KR102064176B1 - Integrated control system for electrical installation systems with maximum efficiency point control and fault diagnosis of motor - Google Patents

Abstract

The present invention relates to an integrated control system for an electric facility system, capable of controlling a maximum efficiency point of a motor and diagnosing a failure, which comprises: a degradation monitoring device; a motor for driving a facility device; an inverter for varying a motor speed; a motor control device for performing a maximum efficiency point control operation and a failure diagnosis operation; and a remote control device.

Description

Integrated control system for electrical installation systems with maximum efficiency point control and fault diagnosis of motor

The present invention provides an integrated control system for an electrical installation system capable of controlling the maximum efficiency point of the motor and monitoring the failure of the motor through the real-time measurement of the input and output power of the inverter. It's about the system.

Electric power consumption by motor is 70% of industrial power in manufacturing field, and it is one of the energy consumption devices which occupies a very large part of national power consumption. The average lifespan of a motor is more than 15 years, and considering the life cycle cost, the energy cost accounts for more than 96%, which is one of the effective means of reducing power consumption.

High efficiency motors are receiving great attention in terms of environmental conservation, power reduction, and cost reduction, and the demand for inverters along with inverter driving motors is increasing to save energy and improve efficiency of energy use.

Motors with quadratic reduction load characteristics, such as fans and pumps, can save energy because the amount of power is proportional to the third power of the rotational speed, eliminating unnecessary extra horsepower when controlling the optimum speed according to the load characteristics. Since the operation rate is determined based on the driver's experience and knowledge in the field, it is operating beyond the horsepower required.

Temperature, vibration, and electrical monitoring techniques are being applied to the failure analysis of the motor. However, the temperature and vibration sensors are practically difficult in industrial applications.

On the other hand, the main industry to apply a motor having a square power reduction, there is a sewage terminal treatment plant, a ventilation system of a factory, etc. At this time, there is a problem that the motor is operated more than necessary horsepower in the field. In addition, the motor continues to run without pause, there is also a problem that there is a lack of measures for maintenance or failure.

Domestic Patent No. 10-1776163 (Registration date September 01, 2017)

In order to solve the above problems, the present invention is to control the maximum efficiency point of the motor through the real-time measurement of the input and output power of the inverter and control the maximum efficiency point of the new type of motor to monitor whether the motor failure And to provide an integrated control system for electrical installation system capable of diagnosing failure.

In addition, the integrated control system for the electric installation system that can control the maximum efficiency point of the motor and diagnose the failure, which can eliminate the unnecessary horsepower and prevent the waste of energy in advance by controlling the speed of the motor with the square reduction by the maximum efficiency point control method. To provide.

In addition, to provide an integrated control system for electric equipment systems that can predict the failure of the motor and control the maximum efficiency point of the motor and diagnose the failure to save the power data in the event of motor or inverter failure for more reliable analysis of the cause of the failure. do.

The object of the present invention is not limited to the above-mentioned object, and other objects which are not mentioned will be clearly understood by those skilled in the art from the following description.

As a means for solving the above problems, the integrated control system for an electrical equipment system capable of controlling the maximum efficiency point and fault diagnosis of the motor according to an embodiment of the present invention, based on at least one of the ultrasonic generation state and the temperature state A deterioration monitoring device for checking and notifying a deterioration state of the facility system; A motor for driving a facility in the electric facility system; An inverter that varies a motor speed through at least one of an output voltage and an output frequency to the motor; A motor control device configured to measure and analyze input and output power of the inverter to perform a maximum efficiency point control operation and a failure diagnosis operation; And a remote control device for remotely controlling the operation of the electric installation system and simultaneously monitoring the operation state of the electric installation system, the motor, and the inverter, wherein the motor control device includes a voltage installed at an input terminal and an output terminal of the inverter. And a power sensing unit configured to measure and notify input power and output power of the inverter through current sensors. A data processing unit configured to extract and output at least one of active power, reactive power, apparent power, accumulated power amount, frequency, phase, and power factor data from at least one of the input power and the output power; A motor speed detector configured to determine a motor speed and a motor torque based on the frequency of the output power; A motor failure detection unit checking a phase and magnitude of an output current after performing dq conversion on the output power, and checking and notifying a motor failure when the phase and magnitude of the output current are unbalanced; And when the command speed is initially input, the motor speed is controlled according to the command speed. After the motor speed is equal to the command speed, the input / output power at the present time is determined based on the active power and the reactive power of the input power and the output power. A motor that calculates the effective power ratio x (n) and repeatedly controls the motor speed so that the deviation from the calculated effective power ratio x (n-1) of the input / output power at the previous point in time is minimized. It may include an efficiency control unit.

