Frequency converter one-driving-three on-site frequency conversion starting circuit applied to water treatment

Abstract

The utility model discloses a one-dragging-three local frequency conversion starting circuit applied to water treatment of a frequency converter, the local manual control circuit comprises two control loops, one control loop comprises a manual knob B, a power frequency starting button SB11, a stop button SB12, a normally closed contact of a contactor KM11, a normally closed contact of a thermal relay FRI and a coil of a contactor KM12 which are sequentially connected in series; the frequency converter overcomes the defects that in the prior art, one frequency converter drives three motors, but frequency conversion starting cannot be conducted on one motor in the local control process, and has the advantage that local control that one frequency converter drives the three motors is completed.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment circuits, and more specifically to a circuit for water treatment with a one-to-three frequency converter capable of on-site frequency conversion starting. Background Art

[0002] This control box is suitable for use in factories, mines, enterprises, shopping malls, hotels, schools, airports, ports, hospitals, high-rise buildings, residential areas, and other locations. It is used for power distribution, lighting distribution, and motor control in low-voltage power grids with an AC 50Hz and a rated operating voltage of AC 380V. It is suitable for indoor wall-mounted and outdoor floor-mounted distribution equipment. It can also be used in power systems with an AC 50Hz and voltage below 500V for controlling fire pumps, submersible pumps, fire fans, fans, and lighting distribution. Control methods include direct starting, star-delta step-down starting, auto-coupling step-down starting, inverter starting, and soft starting. Disconnectors and fuses can also be used as disconnect points. Commonly used atlases include the 99D303-2 Standard Atlas for Common Fans and the 01D303-3 Standard Atlas for Common Water Pumps.

[0003] The three existing motors need to work at the same time, but the power of the motors is relatively large. The larger power motors must be started by a frequency converter, and the motors also need to be adjusted. The existing method is to drive the three motors through three frequency converters.

[0004] There is currently one frequency converter driving three motors, but during local control, it is impossible to perform frequency conversion starting on one motor.

[0005] If three inverters are used to drive three motors, even if it can be handled, it will cause waste of resources and significantly increase costs.

[0006] Therefore, a circuit is provided to solve the above-mentioned problems. Summary of the Invention

[0007] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and to provide a three-in-one inverter capable of on-site variable frequency starting for application in a water treatment circuit.

[0008] The purpose of this utility model is to implement the following technical solution: a frequency converter with one-to-three functions capable of on-site frequency conversion starting is applied to a water treatment circuit, which is installed in a frequency conversion control cabinet, which is connected to an external power supply through wires. The frequency conversion control cabinet is provided with a control circuit for controlling three raw water pumps ABC, each of which is provided with a matching motor on the control circuit of the raw water pump, and the raw water pumps are all installed on the external power supply through a thermal relay, a contactor, a frequency converter, and an air switch.

[0009] The motor is provided with two control circuits, namely a local manual control circuit and a remote control circuit.

[0010] The local manual control circuit includes two control loops, one of which is the manual knob B, power frequency start button SB11, stop button SB12, normally closed contact of contactor KM11, normally closed contact of thermal relay FRI and coil of contactor KM12, which are installed in series.

[0011] The other control circuit is the manual knob B, the frequency conversion start button KM12, the stop button SB12, the normally closed contact of the contactor KM11, the normally closed contact of the thermal relay FRI and the coil of the contactor KM12, which are connected in series.

[0012] The remote control circuit includes two control loops, one of which is the normally open contact of the remote relay 1K1A, the normally open contact of the power frequency PLC output intermediate relay M, the normally closed contact of the contactor KM11, the normally closed contact of the thermal relay FR1 and the coil of the contactor KM12, which are installed in series.

[0013] The other control circuit is the normally open contact of the remote relay 1KA1, the normally open contact of the variable frequency PLC output intermediate relay N, and the coil of the contactor KM11 connected in series.

[0014] In the above technical solution: a local remote switching control circuit is installed between the external power supplies, and the local remote switching control circuit includes an automatic knob A and a coil of a remote signal relay 1K1 which are sequentially arranged in series.

[0015] In the above technical solution: a holding switch X00 is provided before the coil of the remote signal relay 1K1, a holding switch X01 is provided before the coil of the remote signal relay KM12, and a holding switch XO2 is provided before the coil of the remote signal relay KM11.

