CN210780535U

CN210780535U - Mechanical bypass of high-voltage frequency converter

Info

Publication number: CN210780535U
Application number: CN201922462523.9U
Authority: CN
Inventors: 郭少明; 黄建军; 孔令凯; 林法坤
Original assignee: Shandong Windsun Electronics Science & Technology Co ltd
Current assignee: Shandong Windsun Electronics Science & Technology Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-06-16
Anticipated expiration: 2029-12-31

Abstract

The utility model discloses a high-voltage inverter machinery bypass, including main control board, machinery bypass board and bypass contactor, the output of every high-voltage inverter all is provided with the bypass contactor, is provided with the signal transfer board between main control board and the machinery bypass board, and the main control board is connected with transfer board optic fibre receiver through optic fibre, and optic fibre launch pad communicates with bypass board optic fibre receiver through optic fibre to realize optical fiber communication; the bypass board optical fiber receiving seat is connected with the control end of the bypass contactor through the NOT gate circuit and the optocoupler circuit in sequence so as to control the power-on and power-off state of the bypass contactor coil. The utility model discloses a high-voltage inverter machinery bypass, the high-voltage inverter who possesses mechanical bypass function can be in the unit damage under the finite quantity, like under the unit fault condition such as unit excessive pressure, unit communication trouble, unit IGBT damage, automatic redundancy trouble unit, and the converter has trouble automatic re-setting function, alright continuation operation behind the trouble unit automatic redundancy.

Description

Mechanical bypass of high-voltage frequency converter

Technical Field

The utility model relates to a high-voltage inverter machinery bypass, more specifically the saying so especially relates to a high-voltage inverter machinery bypass.

Background

The application of the high-voltage frequency converter in the field of electric transmission has a profound significance, and the high-voltage frequency converter is widely applied to industries such as power generation, petroleum, coal mines and metallurgy. Considering that the stability requirement of a plurality of fields on the frequency converter is high, in order to avoid the shutdown of the high-voltage frequency converter caused by unit failure to bring economic loss to customers and improve the reliability of the high-voltage frequency converter, a mechanical bypass technology of the high-voltage frequency converter capable of carrying out automatic redundancy of units is used for oil.

At present, a mechanical bypass control system often performs information interaction with a main control board directly, namely, the mechanical bypass control system directly controls a mechanical bypass contactor as a main control, but the scheme also improves the workload of the main control system for executing information processing exponentially, prolongs the execution cycle time of the main control system, and reduces the execution efficiency of the whole main control system.

The rated input voltage of the whole high-voltage frequency converter is assumed to be 10kV, the power is 1000kW, 18 power units are provided, the input voltage of each unit is 690VAC, therefore, the rated current of the contactor is required to be more than or equal to 144A, the rated voltage of a main contact is required to be more than or equal to 1kVAC, a coil is controlled by 24V, the reliable action of the contactor is required to be ensured during design, and the contactor is installed in a power unit cabinet, so that 10kV high-voltage interference exists, and the power supply stability of the contactor is required to be ensured and is not allowed.

Disclosure of Invention

The utility model discloses an overcome above-mentioned technical problem's shortcoming, provide a high-voltage inverter machinery bypass.

The utility model discloses a high-voltage inverter machinery bypass, including main control board, machinery bypass board and bypass contactor, the output of every high-voltage inverter all is provided with the bypass contactor, and an output of high-voltage inverter exports to the load behind bypass contactor's normally closed point, and two output terminals of high-voltage inverter connect in bypass contactor's normal open point; the method is characterized in that: a signal transfer board is arranged between the main control board and the mechanical bypass board, the signal transfer board consists of a microprocessor, and a transfer board optical fiber receiving seat and an optical fiber transmitting seat circuit which are connected with the microprocessor, and the optical fiber transmitting seat circuit is connected with an optical fiber transmitting seat; the mechanical bypass plate is provided with a bypass plate optical fiber receiving seat; the main control board is connected with the optical fiber receiving seat of the transfer board through optical fibers so as to realize the communication between the main control board and the signal transfer board, and the optical fiber transmitting seat is communicated with the optical fiber receiving seat of the bypass board through optical fibers so as to realize the communication between the signal transfer board and the mechanical bypass board; the bypass board optical fiber receiving seat is connected with the control end of the bypass contactor through the NOT gate circuit and the optocoupler circuit in sequence so as to control the power-on and power-off state of the bypass contactor coil.