The motor efficiency control unit may further include a function of adjusting at least one of an output voltage and an output frequency of the inverter according to a control result of the motor speed.

"에 따라 산출하며, 상기 Pout-d는 출력 무효 전력, 상기 Pout-q는 출력 유효 전력, 상기 Pin-d는 입력 무효 전력, 상기 Pin-q는 입력 유효 전력인 것을 특징으로 한다.The motor efficiency controller determines the effective power ratio x (n) of the input / output power at the present time.

Pout-d is output reactive power, Pout-q is output active power, Pin-d is input reactive power, and Pin-q is input active power.

The motor efficiency control unit changes the effective power ratio change value y (n) = (x (n-1) -x (n)) of the input / output power at the present time point n and the input / output power at the past time point n-1. After acquiring and comparing the effective power ratio change value y (n) = (x (n-1) -x (n)), the motor speed control operation is performed only when the same state of the comparison is repeated for a predetermined number of times or more. It characterized in that to perform.

At this time, the motor efficiency control unit decreases the motor speed when the change value y (n-1) of the past time point is larger than the change value y (n) of the present time point while the motor speed is not increased. When the motor speed is increased, and the motor speed is increased, the motor speed is decreased when the change value y (n-1) of the past time point is larger than the change value y (n) of the current time point. It is characterized by increasing the.

The motor control apparatus may further include a display unit which visually visualizes and outputs information related to the operation of the motor control apparatus.

The integrated control system for an electric equipment system capable of controlling the maximum efficiency point of the motor and diagnosing a fault of the present invention performs a maximum efficiency point control of the motor through real-time measurement of the motor driving the electrical equipment, thereby achieving a motor having a square power reduction. Eliminates unnecessary horsepower to prevent energy waste.

In addition, by enabling the prediction and notification of motor failures, the cost and time required for motor management can be significantly reduced.

1 is a view showing an integrated control system for an electrical installation system capable of controlling the maximum efficiency point and fault diagnosis of a motor according to an embodiment of the present invention.
2 to 6 are views showing screens provided with a remote control and energy degradation monitoring system according to an embodiment of the present invention.
7 is a diagram illustrating a motor control apparatus capable of controlling a maximum efficiency point of a motor and diagnosing a failure according to an embodiment of the present invention.
8 is a view for explaining a motor speed measuring method of the motor control apparatus according to an embodiment of the present invention.
9 and 10 are views for explaining a method of determining whether a motor failure of the motor control apparatus according to an embodiment of the present invention.
11 is a view for explaining a method of controlling the maximum efficiency point of the motor of the motor control apparatus according to an embodiment of the present invention.
12 is a view for explaining the power efficiency according to the motor maximum efficiency point control method of the motor control apparatus according to an embodiment of the present invention.

The objects and effects of the present invention and the technical configurations for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators.

However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms. The present embodiments are merely provided to complete the disclosure of the present invention and to fully inform the scope of the invention to those skilled in the art, and the present invention is defined by the scope of the claims. It will be. Therefore, the definition should be made based on the contents throughout the specification.

1 is a view showing an integrated control system for an electrical installation system capable of controlling the maximum efficiency point and fault diagnosis of the electrical installation system motor according to an embodiment of the present invention.