[0016] In the above technical solution: a frequency converter starting control circuit is installed on the external power supply side. The frequency converter starting control circuit includes three normally open contacts of contactor KM11, normally open contacts of contactor KM21, and normally open contacts of contactor KM31 arranged in parallel, the three parallel common output terminals and the normally closed point of the frequency converter fault signal 1K11F, and the coil of the intermediate relay 1K10 that starts the frequency converter is connected in series.

[0017] The utility model has the following advantages: 1. After the utility model is powered on and running, when the three motors need to be used, the frequency conversion start pump A is started first. When the frequency converter frequency reaches the threshold, the frequency conversion start is stopped, and the power frequency start button of pump A in the manual control circuit is pressed to complete the power start of pump A. At this time, the frequency converter can be used to start raw water pumps B and C.

[0018] When the frequency converter starts the raw water pump B, when the frequency converter reaches the threshold, the frequency converter start is stopped, and the power frequency start button of the B pump in the manual control loop is pressed to complete the power start of the B pump. At this time, the raw water pump C can be started by the frequency converter.

[0019] The raw water pump C can be started and adjusted directly by the frequency converter, thus completing the local control of one frequency converter driving three motors.

[0020] The utility model has been put into use at a construction site in Xuancheng, Anhui Province, and has achieved great economic value. It fundamentally solves the various drawbacks that one frequency converter cannot drive three high-power motors. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0022] Figure 2 This is a schematic diagram of the structure of the Zhongyuan water pump A of the present utility model.

[0023] Figure 3 This is a schematic diagram of the structure of the Zhongyuan water pump B in this utility model.

[0024] Figure 4 This is a schematic diagram of the structure of the Zhongyuan water pump C in this utility model.

[0025] Figure 5 This is a schematic diagram of the fault structure of the Zhongyuan water pump in this utility model.

[0026] Figure 6 This is a structural diagram of the frequency converter in the utility model. DETAILED DESCRIPTION

[0027] The following describes the implementation of the present invention in detail with reference to the accompanying drawings. However, these drawings do not limit the present invention and are merely examples. The advantages of the present invention will become clearer and easier to understand through the illustrations.

[0028] Reference Figure 1-2 As shown: The specific situation of raw water pump A is as follows: A frequency converter with one-to-three function can start the frequency conversion on-site in the water treatment circuit. It is installed in the frequency conversion control cabinet, which is connected to the external power supply through wires.

[0029] A frequency converter with one-to-three functions and on-site frequency conversion starting is used in a water treatment circuit. It is installed in a frequency conversion control cabinet, which is connected to an external power supply via wires. The frequency conversion control cabinet is provided with a control circuit for controlling three raw water pumps ABC. Each raw water pump control circuit is provided with a matching motor. The raw water pumps are all installed on the external power supply via a thermal relay, contactor, frequency converter, and circuit breaker.

[0030] The motor is provided with two control circuits, namely a local manual control circuit and a remote control circuit.

[0031] The local manual control circuit includes two control loops, one of which is the manual knob B, power frequency start button SB11, stop button SB12, normally closed contact of contactor KM11, normally closed contact of thermal relay FRI and coil of contactor KM12, which are installed in series.

[0032] The other control circuit is the manual knob B, the frequency conversion start button KM12, the stop button SB12, the normally closed contact of the contactor KM11, the normally closed contact of the thermal relay FRI and the coil of the contactor KM12, which are connected in series.

[0033] The remote control circuit includes two control loops, one of which is the normally open contact of the remote relay 1K1A, the normally open contact of the power frequency PLC output intermediate relay M, the normally closed contact of the contactor KM11, the normally closed contact of the thermal relay FR1 and the coil of the contactor KM12, which are installed in series.

[0034] The other control circuit is the normally open contact of the remote relay 1KA1, the normally open contact of the variable frequency PLC output intermediate relay N, and the coil of the contactor KM11 connected in series.

[0035] A local remote switching control circuit is installed between the external power supplies. The local remote switching control circuit includes the automatic knob A and the coil of the remote signal relay 1K1 arranged in series (the automatic knob A and the manual knob B are integrated and installed in a control box).