The utility model discloses a high-voltage inverter machinery bypass, microprocessor in the signal transfer board adopts the CPLD device, is provided with first 5V power conversion module and 3.3V power conversion module in the signal transfer board, and the light signal that the main control board transmitted is converted into the 5V signal of telecommunication through first 5V power conversion module, and the 5V signal of telecommunication is converted into the 3.3V signal of telecommunication through 3.3V power conversion module again and is sent CPLD microprocessor; the number of the optical fiber launching seats in the signal transfer plate is 24.

The utility model discloses a high-voltage inverter machinery bypass, be provided with step-down transformer, AC/DC conversion module and second 5V power conversion module in the machinery bypass board.

The utility model discloses a high-voltage inverter machinery bypass, main control board and signal transfer board are installed in the main control cabinet, machinery bypass board and bypass contactor are installed in converter power cabinet.

The utility model discloses a high-voltage inverter machinery bypass, machinery bypass board, bypass contactor and step-down transformer are all installed in a machinery bypass box.

The utility model has the advantages that: the high-voltage frequency converter mechanical bypass can continue to operate without stopping the automatic redundancy unit when the whole machine has a fault in operation, and the function has great significance for various field applications, such as steel plants, cement plants and thermal power plants, which have long-term effects and need long-term operation of the frequency converter, and each stop can bring huge economic loss; the high-voltage frequency converter with the mechanical bypass function can automatically redundancy fault units under the condition that units are damaged in a limited number, such as unit overvoltage, unit communication fault, unit IGBT damage and other unit faults. And the frequency converter has a fault automatic reset function, and the fault unit can continue to operate after automatic redundancy.

Drawings

Fig. 1 is a schematic circuit diagram of a mechanical bypass of a high-voltage inverter according to the present invention;

FIG. 2 is a schematic diagram of a main loop connection of a high-voltage inverter;

fig. 3 is a logic flow diagram of the mechanical bypass of the high-voltage inverter according to the present invention;

fig. 4 is a schematic diagram of the signal transfer board according to the present invention;

fig. 5 is a schematic view of the mechanical bypass plate according to the present invention.

In the figure: the system comprises a main control board 1, a signal transfer board 2, a mechanical bypass board 3, a bypass contactor 4, a microprocessor 5, a transfer board optical fiber receiving seat 6, an optical fiber transmitting seat circuit 7, an optical fiber transmitting seat 8 and a bypass board optical fiber receiving seat 9; the power supply comprises a 10 frequency converter, 11 first 5V power supply conversion modules, 123.3V power supply conversion modules, 13 NOT gate circuits, 14 optical coupler circuits, 15 step-down transformers, 16 AC/DC conversion modules and 17 second 5V power supply conversion modules.

Detailed Description

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

As shown in fig. 1, the utility model discloses a circuit schematic diagram of high-voltage inverter machinery bypass is given, it is by main control board 1, signal transfer board 2, machinery bypass board 3 and bypass contactor 4 are constituteed, as shown in fig. 2, high-voltage inverter major loop connection schematic diagram has been given, shown bypass contactor 4 sets up in the output of converter, an output of converter is exported to the load through bypass contactor 4's normally closed point, two output of converter connect in bypass contactor 4's the same normal open point, when high-voltage inverter had no trouble, bypass contactor 4's coil did not energize, bypass contactor 4 does not move, high-voltage inverter normally outputs; when the high-voltage frequency converter has unit faults such as unit overvoltage, unit communication fault and unit IGBT damage, the coil of the bypass contactor 4 is electrified, the normally closed point of the bypass contactor 4 is disconnected, the normally open point is closed, the corresponding high-voltage frequency converter stops outputting, and automatic redundancy is realized.

