KR20240154183A - Scb device : smart control for brake horsepower device - Google Patents

Abstract

A smart shaft power control device using an inverter is disclosed, which independently controls a motor according to an embodiment of the present invention, detects shaft power itself, which is the sum of a transfer coefficient and a passive power connected to the motor, as an apparent current (Ia) which is electrical energy, classifies the phase difference between the apparent current (Ia) and the active current (Ir), and then converts the value of the active current into DC 4 to 20 mA to control the inverter.

Description

Smart shaft power control device using inverter {SCB DEVICE: SMART CONTROL FOR BRAKE HORSEPOWER DEVICE}

The present invention independently controls the motor, detects the shaft power itself, which is the sum of the transmission coefficient and the passive power connected to the motor, as an apparent current (Ia), which is electric energy, classifies the phase difference between the apparent current (Ia) and the active current (Ir), and then converts the value of the active current to DC 4 to 20 mA to control the inverter, thereby obtaining the general device efficiency formula. When,

Electrical efficiency , in other words So,

When applying the control characteristics of the present invention If the relationship is established and expressed as the torque (To), which is the rotational power of the motor,

To (Nm) becomes

Load torque pump shaft power (TL)

Blower and fan shaft power (TL) Become

TLAs a result, the holding torque (To) and the load torque (TL) are The relationship is established. To

TL

TL 상태를 유지하기 위해 TL에 맞추어 따라가게 되는 형상으로서,This is similar to the relationship between the impedance of the power-side holding torque (Zo) and the impedance of the load torque (ZL) being Zo ZL. In other words, when looking at this from the load ratio aspect of the motor, the power-side holding torque (To) is To regardless of the load ratio that changes in the work process.

As a shape that follows the TL to maintain the TL state,

1) Efficiency is maximized and maintained at 98~99.99%.

2) The loss is improved to close to “0”,

3) It is a system that always supplies the optimal power consumption, that is, only the electric energy necessary to perform the work process, thereby realizing the lowest power consumption, optimal device efficiency, and minimum loss.

And the present invention pursues energy rationalization through optimal control technology and combines two types of automatic control: dynamic characteristic and static characteristic functions. Here, the dynamic characteristic is a PI (Proportion Integral) value that outputs an output value in proportion to the input (Input Scanning) value, and the static characteristic is a function that outputs an output inversely proportional to the input (Input Scanning) value, thereby outputting a value inversely proportional to the input value or the same as the input value to maintain a constant amount or pressure.

The Smart Control for Brake Horsepower Device (SCB DEVICE) using an inverter mainly includes the rotation speed and torque of the motor, and it has the following functions: detection of voltage and current, detection and command by the scanning delay system in detection, dynamic and static characteristic functions by forward and reverse control, automatic and manual functions, sensor and sensorless, basic rate reduction function among the components of electricity rates by demand control, 485 and network communication functions, etc. All of these functions are configured with a digital touch screen.

In general, the control methods of motors include VS (Variable Speed Control), VVVF (Variable Voltage Variable Frequency: Inverter), Magnetic Control, etc., and among these, the main inverter control includes reduced torque control, vector control, sensorless vector control, and sensor feedback control. Here, the technology of the present invention belongs to “sensorless auto shaft power control” or “smart shaft power control.”

Meanwhile, there may be concerns about mistaking the differences between sensorless vector control and the present invention, so the differences are mentioned as follows.

1) Sensorless vector control is a type of vector control method. While general vector control targets torque current (it) and flux current (i∮) as controls, sensorless vector control targets torque voltage (Vts) and flux voltage (V∮s) as controls to maintain torque and flux in a vector manner. Although a speed detection sensor is required for vector control, sensorless vector control refers to the function of commanding the frequency as a value close to the speed by a speed estimation circuit.

2) The sensorless control function of the smart shaft power control device is a V/F pattern function that determines which frequency is appropriate for the changing supply voltage in the V.V.V.F action, as the sensorless vector control above is ultimately intended to create a vector phase between torque and magnetic flux, whereas this technology is a technology that supplies the V/F pattern mentioned above but determines the optimal V/F pattern position suitable for the appropriate shaft power, and can be said to be a technology that selects and utilizes the V/F pattern position of the inverter that applies sensorless vector control to match the optimal shaft power.

And the feedback control mostly applied in industrial sites is a 100% analog control method, and it is known that there are many errors due to the occurrence of noise and harmonics, and that the decision values mostly fluctuate, so the efficiency and accuracy are low. However, the technology of the present invention has secured a technology that far surpasses analog in terms of increased efficiency and accuracy by modulating the signal from analog to digital again and digitizing it 100%.

