the other hand, when the three-phase induction motor 600 for the air conditioner compressor is used in the regenerative braking region (that is, the slip is negative), the regenerative energy is accumulated in the capacitor C of the smoothing circuit unit 300 and the DC voltage is In general, the energy stored by the inertia of the machine including the motor is larger than the energy stored in the capacitor.

Therefore, in the present invention, when a brake circuit unit 500 is installed between the output terminal of the smoothing circuit unit 300 and the input terminal of the inverter 400 to rapidly brake the three-phase induction motor 600 for the air conditioner compressor, a reversible converter is used. The increase of the DC voltage affecting the braking of the three-phase induction motor 600 was prevented by regenerating the power or consuming the regenerative power through the brake circuit (switch and resistor).

On the other hand, when the temperature of the three-phase induction motor 600 for an air conditioner compressor is excessively high, the possibility of damage to the entire system increases, and furthermore, there is a risk of fire.

In order to prevent this problem, the three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention includes a temperature sensor 610 for detecting the temperature of the three-phase induction motor 600, and control The module 800 may be configured to control at least one of the inverter 400 and the brake circuit unit 500 based on the detection result of the temperature sensor 610 .

To this end, the control module 800 is configured to include an inverter control unit 810 , a brake circuit control unit 820 , and a specific resistance value correcting unit 830 as shown in FIG. 2 .

The inverter control unit 810 performs a function of controlling the on/off of a plurality of switching elements provided in the inverter 400 , and the brake circuit unit control unit 820 turns on/off the switches provided in the brake circuit unit 500 . It performs the function to control off.

Specifically, when the temperature of the three-phase induction motor 600 detected by the temperature sensor 610 reaches a preset temperature A, the inverter control unit 810 rotates the three-phase induction motor 600 . The temperature rise of the three-phase induction motor 600 can be suppressed by being configured to control the plurality of switching elements in a direction to reduce the speed.

When the temperature of the three-phase induction motor 600 detected by the temperature sensor 610 reaches a preset temperature B, the brake circuit unit control unit 820 controls the switch of the brake circuit unit 500 to It may be configured to stop driving the three-phase induction motor 600, where temperature B is a temperature higher than temperature A.

That is, when the temperature of the three-phase induction motor 600 rises, the control module 800 sequentially controls the driving of the three-phase induction motor 600 over two steps, so that the sudden It is possible to prevent a stoppage of operation.

On the other hand, the temperature sensor 610 attached to the three-phase induction motor 600 is configured to include a plurality of temperature detection elements, these temperature detection elements have a specific resistance value, which is a unique characteristic of the element, and the temperature sensor 610 ) is calculated by reflecting the specific resistance value, which is a constant of the temperature detection element, and this specific resistance value may change due to long-term use of the temperature sensor 610 and external impact, and thereby the measured temperature will decrease the reliability of

In order to prevent this problem, the control module 800 may include a specific resistance value correcting unit 830 , and the resistive resistance value correcting unit 830 is a function of a plurality of temperature detection elements provided by the temperature sensor 610 . It performs a function of calculating the correct temperature of the three-phase induction motor 600 by correcting at least one specific resistance value among the specific resistance values.

Specifically, the specific resistance value correction unit 830 includes a temperature input unit 831, a temperature comparison unit 832, an error detection unit 833, a specific resistance value correcting unit 834, and a temperature output unit (830), as shown in FIG. 835), and below, each detailed configuration is provided on the assumption that the temperature sensor 610 includes three temperature detection elements, that is, a first temperature detection element, a second temperature detection element, and a third temperature detection element. to be explained.

The temperature input unit 831 performs a function of receiving the first temperature, the second temperature, and the third temperature from the first temperature detection element, the second temperature detection element, and the third temperature detection element, respectively, and the temperature comparison unit 832 is a configuration for comparing differences between a plurality of temperatures detected by the three temperature detection devices, that is, a first temperature, a second temperature, and a third temperature.

The error detection unit 833 detects a temperature detection element having an error in specific resistance among a plurality of temperature detection elements based on the comparison result of the first temperature, the second temperature, and the third temperature in the temperature comparison unit 832 described above. It performs the detection function.

For example, when the difference between the first temperature detected by the first temperature detection element among the three temperature detection elements and the second temperature and the third temperature is greater than a preset range, the error detection unit 833 may set the first temperature It is judged that there is an error in the specific resistance value of the detection element.

The specific resistance value correction unit 834 performs a function of correcting the specific resistance value of the temperature detection device detected by the error detection unit 833 .

For example, when the error detection unit 833 determines that there is an error in the specific resistance value of the first temperature detection device, the specific resistance value correcting unit 834 adjusts the first temperature detected by the first temperature detection device to the second temperature detection device. Correction is made based on the second temperature and the third temperature detected by the temperature detecting element and the third temperature detecting element.

