KR20030087863A - Method for checking invertor error - Google Patents

Abstract

PURPOSE: A method for inspecting an error of an inverter is provided to precisely inspect the error of the inverter by detecting overload and overheat of an inverter pump and an output frequency of an inverter section. CONSTITUTION: In an inverter mode, an error of an inverter section or an inverter pump is determined by detecting an abnormal signal transmitted from the inverter section(S1). If the inverter pump or the inverter section is normally operated, it is determined whether or not an operating frequency of the inverter pump calculated by an output frequency of the inverter section is in a normal state(S5). If the operating frequency of the inverter pump is in a normal sate, the inverter mode is maintained(S6). If the inverter pump or the inverter section is not operated properly or the operating frequency of the inverter pump is in an abnormal state, a sequential mode is carried out(S7).

Description

How to monitor inverter faults {Method for checking invertor error}

The present invention relates to an inverter fault monitoring method of a pressurized water supply system, and more particularly, to an inverter fault monitoring method capable of double monitoring of an inverter fault by sensing an abnormal state of an inverter section and an output frequency of the inverter section.

In general, the high-cost reservoir water supply system is a method of dropping the water in the open reservoir installed on the roof of the building by gravity to feed the water in the building. The high water tank water supply method requires pumping of underground or ground water to the water tank installed on the roof of the building by the pump, so that the power consumption is high and the construction cost is increased when the water is loaded by the water tank. In addition, the high-water reservoir water supply method has a hygiene problem due to the accumulation of suspended matter in the reservoir, invasion of foreign matters and insects, or proliferation of bacteria.

Therefore, a pressurized water supply system that directly pulls up the water stored in the underground reservoir and supplies it to the user without using the expensive reservoir is used.

1 is a block diagram of a general pressurized water supply system.

A general pressurized water supply system includes a control unit 11, a standard pump (P1) (P2) (P3) (P4) (P5) (P6), low flow pump (NP), reservoir (13), inverter unit 15, pressure tank 17, the water sensor 19 and the pressure sensor 21. In the above, the standard pumps P1, P2, P3, P4, P5, and P6 operate in an inverter mode and a sequential mode.

The reservoir 13 stores the water to be pumped (pump-ing) to the user supplied through the straight pipe (25).

A plurality of standard pumps P1, P2, P3, P4, P5, and P6, for example, six are installed in parallel to supply water from the reservoir 13 to the user. That is, one or two or more selected by the control unit 11 is driven to supply the water of the reservoir 13 to the user through the suction pipe 27 and the discharge pipe 29.

The inverter unit 15 controls the output of the predetermined standard pumps P1, P2, P3, P4, P5, and P6 in accordance with the pressure of the discharge pipe 29. In the above, the control unit 11 sets any one of the predetermined standard pumps P1, P2, P3, P4, P5, and P6 as inverter pumps so that the output is gradually increased and the output is maximized. Even if the pressure in the discharge pipe 29 is low, the remaining set as the auxiliary pump is sequentially operated at the maximum output. However, when the pressure of the discharge pipe 29 is increased by the operation of the remaining standard pump set as the auxiliary pump, the inverter unit 15 lowers the output of the standard pump set as the inverter pump, so that the total output pressure is discharged from the discharge pipe 29. Matches The control unit 11 converts the pressure of the discharge pipe 29 into an analog value to determine the number of operation of the standard pumps P1, P2, P3, P4, P5, and P6, and the inverter unit 15 Determine the number of revolutions of the standard pump and provide it.

The standard pumps P1, P2, P3, P4, P5 and P6 may operate in sequential mode. In the sequential mode, the inverter unit 15 does not operate so that all the standard pumps P1, P2, P3, P4, P5, and P6 are controlled by the controller 11. In the sequential mode, any one of the standard pumps P1, P2, P3, P4, P5, and P6 is initially set as the main pump to be operated, and the remaining pressure is used as the auxiliary pump. In accordance with the operation of the main pump, and if the pressure of the discharge pipe 29 is still lower than the predetermined pressure to operate the auxiliary pump sequentially.

The low flow rate pump NP operates under the control of the control unit 11 when the amount of water used is low, such as at night. The control unit 11 stops the operation of the standard pump (P1) (P2) (P3) (P4) (P5) (P6) during the time when the amount of water is low, such as at night, and the amount of water consumed less power consumption due to the small amount of water supply Start the pump (NP).

