Portable high-voltage soft starting device

Abstract

A portable high-voltage soft starting device comprises a cabinet body, a sensor, a current transformer, a voltage transformer, a starting switch, an operation switch, an adjustable reactance device, an overvoltage protector, a zero sequence current transformer, an incoming cable, an outgoing cable, a copper bar lead and a movable tray. The inlet cable is connected to the sensors, and the sensors are sequentially connected to the upper ports of the current transformers through copper bar leads; the lower port of the current transformer is connected with the upper ports of the starting switch and the operation switch; the lower port of the starting switch is connected with the input end of the adjustable reactance device, and the output end of the adjustable reactance device is connected with the lower port of the operation switch; the outlet cable passes through the zero sequence current transformer and is connected with the lower port of the operation switch. The overvoltage protector is connected to the lower port of the operation switch; and the voltage transformer is connected in parallel with the lower port of the current transformer. The cabinet body is fixed on the movable tray, and three rows of ground trundles are fixed on the movable tray. The problem that an existing soft starter is inconvenient to move and install is solved, and the motor can be started without an external control power supply.

Description

Technical Field

[0001] The utility model relates to the field of high-voltage motor starting equipment, in particular to a portable high-voltage soft starting device. Background Art

[0002] With the rapid development of large-scale modern enterprises in China, the number of high-voltage motors installed in large equipment is increasing. As motor capacity increases, direct starting can no longer meet the needs of productivity development. The problems caused by direct starting directly affect the safe operation of the motor itself and even the safe power supply of the power grid. As a result, the application of soft starting devices to start high-voltage motors is becoming more and more widespread.

[0003] Currently, the soft start devices used more frequently in the market include series fixed reactor starting, series water resistor starting, solid-state thyristor control starting, inverter soft starting, etc. The above soft starters have the following problems:

[0004] 1. The soft starter is large in size and occupies a large space. When it is far away from the incoming power supply, it cannot accurately measure the voltage of the three-phase incoming power supply. If real-time measurement is required, an additional voltage transformer cabinet is required.

[0005] 2. The greater the motor power, the heavier the soft starter device is, which is very inconvenient to transport and install. A heavy crane can be used for lifting outdoors, but large lifting equipment cannot be used for installation indoors. Usually, manpower is used to slowly move it using crowbars and rollers, which is time-consuming and labor-intensive. In serious cases, the soft starter device may tilt and fall, crushing the construction workers. Summary of the Invention

[0006] The main purpose of the utility model is to provide a portable high-voltage soft starting device, which solves the problems of large volume and inconvenient installation and transportation of the high-voltage soft starting device in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to the utility model, a portable high-voltage soft starting device is provided, which includes: a cabinet, a sensor, a current transformer, a voltage transformer, a starting switch, an operating switch, an adjustable reactance device, an overvoltage protector, a zero-sequence current transformer, an incoming cable, an outgoing cable, a copper bus conductor and a movable tray.

[0008] The incoming cable is connected to the copper busbar conductor of the sensor; the sensor is connected to the upper port of the current transformer in turn through the copper busbar conductor; the lower port of the current transformer is simultaneously connected to the upper ports of the starting switch and the running switch; the lower port of the starting switch is connected to the input end of the adjustable reactance device, and the output end of the adjustable reactance device is connected to the lower port of the running switch; the outgoing cable passes through the zero-sequence current transformer and is connected to the copper busbar conductor of the lower port of the running switch; the overvoltage protector is connected between the lower port of the running switch and the ground; and the voltage transformer is connected in parallel to the lower port of the current transformer.

[0009] Furthermore, the sensor, current transformer and voltage transformer are arranged close to the top of the cabinet.

[0010] Furthermore, the starting switch and the running switch are arranged in the middle of the cabinet, and the adjustable reactance device is arranged close to the front panel of the cabinet.

[0011] Furthermore, the overvoltage protector is arranged at the lower rear end of the cabinet.

