Frequency converter control electric protection system

Abstract

The utility model relates to the technical field of power-off protection, in particular to a frequency converter control electric protection system, which comprises a pre-stage control unit, a first post-stage control unit and a second post-stage control unit, the output end of the front-stage control unit is connected with a front-stage control electric inlet wire, the input end of the first rear-stage control unit is connected with a rear-stage control electric inlet wire, and the input end of the second rear-stage control unit is connected with the rear-stage control electric inlet wire. The output end of the first rear-stage control unit and the output end of the second rear-stage control unit are connected with the input end of the front-stage control unit. According to the utility model, the pre-stage control unit and the two post-stage control units are adopted to provide a power-off protection function, so that the normal operation of the frequency converter in a relatively severe power supply environment is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power-off protection, and particularly relates to a frequency converter control power protection system. Background Art

[0002] In the actual use of industrial frequency conversion equipment, situations such as automatic switching of dual power supplies, automatic reclosing, and non-standard personnel operations often occur, resulting in frequent power outages in a short period of time, which can easily cause damage to the hardware and software data of the equipment. Content of the Utility Model

[0003] In view of the above deficiencies in the prior art, the utility model provides a frequency converter control power protection system.

[0004] In order to achieve the above-mentioned utility model purpose, the technical solution adopted by the utility model is as follows:

[0005] A frequency converter control power protection system includes a pre-stage control unit, a first post-stage control unit, and a second post-stage control unit; the output end of the pre-stage control unit is connected to the pre-stage control power incoming line, the input end of the first post-stage control unit is connected to the post-stage control power incoming line, the input end of the second post-stage control unit is connected to the post-stage control power incoming line, and the output ends of the first post-stage control unit and the second post-stage control unit are both connected to the input end of the pre-stage control unit.

[0006] Further, the pre-stage control unit includes a first relay, and the contact of the first relay is connected to the pre-stage control power incoming line.

[0007] Further, the first post-stage control unit includes a second relay, and the coil of the second relay is connected to the post-stage control power incoming line.

[0008] Further, the second post-stage control unit includes a full-wave rectifier circuit and a first charge and discharge circuit; the input end of the full-wave rectifier circuit is connected to the post-stage control power incoming line, and the output end of the full-wave rectifier circuit is connected to the input end of the first charge and discharge circuit; the output end of the first charge and discharge circuit is respectively connected to one end of the coil of the first relay and the third contact of the second relay, and the other end of the coil of the first relay is connected to the fourth contact of the second relay.

[0009] Further, the full-wave rectifier circuit includes a diode bridge structure.

[0010] Further, the first charge and discharge circuit includes a second resistor, a second capacitor, a third resistor, and a fifth diode; one end of the second resistor is connected to the first output end of the diode bridge structure, and the other end of the second resistor is respectively connected to one end of the second capacitor and one end of the third resistor; the other end of the third resistor is respectively connected to the third contact of the second relay and the negative electrode of the fifth diode; the other end of the second capacitor, the positive electrode of the fifth diode, and one end of the coil of the first relay are all connected to the second output end of the diode bridge structure.

[0011] Further, the first contact and the second contact of the second relay are connected to the frequency conversion controller.

[0012] Further, it further includes a switching power supply and a second charge and discharge circuit; the input end of the switching power supply is connected to the incoming line of the post-stage control power supply, and the output end of the switching power supply is connected to the input end of the second charge and discharge circuit; the output end of the second charge and discharge circuit is connected to the input end of the standby power supply of the frequency conversion controller.

[0013] Further, the second charge and discharge circuit includes a first resistor, a first capacitor, and a sixth diode; one end of the first resistor is connected to the first output end of the switching power supply, and the other end of the first resistor is respectively connected to the positive electrode of the sixth diode and one end of the first capacitor; the negative electrode of the sixth diode is connected to the fifth contact of the second relay, and the sixth contact of the second relay is connected to the input end of the standby power supply of the frequency conversion controller; the other end of the first capacitor is respectively connected to the second output end of the switching power supply and the input end of the standby power supply of the frequency conversion controller.

[0014] The utility model has the following beneficial effects:

[0015] Aiming at the problem of harsh power supply environment in the actual application environment of industrial frequency converters, the utility model adopts a pre-stage control unit and two post-stage control units to provide functions such as frequent power-off protection and controller delay power-off protection, so as to ensure the normal operation of the frequency converter in a relatively harsh power supply environment. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a frequency converter control power protection system;

[0017] Figure 2 It is a schematic principle diagram of a frequency converter control power protection system. Detailed Embodiment

[0018] The following describes the specific embodiments of the present utility model to facilitate those skilled in the art of this technology to understand the present utility model. However, it should be clear that the present utility model is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of this technology, as long as various changes are within the spirit and scope of the present utility model defined and determined by the appended claims, these changes are obvious, and all utility models created using the concept of the present utility model are within the scope of protection.