Specifically, the specific resistance value of the first temperature detecting element may be corrected so that the first temperature becomes an average value of the second temperature and the third temperature, and the intrinsic coefficient of the first temperature detecting unit may be corrected through various other algorithms. There will be.

The temperature output unit 835 performs a function of calculating the temperature of the three-phase induction motor 600 based on the correction result of the specific resistance value correcting unit, and as a result, the inverter control unit 810 and the brake circuit control unit 820 ) controls the inverter 400 and the brake circuit unit 500 based on the final corrected temperature output from the temperature output unit 835 .

In addition, in the three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive according to an embodiment of the present invention, the fire extinguishing member 700 may be disposed around the three-phase induction motor 600 as shown in FIG. 1 .

This is to prevent the spread of fire when a fire occurs due to the heat of the three-phase induction motor 600, and such a fire extinguishing member is made of an elastic material such as flame retardant and flame retardant rubber, and the fire extinguishing material and air inside the outer shell is configured to be charged.

That is, when the temperature around the fire extinguishing element rises due to the occurrence of a fire, the fire extinguishing element expands by the air inside, and when the outer shell of the fire extinguishing element ruptures, the extinguishing material contained therein is sprayed around the three-phase induction motor 600. It can prevent or delay the spread of fire.

In particular, because the fire extinguishing member is not a fire, but the heat around the three-phase induction motor 600, the outer shell only expands to some extent due to the air inside, but does not burst, and the temperature is lowered and the outer shell contracts again. In particular, if the shell expands beyond the threshold at which the elasticity can be lowered and then contracts, the shell becomes brittle or undergoes thermal deformation so that it does not rupture even if the shell expands in case of an actual fire.

In order to prevent such a problem, it is necessary to replace the fire extinguishing member that has repeatedly expanded and contracted several times.

Therefore, in order to easily determine whether to replace the fire extinguishing member, the outer skin of the fire extinguishing member may be formed to change the color of the surface according to the degree of heat, and it is preferable that the color change is irreversible.

Specifically, when the temperature around the fire extinguishing member 700 rises to such an extent that a fire does not occur and the temperature of the outer shell reaches a preset temperature, the outer shell expands and the color of the outer shell changes.

Afterwards, when the surrounding temperature of the fire extinguishing member 700 is lowered and the outer shell is contracted, the changed color does not return to the original color, so that the administrator can easily visually see that the outer skin of the fire extinguishing member 700 has a history of expansion to the extent that it is damaged. can be confirmed, and through this, it is possible to easily replace the fire extinguishing member 700 .

As mentioned above, although the present invention has been described in detail using preferred embodiments, the scope of the present invention is not limited to specific embodiments and should be construed according to the appended claims. In addition, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the present invention.

100: auxiliary alternator
200: converter
300; smooth circuit
400: inverter
500: brake circuit unit
600: 3-phase induction motor for air conditioner compressor
700: fire extinguishing member
800: control module

Claims (5)

a converter for full-wave rectification of each of the three-phase AC voltages output from the auxiliary AC generator into DC voltages;
a smoothing circuit unit for removing the ripple voltage included in the output voltage of the converter;
The DC voltage output through the smoothing circuit unit is turned on/off at a predetermined time so as to supply a voltage having the characteristics of a variable voltage variable frequency (VVVF) and a variable voltage constant frequency (VVCF). an inverter that converts the AC voltage of the rated frequency of the induction motor and applies it to each terminal (U, V, W) of the 3-phase induction motor for air conditioner compressor;
a brake circuit unit that regenerates power to a reversible converter or consumes regenerative power through a brake circuit when sudden braking of the three-phase induction motor is required to prevent an increase in DC voltage; and
a control module for controlling at least one of the inverter and the brake circuit unit;
including,
The control module controls at least one of the inverter and the brake circuit unit based on a detection result of a temperature sensor attached to the three-phase induction motor.
The method according to claim 1, wherein the control module,
an inverter control unit for controlling on/off of a plurality of switching elements provided in the inverter;
a brake circuit unit control unit for controlling on/off of a switch provided in the brake circuit unit;
A three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive comprising a.
3. The method according to claim 2,
When the temperature of the three-phase induction motor detected by the temperature sensor reaches a preset temperature A,
The inverter control unit is a three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive to control the plurality of switching elements in a direction to reduce the rotational speed of the three-phase induction motor.
4. The method according to claim 3,
When the temperature of the three-phase induction motor detected by the temperature sensor reaches a preset temperature B,
The brake circuit unit control unit controls the switch of the brake circuit unit to stop driving of the three-phase induction motor,
The temperature B is a three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive higher than the temperature A.
4. The method according to claim 3,
The temperature sensor is configured to include a plurality of temperature detection elements,
The control module may include: a specific resistance value correcting unit for correcting specific resistance values of the plurality of temperature detection devices;
A three-phase induction motor system for driving an air conditioner compressor of a diesel locomotive further comprising a.

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