Referring to FIG. 1, the system 100 of the present invention is for remotely controlling and monitoring the operation of various electric equipments provided in a sewage terminal treatment system, a factory ventilation system, and the like. , An inverter 130, a motor control device 140, a facility sensor 150, a remote control device 160, and the like.

However, hereinafter, for convenience of explanation, the sewage terminal treatment system will be described as an example of the installation equipment, the pump provided in the electrical installation system, sewage terminal treatment system.

The deterioration monitoring apparatus 110 is distributed in the sewage terminal treatment system, and includes a plurality of ultrasonic sensors for detecting whether an arc or discharge occurs at each installation point and a temperature sensor for sensing a temperature. Based on the arc generation pattern and the temperature change pattern, the deterioration status of each installation point or the entire system is checked and notified.

The motor 120 actually drives the pump. In particular, the motor of the present invention is a quadratic reduction motor, the amount of power is proportional to the third power of the motor speed, it is possible to remove the unnecessary margin horsepower at the optimum speed control according to the load characteristics. In other words, the optimum speed control can significantly reduce the energy consumption.

The inverter 130 converts the input power to generate the output power, but changes the output voltage and the output frequency under the control of the motor controller 140. That is, the motor speed can be controlled through the output voltage and the output frequency.

The motor control device 140 includes a voltage sensor and a current sensor installed at each of an input terminal and an output terminal of the inverter 130, and measure the inverter input power and output power in real time. Then, the power conversion condition of the inverter 130 is adjusted at any time based on the measurement result, and at the same time, the calculation and notification of the failure of the motor 120 are performed.

The facility sensor 150 senses and notifies the operating environment of the electric facility system. For example, a sewage end treatment system may sense and report pump pressure, pump flow rate, tank level, automatic valve position, automatic valve opening rate, heater status, and the like.

The remote control device 160 remotely controls the operation of the electrical equipment system and simultaneously monitors the operation status of the electrical equipment system, the motor, and the inverter. In this case, the remote control device 160 uses a PLC communication method, a wireless communication method (for example, Long Range) together, an electric facility system, a degradation monitoring device 110, a motor control device 140, and a facility. Communicate with sensor 150 and the like. For example, the electrical monitoring system may communicate with the degradation monitoring device 110, the motor control device 140, and the facility sensor 150 in a wireless communication method with a PLC communication method.

In particular, the remote control device 160 of the present invention configures the control menu on a graphic basis, through which the pump driving environment setting, PLC and inverter settings, deterioration status monitoring, pump status monitoring, inverter status monitoring, equipment sensor monitoring, valve Various operations such as monitoring and control can be performed.

More specifically, by configuring and providing a driving environment setting screen as shown in FIG. 2, the user receives information about an operation setting value of a pump, a PLC setting value, an inverter and a deterioration monitoring device driving condition, and the like, and drives the system based thereon. Allows overall control of the environment.

Degradation monitoring results, motor speed, pump start, power information, cumulative flow rate information, flow meter, pressure gauge, pump status, heater status, tank status, valve status, sensor status, The inverter state, the operation mode, the automatic valve opening rate, and the like are identified, and a screen for collectively providing them to the user can be configured and provided as shown in FIG. 3.

Also, based on the information provided from the motor control device 140, the three-phase input voltage / current, three-phase output voltage / current, inverter efficiency, inverter vector, motor power factor, motor current speed, motor current torque, etc. It may also be able to provide additional through the screen as shown in FIG.

In addition, it saves and manages alarm occurrence conditions and analyzes the monitoring result value according to the alarm occurrence conditions to determine whether an alarm has occurred. When an alarm occurs, the alarm screen as shown in FIG. 6 is displayed to identify the current problem more quickly and allow the user to immediately take a follow-up action corresponding to the current state.

In addition, the remote control device 160 stores and manages electric system control values and monitoring values, and can also retrieve and view necessary data at the user's request. In particular, if the motor failure state is maintained for more than a certain time, the drive is stopped by the inverter, and the data of the motor failure state detection section (or the section before the detection of the motor failure state) is stored, so that the user can later determine the cause of the failure. Allow for precise analysis.