[0019] As Figure 1 shown, a frequency converter control electric protection system provided by an embodiment of the present utility model includes a pre-stage control unit, a first post-stage control unit, and a second post-stage control unit; the output end of the pre-stage control unit is connected to the pre-stage control power supply incoming line, the input end of the first post-stage control unit is connected to the post-stage control power supply incoming line, the input end of the second post-stage control unit is connected to the post-stage control power supply incoming line, and the output ends of the first post-stage control unit and the second post-stage control unit are both connected to the input end of the pre-stage control unit.

[0020] The present utility model adopts a pre-stage control unit and two post-stage control units, which can protect the post-stage control circuit from normal operation in scenarios such as frequent power outages or power supply switching of the power supply.

[0021] In an optional manner of this embodiment, as Figure 2 shown, the pre-stage control unit includes a first relay, and the contact of the first relay is connected to the pre-stage control power supply incoming line.

[0022] The first post-stage control unit includes a second relay, and the coil of the second relay is connected to the post-stage control power supply incoming line.

[0023] The second post-stage control unit includes a full-wave rectifier circuit and a first charge and discharge circuit; the input end of the full-wave rectifier circuit is connected to the post-stage control power supply incoming line, the output end of the full-wave rectifier circuit is connected to the input end of the first charge and discharge circuit; the output end of the first charge and discharge circuit is respectively connected to one end of the coil of the first relay and the third contact of the second relay, and the other end of the coil of the first relay is connected to the fourth contact of the second relay.

[0024] The full-wave rectifier circuit includes a diode bridge structure.

[0025] The first charge and discharge circuit includes a second resistor, a second capacitor, a third resistor, and a fifth diode; one end of the second resistor is connected to the first output end of the diode bridge structure, and the other end of the second resistor is respectively connected to one end of the second capacitor and one end of the third resistor; the other end of the third resistor is respectively connected to the third contact of the second relay and the negative electrode of the fifth diode; the other end of the second capacitor, the positive electrode of the fifth diode, and one end of the coil of the first relay are all connected to the second output end of the diode bridge structure.

[0026] The first contact and the second contact of the second relay are connected to the frequency conversion controller.

[0027] In this embodiment, the pre-stage control power supply line passes through the normally closed contact of the first relay KT, the coil of the second relay K1 is energized, and the third contact 13 and the fourth contact 14 are disconnected. At the same time, the alternating current is rectified by the rectifier diodes D1, D2, D3, and D4 of the full-wave rectifier circuit to output direct current, which is charged and limited by the second resistor R2 and then charges the second capacitor C2 for energy storage.

[0028] During the capacitor charging process, after being current-limited by the third resistor R3, it is voltage-divided with the fifth diode D5. When the voltage across the fifth diode D5 exceeds its regulated set value, the fifth diode D5 will be broken down and conducted. Until the second capacitor C2 rises to the rated voltage, the fifth diode D5 maintains its current state. Since the third contact 13 and the fourth contact 14 of the second relay K1 are in the disconnected state, the coil of the first relay KT will not be energized, and the first relay KT does not operate.

[0029] If the pre-stage control power supply is normally powered at this time, the system will not affect the pre-stage and post-stage of the power supply, and the control power supply circuit will work normally.

[0030] If the pre-stage control power supply is powered off at this time, the coil of the second relay K1 is powered off, and the normally closed third contact 13 and fourth contact 14 are closed. The coil of the first relay KT will be connected in parallel across the two ends of the fifth diode D5. Utilizing the characteristic that the voltage across the fifth diode D5 can basically remain unchanged after being reversely broken down, the voltage across the coil of the first relay KT will be clamped at the rated voltage by the fifth diode D5. The main contact of the first relay KT is disconnected. At this time, the second capacitor C2 will maintain the power supply to the coil of the first relay KT. Before the second capacitor C2 discharges to the set time, the main contact of the first relay KT is in the disconnected state. At this time, whether the pre-stage has a power failure or frequent power-on, the post-stage is not powered on. When the set discharge time of the second capacitor C2 is reached, the coil of the first relay KT will not be able to disconnect the contact, and the main contact of the first relay KT is closed. When the pre-stage is normally powered at this time, the post-stage can work normally.

[0031] In an alternative embodiment of the present embodiment, it further includes a switching power supply and a second charge and discharge circuit; the input end of the switching power supply is connected to the incoming line of the post-stage control power supply, and the output end of the switching power supply is connected to the input end of the second charge and discharge circuit; the output end of the second charge and discharge circuit is connected to the input end of the standby power supply of the frequency conversion controller.

