CN211981775U

CN211981775U - High-voltage rectification topological structure of 10kV variable frequency motor all-in-one machine

Info

Publication number: CN211981775U
Application number: CN202020579139.7U
Authority: CN
Inventors: 荣凯; 申发花; 蔡宝柱; 马广府
Original assignee: Shandong Windsun Electronics Science & Technology Co ltd
Current assignee: Shandong Windsun Electronics Science & Technology Co ltd
Priority date: 2020-04-17
Filing date: 2020-04-17
Publication date: 2020-11-20
Anticipated expiration: 2030-04-17

Abstract

The utility model discloses a 10kV inverter motor all-in-one high pressure rectification topological structure, which comprises a transformer, four rectification filter module, direct current busbar voltage acquisition circuit, a controller, the transformer secondary has 4 groups of windings, a rectification filter module is connected to every group secondary winding, rectification filter module establishes ties and forms direct current generating line, direct current busbar voltage acquisition circuit connects direct current generating line and controller, rectification filter module control end is connected to the controller, input voltage acquisition circuit in addition, four IGBT repayment units, a set of secondary winding of IGBT repayment unit connection transformer, parallelly connected with a rectification filter module, input voltage acquisition circuit is connected to between rectification filter module input and the controller, IGBT repayment unit control end is connected to the controller. The utility model discloses the 10kV frequency conversion all-in-one of using compact structure effectively solves the energy repayment problem under problem, the motor power generation state that power-on impact current problem, busbar voltage receive input voltage to influence, the more effective reliable operation of assurance equipment.

Description

High-voltage rectification topological structure of 10kV variable frequency motor all-in-one machine

Technical Field

The utility model relates to an energy-conserving converter art field specifically is a rectifier of converter.

Background

At present, the speed regulation of a 10kV high-voltage motor is generally realized by adopting a high-voltage frequency converter of a multi-level cascade technology and structurally adopting a mode of connecting power units in series. Because the units are connected in series, the power supply of each power unit must be independent of each other, so that the frequency converter itself must have a multi-winding phase-shifting transformer. For a 10kV plant, there are 8 power cells per phase and 24 power cells for three phases together, thus requiring 24 independent sets of secondary windings. The manufacturing process of the transformer is quite complicated. Especially, for a high-power phase-shifting transformer, it is very difficult to make a large-sized transformer with 24 windings. The 24 power units must be connected with the corresponding secondary windings, so that the production process of the whole frequency converter is complex and the production efficiency is influenced.

The 10kV high-voltage frequency converter power unit is subjected to uncontrolled rectification, the influence of the size of an input power grid on the bus voltage is large, the amplitude of a PWM signal is changed when the frequency converter outputs in an inverting mode, and therefore the size of output voltage and the input voltage are changed greatly.

When 10kV equipment transmits power, uncontrolled rectification and a power unit are subjected to large impact current due to direct high-voltage access of the equipment, so that large potential safety hazards are brought to the equipment, and some designs increase buffer resistors on a high-voltage side and can improve the impact to a certain extent. However, the design increases the size of the cabinet body and the structural design is complex. Adding excessive cost.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the more complicated of the phase shift voltage transformer design technology who proposes among the above-mentioned background art, rectifier bus voltage is uncontrolled, go up a series of problems that there is impulse current, provided a 10kV high voltage inverter motor all-in-one high pressure rectification topological structure.

In order to achieve the above object, the utility model provides a following technical scheme:

the transformer comprises a transformer, four rectifier and filter modules, a direct current bus voltage acquisition circuit and a controller, wherein 4 groups of windings are arranged on a secondary side of the transformer, each group of secondary windings is connected with one rectifier and filter module, the rectifier and filter modules are connected in series to form a direct current bus, the direct current bus voltage acquisition circuit is connected with the direct current bus and the controller, the controller is connected with a control end of the rectifier and filter module, the transformer also comprises an input voltage acquisition circuit and four IGBT feedback units, one IGBT feedback unit is connected with one group of secondary windings of the transformer and is connected with one rectifier and filter module in parallel, the input voltage acquisition circuit is connected between an input end of the rectifier and filter module and the controller, and the controller is connected with.

Preferably, one rectifying and filtering module comprises a silicon controlled rectifier unit and a filter capacitor, and the filter capacitor is connected with the direct current end of the silicon controlled rectifier unit in parallel.

According to the preferred scheme, the controller is connected with the control end of the silicon controlled rectifier rectifying unit through the silicon controlled rectifier driving circuit, and the controller is connected with the IGBT feedback unit through the IGBT driving circuit.

Utilize the utility model discloses a high-voltage rectification topological structure uses in 10kV high-voltage inverter motor all-in-one, and the 10kV frequency conversion all-in-one of preparation compact structure effectively solves the electric impulse current problem on the 10kV high-voltage inverter motor all-in-one, solves the problem that rectifier bus voltage receives the input voltage influence simultaneously, solves the energy repayment problem under the motor power generation state, the reliable operation of more effectual assurance 10kV high-voltage inverter motor all-in-one.

