CN213585609U - Soft starter and soft starting device based on electronic transformer - Google Patents

Abstract

The utility model discloses a soft starter and soft starting drive based on electronic transformer relates to motor starting technical field to solve the technical problem of magnetic saturation, ferromagnetic resonance. In the soft starter based on the electronic transformer, the input end of the electronic voltage transformer is electrically connected with the power supply line of the motor, and the output end of the electronic voltage transformer is connected with the first input end of the controller. The input end of the thyristor valve component is electrically connected with the power supply circuit, and the output end of the thyristor valve component is connected with the input end of the electronic current transformer. And a first output end of the electronic current transformer is electrically connected with the motor, and a second output end of the electronic current transformer is connected with a second input end of the controller. The output end of the controller is connected with the input end of the thyristor valve component. The utility model also provides an applied above-mentioned electronic transformer's soft starting device of soft starter.

Description

Soft starter and soft starting device based on electronic transformer

Technical Field

The utility model relates to a motor starting technical field especially relates to a soft starter and soft starting drive based on electronic transformer.

Background

The high-voltage solid soft starter is a new type medium-high voltage motor soft starter, mainly applicable to medium-high voltage AC motor below 10KV, and adopts advanced DSP (Digital Signal processing) control technique, power electronic technique and its main constitution are three-phase anti-parallel thyristor and its electronic control circuit which are series-connected between power supply and controlled motor.

In the high-voltage solid-state soft starter in the prior art, an electromagnetic voltage transformer and an electromagnetic current transformer are generally adopted to collect the voltage and the current of a primary system. However, when an electromagnetic voltage transformer and an electromagnetic current transformer are used, a measured signal is easily coupled with a secondary coil through an iron core, and the electromagnetic voltage transformer and the electromagnetic current transformer have problems of magnetic saturation, ferromagnetic resonance and the like.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a soft starter and soft starting drive based on electronic transformer for when solving and adopting electromagnetic type voltage transformer and electromagnetic type current transformer, measured signal passes through the iron core coupling with secondary coil, and there is magnetic saturation in electromagnetic type voltage transformer and electromagnetic type current transformer, and ferromagnetic resonance scheduling problem.

In order to achieve the above object, the present invention provides a soft starter based on an electronic transformer, which is used for starting a motor. The soft starter based on the electronic transformer comprises: the electronic voltage transformer, the thyristor valve component, the electronic current transformer, the controller.

The input end of the electronic voltage transformer is electrically connected with the power supply line of the motor, and the output end of the electronic voltage transformer is connected with the first input end of the controller. The input end of the thyristor valve component is electrically connected with the power supply circuit, and the output end of the thyristor valve component is connected with the input end of the electronic current transformer. And a first output end of the electronic current transformer is electrically connected with the motor, and a second output end of the electronic current transformer is connected with a second input end of the controller. The output end of the controller is connected with the input end of the thyristor valve component.

Compared with the prior art, the utility model provides an among the soft starter based on electronic transformer, through utilizing the voltage value among the electronic voltage transformer collection power supply line, utilize electronic current transformer to gather the current value among the power supply line, then transmit for the controller after handling above-mentioned voltage value, the current value who gathers. And then the controller controls the soft starter to work according to the processed voltage value and current value so as to ensure that the voltage and the current in the soft starter and the motor meet the requirements and play a role in monitoring and protection. Further, the output end of the controller is connected with the input end of the thyristor valve component, and the controller can control the starting of the motor by controlling the thyristor valve component. Because the utility model discloses an electronic voltage transformer and electronic current transformer do not have the iron core, so measured signal can not pass through the iron core coupling with secondary coil, and then can not produce the magnetic saturation to and ferromagnetic resonance's problem, thereby improve soft starter's performance.

The utility model also provides a soft starting device, this soft starting device include above-mentioned technical scheme soft starter based on electronic transformer.

Compared with the prior art, the utility model provides a soft starting device's beneficial effect and above-mentioned technical scheme the beneficial effect based on electronic transformer's soft starter is the same, and the here is not repeated.

Drawings

The accompanying drawings, which are described herein, serve to provide a further understanding of the invention and constitute a part of this specification, and the exemplary embodiments and descriptions thereof are provided for explaining the invention without unduly limiting it. In the drawings:

fig. 1 shows a schematic circuit diagram of a soft starter based on an electronic transformer according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an electronic current transformer according to an embodiment of the present invention;

fig. 3 is a schematic diagram of an electronic voltage transformer according to an embodiment of the present invention;

fig. 4 shows a unit diagram of a soft starter based on an electronic transformer according to an embodiment of the present invention;

fig. 5 is an assembly view of a soft start apparatus provided by an embodiment of the present invention;

fig. 6 shows a layout diagram of a soft start device according to an embodiment of the present invention.

Reference numerals:

