Industrial electrical dual-frequency conversion switching controller

Abstract

The utility model discloses a dual-frequency conversion switching controller for industrial electrical equipment. The dual-frequency conversion switching controller comprises a power supply parallel circuit, a main / standby frequency conversion selection circuit, a delay start-stop circuit, a fault monitoring alarm circuit and a plurality of input / output terminals, the main / standby frequency conversion selection circuit comprises an SA selection switch for selecting a main / standby frequency converter; the delay start-stop circuit comprises a plurality of start-stop relays, an operation holding relay, a time relay and a contactor control relay; the fault monitoring alarm circuit comprises two fault lamps used for indicating faults of the frequency converter and a frequency converter fault relay used for receiving fault signals and controlling switching. According to the dual-frequency-conversion switching controller, seamless switching of the main frequency converter and the standby frequency converter in an industrial electrical system can be realized through cooperative work of the circuits, and the stability and the reliability of the system are improved. When the main frequency converter breaks down, the standby frequency converter can rapidly take over work, and continuity of the production process is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of double - frequency conversion switching controllers, and specifically to a double - frequency conversion switching controller for industrial electricity. Background Art

[0002] In large - scale enterprises such as petrochemical, refining, fine chemical, and polyester new materials, continuous and stable production, long - term operation of equipment, improvement of the first - class product rate, reduction of the non - conforming rate, energy conservation and consumption reduction, and optimization of process parameters are reliable guarantees for the safe production and increased efficiency of enterprises. Frequency conversion drive plays an increasingly important role in the production process. With the wide application of frequency conversion drive control in the field of industrial electricity, the requirements for its reliability, durability, and stability are getting higher and higher. In the normal use process of electronic components in the frequency converter, the aging life is reduced due to heat generation. At the same time, the frequency conversion drive equipment will also cause faults and damages to the frequency converter due to over - current, over - voltage, etc. These problems seriously affect the safe production and product qualification rate of chemical enterprises or manufacturing industries. Therefore, while improving the product quality of the frequency converter itself, it is necessary to continuously innovate research and actively explore ways to reduce the impact of frequency conversion faults on production. Using two frequency converters to drive one device is the most effective solution currently available. In this context, how to effectively select and control the stable operation of one frequency converter and effectively solve the mutual switching of frequency converters under faults is one of the hotspots in the current technical field. Therefore, a double - frequency conversion switching controller for industrial electricity is proposed. Content of the Utility Model

[0003] To solve the above problems, that is, to solve the problems proposed in the above background art, the utility model proposes a double - frequency conversion switching controller for industrial electricity, which includes a power supply parallel circuit. The power supply parallel circuit is connected to a main - standby frequency conversion selection circuit, a delay start - stop circuit, a fault monitoring and alarm circuit, and a number of input and output terminals;

[0004] The main - standby frequency conversion selection circuit includes an SA selection switch for main - standby frequency converter selection and a control logic circuit connected to the SA selection switch;

[0005] The delay start - stop circuit includes a number of start - stop relays, a running hold relay, a time relay, and a contactor control relay;

[0006] The fault monitoring and alarm circuit includes two fault lights HY1 and HY2 for indicating frequency converter faults and a frequency converter fault relay for receiving fault signals and controlling switching;

[0007] The number of input and output terminals includes interfaces for connecting external control signals and feedback signals to achieve communication and control with external devices.

[0008] A further setting of the present utility model is as follows: The start-stop relay specifically includes: the VFD1 frequency converter start relay KA1, the VFD2 frequency converter start relay KA2, and the VFD1 and VFD2 frequency converter stop relay KA3;

[0009] The running hold relay includes: the VFD1 frequency converter running hold relay KA7 and the VFD2 frequency converter running hold relay KA9;

[0010] The time relay specifically includes: the VFD1 frequency converter delay start time relay KT1, the VFD2 frequency converter delay start time relay KT2, and the KM1 and KM2 contactor delay disconnection time relay KT3;

[0011] The contactor control relay specifically includes: the contactor KM1 control relay KA11 and the contactor KM2 control relay KA12;

[0012] The frequency converter fault relay is specifically the VFD1 frequency converter fault relay KA6 and the VFD2 frequency converter fault relay KA8.

[0013] A further setting of the present utility model is as follows: The power supply parallel circuit includes a controller configured first power conversion input circuit, a second power conversion input circuit, a third power input circuit, and a third power output circuit for supplying power to the frequency converter control unit.