[0036] A hold switch, X00, is placed before the coil of remote signal relay 1K1, a hold switch, X01, is placed before the coil of remote signal relay KM12, and a hold switch, X02, is placed before the coil of remote signal relay KM11. The presence of these hold switches eliminates the need for a person to constantly press the start button, enhancing the overall automation level of the present invention.

[0037] A frequency converter starting control circuit is installed on the external power supply side. The frequency converter starting control circuit includes three normally open contacts of contactor KM11, contactor KM21, and contactor KM31 arranged in parallel, the three parallel common output terminals and the normally closed point of the frequency converter fault signal 1K11F, and the coil of the intermediate relay 1K10 that starts the frequency converter is connected in series.

[0038] The inverter startup control loop is used to inform the inverter when to start so that the inverter can operate normally.

[0039] Raw water pump B has the same parts except that it does not have a local remote switching control circuit and a frequency converter starting control circuit. Raw water pump B and raw water pump A share a local remote switching control circuit and a frequency converter starting control circuit. Figure 3 shown.

[0040] Raw water pump C has the same parts except that it does not have a local remote switching control circuit and a frequency converter start control circuit. Raw water pump C and raw water pump A share a local remote switching control circuit and a frequency converter start control circuit. Figure 4 shown.

[0041] The wiring control circuit of the inverter is as follows Figure 6 The figure shows the conventional wiring method, which will not be described in detail here.

[0042] Figure 5 This is a conventional circuit diagram for overload failure of three raw water pumps and inverter failure, which is also a conventional layout structure and will not be described in detail here.

[0043] The parts not described in detail above are all prior art.

Claims

1. A frequency converter with one-to-three functions and on-site frequency conversion starting is applied to a circuit for water treatment. It is installed in a frequency conversion control cabinet, which is connected to an external power supply through wires. The frequency conversion control cabinet is provided with a control circuit for controlling three raw water pumps ABC. Each raw water pump control circuit is provided with a matching motor. The raw water pumps are installed on an external power supply through a thermal relay, a contactor, a frequency converter, and an air switch. It is characterized in that: The motor is provided with two control circuits, namely a local manual control circuit and a remote control circuit. The local manual control circuit includes two control loops, one of which is a manual knob B, power frequency start button SB11, stop button SB12, normally closed contact of contactor KM11, normally closed contact of thermal relay FRI and coil of contactor KM12, which are installed in series. The other control circuit is the manual knob B, the frequency conversion start button KM12, the stop button SB12, the normally closed contact of the contactor KM11, the normally closed contact of the thermal relay FRI and the coil of the contactor KM12, which are connected in series. The remote control circuit includes two control loops, one of which is the normally open contact of the remote relay 1K1A, the normally open contact of the power frequency PLC output intermediate relay M, the normally closed contact of the contactor KM11, the normally closed contact of the thermal relay FR1 and the coil of the contactor KM12, which are installed in series. Another control circuit is to connect the normally open contact of 1KA1 of the remote relay, the normally open contact of the variable frequency PLC output intermediate relay N, and the coil of the contactor KM11 in series in sequence.

2. According to claim 1, a frequency converter with one-to-three functions capable of on-site frequency conversion starting is applied to a water treatment circuit, characterized in that: A local remote switching control circuit is installed between the external power supplies, and the local remote switching control circuit includes an automatic knob A and a coil of a remote signal relay 1K1 which are sequentially arranged in series.

3. According to claim 1, a frequency converter with one-to-three functions capable of on-site frequency conversion starting is applied to a water treatment circuit, characterized in that: A holding switch X00 is provided before the coil of the remote signal relay 1K1, a holding switch X01 is provided before the coil of the remote signal relay KM12, and a holding switch XO2 is provided before the coil of the remote signal relay KM11.

4. According to claim 1, a frequency converter with one-to-three functions capable of on-site frequency conversion starting is applied to a water treatment circuit, characterized in that: A frequency converter starting control circuit is installed on the external power supply side. The frequency converter starting control circuit includes three normally open contacts of contactor KM11 arranged in parallel, the normally open contact of contactor KM21, the normally open contact of contactor KM31, the three parallel common output terminals and the normally closed point of the frequency converter fault signal 1K11F, and the intermediate relay 1K10 coil of the starting frequency converter is connected in series.

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