the device comprises an electronic voltage transformer 1, a capacitive voltage divider 10, a second photoelectric converter 11, a thyristor valve assembly 2, a thyristor 20, a forward and reverse parallel thyristor assembly 21, a thyristor valve assembly unit 22, an electronic current transformer 3, a sampling coil 30, an energy taking coil 31, a first photoelectric converter 32, a controller 4, a power supply line 5, a reactor 6, a motor M, a fuse FU, a DXN (high voltage live display), a KM1 (first contactor), and a KM2, wherein the first contactor is arranged on the substrate of the device; 70 is a current collecting unit, 71 is a voltage collecting unit, 72 is a merging unit, 73 is a comprehensive control unit, 730 is a starting logic controller, 731 is a monitoring controller, 732 is an external communication controller, 733 is a first analog-to-digital converter, 734 is a second analog-to-digital converter, 735 is a first comparator, 736 is a second comparator; 74 is an execution unit, 75 is a human-computer interaction unit, and 750 is a touch screen; 76 is a trigger unit, 760 is a voltage collector, 761 is a voltage comparator, 762 is a voltage follower, and 763 is a trigger; 77 is a dynamic monitoring unit, 770 is an FPGA logic gate builder, 771 is a microsecond time divider, 772 is a plurality of groups of comparators, 773 is a balance calculator, 774 is a balance determiner; 78 is a fiber input device, 79 is a fiber output device; 80 is a cabinet body, 83 is a first lead, 84 is a lead-out cable, 85 is a thyristor valve component lead-out copper bar, 87 is a reactor lead-in, 88 is a thyristor valve component lead-in cable, 90 is a lead-in connecting copper bar, 91 is a high-voltage insulator, and 92 is a thyristor valve component lead-in copper bar; PV1 is a first voltmeter, PV2 is a second voltmeter, PA is an ammeter, 93 is an indicator light, 94 is an electromagnetic lock, 95 is a button, and 96 is a change-over switch.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to illustrate the present invention in further detail. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The high-voltage solid soft starter is a new type medium-high voltage motor soft starter, mainly applicable to medium-high voltage AC motor below 10KV, and adopts advanced DSP (Digital Signal processing) control technique, power electronic technique and its main constitution are three-phase anti-parallel thyristor and its electronic control circuit which are series-connected between power supply and controlled motor. The conduction angle of the three-phase positive and negative parallel thyristors is controlled by different methods, so that the input voltage of the controlled motor is changed according to different requirements, and different functions can be realized.

The thyristor is also called a Silicon Controlled Rectifier (SCR), and is a high-power electrical component. It has the advantages of small volume, high efficiency, long service life, etc. In an automatic control system, the device can be used as a high-power driving device to realize the control of high-power equipment by using a low-power control. It is widely applied to speed regulating systems, power regulating systems and follow-up systems of alternating current and direct current motors. Meanwhile, the motor has the advantages of continuously adjustable voltage, relatively low price, simplicity in use and the like, has a plurality of auxiliary functions, and is widely applied to starting control of the high-voltage asynchronous motor.

In the high-voltage solid-state soft starter in the prior art, an electromagnetic voltage transformer and an electromagnetic current transformer are generally adopted to collect the voltage and the current of a primary system. However, when an electromagnetic voltage transformer and an electromagnetic current transformer are used, a measured signal is easily coupled with a secondary coil through an iron core, and the electromagnetic voltage transformer and the electromagnetic current transformer have problems of magnetic saturation, ferromagnetic resonance and the like.

In order to solve the technical problem, the embodiment of the utility model provides a soft starter based on electronic transformer. The soft starter based on the electronic transformer is used for starting the motor.

Fig. 1 shows a partial circuit diagram of a soft starter based on an electronic transformer according to an embodiment of the present invention. Referring to fig. 1, the soft starter based on the electronic transformer includes: the device comprises an electronic voltage transformer 1, a thyristor valve assembly 2, an electronic current transformer 3 and a controller 4. The input end of the electronic voltage transformer 1 is electrically connected with the power supply line 5 of the motor M, and the output end of the electronic voltage transformer 1 is connected with the first input end of the controller 4. The input end of the thyristor valve component 2 is electrically connected with the power supply line 5, and the output end of the thyristor valve component 2 is connected with the input end of the electronic current transformer 3. A first output end of the electronic current transformer 3 is electrically connected with the motor M, and a second output end of the electronic current transformer 3 is connected with a second input end of the controller 4. The output of the controller 4 is connected to the input of the thyristor valve assembly 2.

The electronic voltage transformer and the electronic current transformer may be collectively referred to as an electronic transformer. An electronic transformer is a power distribution device consisting of one or more voltage or current sensors connected to a transmission system and to a secondary converter, for transmitting quantities proportional to the quantities being measured, to measurement instruments, meters and relay protection or control devices. In the case of a digital interface, a group of electronic transformers share a merging unit to accomplish this function.

Referring to fig. 1, adopt the utility model provides a soft starter based on electronic transformer, through utilizing electronic voltage transformer 1 to gather the primary voltage numerical value in the power supply line 5, obtain the secondary voltage numerical value through electronic voltage transformer 1's processing. The electronic current transformer 3 is used for collecting a primary current value in the power supply line 5, and a secondary current value is obtained through processing of the electronic current transformer 3. Then, the secondary voltage value and the secondary current value are transmitted to the controller 4. And then the controller 4 controls the conduction angle of the thyristor valve assembly 2 according to the secondary voltage value and the secondary current value, so as to control the voltage and the current in the motor M, gradually increase the voltage and the current on the motor M, and smoothly increase the torque of the motor M until the motor is accelerated to full-speed operation. Because the embodiment of the utility model provides an adopt electronic voltage transformer 1 and electronic current transformer 3, do not have the iron core, so measured signal can not pass through the iron core coupling with secondary coil, and then can not produce magnetic saturation to and ferromagnetic resonance's problem, thereby improve soft starter's performance.

As a possible implementation manner, referring to fig. 1, the soft starter based on the electronic transformer may further include: fuse FU, high-voltage live display device DXN, and reactor 6. Fuse FU's first end is connected with 5 electricity in the power supply line, and fuse FU's second end is connected with electronic voltage transformer 1's input electricity. The first end of the high-voltage live display device DXN is electrically connected with the power supply line 5, and the second end of the high-voltage live display device DXN is grounded. An input end of the reactor 6 is electrically connected with the power supply line 5, and an output end of the reactor 6 is electrically connected with an input end of the thyristor valve assembly 2.