Republic of Korea Patent No. 10-2075875

The present invention was derived from the background described above, and aims to optimize shaft power by a touch screen method through digitalization to consume minimal electric energy, while also implementing automatic control. In addition, the purpose is to provide a new motor control method capable of stably and optimally performing speed control, slip control, torque control, automatic dynamic characteristic control, and static characteristic control of the motor.

In order to achieve the above-mentioned purpose, the two major aspects of the present invention are a means for generating and generating pulses corresponding to the rotational speed of the motor through an inverter that supplies voltage and frequency to the motor, a means for detecting the current supplied to the motor, and a means for feeding back information acquired through the means for detecting the current and performing proportional/integral/computation to perform a speed command by the power reserve torque of the inverter, also known as power torque (To).

TL의 관계가 성립되도록 구성하는 모터제어장치를 제공한다(아래는 부하토크 생성도).This power torque (To) drives the inverter by a signal of DC 4 to 20 mA, so the power transmitted, i.e. the power torque (To), and the power consumed (shaft power), i.e. the load torque (TL), are always To.

A motor control device configured to establish a TL relationship is provided (load torque generation diagram below).

Among the electric energy generated by the above axial force, the current is detected and sent to the C.P.U. and then converted to 4 to 20 mA. This means that when the relationship between the power torque (To) and the load torque (TL) becomes To > TL, the power reserve torque is recognized as being slightly greater than the load torque, so the number of mA supplied from the Main CPU decreases so that the value of To decreases. On the contrary, when the state To < TL, the power reserve torque is recognized as being slightly smaller than the load torque, so the rotational power of the motor may decrease or stop, so the value of To is increased so that the To TL relationship is always maintained. And all of these operation signals are processed within 1/100,000 sec, which is the processing speed of the Main CPU.

출력값과 같은 논리가 성립되므로, 일반적인 모터의 경우에 부하율이 변동되면 효율(역율)도 함께 변화되는데, 농형유도전동기(squirrel cage induction motor)의 경우에는 정격 부하율이 100%일 때 효율은 83%가 되고, 부하율을 50%로 가정한다면 {0.83×0.5=0.415(41.5%)}로 낮아지게 되지만, 본 발명의 경우에는 부하율의 높낮이에 관계없이 항상 98~99%의 효율(역율)을 유지하게 된다.In this way, the relationship between input (power sent: power torque) and output (power used: load torque) is the input value

Since the same logic as the output value is established, in the case of a general motor, when the load ratio changes, the efficiency (power factor) also changes. In the case of a squirrel cage induction motor, the efficiency is 83% when the rated load ratio is 100%, and if the load ratio is assumed to be 50%, it decreases to {0.83 × 0.5 = 0.415 (41.5%)}, but in the case of the present invention, the efficiency (power factor) is always maintained at 98 to 99% regardless of the high or low load ratio.

And the present invention adds an electric energy saving function by the optimal control method mentioned above, and adds a super economic function, also known as a scanning delay time function. This is a function that sets an appropriate scanning delay time as shown in Figure 3 and provides a command with an average value during the scanning delay time when there is a rapid change in power due to frequent changes in shaft power and the ups and downs are severe like waves, or resistance such as cavitation, surging, and vapor lock occurring in the pipeline. This is a function that enables smooth cruise control by setting an appropriate scanning delay time and providing a command. This is the same principle as when a driver frequently and suddenly uses the accelerator or brake when driving a car, fuel consumption increases.

In addition, the present invention has an external command control function. In general, in order to lower the basic rate in the electricity bill, there is a device that temporarily blocks the operation when a situation occurs in which the capacity of the electricity supply contract is exceeded only for non-essential loads such as water pumps and fans by the demand controller, but it cannot be applied to essential loads belonging to the production process because the operation cannot be blocked. However, in the present invention, there is an external command function that can be applied to essential loads as well, which is a function that slows down from slow up. This is a function that slows down the height of the corresponding load in the work process when an “ON” or “OFF” signal is input from the demand controller, which is an external signal, and then returns to the original state and is automatically controlled after a few seconds when the peak value of the load decreases. If this function is actually introduced, it can greatly contribute to reducing the basic rate in the electricity bill.

