Loop structure for preventing inverse power transmission of inverter power supply module
By designing a circuit structure to prevent the inverter power supply module from being reversed in the ultrasonic current measurement device of the hydroelectric unit, and using the power supply contactor to isolate the power supply circuit, the safety hazards of reverse power supply caused by leakage of semiconductor devices are solved, and the safety of the system is improved and operation and maintenance efficiency.
Patent Information
- Application Number
- CN202420827000.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-19
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-04-19
AI Technical Summary
In the ultrasonic current measurement device of the giant hydroelectric unit, the semiconductor devices of the inverter power module are prone to shutdown and leakage during long-term high load use and aging, resulting in a degradation of the isolation performance between the AC input and the DC output, which may occur. The anti-power transmission phenomenon threatens personal safety and equipment stability.
A circuit structure is designed to prevent the inverted power supply module from being reversed. By setting the first and second power isolation contactors between the AC power supply circuit and the DC power supply circuit, the power supply circuit is completely isolated by the dynamic contacts to avoid reverse The occurrence of power transmission.
It effectively enhances the maintenance safety and equipment protection level of the hydropower unit, reduces the risks caused by reverse power transmission, improves personnel safety and operation and maintenance efficiency during maintenance, and simplifies the maintenance operation process.
Smart Images
Figure CN222147150U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of inverter power supply modules and is applied to the power supply process of a main cabinet of an ultrasonic flow measuring device of a hydroelectric generator set. It is specifically a circuit structure for preventing the inverter power supply module from sending power in reverse. Background Art
[0002] In the modern energy system, giant hydropower units are large-scale renewable energy facilities, and their operating efficiency and safety are of vital importance. In order to accurately monitor the working status of the turbine and ensure efficient power generation, it is common practice to equip the unit with an ultrasonic flow measurement device. This type of device uses ultrasonic technology to accurately measure the flow rate of water diversion through the turbine. The industrial computer collects flow velocity data at different positions in the pressure steel pipe and uses relevant algorithms to calculate the actual flow rate of the turbine. This data, combined with the real-time active power output of the unit, can evaluate the overall working efficiency of the hydropower unit in real time, providing a key basis for optimizing operation strategies, preventing failures and maintenance decisions.
[0003] In order to ensure the stable and reliable operation of the industrial computer system and prevent data collection interruption or false alarm caused by power failure, a dual power supply redundant design is usually adopted. That is, one AC220V power supply and one DC220V power supply are configured, and both power supplies are connected to the inverter power module at the same time. The inverter power module plays a key role in power conversion and management in this architecture. It can automatically switch or use two power supplies at the same time to ensure that when any power supply is abnormal, the other power supply can continue to supply power to the industrial computer, effectively improving the reliability of the power supply system.
[0004] However, although the dual power supply redundant design significantly enhances the power supply stability of industrial computers, the characteristics of the semiconductor devices inside the existing inverter power module and the problems that may arise during long-term use constitute potential safety hazards. Semiconductor devices, especially power devices such as IGBT and MOSFET, are prone to shutdown leakage during long-term high-load operation and their own aging process. This phenomenon gradually intensifies with the increase of service life and the continuous heating of components, resulting in the degradation of the isolation performance between the AC input and DC output terminals inside the inverter power module.
[0005] Specifically, due to the increased leakage of semiconductor devices, an unexpected current path may appear between the AC input circuit and the DC output circuit, which should have been effectively isolated. When a power supply (such as the AC power supply) is powered off for some reason, and the inverter power module is still powered by another power supply (such as the DC power supply), the AC circuit in the power-off state may theoretically sense the voltage "reversely sent" from the DC circuit, forming the so-called "reverse power" phenomenon. In this case, if maintenance personnel touch the AC circuit that has been powered off without taking appropriate protective measures, they will face the risk of electric shock, which seriously threatens personal safety and may also cause accidental damage to related electrical equipment.
[0006] Therefore, although the existing ultrasonic flow measurement system of giant hydropower units and its dual power redundant power supply scheme have played an important role in improving the accuracy of unit efficiency monitoring and power supply reliability, the shutdown leakage problem of semiconductor devices inside the inverter power module and the safety hazard of reverse power transmission caused by it have become a bottleneck restricting the overall safety and operation and maintenance efficiency of the system. It is urgent to develop new improvement measures to effectively suppress the leakage of semiconductor devices, strengthen the safety isolation between power circuits, eliminate the risk of reverse power transmission, and ensure the efficient operation of giant hydropower units while protecting the personal safety of workers and the stable operation of equipment. Utility Model Content
[0007] Based on the current status in the background technology, the purpose of the utility model is to solve the potential safety hazard problem of reverse power transmission of the inverter power module in the application scenario of the ultrasonic flow measuring device of the hydropower unit, and therefore proposes a circuit structure to prevent the reverse power transmission of the inverter power module; when the corresponding circuit is powered off, the utility model can use the contactor's moving contacts to completely isolate the power supply circuit from the input end corresponding to the inverter power module of the ultrasonic flow measuring device of the hydropower unit, thereby avoiding safety accidents caused by reverse power transmission.
[0008] The utility model adopts the following technical solutions to achieve the purpose:
[0009] A circuit structure for preventing an inverter power module from reverse power transmission comprises an inverter power module, an AC power supply circuit and a DC power supply circuit, wherein the inverter power module is connected to the AC power supply circuit and the DC power supply circuit respectively; a first power supply isolation contactor is arranged between the AC power supply circuit and the inverter power module, and a second power supply isolation contactor is arranged between the DC power supply circuit and the inverter power module; the first power supply isolation contactor has a first make contact, which is located between a lower-level AC normally open auxiliary contact of the AC power supply circuit and the inverter power module; the second power supply isolation contactor has a second make contact, which is located between a lower-level DC normally open auxiliary contact of the DC power supply circuit and the inverter power module.