Illustratively, referring to fig. 1, a first end of the fuse FU is electrically connected to the power supply line 5, and a second end of the fuse FU is electrically connected to the input end of the electronic voltage transformer 1, that is, the fuse FU is connected in series to the electronic voltage transformer 1. When the current value passing through the electronic voltage transformer 1 exceeds the rated value of the electronic voltage transformer 1, the fuse FU fuses the melt by the heat generated by the fuse FU, and the circuit is disconnected, so that the electronic voltage transformer 1 is not damaged. Because the first end of the high-voltage live display device DXN is electrically connected with the power supply line 5, and the second end of the high-voltage live display device DXN is grounded, after the soft starter is powered on, the high-voltage live display device DXN can be used for detecting whether the circuit is powered on or not. When having high-voltage electricity, the pilot lamp of the display (installing on cabinet body panel) of high-voltage electricity display device DXN lights, reminds the staff this soft starter for the circular telegram state to be used for guaranteeing staff's power consumption safety, also observe in real time simultaneously whether the power supply of soft starter is normal. The reactor 6 is used for absorbing external high-frequency sudden change, and can eliminate current peak at the moment of starting the motor, so that damage to the thyristor due to impact of peak current is avoided.

As a possible implementation, referring to fig. 1, the soft starter based on the electronic transformer further includes: a first contactor KM1 and a second contactor KM 2. The first end of the first contactor KM1 is electrically connected to the power supply line 5, and the second end of the first contactor KM1 is electrically connected to the input terminal of the reactor 6. A first end of the second contactor KM2 is electrically connected to a second end of the first contactor KM1, a second end of the second contactor KM2 is electrically connected to an input terminal of the electronic current transformer 3, and the second contactor KM2 is connected in parallel to the thyristor valve assembly 2.

For example, referring to fig. 1, the first end of the second contactor KM2 is electrically connected to the second end of the first contactor KM1, and the first end of the second contactor KM2 is also electrically connected to the input terminal of the reactor 6. When the first contactor KM1 was closed, the soft starter started to operate. At the moment, the current passes through the reactor 6, the thyristor valve assembly 2 and the electronic current transformer 3 in sequence from a power supply (for example, three-phase power) through the first contactor KM1 to reach the motor M. Under the action of the controller 4 and the thyristor valve assembly 2, the motor M is started slowly, when the motor M reaches full speed, the second contactor KM2 is closed, the thyristor valve assembly 2 is turned off, and the motor M is switched to bypass operation. When the motor M is switched to the bypass operation and the thyristor valve component 2 is turned off, the thyristor valve component 2 does not work at the moment, the effect of protecting the thyristor valve component 2 can be achieved, and the loss of the thyristor valve component 2 is reduced. The first contactor KM1 may be a first vacuum contactor, and the second contactor KM2 may be a second vacuum contactor. It should be understood that the first contactor KM1 and the second contactor KM2 may also be other devices suitable for practical use, and are not limited to being vacuum contactors.

As a possible implementation manner, fig. 2 shows a schematic diagram of an electronic current transformer provided in an embodiment of the present invention. Referring to fig. 2, the electronic current transformer includes: a sampling coil 30, an energy-extracting coil 31, and a first photoelectric converter 32. The input end of the sampling coil 30 is electrically connected with the power supply line 5, and the output end of the sampling coil 30 is connected with the current sampling end of the first photoelectric converter 32. The input end of the energy-extracting coil 31 is electrically connected to the power supply line 5, and the output end of the energy-extracting coil 31 is connected to the power supply end of the first photoelectric converter 32. The output of the first photoelectric converter 32 is connected to a second input of the controller.

For example, referring to fig. 2, since the input end of the energy-extracting coil 31 is electrically connected to the power supply line 5, and the output end of the energy-extracting coil 31 is connected to the power supply end of the first photoelectric converter 32, the energy-extracting coil 31 may provide operating power for the first photoelectric converter 32, so that the first photoelectric converter 32 operates normally. In the process of connecting the energy-extracting coil 31 and the first photoelectric converter 32, the primary current is amplified, rectified and stabilized, and then transmitted to the power supply terminal of the first photoelectric converter 32. Since the input end of the sampling coil 30 is electrically connected to the power supply line 5, the sampling coil 30 may be configured to collect a primary current value provided to the motor M by the three-phase power in the power supply line 5, and transmit the collected primary current value to the first photoelectric converter 32.

Referring to fig. 2, the first photoelectric converter 32 may perform integral amplification, differential amplification, power amplification, and the like on the current, and the first photoelectric converter 32 may have therein a phase modulation circuit, an integration circuit, and the like. Inside the first photoelectric converter 32, the primary current is processed to obtain a secondary current. The secondary current can be calculated, for example, by the following formula: i (t) - ((0) -) e (t) dt/N. The above formula is an integral function, where N represents the mutual inductance between the bus bars of the coil, i (t) represents the measured current, e (t) represents the output voltage of the coil, and i (0) represents the theoretical value in the ideal state. After the sampling coil 30 transmits the collected primary current value to the first photoelectric converter 32, the first photoelectric converter 32 performs integral differential amplification processing on the electrical signal, and converts the processed electrical signal into an optical signal.

As a possible implementation manner, fig. 3 shows a schematic diagram of an electronic voltage transformer provided by an embodiment of the present invention. Referring to fig. 3, the electronic voltage transformer includes: a capacitive divider 10 and a second photoelectric converter 11. The input end of the capacitive voltage divider 10 is electrically connected with the power supply line, and the output end of the capacitive voltage divider 10 is connected with the input end of the second photoelectric converter 11. The output of the second photoelectric converter 11 is connected to a first input of the controller.

