A multi-location start-stop control device and design method thereof

Abstract

The present application relates to a multi-location start-stop control device and a design method thereof. The multi-location start-stop control device is composed of a local control device and more than one remote control device. The local control device is composed of a switch electrical device and a contactor connected in series. The remote control device is connected to the local control device through a switch power supply and an AC circuit breaker. The switch electrical device of the local control device includes a local control device stop button and a local control device start button connected in series. The local control device start button is used to control the operation of the contactor. The DC intermediate relay group is used to control the operation of the remote control device. The cross-sectional area of ​​the control cable satisfies the following formula: #imgabs0#S is the cross-sectional area of ​​the control cable; U n is the nominal voltage of the control circuit; P is the absorption power of the QAC coil; L max The maximum distance between the local control device and the remote control device. The application also includes a design method for the multi-location start-stop control device. The application has a simple structure, is easy to use, reliable, adaptable and safe.

Description

Technical Field

[0001] The present application relates to a multi-location start-stop control device and a design method thereof, which are mainly applicable to the multi-location control and design of low-voltage electrical appliances. Background Art

[0002] The control of fans, lighting, and installation lines requires control in two or more locations. The commonly used control method is to achieve multi-location control through the contactor AC 220V auxiliary contact. This method has the following disadvantages [1~5] :

[0003] The capacitance between the wires of the long-distance control line causes the contactor to fail to disconnect reliably;

[0004] The voltage drop of the long-distance control line causes the contactor to be unable to open and close reliably;

[0005] The AC 220V control circuit is used in outdoor, humid places and lacks protection against electric shock;

[0006] The local control device cannot release the remote control, which brings danger to inspection and maintenance.

[0007] [1] Tang Ying. Several issues to be noted in the design of low voltage motor control circuits [J]. Building Electrical, 2010, 29(4): 14-18;

[0008] [2] GB / T 14048.6-2016 Low-voltage switchgear and controlgear Part 4-2: Contactors and motor starters for AC motors, semiconductor controllers and starters (including soft starters) [S];

[0009] [3] China Aviation Planning and Design Research Institute Co., Ltd. Industrial and Civil Power Supply and Distribution Design Manual [M]. 4th Edition. Beijing: China Electric Power Press, 2016;

[0010] [4] Zheng Kai, Zheng Huayu. Comparison of fire fan control circuits in the new and old versions of "Common Fan Control Circuit Diagrams" [J]. Modern Building Electrical, 2017, 8(10): 49-52;

[0011] [5] Zheng Kai, Ni Gaojun. Analysis of long distance control circuit of contactor[J]. Building Electrical, 2018, 37(2): 17-20. Summary of the invention

[0012] The technical problem solved by the present application is to overcome the above-mentioned deficiencies in the prior art and to provide a multi-location start-stop control device and a design method thereof with a simple structure, easy use and good effect. A DC control circuit is adopted to avoid the inability to disconnect reliably due to the capacitance between the wires, thereby improving the reliability of the control circuit; safety is improved by adopting a safe extra-low voltage; the cross-sectional area of ​​the control cable is reasonably selected to meet the requirements of different control distances; the power box can release remote control to improve the safety of maintenance personnel.

[0013] The technical solution adopted by the present application to solve the above technical problems includes: a multi-site start-stop control device, which is composed of a local control device and one or more remote control devices, the local control device is electrically connected to the AC power supply of the distribution network, and the power-consuming equipment is electrically connected to the local control device; the remote control device is connected to the local control device through a control cable, and the control cable has no less than three cores, and is characterized in that the local control device is composed of a switch and a contactor in series, and the remote control device is connected to the local control device through a switch power supply and an AC circuit breaker. The switch of the local control device includes a local control device stop button and a local control device start button connected in series, and the local control device start button is used to control the contactor to work, and the DC intermediate relay group is used to control (realize) the remote control device to work, and the cross-sectional area of ​​the control cable satisfies the following formula:

[0014]

[0015] Where S is the cross-sectional area of ​​the control cable; U n is the nominal voltage of the control circuit; P is the absorption power of the QAC coil; L max It is the maximum distance between the local control device and the remote control device.

[0016] The AC power supply adopts a single-phase AC power supply, one end of the single-phase AC power supply is connected to one end of a stop button of a local control device, one end of a normally open contact of an AC intermediate relay, and one end of an AC circuit breaker through a fuse, the other end of the stop button of the local control device is connected to one end of a start button of the local control device and one end of a normally open contact of an AC contactor, the other end of the start button of the local control device and the other end of the normally open contact of the AC contactor are connected to a normally closed contact group of a DC intermediate relay, the normally closed contact group of the DC intermediate relay is connected to the other end of the single-phase AC power supply through a contactor coil, the other end of the AC circuit breaker is connected to one end of the AC side of a switching power supply, and the other end of the single-phase AC power supply is connected to the other end of the AC side of the switching power supply.

[0017] The technical solution adopted by the present application to solve the above technical problems also includes: a design method of the above multi-location start-stop control device, which is characterized by comprising the following steps:

[0018] Determine how many remote control devices are needed based on actual demand;

[0019] Determine the installation location of the local control device and the wiring (routing) plan of the control cable according to the actual demand and the shortest control cable requirement;

[0020] The specific architecture and parameters are designed according to the actual demand and the above-mentioned multi-location start-stop control devices.