Drawings

FIG. 1 is a schematic diagram of the series-connected high voltage DC bus of the present invention;

FIG. 2 is a schematic diagram of the IGBT feedback and SCR unit connections;

fig. 3 is a control block diagram of the high-voltage direct-current bus.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

A high-voltage rectification topological structure of a 10kV high-voltage variable-frequency motor all-in-one machine comprises a transformer 1 and rectification and

filtering modules

2, 3, 4 and 5, wherein the transformer 1 is provided with 4 groups of secondary windings, and each group of secondary windings is connected with one rectification and filtering module as shown in figure 2. The mode that the rectification filter modules are connected in series to form a high-voltage direct-current bus is shown in fig. 1, and the

rectification filter modules

2, 3, 4 and 5 are connected in series to form a high-voltage direct-current bus 14140V which provides direct-current bus voltage of an inverter circuit of the variable-frequency control motor. The voltage level of each rectifying and filtering module is 3535V.

As shown in fig. 2, the direct current end of the silicon controlled rectifier unit 7 is connected in parallel with a filter capacitor, each set of secondary windings is connected with an IGBT feedback unit 6, and the IGBT feedback unit 6 is connected in parallel with the silicon controlled rectifier unit 7.

The input end of the input voltage acquisition circuit 8 is connected with three attenuation resistors, three-phase VA, VB and VC voltages are attenuated into weak voltage signals, the weak voltage signals are isolated by the optical coupler and decomposed, and the output end of the input voltage acquisition circuit sends out three-phase voltage angle signals to the controller 9.

The input end of the dc bus acquisition circuit 10 is a dc bus voltage, which is attenuated by a differential resistor, and conditioned by an operational amplifier to obtain a sampling signal of the dc bus, and the output end sends the sampling signal of the dc bus to the controller 9.

The input voltage acquisition circuit 8 is connected with the three-phase input ends of the silicon controlled rectifier unit 7 and the IGBT feedback unit, three-phase input VA, VB and VC voltage signals enter the input voltage acquisition circuit 8, the input voltage acquisition circuit 8 extracts angle signals of three-phase voltage information through optical coupling isolation and signal decomposition, and the angle signals are sent to the controller 9, and are electrically isolated from the controller 9. The controller 9 obtains the phase of the power grid according to the input voltage, the controller 9 controls the IGBT feedback unit 6 to be conducted in order through the IGBT driving circuit 12, energy is fed back to the power grid, the effect of stabilizing a direct current bus is guaranteed when the motor is in a power generation state, namely the rectifying device can achieve bidirectional flow of the energy, and the bus voltage of the high-voltage rectifying device is guaranteed to be maintained at a target value.

The direct current bus acquisition circuit 10 differentially attenuates the high voltage signal into a weak bus voltage signal, and the weak bus voltage signal is sent to the controller 9, and the value of the bus voltage is acquired through AD acquisition and used for controlling the conduction angle of the silicon controlled rectifier unit 7. The controller 9 is according to bus voltage, through the PID regulator, the output is used for controlling the conduction signal of silicon controlled rectifier unit 7, with signal transmission to silicon controlled rectifier drive circuit 11, and then drive the silicon controlled rectifier, trigger the conduction angle of silicon controlled rectifier, can control the conduction voltage of controllable rectifier unit 7, and then can control the size of bus voltage after the rectification, after the high voltage is gone up, silicon controlled rectifier unit 7 can effectively realize the function of precharging, avoid the impulse current when going up the electricity, realize the target of stabilizing direct current bus voltage.

Claims

1.10kV inverter motor all-in-one high pressure rectification topological structure, including transformer, four rectification filter modules, direct current bus voltage acquisition circuit, controller, the transformer secondary has 4 groups of windings, and every group secondary winding connects one rectification filter module, rectification filter module establishes ties and forms direct current bus, direct current bus voltage acquisition circuit connects direct current bus with the controller, the controller is connected rectification filter module control end, characterized by: the transformer further comprises an input voltage acquisition circuit and four IGBT feedback units, wherein one IGBT feedback unit is connected with one group of secondary windings of the transformer and is connected with one rectifying and filtering module in parallel, the input voltage acquisition circuit is connected between the input end of the rectifying and filtering module and the controller, and the controller is connected with the control end of the IGBT feedback unit.

2. The 10kV variable frequency motor all-in-one machine high-voltage rectification topological structure as claimed in claim 1, which is characterized in that: and one rectifying and filtering module comprises a silicon controlled rectifier unit and a filtering capacitor, and the filtering capacitor is connected with the direct current end of the silicon controlled rectifier unit in parallel.

3. The 10kV variable frequency motor all-in-one machine high-voltage rectification topological structure as claimed in claim 2, which is characterized in that: the controller is connected with the control end of the silicon controlled rectifier rectifying unit through the silicon controlled rectifier driving circuit.

4. The 10kV variable frequency motor all-in-one machine high-voltage rectification topological structure as claimed in claim 1, which is characterized in that: the controller is connected with the IGBT feedback unit through an IGBT driving circuit.