In addition, the present invention has an auto chasing control of shaft power. This is not a method in which a person sets the highest and lowest points of the work process, sets a limit point, and then operates, but a function that automatically determines the shaft power required to perform the work process and operates it. If pipeline resistance such as cavitation, surging, or vapor lock occurs in a pump or blower, the fluid will fluctuate and the shaft power itself will fluctuate significantly due to this, but this is unrelated to the power required to perform the work process. Therefore, as shown in Fig. 2, the torque command value including PI and differential control (D) is calculated using the mathematical formula of Equation 4 as a function of selecting the lowest point of the same period and utilizing the process cycle value, and if the torque command value is greater than the target torque (TL) of the previous cycle, the target value (To) of the previous cycle is set as the torque command value To(t) of the next cycle, and if the torque compensation value (Tot) is less than or equal to the previous target value (To), the target torque (TL) of the previous cycle is compensated to calculate the torque command value To(t) of the next cycle. The purpose of this function is to implement the best production rationalization while consuming the optimal power consumption, and it can be implemented by selecting the 1 minute, 2 minutes, and 3 minute modes, or it can be continuously and repeatedly implemented.

This is shown in the configuration diagram (attached figures 5, 6, 7), and the generation cycle is as shown in Figure 2.

In addition, the present invention is a function that automatically responds to changes in the opening and closing degree of the valve or damper, the pipe resistance, etc. described above in the work process of a cooling water pump, a cold water pump, a refrigerant pump, a hot water pump, and a fan to determine the operating point. On the other hand, this technology is a function that simultaneously increases and decreases the frequency according to the degree of temperature rise and fall when the ambient temperature changes at the preset operating point. This applies the logic of Joule's law in thermodynamics, "the logic of the energy (H) required to raise the temperature of 1g (gram) of water by 1℃ (H = 1cal = 4.186 (Joul: Watt) ≒ 4.2 (Joul: Watt))". At this time, the thermocouple that detects the ambient temperature must select a wire type, and the transmitter must be a micro type mounted on the outer frame of the device to which the present invention is applied so as to react instantaneously to changes in the external ambient temperature. In addition, since the control signal of the present invention is 4 to 20 mA, if the thermocouple signal is selected as 4 to 20 mA, the input signal of the CPU cannot be OR (logical sum), so a circuit configuration that changes the thermocouple signal 4 to 20 mA into a variable resistance value so that logical sum can be formed is a prerequisite.

The present invention applies a new algorithm to the torque detection unit (105) of the electric energy (motor power consumption) generated by the shaft power (Figure 1) and applies the P.I.D control and the main CPU (106) to perform torque control, speed control, and automatic control of dynamic and static characteristics of the motor in parallel, thereby obtaining the effect of saving electric energy through optimal control of the motor power load and performing automatic control of the motor.

Figure 1 is a flow chart of the torque control method of the present invention.
Figure 2 is a block diagram (100) of a main control board according to an embodiment of the present invention.
Figure 3 is a block diagram (200) of an LCD control board according to an embodiment of the present invention.
Figure 4 is a power supply block diagram.
Figure 5 is a power circuit diagram.
Fig. 6 is a switching power circuit.
Figure 7 shows the main CPU section.
Fig. 8 is the PWM output section.
Figure 9 shows the CT AC load current input circuit.
Fig. 10 is a 485 communication circuit.
Figure 11 is a circuit diagram of the environmental control function.

Hereinafter, more specific embodiments of the present invention will be described based on the drawings and attachments described below. For reference, in the present specification, when one element is connected, coupled, or electrically connected (wired) with another element, it includes not only cases where it is directly connected, coupled, or electrically connected (wired) with another element, but also cases where it is indirectly connected, coupled, or electrically connected (wired) with another element in between.

Also, when one component is directly connected or directly combined with another component, it means that no other element is intervening. Also, when a part includes or has a certain component, it does not mean that it excludes other components, but rather that it also includes or has other components, unless there is a specific description to the contrary.

The “smart shaft power control device (also known as a motor power load control device)” of the present invention, as shown in the drawings of FIGS. 1, 2, and 3, includes a main power supply unit (118), a power operation unit (117), an inverter (114) for supplying driving power to a motor (116), a main CPU (106), a serial communication controller (102), a power regulator (103), a shaft power load current detector (104), a switching power supply (119), an auxiliary CPU (105), a touch A/D converter (203), a backlight controller (104), an SD RAM (207), an SD Memory (208), a touch LCD panel (201), a 485 communication port (112), a network communication port (113), etc.

In addition, it includes auxiliary control functions such as an auto chasing controller (101), scanning delay time function, environment control function (environment controller: 107), and external command controller (demand controller: 109), and these are transmitted to the main CPU (106) through a serial communication controller (102) by a digital signal from the auxiliary CPU (coprocessor: 204), and all commands are made by a touch LCD (201).