For example, referring to fig. 3, the capacitive voltage divider 10 may include a capacitor C1, a capacitor C2, and a resistor R. The specific connection relationship may be that the first terminal of the capacitor C1 is electrically connected to the power source U1, the second terminal of the capacitor C1 is electrically connected to the first terminal of the capacitor C2, the second terminal of the capacitor C2 is electrically connected to the power source U1, and the second terminal of the capacitor C2 is grounded. The first end of the resistor R is electrically connected with the first end of the capacitor C2, the second end of the resistor R is electrically connected with the second end of the capacitor C2, the voltage in the power supply line can be collected through the capacitive voltage divider 10, and the collected voltage is transmitted to the second photoelectric converter 11.

Referring to fig. 3, the second photoelectric converter 11 described above may implement integral amplification, differential amplification, power amplification, and the like of the voltage, and the second photoelectric converter 11 may have therein a phase modulation circuit, an integration circuit, and the like. Inside the second photoelectric converter 11, the primary voltage is processed to obtain a secondary voltage. The secondary voltage can be calculated, for example, by the following formula: u2 ═ j ω RC1U 1. U2 represents the secondary voltage value output by the electronic transformer, U1 represents the primary voltage value, C1 represents the high-voltage-side capacitance value, and R represents the voltage-dividing resistance value. j denotes complex units, j ω C1 denotes the capacitive reactance of C1. The above equation is a derivative function. The electronic voltage transformer may divide the voltage by the capacitive voltage divider 10, and then the second photoelectric converter 11 may perform integral difference amplification processing on the divided secondary voltage signal and convert the processed signal into an optical signal.

As a possible implementation, referring to fig. 2, the output end of the first photoelectric converter 32 has a first optical fiber interface, and the second input end of the controller has a second optical fiber interface. The output end of the first photoelectric converter 32 is connected with the second input end of the controller through the first optical fiber interface and the second optical fiber interface. Referring to fig. 3, the output end of the second photoelectric converter 11 has a third optical fiber interface, and the first input end of the controller has a fourth optical fiber interface. The output end of the second photoelectric converter 11 is connected with the first input end of the controller through a third optical fiber interface and a fourth optical fiber interface.

Referring to fig. 2 and 3, in the prior art, the electromagnetic current transformer and the electromagnetic voltage transformer are in electrical signal transmission with the controller, and are interfered by an electromagnetic field through the electrical signal transmission, so that the reliability of information transmission is reduced. In the embodiment of the present invention, the first photoelectric converter 32 and the second photoelectric converter 11 are respectively connected to the controller through optical fibers, and at this time, the signals transmitted between the first photoelectric converter 32 and the controller and the second photoelectric converter 11 are optical signals. The signal transmission is carried out through the optical fiber, so that the interference of an electromagnetic field can be effectively avoided, the anti-electromagnetic interference capability is improved, and the reliability is improved. Further, even if the electromagnetic transformer in the prior art also adopts the optical fiber transmission method, an additional photoelectric converter is required. At the same time, the cost of the equipment is increased, and due to the property problem of the electromagnetic mutual inductor, the problems of magnetic saturation, ferromagnetic resonance and the like still exist.

Referring to fig. 1, 2 and 3, still further, in the actual control connection circuit of the motor, the motor is connected with a thyristor valve assembly, a three-phase power, a controller, etc. Because the voltage that three-phase power provided is 6000V generally, or 10000V, three-phase power provides high voltage, heavy current promptly. When the motor is controlled to start by using an integrated component such as a controller, if the high voltage provided by the three-phase power is provided, a large current directly flows through the controller or other integrated components, which may cause the controller or other integrated components to be burnt. The electronic current transformer can effectively isolate high voltage and large current on one hand, and on the other hand, because the electronic transformer is a light-load coil, the electronic current transformer cannot generate high voltage when the electronic current transformer is open-circuited for the second time, and cannot generate large current when the electronic voltage transformer is short-circuited for the second time. Meanwhile, when optical fibers are used for signal transmission, signals on a high-voltage side are transmitted to secondary equipment through the optical fibers, a high-voltage loop and a secondary loop are completely isolated electrically, the problems of short circuit and open circuit of the secondary loop caused by electromagnetic transformers (namely electromagnetic current transformers and electromagnetic voltage transformers) in the prior art are solved, and meanwhile, the anti-electromagnetic interference capability is further improved through optical fiber transmission. Furthermore, the system can be conveniently communicated with other electronic instruments and microcomputer measurement and control protection equipment. The digital signal output by the electronic transformer is beneficial to data communication, the electronic transformer and a device needing to utilize the signal of the electronic transformer can be integrated into a system network through a specific protocol, data sharing is realized, and a large amount of secondary cables are saved. In addition, the electronic transformer also has the advantages of small volume, light weight and low cost, and can reduce the engineering investment cost.

As a possible implementation, referring to fig. 1, the thyristor valve assembly 2 may include at least one set of forward and reverse parallel thyristors.

For example, referring to fig. 1, the thyristor valve assembly 2 may include at least one set of forward and reverse parallel thyristors (two thyristors 20), and may further include a trigger plate, etc. Since the output of the controller 4 is electrically connected to the input of the thyristor valve assembly 2, the controller 4 can be electrically connected to at least one set of forward and reverse parallel thyristors. The controller 4 controls the conduction angle of at least one group of positive and negative parallel thyristors, and further controls the input voltage of the motor M so as to realize the control of starting the motor M.

As a possible implementation, referring to fig. 4, the controller may include a first analog-to-digital converter 733, a second analog-to-digital converter 734, a first comparator 735, and a second comparator 736. A first end of the first analog-to-digital converter 733 is connected to an output end of the electronic voltage transformer, and a second end of the first analog-to-digital converter 733 is electrically connected to the first comparator 735. A first end of the second analog-to-digital converter 734 is connected to the output end of the electronic current transformer, and a second end of the second analog-to-digital converter 734 is electrically connected to the second comparator 736.