[0014] A further setting of the present utility model is as follows: It further includes a power supply fuse circuit and a power supply reverse connection prevention circuit; the power supply fuse circuit includes fuses FU1 - FU9 for preventing circuit damage caused by overload or short circuit; the power supply reverse connection prevention circuit includes reverse connection prevention diodes D1 - D4;

[0015] A further setting of the present utility model is as follows: The input and output terminals include external command input terminals, fault signal input terminals, running signal input terminals, external main circuit contactor output terminals, frequency converter delay start output terminals, frequency converter stop output terminals, frequency converter fault alarm output terminals, and controller protective grounding terminals.

[0016] The beneficial technical effects of the present utility model are as follows: Through the coordinated operation of the above circuits, the dual - frequency conversion switching controller of the present utility model can achieve seamless switching between the main and standby frequency converters in the industrial electrical system, improving the stability and reliability of the system. When the main frequency converter fails, the standby frequency converter can quickly take over the work to ensure the continuity of the production process. At the same time, the fault monitoring and alarm circuit can promptly detect and report abnormal situations in the system, facilitating maintenance personnel to handle problems in a timely manner and avoiding greater production losses. Description of the Drawings

[0017] Figure 1The structural schematic diagram of the present utility model is shown. Specific embodiments

[0018] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0019] Please refer to Figure 1 , the present utility model provides a technical solution: a dual-frequency conversion switching controller for industrial electricity, including a power supply parallel circuit, the power supply parallel circuit is connected with a main and standby frequency conversion selection circuit, a delay start-stop circuit, a fault monitoring and alarm circuit, and a plurality of input and output terminals;

[0020] The main and standby frequency conversion selection circuit includes an SA selection switch for main and standby frequency conversion selection, and a control logic circuit connected to the SA selection switch; this switch has two gears: Gear 1: VFD1 main frequency conversion, VFD2 standby frequency conversion, Gear 2: VFD1 standby frequency conversion, VFD2 main frequency conversion. The online selection function of the main and standby frequency conversions is completed by selecting the gear.

[0021] The delay start-stop circuit includes: a plurality of start-stop relays, a running hold relay, a time relay, and a contactor control relay, which are used to provide necessary delay during the switching process to ensure the smooth switching of the frequency converter;

[0022] The fault monitoring and alarm circuit includes two fault lights HY1 and HY2 for indicating the faults of the frequency converter and a frequency converter fault relay for receiving fault signals and controlling the switching;

[0023] The plurality of input and output terminals include interfaces for connecting external control signals and feedback signals to realize communication and control with external devices; and directly pluggable terminals are selected to make the wiring of the controller simple, and there is no need to disconnect the wiring when maintaining and replacing.

[0024] The start-stop relay specifically includes: a VFD1 frequency converter start relay KA1, a VFD2 frequency converter start relay KA2, and a VFD1 and VFD2 frequency converter stop relay KA3;

[0025] The running hold relay includes: a VFD1 frequency converter running hold relay KA7 and a VFD2 frequency converter running hold relay KA9;

[0026] The time relays specifically include: the VFD1 frequency converter delay start time relay KT1, the VFD2 frequency converter delay start time relay KT2, and the KM1 and KM2 contactor delay disconnection time relay KT3;

[0027] The contactor control relays specifically include: the contactor KM1 control relay KA11 and the contactor KM2 control relay KA12.

[0028] The frequency converter fault relays are specifically the VFD1 frequency converter fault relay KA6 and the VFD2 frequency converter fault relay KA8;

[0029] The power supply parallel circuit includes a controller configured with a first power conversion input circuit (AC220V / DC24V), a second power conversion input circuit (AC220V / DC24V), a third power input circuit (DC24V), and a third power output circuit (DC24V) for supplying power to the frequency converter control unit.

[0030] The controller adopts a dual - path AC power supply input and a single - path DC24V DC power supply input, which can meet different voltage levels, realize the power redundancy function, and ensure the reliability of power supply.

[0031] The controller is designed with a single - path DC24 output power supply to provide control power for the frequency converter control unit, solve the demand for the DC24V DC power supply of the frequency converter, reduce the setting of the DC power supply in the electrical circuit, and save costs.

[0032] It also includes a power supply fuse circuit, a power supply reverse - connection prevention circuit, and an anti - interference circuit;

[0033] The power supply fuse circuit includes fuses FU1 - FU9 for preventing circuit damage caused by overload or short - circuit;

[0034] The power supply reverse - connection prevention circuit includes reverse - connection prevention diodes D1 - D4, which are respectively connected in series in the power supply parallel circuit to ensure the correct power input direction and prevent the power supply parallel circuit from generating circulating current and burning out the power supply circuit;

[0035] The input and output terminals include external command input terminals, fault signal input terminals, running signal input terminals, external main circuit contactor output terminals, frequency converter delay start output terminals, frequency converter stop output terminals, frequency converter fault alarm output terminals, and controller protective grounding terminals.