7 is a diagram illustrating a motor control apparatus capable of controlling a maximum efficiency point of a motor and diagnosing a failure according to an embodiment of the present invention.

Referring to FIG. 7, the motor control apparatus of the present invention includes a power sensing unit 411 to 414, a data processing unit 420, a motor speed detector 430, a motor failure detector 440, and a motor efficiency controller 450. , And the communication unit 460 and the like.

 The power sensing units 411 to 414 are three-phase voltage sensors 411 and three-phase current sensors 412 connected to the input terminal of the inverter 130, three-phase voltage sensors 411 and three connected to the output terminals of the inverter 130. A phase current sensor 412 is provided through which the input voltage, input current, output voltage, and output current of the inverter 130 are measured and reported.

The data processing unit 420 has an input of the inverter 130 having a frequency of 60 Hz fixed by a system three-phase voltage and current. Therefore, the inverter input is digitally detected by sampling at 1920Hz (32 Sample) and processed into necessary data through discrete Fourier transform and frequency calculation. For example, it may be possible to obtain and output effective, reactive, apparent, cumulative power amounts and frequency, phase, and power factor data of input / output power from input / output power.

The motor state detecting unit 430 determines the motor speed and the motor torque based on the frequency of the output voltage or the output current measured by the power sensing units 411 to 414.

For reference, unlike the input power of the inverter 130, since the output power of the inverter has a variable frequency (motor speed), a separate analog circuit for frequency measurement is required. Accordingly, the present invention includes a zero crossing detector configured as shown in FIG. 8, and detects the frequency of the output voltage or the output current. Then, the current detected frequency is converted into motor speed according to Equation 1.

[Equation 1]

At this time, the number of motor poles is a constant value determined according to the motor type.

The motor torque may also be calculated by Equation 2 based on the motor speed of Equation 1.

[Equation 2]

At this time, the motor efficiency is a constant value determined according to the motor type.

The motor failure detection unit 440 performs a dq conversion on the output voltage and the output current, and checks whether or not an unbalance condition occurs based on the dq conversion result, so as to confirm and notify the failure of the motor. That is, in the present invention, it is possible to determine whether the failure of the motor through the dq conversion of the output voltage / current of the inverter.

The d-axis is the axis in which the magnetic flux of the motor is generated and is selected in the direction of the magnetic flux generated in the stator U-phase winding, and the q-axis is selected as the axis of the current generating torque in the axis perpendicular to the d-axis.

When the output voltage / current of the inverter is expressed in the stationary coordinate system and the rotational coordinate system through the conversion of dq, the signal generation pattern in each coordinate system is completely different depending on whether the motor is broken as shown in FIGS. 9 and 10. This is because the voltage and current of a normal motor have the same phase and magnitude, but the voltage and current of a faulty motor have the phase and magnitude of an unbalanced state.

Therefore, in the present invention, after converting the output voltage / current of the inverter dq, it is easy to check whether the motor failure through the signal generation pattern at this time.

The stationary coordinate system is a coordinate system in which the coordinate axis is not rotated and is stopped, and may be expressed as in Equation 3 below.

[Equation 3]

The rotation coordinate system is a coordinate system that also rotates the d-q axis together in the direction of the stationary coordinate vector sum, which is a coordinate system that rotates at an angular velocity w, and can be obtained as the rotation coordinate system from the stationary coordinate system as in Equation 4. At this time, each speed can be obtained by the frequency value of the voltage.

[Equation 4]

The motor efficiency control unit 450 may vary the motor speed from time to time in the maximum efficiency point control scheme, thereby minimizing energy consumption by the motor. To this end, when the command speed is initially input, the motor speed is controlled according to the command speed. After the motor speed is equal to the command speed, the input / output at the present time is based on the active power and the reactive power of the input power and the output power. The effective and non-effective power ratio x (n) of the electric power is calculated, and the motor speed is repeatedly controlled so that the deviation from the calculated and invalid power ratio (x (n)) of the input / output power at the past point in time is minimized. In addition, at least one of the output voltage and the output frequency of the inverter 130 is further controlled according to the control result of the motor speed, thereby allowing the motor speed to be substantially changed.