For example, referring to fig. 1 and fig. 4, after the electronic voltage transformer 1 converts the collected primary voltage into a secondary voltage, the secondary voltage is transmitted to the controller 4, and the first analog-to-digital converter 733 in the controller 4 processes the secondary voltage to obtain a measured voltage value, and transmits the measured voltage value to the first comparator 735. In the actual use process, a voltage value can be set in the controller 4 in advance, and the first comparator 735 is used for comparing the preset voltage value with the actually-measured voltage value so as to judge whether the voltage value in the power supply line 5 meets the actual requirement, thereby avoiding the conditions of overvoltage or undervoltage and the like from influencing the starting of the motor M. For example, when the measured voltage value is greater than the preset voltage value, it indicates that an overvoltage condition occurs in the power supply line 5, and at this time, the controller 4 may control the first contactor KM1 in the circuit to be turned off, so as to protect the circuit from being burned out, and ensure the safety of the motor M and other components.

Referring to fig. 1 and 4, the electronic current transformer 3 converts the acquired primary current into a secondary current, and transmits the secondary current to the controller 4, and the second analog-to-digital converter 734 in the controller 4 processes the secondary current to obtain an actually measured current value, and transmits the actually measured current value to the second comparator 736. In the actual use process, a current value can be set in the controller 4 in advance, and the second comparator 736 is used for comparing the preset current value with the actually-measured current value so as to judge whether the current value in the power supply line 5 meets the actual requirement, thereby avoiding the conditions of overload, underload or locked rotor from affecting the starting of the motor M. For example, when the measured current value is greater than the preset current value, it indicates that the overcurrent condition occurs in the power supply line 5, and at this time, the controller 4 may control the first contactor KM1 in the circuit to be turned off, so as to protect the circuit from being burned out, and ensure the safety of the motor M and other components.

The embodiment of the utility model provides a can carry out the division of functional module to the soft starter based on electronic transformer according to above-mentioned device, for example, can correspond each functional module of each functional partitioning, also can be integrated in a processing module with two or more than two functions. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. It should be noted that, the division of the modules in the embodiments of the present invention is schematic, and only one logic function division is used, and there may be another division manner in actual implementation.

In the embodiment of the present invention, referring to fig. 4, the above-mentioned soft starter based on the electronic transformer may include a current collecting unit 70, a voltage collecting unit 71, a merging unit 72, an integrated control unit 73, an execution unit 74, a thyristor valve assembly unit 22, a human-computer interaction unit 75, a triggering unit 76, and a dynamic monitoring unit 77.

Illustratively, referring to fig. 1 and 4, the current collecting unit 70 is mainly composed of an electronic current transformer 3, and is configured to collect a primary current value in the power supply line 5, and obtain a secondary current value after processing by the electronic current transformer 3. Similarly, the voltage collecting unit 71 is mainly composed of the electronic voltage transformer 1, and is configured to collect a primary voltage value in the power supply line 5, and obtain a secondary voltage value after processing by the electronic voltage transformer 1. The secondary current value and the secondary voltage value are transmitted to the merging unit 72 by the current collecting unit 70 and the voltage collecting unit 71 in the form of optical fiber signals. The merging unit 72 performs synchronous processing on the secondary current and the secondary voltage to obtain a quasi-synchronous periodic voltage signal and a quasi-synchronous periodic current signal, so that the integrated control unit 73 performs analog-to-digital processing. The merging unit 72 then transmits the quasi-synchronous voltage signal and current signal to the integrated control unit 73 by means of optical fiber signals. The integrated control unit 73 can perform analog-to-digital processing on the synchronized voltage signal and current signal, thereby monitoring and protecting the current and voltage of the system. Since optical fiber transmission is used, corresponding optical fiber input 78 and optical fiber output 79 may be provided in the integrated control unit 73 for receiving and transmitting optical fiber signals. It should be understood that the integrated control unit 73 may further include a start logic controller 730, a monitoring controller 731, and an external communication controller 732. The integrated control unit 73 is a core part of the soft starter based on the electronic transformer, and the integrated control unit 73 sends out trigger pulses of the thyristor and analyzes and processes various information.

Referring to fig. 4, the human-computer interaction unit 75 may include a touch screen 750 for inputting and displaying information, and a user may input information such as motor parameters, voltage levels, voltage protection setting values, current protection setting values, and start curves through the touch screen 750. The human-computer interaction unit 75 can then transmit the information to the integrated control unit 73 by means of electrical signals, and the integrated control unit 73 transmits the information to the dynamic monitoring unit 77 by means of optical fibers. Further, since the integrated control unit 73 can receive the voltage signal and the current signal (the secondary voltage and the secondary current) in quasi-synchronization, a voltage transformer transformation ratio and a current transformer transformation ratio are provided in the integrated control unit 73. The primary voltage value (actually measured voltage value) can be obtained by multiplying the secondary voltage value by the transformation ratio of the voltage transformer, and the primary current value (actually measured current value) can be obtained by multiplying the secondary current value by the transformation ratio of the current transformer. Then, the integrated control unit 73 displays the primary voltage value and the primary current value obtained by calculation on a human-computer interaction interface through the human-computer interaction unit 75, so that the voltage value and the current value in the circuit can be observed in real time, and data support is provided for the starting motor.