[0012] Furthermore, a portable high-voltage soft start device also includes a cable chamber and a low-voltage chamber; the cable chamber is arranged at the rear of the cabinet, and the incoming cable, outgoing cable, and zero-sequence current transformer are installed inside; the low-voltage chamber is arranged at the front top of the cabinet.

[0013] Furthermore, the voltage transformer is provided with two sets of coils, one set of coils provides PT100V voltage for monitoring the voltage level provided by the incoming cable, and the other set of coils provides 380V three-wire and four-wire power supply for controlling the opening and closing of the starting switch, the running switch and the adjustable reactance device.

[0014] As described above, when the incoming cable is connected to high voltage, the voltage transformer provides control power. The control flow: A start command is output, the start switch is closed, and starting begins. The adjustable reactance device is put into operation. The impedance between the input and output terminals of the adjustable reactance device is automatically adjustable. The input and output terminals of the adjustable reactance device function as a current path, with only impedance present. Initially, the impedance is at its highest, resulting in a low starting voltage for the high-voltage motor, which begins to rotate slowly. The adjustable reactance device automatically adjusts itself based on the starting current, gradually reducing its impedance to gradually increase the starting voltage, boosting the starting torque and accelerating the speed. When the motor reaches or approaches the rated speed, the adjustable reactance device automatically issues a command to close the run switch and open the start switch. Since the run switch is connected in parallel to the input and output terminals of the adjustable reactance device, closing it directly supplies normal operating voltage to the high-voltage motor, enabling normal operation. Starting is complete, and the adjustable reactance device is deactivated.

[0015] Furthermore, the cabinet is installed on a mobile pallet; three rows of casters are fixed at the bottom of the mobile pallet, and the casters support the cabinet at a height of Hmm from the ground; H is greater than the thickness of the forklift arm, which facilitates forklifts or ground cows to carry and install in the distribution room.

[0016] Due to the adoption of the above technical solution, the utility model has the following advantages:

[0017] 1. The structural design is reasonable, which can effectively reduce the overall volume and solve the problem of large volume of high-voltage soft starters in the existing technology;

[0018] 2. After the incoming and outgoing cables are installed and powered on normally, there is no need to configure other control power supplies. The voltage transformer transmits and outputs AC 380V+N three-phase four-wire control power, which is particularly suitable for use in special environments where there is no low-voltage power supply, such as emergency management assistance for flood disasters and underground mines;

[0019] 3. The combination of mobile pallet and cabinet makes the transportation and installation of the entire equipment more convenient, saving time, labor and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0021] In the attached figure:

[0022] Figure 1 This is a structural diagram of a portable high-voltage soft starting device according to an embodiment of the present utility model;

[0023] Figure 2 It is a front schematic diagram of a portable high-voltage soft starting device according to an embodiment of the present utility model.

[0024] The above drawings include the following reference numerals:

[0025] 1. Cabinet; 2. Sensor; 3. Current transformer; 4. Voltage transformer; 5. Operation switch; 6. Starting switch; 7. Adjustable reactance device; 8. Overvoltage protector; 9. Copper busbar conductor; 10. Zero-sequence current transformer; 11. Incoming cable; 12. Outgoing cable; 13. Casters; a. Low-voltage room; b. Cable room; c. Mobile pallet; H. Height from the ground. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present invention, the following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings.

[0027] like Figure 1 As shown, a portable high-voltage soft starting device comprises: a cabinet (1), a sensor (2), a current transformer (3), a voltage transformer (4), a starting switch (6), an operating switch (5), an adjustable reactance device (7), an overvoltage protector (8), a zero-sequence current transformer (10), an incoming cable (11), an outgoing cable (12), a copper busbar conductor (9), and a movable tray (c).