The inverter (114) converts AC → DC → AC using a number of switching elements (FET, IGBT, etc.). In addition, a power supply for supplying power to the inverter and a direct connection (bypass) function for allowing power to be supplied without going through the inverter in the event of an abnormality are configured, and a PWM signal generated from the Main CPU (106) is input to the gate terminal or base terminal of a number of switching elements that can utilize the inverter function. In the torque control method flow chart (Fig. 1), the detection value of the set or input parameter, that is, the torque generation step of the main power supply 3 input unit, starts from the main power supply 3 torque generation step (118) and is transmitted to the Main CPU (106) through the power input current detector (110), and the current detection value generated from the Main CPU (106) is transmitted to the torque command device (111: To) through the switching power device (119) to drive the inverter (114). Meanwhile, the inverter output value (115) is transmitted to the shaft power load current detector (current amplification and phase conversion unit: 104) and the load torque detector (105: TL), which is then converted into the values of the power reserve torque value (To) and the load torque (TL) in the main CPU.

The P.I.D controller value formed in the Main CPU is transmitted from the torque command device (111) to the inverter (114) as the power reserve torque value (To) through the switching power device (119), and the load current (shaft power) value (104) output from the inverter is displayed as the load torque detection value (105: TL) by the shaft power and transmitted again to the Main CPU (106), and the power input current detector (110) value is transmitted to the inverter (114) again through the Main CPU (106), and the load torque (105: TL) is detected through the shaft power detector (104) and then supplied to the Main CPU, which is repeated. At this time, if the torque command and torque compensation value do not meet the condition of To TL, the deviation is corrected in the deviation corrector (120), and then the power reserve torque value (To) is transmitted to the torque command device, which is also repeated.

In addition, all data values of the Main CPU (106) and the torque command device (To: 111) that calculate the P.I.D control and the torque command and torque compensation reference values are transmitted to the auxiliary CPU (205) through the serial communication controller (102), and the values of the shaft power automatic tracking command device (101), the environment controller (107), the external command device (109), the scanning delay controller (120), etc., which are various command values generated through the touch screen (201), are transmitted to the auxiliary CPU (205) through the touch A/D converter (203), and the values through the serial communication controller (102) are repeatedly transmitted to the Main CPU (106).

Below, the Main CPU configuration is described in detail with reference to FIG. 2. The Main CPU is responsible for functions such as P.I.D (proportional, integral, differential) control and torque command and torque compensation reference value calculation, and is responsible for the shaft power automatic tracking function (Auto Chasing Circuit: 101), external command function (Demand Control Circuit: 109), environment control function (Environment Control Circuit: 107), scanning delay control function (Scanning Delay Control Circuit: 120), etc. commanded through the touch LCD in the auxiliary CPU Corprocessor (205), and in addition, it includes functions such as a serial communication controller (Serial Communication Controller: 102), a 485 communication port (RS 485 Com. Port: 112), and a network communication (Ethernet Com. Port: 113) to perform the various commands mentioned above through the touch screen (201).

Meanwhile, the auxiliary CPU (Aux. Coprocessor: 205), which is linked to the Touch LCD (Touch LCD: 201) and includes various command and setting functions, provides various command and control functions and setting functions through the Serial Communication Controller (Serial Communication Controller: 102), and includes an SD RAM (Synchronous Dynamic Random Access Memory: 207) for data storage, a synchronous memory card (SD Memory Card: 208), and a backlight controller (Back Light Controller: 203) for the Touch LCD (201).

Also, among the detailed functions included in the Main CPU (106) and the Auxiliary CPU (204), the shaft power automatic tracking command device (aka Auto Chasing Controller; Automatic Chasing Controller: 101, Figure 8 forms a separate program in the Auxiliary CPU (204) and has the components as shown in Figure 8, and more specifically, as shown in Figures 1 and 2, the shaft power load current detection function (115, 104) automatically determines the operating pattern (Pattern) by calculating the lowest point (Min) among the maximum (Max) and the lowest point among the minimum (Min) during one (One Cycle), two (Two Cycle), and three (Three Cycle) process cycles as shown in Figure 2, and then drives with that value, and this is repeated every three minutes.

In addition, the scanning delay controller (120) is formed by a separate program in the auxiliary CPU (204) as shown in Figure 3 below, and in more detail, when the value of the shaft power load current detection function (115, 104) has a large fluctuation and shakes, it calculates the average for the set time of 1 second, 2 seconds, ......, 10 seconds, and then commands the main CPU (106) as the average value through the torque command unit (111). This is similar to the case where a lot of fuel is consumed when the accelerator or brake is frequently applied or used when driving a car, and it is a supplementary function to prepare for cases such as the above that occur due to external factors in addition to the basic optimal driving function. In fact, through testing in industrial settings, we found that when pipe resistance such as cavitation, surging, and vapor lock occurs in the pipe, an average of 5-7% more power is consumed, and as a result of applying this function, it was confirmed that more than 5% more electric energy was saved in power consumption compared to previous cases.