Referring to fig. 4, since the integrated control unit 73 may include therein a first analog-to-digital converter 733, a second analog-to-digital converter 734, a first comparator 735, and a second comparator 736. And the integrated control unit 73 may perform analog-to-digital processing on the voltage signal and the current signal in the same period, so that the secondary voltage value is processed by the first analog-to-digital converter 733 to obtain an actual measured voltage value, and the actual measured voltage value is transmitted to the first comparator 735. The second analog-to-digital converter 734 processes the secondary current value to obtain a measured current value, and transmits the measured current value to the second comparator 736. The measured voltage values described here are to be understood as the primary voltage values obtained in the foregoing description by the secondary voltage values x the transformation ratio of the voltage transformer. Similarly, the measured current value can be understood as the primary current value obtained by multiplying the secondary current value by the transformation ratio of the current transformer in the foregoing.

Referring to fig. 1 and 4, in an actual use process, the first comparator 735 is used to compare the voltage protection fixed value with the actually measured voltage value, so as to determine whether the voltage value in the power supply line 5 meets the actual requirement, and avoid the occurrence of overvoltage or undervoltage to affect the starting of the motor M. For example, when the measured voltage value is greater than the voltage protection fixed value, it indicates that an overvoltage condition occurs in the power supply line 5, and at this time, the controller 4 may control the first contactor KM1 in the circuit to be turned off, so as to protect the circuit from being burned out, and ensure the safety of the motor M and other components. The second comparator 736 is used to compare the current protection constant value with the actually measured current value to determine whether the current value in the power supply line 5 meets the actual requirement, thereby avoiding the conditions of overload, underload or locked rotor from affecting the starting of the motor M. For example, when the measured current value is greater than the current protection fixed value, it indicates that the overcurrent condition occurs in the power supply line 5, and at this time, the controller 4 may control the first contactor KM1 in the circuit to be turned off, so as to protect the circuit from being burned out, and ensure the safety of the motor M and other components. Meanwhile, when an abnormality occurs, the detailed information of the abnormality is displayed on a human-computer interaction interface (such as the touch screen 750) to remind a user of timely handling and paying attention to power utilization safety. The detailed abnormality information may include information such as a measured voltage value, a measured current value, and a protection state when an abnormality occurs. The protection states may include overvoltage protection, undervoltage protection, overload protection, underload protection, locked rotor protection, phase sequence protection, open phase protection, and the like.

Referring to fig. 4, since the integrated control unit 73 and the dynamic monitoring unit 77 are connected by optical fibers, corresponding optical fiber input and output devices 78 and 79 are also provided in the dynamic monitoring unit 77 for receiving and transmitting optical fiber signals. It should be understood that the dynamic monitoring unit 77 may further include an FPGA (Field Programmable Gate Array) logic Gate builder 770, a microsecond time divider 771, a plurality of sets of comparators 772, a balance calculator 773, and a balance determiner 774. The dynamic monitoring unit 77 cuts the acquired voltage signals through the microsecond time divider 771, and sends the voltage signals to the FPGA logic gate builder 770 at the same time to perform calculation of a plurality of groups of angle coefficients, the output result enters the balance calculator 773 for calculation, and the balance determiner 774 performs determination. When the set range exceeds the preset value, the integrated control unit 73 is instructed through the optical fiber, and the integrated control unit 73 instructs the execution unit 74 to trip the first contactor KM1, so as to protect the thyristor valve assembly with differential performance from further damage.

Referring to fig. 4, the dynamic monitoring unit 77 and the triggering unit 76 are also connected by optical fibers, so corresponding optical fiber input and output devices 78 and 79 are also provided in the triggering unit 76 for receiving and transmitting optical fiber signals. It should be understood that the trigger unit 76 may further include a voltage collector 760, a voltage comparator 761, a voltage follower 762, and a flip-flop 763. The trigger unit 76 collects the voltage across the thyristor, and feeds back the voltage to the dynamic monitoring unit 77 through the voltage comparator 761 and the optical fiber. The trigger unit 76 and the thyristor valve assembly unit 22 perform transmission of information by electrical signals. It should be understood that the above-mentioned trigger units 76 and thyristor valve assembly units 22 are in one-to-one correspondence, and the number of trigger units 76 and thyristor valve assembly units 22 is configured according to voltage levels, for example: when starting a 10KV motor, 5 sets of trigger units 76 and 5 sets of thyristor valve assembly units 22 may be configured. When starting a 6KV electrical machine, 3 sets of firing units 76 and 3 sets of thyristor valve assembly units 22 may be configured. The integrated control unit 73 and the execution unit 74 are electrically connected. The execution unit 74 may include not only the first contactor KM1 but also the second contactor KM 2. The thyristor valve module unit 22 may include one set of forward and reverse parallel thyristor modules 21 or N sets of forward and reverse parallel thyristor modules.

Referring to fig. 1 and 4, the dynamic monitoring unit 77 may be used to monitor the status of components in the circuit, for example, to detect whether a thyristor in the thyristor valve assembly unit 22 is broken down, or to detect whether a damaged component is present. When a damaged component is detected, the dynamic monitoring unit 77 transmits the state information of the component to the integrated control unit 73. At this time, the integrated control unit 73 receives not only the actually measured voltage value and the actually measured current value in the circuit, but also the state information of the components, and determines the working state of the soft starter by comprehensively judging the information, that is, whether there is an abnormality. If any one of the actually measured voltage value, the actually measured current value and the state information of the components has a problem and does not meet the working requirement, the comprehensive control unit 73 sends an instruction to the execution unit 74 to disconnect the first contactor KM1 in the execution unit 74, and transmits related abnormal information to the human-computer interaction unit 75 to be displayed.

Several possible implementations are described below as examples, it being understood that the following description is only to be understood as not limiting in particular. The embodiment of the utility model provides a soft starter based on electronic transformer's starting mode has three kinds, is voltage slope starting, constant current starting, kick starting respectively.