The pressure tank 17 is discharged when the pressure of the discharge pipe 29 is increased by the water pumped by starting the standard pumps P1, P2, P3, P4, P5, and P6. The unused water is accumulated to supply water to the user through the discharge pipe 29 by the accumulated pressure even when the standard pumps P1, P2, P3, P4, P5, and P6 are stopped. Therefore, the number of starts of the standard pumps P1, P2, P3, P4, P5, and P6 can be reduced to extend the life of the pump and save energy.

The water sensor 19 detects the presence or absence of water in the suction pipe 29. When the standard pumps P1, P2, P3, P4, P5, and P6 operate in the absence of water in the suction pipe 29, failure may occur due to idling. Therefore, the water detection sensor 19 detects the pipeline state of the suction pipe 27 and transmits it to the control unit 11. When the water detection sensor 19 detects that there is no water in the suction pipe 27, the control unit 11 Standard pumps P1, P2, P3, P4, P5, and P6 are operated to prevent idling, thereby preventing failure.

The pressure sensor 21 senses the pressure by the water in the discharge pipe 29 and transmits it to the control unit 11. Accordingly, the control unit 11 calculates the proportional integral derivative (PID) of the pressure value delivered by the pressure sensor 21 to calculate the number of operating units of the standard pumps P1, P2, P3, P4, P5 and P6. The inverter unit 15 determines the rotation speed of the predetermined standard pump used as the inverter pump.

In the above-mentioned pressurized water supply system, the set pressure SP of the discharge pipe is set to a predetermined value, for example, 3.0 bar during the inverter mode operation, and the current pressure CP of the discharge pipe is lowered using water to return the inverter pump. When the pressure RP, for example 2.5 bar, is reached, the inverter pump is operated to increase the current pressure CP of the discharge pipe. When the present pressure CP of the discharge tube is lower than the set pressure SP by the operation of the inverter pump, arbitrary auxiliary pumps are sequentially operated to increase the present pressure CP of the discharge tube. When the present pressure CP of the discharge pipe is higher than the set pressure SP, the discharge pressure is lowered by operating in the opposite direction to the increase.

Conventionally, the inverter unit 15 detects an abnormality and transmits an abnormal signal to the controller 11 when an abnormality occurs in the inverter pump or the inverter unit. Accordingly, the control unit 11 stops the control of the inverter unit 15 and directly controls the standard pumps P1, P2, P3, P4, P5, and P6. That is, the controller 11 stops the standard pumps P1, P2, P3, P4, P5, and P6 from being operated in the inverter mode and converts them into the sequential mode. Therefore, even when the inverter is abnormal, the current pressure CP of the discharge pipe of the pressurized water supply system is prevented from dropping, thereby making it possible to supply water smoothly.

However, in the related art, only an abnormal state such as a power supply voltage abnormality, disconnection and short circuit, an overload or overheating of the inverter pump, and an abnormal state of an output frequency of the inverter unit cannot be detected.

Accordingly, an object of the present invention is to detect an abnormal state of the output frequency of the inverter unit, as well as an abnormal state such as power supply voltage abnormality, disconnection and short circuit, overload or overheating of the inverter pump, and abnormality of the inverter to accurately detect the abnormality of the inverter. To provide a monitoring method.

Inverter fault monitoring method according to the present invention for achieving the above object is a first step of determining whether there is a fault in the inverter pump or the inverter unit by detecting a fault signal transmitted from the inverter unit in the inverter mode, the inverter pump or inverter A second step of determining whether the inverter pump operating frequency calculated by the output frequency of the inverter unit is abnormal when it is determined that the unit is operating normally; and maintaining the operation of the inverter mode when the inverter pump operating frequency is determined to be normal. And a third step of stopping the operation of the inverter mode and switching to sequential mode operation when the inverter pump or the inverter unit abnormally operates in the first step or when the inverter pump operating frequency is determined to be abnormal in the second step. It includes 4 steps.

In the first step, the output frequency of the inverter unit may be output in a current state or a voltage state.

In the inverter pump operating frequency is a first process of converting the output frequency of the current state or voltage state into current data or voltage data, a second process of converting the current data or voltage data into an A / D value, and Comprising a third process of calculating the operating frequency of the inverter pump by calculating the A / D value and the following (Equation 1) or (Equation 2).

[Equation 1]

[Equation 2]

1 is a block diagram of a general pressurized water supply system.

2 is a flow chart showing an inverter fault monitoring method according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a flowchart illustrating an inverter fault monitoring method according to the present invention.

First, in step 1 (S1), it is determined whether an abnormal signal is generated in the inverter unit in the inverter mode. When an abnormality such as an abnormality in power supply voltage, disconnection and short circuit, overload or overheating of the inverter pump occurs, the inverter detects this, and thereby transmits an abnormal signal to the controller. That is, when an abnormality occurs in the inverter pump or the inverter part, a relay inside the inverter part makes a contact and outputs an abnormal signal, and the controller detects the abnormal signal and determines that the abnormality has occurred in the inverter pump or the inverter part.