[0028] The incoming cable (11) is connected to the copper busbar conductor (9) of the sensor (2); the sensor (2) is connected to the upper port of the current transformer (3) in turn through the copper busbar conductor (9); the lower port of the current transformer (3) is simultaneously connected to the upper ports of the starting switch (6) and the running switch (5); the lower port of the starting switch (6) is connected to the input end of the adjustable reactance device (7), and the output end of the adjustable reactance device (7) is connected to the lower port of the running switch (5); the outgoing cable (12) passes through the zero-sequence current transformer (10) and is connected to the copper busbar conductor (9) of the lower port of the running switch (5); the overvoltage protector (8) is connected between the lower port of the running switch (5) and the ground; and the voltage transformer (4) is connected to the lower port of the current transformer (3).

[0029] In this embodiment, the sensor (2), the current transformer (3) and the voltage transformer (4) are arranged close to the top of the cabinet (1).

[0030] Furthermore, the starting switch (6) and the running switch (5) are arranged in the middle of the cabinet (1), and the adjustable reactance device (7) is arranged close to the front panel of the cabinet (1).

[0031] Furthermore, the overvoltage protector (8) is arranged at the lower rear end of the cabinet (1).

[0032] In this embodiment, a portable high-voltage soft start device further comprises a cable chamber (b) and a low-voltage chamber (a); the cable chamber (b) is arranged at the rear outside the cabinet (1), and is installed with an incoming cable (11), an outgoing cable (12), and a zero-sequence current transformer (10); the incoming cable (11) enters the cable chamber (b) along the rear of the cabinet (1) and is connected to the copper busbar conductor (9) of the sensor (2). The outgoing cable (12) enters the cable chamber (b) along the rear of the cabinet (1), passes through the zero-sequence current transformer (10), and is connected to the copper busbar conductor (9) at the lower end of the operating switch (5). The low-voltage chamber (a) is arranged at the front top of the cabinet (1), and secondary control components, secondary transfer terminals, and wire troughs are installed in the low-voltage chamber (a). Instruments such as control buttons, status indicator lights, current and voltage monitoring devices, transfer switches, and motor-type microcomputer protection devices are installed on the front panel of the low-voltage chamber (a), with intuitive display and easy operation.

[0033] In this embodiment, the voltage transformer (4) is provided with two sets of coils, one set of coils provides PT100V voltage for monitoring the voltage level provided by the incoming cable (11), and the other set of coils provides 380V three-wire and four-wire power for controlling the opening and closing of the starting switch (6), the operating switch (5) and the adjustable reactance device (7).

[0034] Furthermore, the working principle of the adjustable reactance device (7) is to connect an adjustable inductor coil in series in the starting circuit of the high-voltage motor to achieve a soft starting effect in which the starting voltage of the motor is adjustable. By changing the magnetic permeability of the magnetic medium in the induced magnetic field of the inductor coil, the magnetic induction intensity of the coil is changed, so that the inductance (impedance) value of the inductor coil decreases from large to small within a predetermined time, so that the inductance (impedance) value of the coil is steplessly adjustable, so that the motor terminal voltage gradually rises to full voltage, and the motor is soft started, which can effectively limit the current when the AC asynchronous motor starts.

[0035] As shown in the above structure, when the incoming cable (11) is connected to the high voltage, the voltage transformer (4) provides the control power supply. The control process is as follows: the start command is output, the start switch (6) is closed, the start begins, the adjustable reactance device (7) is put into operation, and the impedance value between the input end and the output end of the adjustable reactance device (7) is automatically adjustable. The input end and the output end of the adjustable reactance device (7) are a current channel between the two ports, and only there is impedance. The impedance value is the largest at the beginning of the start. At this time, the high-voltage motor obtains a lower starting voltage and begins to rotate slowly. The adjustable reactance device (7) will automatically adjust according to the size of the starting current, gradually reducing its own impedance value to gradually increase the starting voltage of the high-voltage motor, increase the starting torque of the high-voltage motor and speed up the speed, until it reaches or approaches the rated speed, the adjustable reactance device (7) will automatically issue a command to automatically close the operating switch (5) and automatically open the starting switch (6). Since the operating switch (5) is connected in parallel to the input and output ends of the adjustable reactance device (7), it directly provides normal operating voltage to the high-voltage motor after closing, so that the high-voltage motor enters normal operation, the starting work is completed, and the adjustable reactance device (7) exits.