Wherein, voltage ramp start: voltage ramp starting is the most common starting mode. The initial voltage is set to a value at which the motor just can drive the load to rotate, and then the voltage gradually and smoothly rises to enable the motor to smoothly accelerate to full-speed operation within a limited ramp time. The soft starting device can determine the linear control output voltage of the slope according to the stalling torque and the starting time.

Starting with constant current: when the soft starting device is started in a constant current mode, the current of the motor quickly reaches a current limiting value, and the high-voltage solid-state soft starter limits the current of the electronic transformer to a constant value. The starting current of the motor is limited to a set constant current value until the motor runs at full speed.

Jump starting: when the soft starting device is started, an additional starting pulse torque is provided for providing the starting torque required when the heavy load is started. The kick voltage and kick time must be set when using the kick start mode.

The comprehensive control unit can control the trigger unit according to a starting curve set by a user through the dynamic monitoring unit, and adjust the conduction angle of the positive and negative parallel thyristors in the thyristor valve component unit, so that the voltage on the motor is controlled, and the voltage and the current on the motor are slowly improved, so that the torque of the motor is smoothly increased until the motor is accelerated to run at full speed.

Participate in fig. 1 and fig. 4, to sum up, in the embodiment of the utility model, gather voltage signal and current signal through adopting electronic voltage transformer 1 and electronic current transformer 3, transmit voltage signal and current signal for merging unit 72 through optic fibre, merging unit 72 carries out the processing in same phase with voltage signal and current signal, voltage signal and current signal with accurate in same phase, transmit for integrated control unit 73 through optic fibre signal, integrated control unit 73 is to the light signal who gathers, handle to realize monitoring and the protection to voltage current in the whole circuit. Further, the integrated control unit 73 displays the primary voltage and the primary current in the circuit on the human-computer interaction interface, when an abnormality occurs, the integrated control unit 73 compares the measured values (the measured voltage value and the measured current value) with the protection setting values (the voltage protection setting value and the current protection setting value), and when the abnormality occurs, the contactor in the execution unit 74 is turned off to realize trip protection, so as to protect the motor M. Meanwhile, the man-machine interaction interface (the touch screen 750) displays detailed information of the protection abnormity.

Compared with the electromagnetic mutual inductor in the prior art, the measured signal is coupled with the secondary coil through the iron core, so that the problems of magnetic saturation, ferromagnetic resonance and the like inevitably exist, the secondary circuit cannot be opened, and the danger of opening a circuit exists at low voltage. Meanwhile, the electromagnetic transformer transmits analog signals, and the transmission of electric signals through the coaxial cable is interfered by an electromagnetic field. Furthermore, the electromagnetic mutual inductor has large volume, heavy weight and high cost, the insulation structure of the electromagnetic mutual inductor is complex, the manufacturing cost rises exponentially along with the voltage equivalence, and when a plurality of different devices are arranged on the site, the secondary wiring on the site is complex, so that the engineering cost is increased.

And the utility model discloses an electronic transformer (electronic voltage transformer and electronic current transformer), do not do the coupling with the iron core, eliminated magnetic saturation and ferromagnetic resonance phenomenon to make electronic transformer operation transient response good, stability is good. High-voltage side signals are transmitted to secondary equipment through optical fibers, the high-voltage circuit and the secondary circuit are completely electrically isolated, the anti-electromagnetic interference capacity is greatly improved, and the danger of low-voltage side open circuits is reduced or eliminated. Furthermore, the digital signal output by the electronic transformer is beneficial to data communication, the electronic transformer and a device which needs to utilize the signal of the electronic transformer can be integrated into a bus network, data sharing is realized, and a large amount of secondary cables are saved. The optical fiber is used for signal transmission, so that the anti-electromagnetic interference capability is improved, the insulation structure is simplified, the insulation performance is enhanced, the system safety and reliability are improved, the safe and reliable operation of a power grid is ensured, and the automation level is also improved. In addition, the electronic transformer has small volume, light weight and low cost, and reduces the engineering investment cost.

The embodiment of the utility model provides a still provide a soft starting device, this soft starting device includes above-mentioned technical scheme soft starter based on electronic transformer.

Compared with the prior art, the embodiment of the utility model provides a soft starting device's beneficial effect and above-mentioned technical scheme the beneficial effect based on electronic transformer's soft starter is the same, and the here is not repeated.

Fig. 5 is an assembly view of a soft start apparatus according to an embodiment of the present invention. Referring to fig. 5, the soft starter is provided with not only the soft starter based on the electronic transformer, but also other components connected with the soft starter. For example: in the cabinet body 80 of the soft starting device, the incoming line connecting copper bar 90 is respectively connected with the high-voltage live display device DXN, the electronic voltage transformer 1 and the first end of the first contactor KM 1. The second end of the first contactor KM1 is connected with the first end of the second contactor KM2 through a first lead 83, and the second end of the first contactor KM1 is connected with a reactor 6 through a reactor inlet wire 87, and after being filtered by the reactor 6, is connected to a thyristor valve assembly inlet copper bar 92 through a thyristor valve assembly inlet cable 88, and is further connected with the thyristor valve assembly 2. The outlet end of the thyristor valve component 2 is fixed by a high-voltage insulator 91 through an outlet copper bar 85 of the thyristor valve component. Further, the second end of the second contactor KM2 is also fixed on the high-voltage insulator 91, and then passes through the electronic current transformer 3 through the outgoing copper bar 85 of the thyristor valve assembly, and is connected to an external motor through the outgoing cable 84 as the outgoing end of the soft start device.