The signal transfer board 2 is composed of a microprocessor 5, a transfer board optical fiber receiving seat 6, an optical fiber transmitting seat circuit 7 and an optical fiber transmitting seat 8, the microprocessor 5 can adopt a CPLD device, the transfer board optical fiber receiving seat 6 is connected with a signal input port of the microprocessor 5, an output end of the microprocessor 5 is connected with an input end of the optical fiber transmitting seat circuit 7, and an output end of the optical fiber transmitting seat circuit 7 is connected with the optical fiber transmitting seat 8. The mechanical bypass board 3 is provided with a bypass board optical fiber receiving seat 9, and the main control board 1 is connected with the transit board optical fiber receiving seat 6 through optical fibers so as to realize optical fiber communication between the main control board 1 and the signal transit board 2. The optical fiber transmitting seat 8 is connected with the bypass board optical fiber receiving seat 9 through optical fibers so as to realize optical fiber communication between the signal transfer board 2 and the mechanical bypass board 3.

Fig. 3 is a logic flow diagram of a mechanical bypass of a high-voltage inverter, and it can be seen that a control signal sent by the main control board 1 is forwarded by the signal transfer board 2, and then control over a plurality of (e.g. 24) mechanical bypass boards can be achieved. Each frequency converter power unit is connected with a mechanical bypass board and a mechanical bypass contactor, so that the independence of the power units is ensured, and when a certain unit fails, the action of the certain unit does not affect other units. The optical fiber transfer board is used as a medium, the unit transmits the fault into the main control board, the main control board makes corresponding logic judgment to interact with the optical fiber transfer board, the problem that the unit fault is transmitted to the main control system and then to the mechanical bypass system is avoided, and the optical fiber is used for signal transmission to avoid the interference of signals in the high-voltage cabinet.

As shown in fig. 4, a schematic diagram of the signal transfer board according to the present invention is shown, and it can be seen that the signal transfer board 2 is further provided with a first 5V power conversion module 11 and a 3.3V power conversion module 12, an optical signal transmitted by the main control board (1) is converted into a 5V electrical signal through the first 5V power conversion module, and the 5V electrical signal is converted into a 3.3V electrical signal through the 3.3V power conversion module and transmitted to the CPLD microprocessor.

As shown in fig. 5, the principle and schematic diagram of the mechanical bypass board of the present invention is shown, which includes a power conversion circuit and a signal driving circuit, the power source of the present invention is obtained by unit input, and then the voltage is reduced by voltage reduction and voltage reduction, and only the input voltage of the power module is output by the power module, which is 24V,5V and 3.3V.

The working principle is that when an optical signal transmitted by the signal transfer plate is received, the driving capability of the optical signal is improved through a NOT gate, and by utilizing the characteristic of an optical coupler, when the optical signal exists, the optical coupler is conducted, the mechanical bypass plate outputs 24V, and the contactor acts. The maximum attracting current of the bypass contactor coil is 0.5A, and the maximum maintaining current is 0.45A.

The mechanical bypass board 3, the bypass contactor 4 and the step-down transformer 15 are all installed in a mechanical bypass box, the box body is sealed safely, and the box is electrically connected with the power unit to complete hardware connection.

Through the scheme of this embodiment, increase mechanical bypass function on original model, do not change current hardware circuit at the maximum scope, only need can reach the mesh through changing the master control program. The signal transfer board is used for processing communication signals in a unified way, and the information processing burden of the main control board is not increased. All communication uses optical fiber communication, interference of high voltage to signals does not exist, and the contactor can stably act. The function of adding the mechanical bypass on the common machine type is realized only by additionally adding a plurality of mechanical bypass boxes and a signal transfer plate, and the compatibility is excellent. The mechanical bypass board power supply can be obtained from the unit input without adding additional power supply, and has less devices, less size and low cost. The human-computer interface connected with the master control system has the functions of checking the state of each unit and giving an alarm to fault information, and can actively bypass the units. After the unit carries out the automatic redundancy function of the unit due to faults, the whole machine can reset automatically and keep the frequency to continue to operate without manual operation, and unattended operation is realized.