[0036] The power supply parallel circuit, the main and standby frequency conversion selection circuit, the delay start-stop circuit, the fault monitoring and alarm circuit, and several input and output terminals are all integrated on a circuit board. The circuit board is installed inside an aluminum alloy protective case, and the surface of the protective case is perforated, having a good ventilation and heat dissipation effect. A fiber material high-temperature resistant insulating paper is arranged between the circuit board and the protective case for insulation protection, effectively preventing the circuit board from contacting the outer shell and causing a short circuit. A DIN rail slot is installed at the bottom of the protective case and fixed on the rail by a rail fixing screw, making the controller easy to install and reliably fixed to the rail.

[0037] The detailed connection means are well-known techniques in the art. The following mainly introduces the working principle and process, and the specific work is as follows.

[0038] Main and standby inverter selection: An SA selection switch is designed on the front surface of the controller. This switch has two gears. Gear 1: VFD1 is the main inverter and VFD2 is the standby inverter. Gear 2: VFD1 is the standby inverter and VFD2 is the main inverter. The main and standby inverter online selection function is completed by selecting the gear.

[0039] Inverter and load contactor delay sequential start-stop control:

[0040] 1. Inverter and load contactor delay sequential start control

[0041] The sequential start control function is to control the load contactor to be energized, connect the output terminal of the inverter to the load, and then delay to start the inverter after the contactor is closed, and the load is energized and operates. This sequential control ensures that the contactor is turned on and off when the inverter has no output, effectively avoiding the impact current generated by the load when the contactor is closed, reducing the starting current, and protecting the inverter module.

[0042] (1) Sequential start control of VFD1 and contactor KM1: Turn the SA selection switch to Gear 1. When the controller receives an external start command (101 and 119 are connected), KT1 and KA1 are energized simultaneously. The normally open contact of KA1 is closed (101 and 119 are connected) to lock the start circuit. The normally open contact of KA1 is closed (101 and 103 are connected) to make KA11 energized. The normally open contact of KA11 is closed (801 and 802 are connected) to instantaneously control the external main circuit contactor KM1 to be energized. After a set delay time, the normally open contact of KT1 is closed after a delay (805 and 806 are connected) to control the VFD1 inverter to start. At this time, the controller completes the start control of the VFD1 inverter. After the controller receives the operation signal (101 and 135 are connected) of the VFD1 inverter, the HR1 operation light is on and KA7 is energized. The normally closed contact of KA7 is opened (121 and 123 are disconnected) to de-energize KT1 and KA1, automatically resetting the start circuit to wait for the next external start command.

[0043] (2) Sequential start control of VFD2 and contactor KM2: Turn the SA selection switch to the 2nd gear. When the controller receives an external start command (101 and 119 are connected), KT2 and KA2 are energized simultaneously. The normally closed contact of KA2 closes (101 and 119 are connected) to self-lock the start circuit. The normally closed contact of KA2 closes (101 and 111 are connected) to energize KA12. The normally closed contact of KA12 closes (803 and 804 are connected) to instantaneously control the external main circuit contactor KM2 to be energized. After a set delay time, the normally closed contact of KT2 closes after a delay (807 and 808 are connected) to control the VFD2 frequency converter to start. At this time, the controller completes the start control of the VFD2 frequency converter. After the controller receives the operation signal of the VFD2 frequency converter (101 and 139 are connected), the HR2 operation light is on and KA9 is energized. The normally open contact of KA9 opens (125 and 127 are disconnected) to de-energize KT2 and KA2, automatically resetting the start circuit to wait for the next external start command.

[0044] 2. Delayed sequential stop control of the frequency converter and the load contactor: The sequential stop control function stops the load from losing power by controlling the frequency converter to stop. After the load stops, the contactor is timed to open. This sequential control ensures that the contactor is opened without load current, effectively avoiding the impact current generated when the contactor is opened under load, protecting the frequency converter module, and extending the service life of the contactor.