Step 2 (S2), if it is determined in step 1 (S1) that no abnormal signal is generated in the inverter pump or the inverter unit, it is determined whether the output frequency output from the inverter unit is a current state or a voltage state. That is, when the output frequency is in the current state, for example, 4 to 20 mA, and in the voltage state, it is 0 to 10V.

Step 3 (S3) converts to voltage data if it is determined in step 2 (S2) that the output frequency is output in a voltage state, and step 4 (S4) converts to output current data if it is determined that the output frequency is output in a current state. do. In the above, the current data or the voltage data is expressed as a voltage, which is converted in the controller.

Since the central processing unit (CPU) of the control unit operates between 0 and 5V, the current data sets the upper limit to 4.5V when the output frequency is 20mA, so it becomes 0.9V at 4mA, so the output frequency of 4 ~ 20mA is 0.9 ~ 4.5V. It can be expressed as a voltage. When the output frequency is 20mA or more, it should be between 4.5 and 5.0V. The output frequency of 0 to 10V can be represented by a voltage of 0 to 4.5V.

Referring to step 5 (S5), it is determined whether the inverter pump operating frequency is abnormal by using the current data or voltage data converted in step 3 (S3) or step 4 (S4).

When A / D conversion of 0.9-4.5V current data into 8 bits is performed, 46-230 is obtained and 0-4.5V voltage data is 0-230. The operating frequency of the inverter pump is calculated by calculating the converted A / D value by Equation 1 or Equation 2. In the above state, the operating frequency is calculated by using Equation 1 in the current state and Equation 2 in the voltage state.

If the minimum operating frequency is 0Hz and the maximum operating frequency is 60Hz, the inverter pump operates normally when the operating frequency of the inverter pump is 0Hz to 60Hz. Therefore, in Equation (1), the operating frequency of the inverter pump is normal when the A / D conversion value is 46 to 230, and is abnormal when it is smaller than 46 or larger than 230. In Equation (1), the operating frequency of the inverter pump is normal when the A / D conversion value is 0 to 230 and is abnormal when it is larger than 230.

Step 6 (S6) maintains the inverter mode operation when it is determined that the inverter pump operating frequency is not abnormal. That is, the inverter mode operation is maintained when the inverter pump operating frequency is determined to be 0 Hz to 60 Hz.

However, at step 1 (S1), the inverter determines that an abnormality has occurred such as an abnormal power supply voltage, disconnection and short circuit, overload or overheating of the inverter pump, or the inverter pump operating frequency is 0 Hz to 60 Hz at step 5 (S5). If it is determined that the abnormal state is not in the range of the control unit stops the pumps are controlled in the inverter mode and converts to the sequential mode control.

As described above, the present invention detects an abnormal state such as power supply voltage abnormality, disconnection and short circuit, overload or overheating of the inverter pump in the inverter mode, and transmits it to the controller to detect an abnormality and output the output frequency output from the inverter unit. Inverter is monitored twice by judging whether the frequency of the inverter pump operating frequency is calculated using the error.

Therefore, the present invention has an advantage of accurately detecting an abnormality of the inverter because it detects an output frequency of the inverter unit as well as an abnormal state such as power voltage abnormality, disconnection and short circuit, overload or overheating of the inverter pump.

Claims (3)

A first step of determining whether an inverter pump or an inverter unit has abnormality by detecting an abnormal signal transmitted from the inverter unit in the inverter mode; A second step of determining whether the inverter pump operating frequency calculated by the output frequency of the inverter unit is abnormal when it is determined that the inverter pump or the inverter unit operates normally; A third step of maintaining the operation of the inverter mode when the inverter pump operating frequency is determined to be normal; An inverter comprising a fourth step of stopping the operation of the inverter mode and switching to a sequential mode operation when the inverter pump or the inverter unit abnormally operates in the first step or the inverter pump operating frequency is determined to be abnormal in the second step. Fault monitoring method. The inverter abnormality monitoring method according to claim 1, wherein the output frequency of the inverter unit is output in a current state or a voltage state in the first step. The method of claim 2, wherein the operating frequency of the inverter pump is a first process of converting the output frequency of the current state or voltage state into current data or voltage data, A second process of converting the current data or voltage data into an A / D value; Inverter fault monitoring method comprising a third step of calculating the operating frequency of the inverter pump by calculating the A / D value and the following Equation 1 or Equation 2. [Equation 1] [Equation 2]