In addition, an external command controller (Demand Controller: 109) is formed by a separate program as shown in Figure 4 below, linked to the Main CPU (106) and the Auxiliary CPU (204) of Figures 1 and 2, and more specifically, when the DEMD (Demand) signal of Figure 7 is input (Normal Open), the input signal is transmitted to the Auxiliary CPU (204), and the Auxiliary CPU outputs a variable resistance value, and the signal output as the resistance value is transmitted to the Main CPU (106) and then combined with the input value of the inverter (114). In the past, when an external command (demand signal: to reduce the maximum demand power, i.e. the basic rate) was used in the process of the maximum demand power controller predicting and monitoring the current power being used and automatically cutting off and inputting the load so that it does not exceed the target power, the effect was minimal because it could only be applied to limitedly routinely used devices such as pumps and blowers. In addition, loads directly related to production, which are useful loads, could not be cut off because they would interfere with production activities, and could only be applied to non-useful loads unrelated to production.

However, if the demand control (109), which is a function of the present invention, is applied, it can be applied to all production fields including devices during industrial production. That is, as shown in Figure 4, when a demand signal is input, the auxiliary CPU (204) outputs a resistance value and transmits it to the main CPU (106), which then controls the inverter (114). This does not cut off the load device, but performs a slow down function that lowers it only for a short time (5 to 10 seconds) equal to the maximum demand power, and then returns after 5 to 10 seconds, and this is repeated. As a result, it is possible to reduce losses in industrial sites due to production interruptions, and also achieve a double effect of reducing the basic rate among electricity rates by more than 20%.

Next is an explanation of the environment control function (Environment Controller: 107). In the case of cooling water, cold water, and refrigerant pumps widely used in industrial sites, it is essential to maintain an appropriate flow rate to maintain or increase the efficiency of various devices for their intended use. This has a condition that cannot be directly affected by the ambient temperature. In a word, the pump capacity is determined after estimating the hottest temperature in the summer and calculating the flow rate required for the devices at that time. However, in various industrial sites, users overlook the diversification of energy consumption due to temperature changes in the four seasons and temperature differences such as day and night, and the reality is that they operate and use 100% of the facility capacity regardless. Accordingly, in order to realize the purpose of {appropriate maintenance flow rate + α function (ambient temperature) = optimal electric energy} required for appropriate cooling, the environmental control function (107) is linked to the Main CPU (106) through the auxiliary CPU (205) from the touch LCD (201) and the serial communication controller (102), and is repeatedly transmitted to the inverter (114) through the torque command device (111) from the Main CPU through the switching power (119) as shown in Fig. 11, which is formed by a separate program. What is important here is that the default value of the environmental control function circuit diagram (Fig. 11), Signal I (To TL), is always maintained, and the ambient temperature detection value, Signal II (4 to 20 mA or 0 to 10 V), becomes {Signal I + α (Signal II)}.

In addition, the motor control device according to an embodiment of the present invention can be used as a sensorless motor power load (optimal) control method, can be used for motor automatic control purposes, and can be applied for the purpose of saving electric energy of the motor power load.

And in terms of motor control methods, it is not necessarily limited to software, touch LCD, or sensorless control methods. It can be implemented with software or hardware, or a combination of software. In this case, hardware also includes application-specific integrated circuits (ASIC).

Although the preferred embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and may be implemented by being variously modified or altered in a specific application process. Even after being implemented by being modified or altered, if the technical matters of the present invention published in the patent claims mentioned below are included, it will be considered that it falls within the scope of the rights of the present invention.

119 : Input transformer
301 : Buzzer
302 : Power regulator
304 : Main CPU
305 : Torque command circuit
306 : Output transformer
307: Environmental adjustment function input signal I
308: Environmental adjustment function input signal II
M ; motor
CT : Transformer
To: Power reserve torque
TL: Load torque (shaft power)

Claims (1)

The power torque of the inverter, aka power torque (To), which performs a speed command by feeding back information obtained through the current detection means and performing proportional/integral/calculation, and generating and generating pulses corresponding to the rotational speed of the motor through the inverter that supplies voltage and frequency to the motor, detecting means for the current supplied to the motor, and performing the speed command.
(Mathematical formula 1)

The diet is formed,
This power torque (To) is characterized by being configured so that the power transmitted, i.e., the power torque (To), and the power consumed (shaft power), i.e., the load torque (TL), are always in a relationship between To TL by driving the inverter with a signal (Signal) of DC 4 to 20 mA.
Smart shaft power control device using inverter.