[0045] (1) Sequential stop control of VFD1 and contactor KM1: Turn the SA selection switch to the 1st gear. When the controller receives an external stop command (101 and 129 are connected), KT3 and KA3 are energized simultaneously. The normally closed contact of KA3 closes (101 and 129 are connected) to self-lock the stop circuit. The normally open contact of KA3 opens (809 and 810 are disconnected) to stop the frequency converter. After a set delay time, the normally open contact of KT3 opens after a delay (103 and 105 are disconnected) to de-energize KA11. The normally closed contact of KA11 opens (801 and 802 are disconnected) to de-energize the contactor KM1. At the same time, the normally closed contact of KA11 opens (129 and 131 are disconnected) to de-energize KT3 and KA3, automatically resetting the stop circuit to wait for the next external stop command.

[0046] (2) Sequential Stop Control of VFD2 and Contactor KM2: Turn the SA selection switch to the 2nd gear. When the controller receives an external stop command (101 and 129 are connected), KT3 and KA3 are energized simultaneously. The normally closed contact of KA3 closes (101 and 129 are connected) to self-lock the stop circuit, and the normally open contact of KA3 opens (811 and 812 are disconnected) to stop the frequency converter. After the set delay time, the normally closed contact of KT3 delays to open (111 and 113 are disconnected) to control KA12 to lose power. The normally open contact of KA12 opens (803 and 804 are disconnected) to make the contactor KM2 lose power. At the same time, the normally open contact of KA12 opens (129 and 131 are disconnected) to make KT3 and KA3 lose power, automatically resetting the stop circuit to wait for the next external stop command.

[0047] Function of Mutual Switching and Alarm of Inverters after Fault:

[0048] When VFD1, the main frequency converter, fails, the controller can control the system to automatically switch to VFD2 for operation; when VFD2, the main frequency converter, fails, the controller can control the system to automatically switch to VFD1 for operation; ensuring successful continuous operation of the load after switching.

[0049] During the normal operation of the frequency converter, due to external mechanical jamming, cable short circuit, or the frequency converter itself, etc., the frequency converter fails and alarms. If the controller receives the fault signal of VFD1 (101 and 133 are connected), the HY1 fault light turns on and KA6 is energized. The normally closed contact of KA6 opens (105 and 107 are disconnected), KA11 loses power, and the KM1 contactor disconnects, completely cutting off the faulty main circuit; the normally open contact of KA6 closes (101 and 125 are closed), and it successfully switches to VFD2 for standby operation.

[0050] If the controller receives the fault signal of VFD2 (101 and 137 are connected), the HY2 fault light turns on and KA8 is energized. The normally closed contact of KA8 opens (113 and 115 are disconnected), KA12 loses power, and the KM2 contactor disconnects, completely cutting off the faulty main circuit; the normally open contact of KA8 closes (101 and 121 are closed), and it successfully switches to VFD1 for standby operation;

[0051] After the controller receives the external fault signal, it not only executes the mutual switching function of the frequency converters, but also the controller fault light turns on. At the same time, the normally open contacts of KA6 and KA8 close (813 and 814 are closed) to send out a remote fault alarm signal, and HG1 and HG2 can effectively monitor the working state of the input power supply.

[0052] Power failure restart function: Given the phenomenon of power grid voltage sags in the existing technology, there is a high probability that the frequency converter and contactor will lose power due to abnormal operation, resulting in unnecessary shutdowns. When a power grid voltage sag occurs, the normally closed contacts of the controllers KA11 and KA12 remain closed, enabling the contactors KM1 and KM2 to be powered on immediately after the power grid voltage sag is restored, and enabling the load to be connected to the power supply and run immediately.

[0053] By integrating the above circuits on a circuit board to form a centralized control integrated circuit and encapsulating it in a protective shell to form a complete functional product, functions such as the delay sequential start and stop control function of the frequency converter and load contactor, the mutual switching and alarm function of the frequency converters after a fault, and the power failure restart function are realized, and a small-capacity DC24V power supply output is provided. The controller of the present utility model has the advantages of small volume, low cost, simple wiring, convenient installation, stable control, reliable switching, strong anti-interference ability, and convenient maintenance. It can be widely applied to fields such as chemical industry, petroleum, electric power, textile, polyester, papermaking, and medicine, and has a reliable control effect on frequency converter-driven equipment with high requirements for operation continuity, and has high versatility for various brands and series of frequency converters sold in the market.