[0036] Furthermore, during the process of the motor starting and the bypass switch short-circuiting the adjustable reactance device (7), an overvoltage is inevitably generated. The overvoltage causes cumulative damage to the insulation of the motor, and several large shocks will burn the motor. The overvoltage protector (8) discharges the overvoltage energy to the ground when the overvoltage occurs, and at the same time limits the overvoltage to the tolerance range of the motor insulation, thereby protecting the insulation of the motor from shock and extending the service life of the motor.

[0037] like Figure 2 As shown, the cabinet (1) is installed on a mobile pallet (c), and the mobile pallet (c) is fixed with three rows of casters (13), 4 in each row, for a total of 12. The casters (13) support the cabinet (1) at a height of H mm from the ground; H is greater than the thickness of the forklift arm of 12 cm, which facilitates the transportation and installation of the forklift or the ground bull in the distribution room.

[0038] The portable high-voltage soft starter of this embodiment is not only provided with casters (13) at the bottom, so that it can be conveniently moved as needed and can be conveniently changed to another application site according to user needs; it also can start and stop the high-voltage motor without providing other control power supplies. The portable high-voltage soft starter has a compact structure and is half the size of a conventional high-voltage soft starter, which greatly saves costs and is convenient for customers.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A portable high-voltage soft starting device, comprising: A cabinet, a sensor, a current transformer, a voltage transformer, a starting switch, an operating switch, an adjustable reactance device, an overvoltage protector, a zero-sequence current transformer, an incoming cable, an outgoing cable, a copper busbar conductor and a movable tray; characterized in that: the incoming cable is connected to the copper busbar conductor of the sensor; the sensor is connected to the upper port of the current transformer in sequence through the copper busbar conductor; the lower port of the current transformer is simultaneously connected to the upper ports of the starting switch and the operating switch; the lower port of the starting switch is connected to the input end of the adjustable reactance device, and the output end of the adjustable reactance device is connected to the lower port of the operating switch; the outgoing cable passes through the zero-sequence current transformer and is connected to the copper busbar conductor of the lower port of the operating switch; the overvoltage protector is connected between the lower port of the operating switch and the ground; and the voltage transformer is connected in parallel to the lower port of the current transformer.

2. A portable high-voltage soft starting device according to claim 1, characterized in that: The sensor, current transformer and voltage transformer are close to the top of the cabinet; the starting switch and operation switch are arranged in the middle of the cabinet; the adjustable reactance device is arranged close to the front panel of the cabinet; the overvoltage protector is arranged at the lower rear end of the cabinet.

3. The portable high-voltage soft starting device according to claim 1, characterized in that: The portable high-voltage soft start device further includes a cable chamber and a low-voltage chamber; the cable chamber is arranged at the rear outside the cabinet body, and is equipped with an incoming cable, an outgoing cable, and a zero-sequence current transformer; the low-voltage chamber is arranged at the front top of the cabinet body.

4. The portable high-voltage soft starting device according to claim 1, characterized in that: The voltage transformer is equipped with two sets of coils, one set of coils provides PT100V voltage for monitoring the voltage level provided by the incoming cable, and the other set of coils provides 380V three-wire and four-wire power supply for controlling the opening and closing of the starting switch, the running switch and the adjustable reactance device.

5. The portable high-voltage soft starting device according to claim 1, characterized in that: The cabinet body is installed on a mobile pallet; the mobile pallet is fixed with three rows of casters, and the casters support the cabinet body at a height of Hmm from the ground; H is greater than the thickness of the forklift arm, which facilitates indoor transportation by forklifts or ground bulls.

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