The utility model discloses for prior art's advantage embodies:

1. the mechanical bypass function is designed on the original machine type, the existing hardware circuit is not changed in the maximum range, and the purpose can be achieved only by changing the main control program.

2. The signal transfer board is used for processing communication signals in a unified way, and the information processing burden of the main control board is not increased.

3. All communication uses optical fiber communication, interference of high voltage to signals does not exist, and the contactor can stably act.

4. The function of adding the mechanical bypass on the common machine type is realized only by additionally adding a plurality of mechanical bypass boxes and a signal transfer plate, and the compatibility is excellent.

5. The mechanical bypass board power supply can be obtained from the unit input without adding additional power supply, and has less devices, less size and low cost.

6. The human-computer interface connected with the master control system has the functions of checking the state of each unit and giving an alarm to fault information, and can actively bypass the units.

7. After the unit carries out the automatic redundancy function of the unit due to faults, the whole machine can reset automatically and keep the frequency to continue to operate without manual operation, and unattended operation is realized.

Claims

1. A high-voltage frequency converter mechanical bypass comprises a main control board (1), a mechanical bypass board (3) and a bypass contactor (4), wherein the output end of each high-voltage frequency converter is provided with the bypass contactor, one output end of each high-voltage frequency converter is output to a load after passing through a normally closed point of the bypass contactor, and two output ends of each high-voltage frequency converter are connected to a normally open point of the bypass contactor; the method is characterized in that: a signal transfer board (2) is arranged between the main control board (1) and the mechanical bypass board (3), the signal transfer board consists of a microprocessor (5), a transfer board optical fiber receiving seat (6) and an optical fiber transmitting seat circuit (7), and the optical fiber transmitting seat circuit is connected with an optical fiber transmitting seat (8); the mechanical bypass plate (3) is provided with a bypass plate optical fiber receiving seat (9); the main control board is connected with the optical fiber receiving seat of the transfer board through optical fibers so as to realize the communication between the main control board and the signal transfer board, and the optical fiber transmitting seat (8) is communicated with the optical fiber receiving seat (9) of the bypass board through optical fibers so as to realize the communication between the signal transfer board and the mechanical bypass board; the bypass board optical fiber receiving seat is connected with the control end of the bypass contactor (4) through a NOT gate circuit (13) and an optical coupler circuit (14) in sequence so as to control the power-on and power-off state of a bypass contactor coil.

2. The mechanical bypass of a high-voltage inverter according to claim 1, wherein: the microprocessor (5) in the signal transfer board (2) adopts a CPLD device, a first 5V power supply conversion module (11) and a 3.3V power supply conversion module (12) are arranged in the signal transfer board, an optical signal transmitted by the main control board (1) is converted into a 5V electric signal through the first 5V power supply conversion module, and the 5V electric signal is converted into a 3.3V electric signal through the 3.3V power supply conversion module and transmitted to the CPLD microprocessor; the number of the optical fiber launching seats (8) in the signal transfer plate is 24.

3. The mechanical bypass of a high-voltage inverter according to claim 1 or 2, wherein: a step-down transformer (15), an AC/DC conversion module (16) and a second 5V power conversion module (17) are arranged in the mechanical bypass board (3).

4. The mechanical bypass of a high-voltage inverter according to claim 1 or 2, wherein: the main control board (1) and the signal transfer board (2) are installed in the main control cabinet, and the mechanical bypass board (3) and the bypass contactor (4) are installed in the frequency converter power cabinet.

5. The mechanical bypass of a high-voltage inverter according to claim 3, wherein: the mechanical bypass board (3), the bypass contactor (4) and the step-down transformer (15) are all installed in a mechanical bypass box.