[0054] The wiring terminals specifically include:

[0055] 101 and 119 are external start command input terminals;

[0056] 101 and 129 are external stop command input terminals;

[0057] 101 and 133 are VFD1 fault signal input terminals;

[0058] 101 and 135 are VFD1 running signal input terminals;

[0059] 101 and 137 are VFD2 fault signal input terminals;

[0060] 101 and 139 are VFD2 running signal input terminals;

[0061] 801 and 802 are output terminals for controlling the external main circuit contactor KM1;

[0062] 803 and 804 are output terminals for controlling the external main circuit contactor KM2;

[0063] 805 and 806 are output terminals for controlling the delayed start of the VFD1 frequency converter;

[0064] 807 and 808 are output terminals for controlling the delayed start of the VFD2 frequency converter;

[0065] 809 and 810 are output terminals for controlling the stop of the VFD1 frequency converter;

[0066] 811 and 812 are the terminals for controlling the VFD2 frequency converter to stop output;

[0067] 813 and 814 are the fault alarm output terminals of the VFD1 and VFD2 frequency converters;

[0068] PE is the protective grounding terminal of the controller

[0069] It also includes several indicator lights

[0070] HG1: The first power indicator light;

[0071] HG2: The second power indicator light;

[0072] HG3: The controller status indicator light;

[0073] HR1: The operating indicator light of the VFD1 frequency converter;

[0074] HR2: The operating indicator light of the VFD2 frequency converter;

[0075] The technical indicators of the controller of the present utility model:

[0076] Operating temperature: -10°C to +50°C;

[0077] Relative humidity: 5% to 95%;

[0078] Input power supply: 2*AC220V, 1*DC24V;

[0079] Output power supply: 1*DC24V;

[0080] Switch quantity node input: dry contact, internally excited by 24VDC;

[0081] Relay node output capacity: dry contact, AC230V / DC24V, 5A;

[0082] Delay setting: 0 to 5000ms;

[0083] Power consumption: less than 3W;

[0084] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A dual frequency conversion switching controller for industrial electrical applications, characterized in that: It includes a power parallel circuit, which is connected with a main and standby frequency conversion selection circuit, a delayed start and stop circuit, a fault monitoring alarm circuit and a plurality of input and output terminals; The master / standby frequency conversion selection circuit includes an SA selection switch for selecting the master / standby frequency converter, and a control logic circuit connected to the SA selection switch; The time-delay start-stop circuit includes a number of start-stop relays, a run-holding relay, a time relay and a contactor control relay; The fault monitoring alarm circuit includes two fault lamps HY1 and HY2 for indicating the inverter fault and an inverter fault relay for receiving the fault signal and controlling the switching; The plurality of input and output terminals include interfaces for connecting external control signals and feedback signals to achieve communication and control with external devices.

2. The dual-frequency switching controller for industrial electrical appliances according to claim 1, characterized in that: The start-stop relays specifically include: VFD1 inverter start relay KA1, VFD2 inverter start relay KA2 and VFD1, VFD2 inverter stop relay KA3; The operation holding relays include: VFD1 inverter operation holding relay KA7 and VFD2 inverter operation holding relay KA9; The time relays specifically include: VFD1 inverter delayed start time relay KT1, VFD2 inverter delayed start time relay KT2 and KM1, KM2 contactor delayed disconnection time relay KT3; The contactor control relay specifically includes: a contactor KM1 control relay KA11 and a contactor KM2 control relay KA12; The inverter fault relays are specifically VFD1 inverter fault relay KA6 and VFD2 inverter fault relay KA8.

3. The dual-frequency switching controller for industrial electrical appliances according to claim 1, characterized in that: The power parallel circuit includes a controller configured with a first power conversion input circuit, a second power conversion input circuit, a third power input circuit and a third power output circuit for supplying power to the inverter control unit.

4. The dual-frequency switching controller for industrial electrical use according to claim 1, characterized in that: It also includes a power supply insurance circuit and a power supply reverse connection protection circuit; the power supply insurance circuit includes fuses FU1-FU9 for preventing circuit damage caused by overload or short circuit; the power supply reverse connection protection circuit includes reverse connection protection diodes D1-D4.

5. The dual-frequency switching controller for industrial electrical appliances according to claim 1, characterized in that: The input and output terminals include external command input terminals, fault signal input terminals, operation signal input terminals, external main circuit contactor output terminals, inverter delayed start output terminals, inverter stop output terminals, inverter fault alarm output terminals and controller protection grounding terminals.

6. The dual-frequency switching controller for industrial electrical appliances according to claim 1, characterized in that: The power parallel circuit, the main and standby frequency conversion selection circuit, the delayed start and stop circuit, the fault monitoring alarm circuit and a plurality of input and output terminals are all integrated on a circuit board. The circuit board is installed inside an aluminum alloy protective shell, and holes are opened on the surface of the protective shell. Fiber material high temperature resistant insulating paper is arranged between the circuit board and the protective shell, and a DIN guide rail slot is installed at the bottom of the protective shell.

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