The communication unit 460 may include a wired communication module and a wireless communication module for supporting wired or wireless communication with the remote control device 160 and the inverter 130. It communicates through a wireless communication method such as Long Range, and communicates with the inverter 130 through a wired communication method such as Ethernet. Of course, if necessary, it is provided with a wired communication module such as RS 232/422/485, it is possible to directly communicate with various external devices through them.

The display unit 470 may include a monitor, an alarm device, a speaker, and the like, and may visually guide various data acquired through the motor control device. For example, it is possible to visually or audibly provide information on an effective power amount, reactive power amount, apparent power amount, cumulative power amount, power frequency, phase, power factor data, motor speed, motor torque, and motor failure.

11 is a view for explaining a method of controlling the maximum efficiency point of the motor of the motor control apparatus according to an embodiment of the present invention.

First, when a command for a rated speed of the motor and a rated load (for example, 100%) is input (S1), the motor control apparatus 140 may output the motor speed through at least one of the output voltage and the output frequency of the inverter 130. Start to control.

Then, the motor controller 140 starts to detect the motor speed (S2), and if the monster speed is equal to the commanded speed (S3), the motor controller 140 measures the inverter input and output power at this time, From this it is to extract the input active / reactive power and output active / reactive power (S4).

And based on Equation 5 to calculate the effective power ratio (x (n)) of the input and output power from the input active / reactive power and the output active / reactive power (S5).

[Equation 5]

At this time, Pout-d is output reactive power, Pout-q is output active power, Pin-d is input reactive power, and Pin-q is input active power.

After checking whether the motor speed is increased (S6), if it does not increase, execute the "No" statement, and if it increases, execute the "Yes" statement.

First, in the "No" syntax, the effective power ratio change value y (n) = (x (n-1) -x (n)) of the input / output power at the current time point n is calculated, and then the change value of the current time point ( y (n)) and the change value y (n-1) of the past time point are compared (S7).

As a result of the comparison of step S7, when the change value y (n-1) of the past viewpoint is larger than the change value y (n) of the present viewpoint (S8), the effective power ratio x (n) and the change value of the present viewpoint After updating (y (n)) to past viewpoint values (x (n-1), y (n-1)) (S9), it is checked whether the same state occurs 10 times or more continuously (S10). That is, in consideration of external disturbance or noise of input / output, the error rate may be changed very largely, and it is determined that the current motor is not optimal efficiency only when the same state is repeated 10 times or more continuously.

If the same state is repeated 10 times or more continuously, after initializing the number of repetitions (count) to "0" (S11), the current motor speed is reduced by a predetermined value (3%) so that the motor efficiency can be optimized ( S12).

As a result of the comparison of step S7, if the change value y (n-1) of the past viewpoint is smaller than the change value y (n) of the present viewpoint (S8), the effective power ratio x (n) of the present viewpoint. And the change value y (n) are updated to past viewpoint values x (n-1) and y (n-1) (S13).

If the same state is repeated 10 times or more consecutively (S14), the number of repetitions (count) is initialized to "0" (S15), and the current motor speed is increased by a preset value (3%) so that the motor efficiency can be adjusted. (S16).

Also, in the "Yes" syntax, the effective power ratio change value y (n) = (x (n-1) -x (n)) of the input / output power at the current point n is calculated, and then the change point y at the present point in time. (n)) and the change value (y (n-1)) of the past time point (S17).

As a result of the comparison of step S17, if the change value y (n-1) of the past viewpoint is larger than the change value y (n) of the present viewpoint (S18), the effective power ratio x (n) and the change value of the present viewpoint (y (n)) is updated with past viewpoint values (x (n-1), y (n-1)) (S19).

If the same state is repeated 10 times or more continuously (S20), after initializing the number of repetitions (count) to "0" (S21), the motor efficiency can be optimized by reducing the current motor speed by a preset value (3%). (S22).