Fig. 6 shows a layout diagram of a soft start device according to an embodiment of the present invention. Referring to fig. 6, a first voltmeter PV1, a second voltmeter PV2, and an ammeter PA are provided on a panel of a cabinet 80 of the soft start apparatus. The first voltmeter PV1 is used for collecting and displaying the size of Uab in the three-phase power, and the second voltmeter PV2 is used for collecting and displaying the size of Ubc in the three-phase power. The ammeter PA is used for collecting current values in the display circuit. And a touch screen 750 for inputting and displaying information. For example, a user may input information such as motor parameters, voltage levels, voltage protection setting values, current protection setting values, and start curves through the touch screen 750, and may also display detailed abnormality information. The embodiment of the utility model provides an in, still be provided with four pilot lamps 93 on the panel of the cabinet body 80, be used for instructing respectively to start information such as completion, in the start, control power, malfunction alerting. And the high-voltage live display device DXN is used for displaying whether the soft starting device is provided with primary high-voltage electricity or not. When the soft starting device is provided with the operating voltage, a high-voltage indicator lamp on a display of the DXN is turned on to warn the workers that the working voltage is charged. When the soft starter does not work, the high-voltage indicator lamp on the display of the high-voltage live display device DXN is not lighted. The electromagnetic lock 94 is used to ensure the safety of the internal components of the soft starter, and is not easily opened when used outdoors, thereby preventing the loss of the components or the occurrence of electric shock. A button 95, a changeover switch 96, and the like are also provided. The embodiment of the present invention provides four buttons 95, which are respectively a start button, a stop button, a reset button, and an emergency stop button. The starting button is used for starting the motor, the stopping button is used for stopping the motor, the resetting button is used for resetting faults, and the emergency stopping button is used for beating when the motor is found to be abnormally operated.

It will be appreciated that the integrated control unit 73 described above with reference to figure 4 is located within a low pressure chamber located behind the front panel of the cabinet. When the controller 4 in fig. 1 is removed, fig. 1 shows a primary circuit (main circuit) in an embodiment of the present invention.

It should be understood that the functions that can be realized by the above-mentioned parts can be set according to the actual situation, and the description herein is only for understanding and not for specific limitation.

In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. An electronic transformer based soft starter for starting a motor, the electronic transformer based soft starter comprising: the electronic voltage transformer, the thyristor valve component, the electronic current transformer and the controller;

the input end of the electronic voltage transformer is electrically connected with a power supply line of the motor, and the output end of the electronic voltage transformer is connected with the first input end of the controller;

the input end of the thyristor valve component is electrically connected with the power supply circuit, and the output end of the thyristor valve component is connected with the input end of the electronic current transformer;

a first output end of the electronic current transformer is electrically connected with the motor, and a second output end of the electronic current transformer is connected with a second input end of the controller;

the output end of the controller is connected with the input end of the thyristor valve component.

2. The electronic transformer-based soft starter of claim 1 further comprising: a fuse, a high-voltage live display device, and a reactor;

the first end of the fuse is electrically connected with the power supply line, and the second end of the fuse is electrically connected with the input end of the electronic voltage transformer;

the first end of the high-voltage live display device is electrically connected with the power supply line, and the second end of the high-voltage live display device is grounded;

the input end of the reactor is electrically connected with the power supply circuit, and the output end of the reactor is electrically connected with the input end of the thyristor valve component.

3. The electronic transformer-based soft starter of claim 2 further comprising: a first contactor and a second contactor;

the first end of the first contactor is electrically connected with the power supply line, and the second end of the first contactor is electrically connected with the input end of the reactor;

and the first end of the second contactor is electrically connected with the second end of the first contactor, and the second end of the second contactor is electrically connected with the input end of the electronic current transformer.

4. The electronic transformer-based soft starter of claim 1, wherein the electronic current transformer comprises: the energy acquisition device comprises a sampling coil, an energy acquisition coil and a first photoelectric converter;

the input end of the sampling coil is electrically connected with the power supply circuit, and the output end of the sampling coil is connected with the current sampling end of the first photoelectric converter;

the input end of the energy taking coil is electrically connected with the power supply circuit, and the output end of the energy taking coil is connected with the power supply end of the first photoelectric converter;

and the output end of the first photoelectric converter is connected with the second input end of the controller.

5. The electronic transformer-based soft starter of claim 4, wherein the output of the first optical-to-electrical converter has a first optical fiber interface, and the second input of the controller has a second optical fiber interface;

the output end of the first photoelectric converter is connected with the second input end of the controller through the first optical fiber interface and the second optical fiber interface.

6. The electronic transformer-based soft starter of claim 1, wherein the electronic voltage transformer comprises: a capacitive voltage divider and a second photoelectric converter;

the input end of the capacitive voltage divider is electrically connected with the power supply line, and the output end of the capacitive voltage divider is connected with the input end of the second photoelectric converter;

and the output end of the second photoelectric converter is connected with the first input end of the controller.

7. The electronic transformer-based soft starter of claim 6 wherein the output of the second optical-to-electrical converter has a third fiber optic interface; the first input end of the controller is provided with a fourth optical fiber interface;

the output end of the second photoelectric converter is connected with the first input end of the controller through the third optical fiber interface and the fourth optical fiber interface.

8. The electronic transformer-based soft starter of claim 1 wherein the thyristor valve assembly comprises at least one set of forward and reverse parallel thyristors.

9. The electronic transformer-based soft starter of claim 1 wherein the controller comprises a first analog-to-digital converter, a second analog-to-digital converter, a first comparator, and a second comparator;

the first end of the first analog-to-digital converter is connected with the output end of the electronic voltage transformer, and the second end of the first analog-to-digital converter is electrically connected with the first comparator;

the first end of the second analog-to-digital converter is connected with the output end of the electronic current transformer, and the second end of the second analog-to-digital converter is electrically connected with the second comparator.

10. A soft starter comprising the electronic transformer-based soft starter of any one of claims 1 to 9.

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