[0032] The second charge and discharge circuit includes a first resistor, a first capacitor and a sixth diode; one end of the first resistor is connected to the first output end of the switching power supply, and the other end of the first resistor is respectively connected to the positive electrode of the sixth diode and one end of the first capacitor; the negative electrode of the sixth diode is connected to the fifth contact of the second relay, and the sixth contact of the second relay is connected to the input end of the standby power supply of the frequency conversion controller; the other end of the first capacitor is respectively connected to the second output end of the switching power supply and the input end of the standby power supply of the frequency conversion controller.

[0033] When the front stage is powered on in this embodiment, the switching power supply U1 will limit the current through the first resistor R1 and then charge the first capacitor C1 for energy storage. After the front stage power supply is powered off, the normally closed fifth contact 15 and sixth contact 16 of the second relay K1 are connected. Utilizing the unidirectional conduction and small conduction voltage drop characteristics of the sixth diode D6, the first capacitor C1 temporarily supplies power to the frequency conversion controller through the sixth diode D6 for 10S - 20S. At the same time, the frequency conversion controller receives the power-off DI signal of the normally closed first contact 11 and second contact 12 of the second relay K1. The frequency conversion controller will save the program operation data and record information such as the fault status within the set time, and wait for the next action according to the actual situation.

[0034] In summary, this system can ensure the normal start-up, operation and stop of the equipment control loop. At the same time, it ensures the normal recording and storage of various operation data, avoids frequent power-on of the equipment, protects the post-stage circuit from frequent voltage impacts, and avoids damage to the equipment and program data caused by frequent power-off and restart of the controller.

[0035] Specific embodiments are applied in the present invention to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

[0036] Those of ordinary skill in the art will realize that the embodiments described herein are for helping readers understand the principles of the present utility model, and it should be understood that the protection scope of the present utility model is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific deformations and combinations that do not depart from the essence of the present utility model based on these technical revelations disclosed by the present utility model, and these deformations and combinations are still within the protection scope of the present utility model.

Claims

1. A frequency converter controlled electrical protection system, characterized in that: It includes a front-stage control unit, a first rear-stage control unit and a second rear-stage control unit; the output end of the front-stage control unit is connected to the front-stage control power input line, the input end of the first rear-stage control unit is connected to the rear-stage control power input line, the input end of the second rear-stage control unit is connected to the rear-stage control power input line, and the output end of the first rear-stage control unit and the output end of the second rear-stage control unit are both connected to the input end of the front-stage control unit.

2. A frequency converter control electric protection system according to claim 1, characterized in that: The front-stage control unit comprises a first relay, and a contact of the first relay is connected to the front-stage control power inlet line.

3. A frequency converter control electric protection system according to claim 2, characterized in that: The first rear-stage control unit includes a second relay, and the coil of the second relay is connected to the rear-stage control power input line.

4. A frequency converter control electric protection system according to claim 3, characterized in that: The second post-stage control unit includes a full-wave rectifier circuit and a first charge and discharge circuit; the input end of the full-wave rectifier circuit is connected to the post-stage control power input line, and the output end of the full-wave rectifier circuit is connected to the input end of the first charge and discharge circuit; the output end of the first charge and discharge circuit is respectively connected to one end of the coil of the first relay and the third contact of the second relay, and the other end of the coil of the first relay is connected to the fourth contact of the second relay.

5. A frequency converter control electric protection system according to claim 4, characterized in that: The full-wave rectifier circuit includes a diode bridge structure.

6. A frequency converter control electric protection system according to claim 5, characterized in that: The first charge and discharge circuit includes a second resistor, a second capacitor, a third resistor and a fifth diode; one end of the second resistor is connected to the first output end of the diode bridge structure, and the other end of the second resistor is respectively connected to one end of the second capacitor and one end of the third resistor; the other end of the third resistor is respectively connected to the third contact of the second relay and the negative electrode of the fifth diode; the other end of the second capacitor, the positive electrode of the fifth diode and one end of the coil of the first relay are all connected to the second output end of the diode bridge structure.

7. A frequency converter control electric protection system according to claim 6, characterized in that: The first contact and the second contact of the second relay are connected to the frequency conversion controller.

8. The inverter control electric protection system according to claim 1, characterized in that: It also includes a switching power supply and a second charging and discharging circuit; the input end of the switching power supply is connected to the rear-stage control power input line, and the output end of the switching power supply is connected to the input end of the second charging and discharging circuit; the output end of the second charging and discharging circuit is connected to the input end of the backup power supply of the frequency conversion controller.

9. A frequency converter control electric protection system according to claim 8, characterized in that: The second charge and discharge circuit includes a first resistor, a first capacitor and a sixth diode; one end of the first resistor is connected to the first output end of the switching power supply, and the other end of the first resistor is respectively connected to the positive electrode of the sixth diode and one end of the first capacitor; the negative electrode of the sixth diode is connected to the fifth contact of the second relay, and the sixth contact of the second relay is connected to the backup power input end of the frequency conversion controller; the other end of the first capacitor is respectively connected to the second output end of the switching power supply and the backup power input end of the frequency conversion controller.

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