On the other hand, when the comparison result of step S17 shows that the change value y (n-1) of the past viewpoint is smaller than the change value y (n) of the present viewpoint (S18), the effective power ratio x (n) of the present viewpoint. ) And the change value y (n) are updated to past viewpoint values x (n-1) and y (n-1) (S23).

When the same state is repeated 10 times or more continuously (S24), after initializing the number of repetitions (count) to "0" (S25), the motor efficiency can be adjusted by increasing the current motor speed by a preset value (3%). (S26).

12 is a view for explaining the power efficiency according to the motor maximum efficiency point control method of the motor control apparatus according to an embodiment of the present invention.

As shown in Figure 12, the present invention by varying the motor speed from time to time, so that the motor efficiency can be maximized, it can be seen that the energy consumption (apparent power) can be effectively reduced unlike the rated operation.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims (6)

A deterioration monitoring device for checking and notifying a deterioration state of the electrical installation system based on at least one of the ultrasonic generation state and the temperature state;
A motor for driving a facility in the electric facility system;
An inverter that varies a motor speed through at least one of an output voltage and an output frequency to the motor;
A motor control device configured to measure and analyze input and output power of the inverter to perform a maximum efficiency point control operation and a failure diagnosis operation; And
Remote control device for remotely controlling the operation of the electrical equipment system and at the same time monitoring the operating state of the electrical equipment system, the motor, the inverter,
The motor control device
A power sensing unit configured to measure and notify input power and output power of the inverter through voltage and current sensors installed at input and output terminals of the inverter;
A data processing unit configured to extract and output at least one of active power, reactive power, apparent power, accumulated power amount, frequency, phase, and power factor data from at least one of the input power and the output power;
A motor speed detector configured to determine a motor speed and a motor torque based on the frequency of the output power;
A motor failure detector for checking a phase and magnitude of an output current after performing a dq conversion on the output power, and checking and notifying a motor failure if the phase and magnitude of the output current are unbalanced; And
When the command speed is initially input, the motor speed is controlled according to the command speed. After the motor speed becomes equal to the command speed, the input / output power at the present time is based on the active power and the reactive power of the input power and the output power. The motor efficiency for calculating the reactive power ratio x (n) and repeatedly controlling the motor speed so that the deviation from the calculated effective power ratio x (n-1) of the input / output power at the past time point is minimized. A control unit;
The motor efficiency control unit
Change in the effective power ratio of the input / output power at the present time point n (y (n) = (x (n-1) -x (n)) and change in the effective power ratio of the input / output power at the past point in time n-1. After acquiring and comparing (y (n) = (x (n-1) -x (n)), the motor speed control operation is performed only when the same state of the comparison results in a repetition more than a preset number of times. Integrated control system for electrical installation system that can control the maximum efficiency point of the motor and diagnose the fault. The method of claim 1, wherein the motor efficiency control unit
And controlling at least one of an output voltage and an output frequency of the inverter according to the control result of the motor speed. The method of claim 1, wherein the motor efficiency control unit
The effective power ratio (x (n)) of input / output power at the present time is "

And Pout-d is output reactive power, Pout-q is output active power, Pin-d is input reactive power, and Pin-q is input effective power. Integrated control system for electrical installation systems with point control and fault diagnosis. delete The method of claim 1, wherein the motor efficiency control unit
In the non-motor speed increase state, when the change value y (n-1) of the past time point is larger than the change value y (n) of the present time point, the motor speed is decreased, and when it is small, the motor speed is increased,
In the motor speed increasing state, when the change value y (n-1) of the past time point is larger than the change value y (n) of the present time point, the motor speed is decreased, and when it is small, the motor speed is increased. Integrated control system for electrical installation systems that allows maximum efficiency control and fault diagnosis of motors. The method of claim 1,
An integrated control system for an electrical installation system capable of controlling the maximum efficiency point of the motor and diagnosing a failure, further comprising a display unit which visually visualizes and outputs information related to the operation of the motor control apparatus.

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