[0021] Compared with the prior art, the present application has the following advantages and effects: simple structure, easy use, use of DC control circuit to avoid the inability to disconnect reliably due to capacitance between wires, and improve the reliability of the control circuit; improve safety by using safe extra-low voltage; reasonably select the cross-sectional area of ​​the control cable to meet the requirements of different control distances; the local control device can release the remote control to improve the safety of maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of primary wiring (control principle) of the embodiment of the present application;

[0023] Figure 2 This is a secondary wiring diagram of an embodiment of the present application;

[0024] Figure 3 This is a wiring diagram of a remote control device according to an embodiment of the present application;

[0025] Figure 4 This is a secondary wiring diagram of a remote control device according to an embodiment of the present application;

[0026] Figure 5 yes Figure 3 The normally open contact wiring diagram of the DC intermediate relay group of the remote control device shown;

[0027] Figure 6 yes Figure 3 The shown diagram is the normally closed contact wiring diagram of the DC intermediate relay group of the remote control device. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below in conjunction with the accompanying drawings and through examples. The following examples are intended to explain the present application but the present application is not limited to the following examples.

[0029] like Figure 1 As shown, the multi-site start-stop control device consists of a local control device and multiple remote control devices. In the figure, n represents the number of remote control devices, and n is greater than or equal to 1. The local control device is connected to the AC power supply AC of the distribution network through a conductor. The AC power supply AC includes but is not limited to 220V, 380V and 660V; the electrical equipment SB is connected to the local control device through a conductor; the above-mentioned conductor includes power cables, bus ducts, bare busbars, etc. The remote control device is connected to the local control device through a control cable. The control cable has no less than 3 cores, and the cross-sectional area of ​​the control cable satisfies the following formula:

[0030]

[0031] Where S is the cross-sectional area of ​​the control cable; U n is the nominal voltage of the control circuit (refer to Figure 3 L, N voltage); P is the QAC coil absorption power; L max It is the maximum distance between the local control device and the remote control device.

[0032] like Figure 2 As shown, the electrical equipment SB is connected to the AC power supply through MCCB and QAC. Among them, MCCB uses circuit breakers or disconnectors + fuses and other switching devices with isolation and protection functions, and QAC uses contactors. MCCB and QAC are installed in the local control device.

[0033] like Figure 3 As shown, the secondary circuit power supply is connected to the single-phase AC power supply (L, N). In the figure, FA is a fuse; QAC is a contactor coil; D is a signal light; SC is a stop button installed on the local control device; SO is a start button installed on the local control device; KZ1 is the coil and normally open contact of the AC intermediate relay; KOI (KO1...KOn) is the normally open contact of the DC intermediate relay group (n is a positive integer greater than 1, the same below); KCI (KC1...KCn) is the normally closed contact of the DC intermediate relay group; MCB is an AC circuit breaker, and the AC side of the switch power supply KC is connected to the secondary circuit through MCB.

[0034] The DC power supply voltage output by the switching power supply KC is not greater than 120V, the output voltage adjustment range is ±10%, the output current range is 0~5A, the operating temperature is -20℃~70℃, the temperature coefficient is ±0.02%, and the electrical equipment SB is connected to the local control device.

[0035] like Figure 4 As shown, SOI (SO1…SOn) is the start button group of n individual control modules installed on the remote control device; SCI (SC1…SCn) is the stop button group of n individual control modules installed on the remote control device; SO1 and SC1 are installed in remote control device one, SOn and SCn are installed in remote control device n; KO1…KOn, KC1…KCn are DC intermediate relays, and all DC intermediate relays are installed in the local control device. The remote control device is connected to the DC power supply DC output terminal of the local control device switch power supply KC through a control cable.

[0036] Figure 3 , Figure 4 The figure shows a schematic diagram of a remote control device. Figure 3For the wiring diagram of the normally open contact KOI of the DC intermediate relay group of the remote control device, refer to Figure 5 , see the wiring diagram of the normally closed contact KCI of the DC intermediate relay group of the remote control device Figure 6 . Figure 5 , Figure 6 The n in Figure 1 The same is shown, which is the number of remote control devices.

[0037] Any simple deformation or combination of the technical features and technical solutions of this application should be considered to fall within the protection scope of this application.

Claims

1. A multi-site start-stop control device, consisting of a local control device and one or more remote control devices, the local control device is electrically connected to the AC power supply of the distribution network, and the power-consuming equipment is electrically connected to the local control device; the remote control device and the local control device are connected by a control cable, and the control cable has no less than three cores, and is characterized by: The local control device is composed of a switch and a contactor connected in series. The remote control device is connected to the local control device through a switch power supply and an AC circuit breaker. The switch of the local control device includes a local control device stop button and a local control device start button connected in series. The local control device start button is used to control the operation of the contactor. The DC intermediate relay group is used to control the operation of the remote control device. The cross-sectional area of ​​the control cable satisfies the following formula: Where S is the cross-sectional area of ​​the control cable; U n is the nominal voltage of the control circuit; P is the absorption power of the QAC coil; L max The maximum distance between the local control device and the remote control device; The AC power supply adopts a single-phase AC power supply, one end of the single-phase AC power supply is connected to one end of a stop button of a local control device, one end of a normally open contact of an AC intermediate relay, and one end of an AC circuit breaker through a fuse, the other end of the stop button of the local control device is connected to one end of a start button of the local control device and one end of a normally open contact of an AC contactor, the other end of the start button of the local control device and the other end of the normally open contact of the AC contactor are connected to a normally closed contact group of a DC intermediate relay, the normally closed contact group of the DC intermediate relay is connected to the other end of the single-phase AC power supply through a contactor coil, the other end of the AC circuit breaker is connected to one end of the AC side of a switching power supply, and the other end of the single-phase AC power supply is connected to the other end of the AC side of the switching power supply.

2. A design method for the multi-location start-stop control device according to claim 1, characterized in that The following steps are involved: Determine how many remote control devices are needed based on actual demand; Determine the installation location of the local control device and the control cable wiring plan according to the actual demand and the shortest control cable requirement; The specific architecture and parameters are designed according to the actual demand and the above-mentioned multi-location start-stop control devices.

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