[0010] Specifically, the AC power supply circuit also includes a lower-level AC power switch S3, which is linked and matched with the lower-level AC normally open auxiliary contact; the DC power supply circuit also includes a lower-level DC power switch S4, which is linked and matched with the lower-level DC normally open auxiliary contact.
[0011] Specifically, the AC power supply circuit also includes an upper AC power switch S1, which has an upper AC normally open auxiliary contact that is linked and matched with it; the DC power supply circuit also includes an upper DC power switch S2, which has an upper DC normally open auxiliary contact that is linked and matched with it; the upper AC normally open auxiliary contact is connected to the lower AC normally open auxiliary contact, and the upper DC normally open auxiliary contact is connected to the lower DC normally open auxiliary contact.
[0012] Specifically, the first power isolation contactor further has a first excitation coil KM1, and the downstream AC power switch S3 is connected to the connection line between the downstream AC normally open auxiliary contact and the first make contact through the first excitation coil KM1.
[0013] Specifically, the second power isolation contactor further has a second excitation coil KM2, and the lower DC power switch S4 is connected to the connection line between the lower DC normally open auxiliary contact and the second make contact through the second excitation coil KM2.
[0014] In summary, due to the adoption of this technical solution, the utility model can improve the maintenance safety of hydropower units and the protection level of equipment and facilities, and has the following beneficial effects:
[0015] 1. The utility model fills the gap in the prior art in dealing with the risk of reverse power transmission of the inverter power module, prevents the reverse power supply phenomenon of the AC and DC circuits through circuit configuration, and enhances the safety performance of the current measurement system of the hydropower unit.
[0016] 2. The utility model fundamentally prevents the occurrence of reverse power transmission by means of physical isolation, thereby reducing the risk of serious casualties and damage to equipment and facilities caused by reverse power transmission of the inverter power module.
[0017] 3. When the upper and lower power switches are manually disconnected, the utility model can automatically trigger and forcibly disconnect the power isolation contactor, ensuring that the AC and DC input power of the inverter power module can be reliably cut off even under special operating conditions such as manual pressurization, avoiding the occurrence of false closing and improving the safety of personnel during maintenance.
[0018] 4. The utility model not only improves the personal safety protection level of the ultrasonic flow measuring device of the hydropower unit during maintenance, but also simplifies the maintenance operation process and reduces the dependence on the professional knowledge and skills of the operators. The operators can perform troubleshooting and repair work more calmly and efficiently, thereby improving the overall operation and maintenance efficiency of the power system. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the connection relationship of the loop structure of the utility model.
[0020] The meanings of the symbols in the accompanying drawings are as follows:
[0021] 1-inverter power module, 2-first make contact, 3-lower-level AC normally open auxiliary contact, 4-second make contact, 5-lower-level DC normally open auxiliary contact, 6, upper-level AC normally open auxiliary contact, 7-upper-level DC normally open auxiliary contact, 8-first AC / DC distribution cabinet, 9-second AC / DC distribution cabinet, 10-power load, 11-AC input interface, 12-DC input interface, 13-AC output interface, 14-ultrasonic flow measuring device host cabinet. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Generally, the components of the embodiment of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0024] Example 1
[0025] like Figure 1As shown, a circuit structure for preventing an inverter power module from reversely transmitting power is applied to an ultrasonic flow measuring device of a hydropower unit, comprising an inverter power module 1, an AC power supply circuit and a DC power supply circuit, wherein the inverter power module 1 is connected to the AC power supply circuit and the DC power supply circuit respectively; a first power isolation contactor is arranged between the AC power supply circuit and the inverter power module 1, and a second power isolation contactor is arranged between the DC power supply circuit and the inverter power module 1; the first power isolation contactor has a first make contact 2, which is located between a lower-level AC normally open auxiliary contact 3 of the AC power supply circuit and the inverter power module 1; the second power isolation contactor has a second make contact 4, which is located between a lower-level DC normally open auxiliary contact 5 of the DC power supply circuit and the inverter power module 1.
[0026] In this embodiment, the AC power supply circuit also includes a downstream AC power switch S3, which is linked and matched with the downstream AC normally open auxiliary contact 3; the DC power supply circuit also includes a downstream DC power switch S4, which is linked and matched with the downstream DC normally open auxiliary contact 5.
[0027] The power switch involved in this embodiment can be a knife switch, but it is equipped with corresponding auxiliary contacts, so that the auxiliary contacts can be linked with the action of the switch, that is, when the knife switch is closed, the corresponding auxiliary contacts are also closed, and exist as an auxiliary component of the knife switch. The components used in this type of auxiliary contacts are all existing common knowledge, and the linkage with the knife switch is also a simple mechanical structure. Those skilled in the art have mastered it and can design it according to actual needs, so it will not be repeated.
[0028] The AC power supply circuit also includes an upper AC power switch S1, which has an upper AC normally open auxiliary contact 6 that is linked and matched with it; the DC power supply circuit also includes an upper DC power switch S2, which has an upper DC normally open auxiliary contact 7 that is linked and matched with it; the upper AC normally open auxiliary contact 6 is connected to the lower AC normally open auxiliary contact 3, and the upper DC normally open auxiliary contact 7 is connected to the lower DC normally open auxiliary contact 5.
[0029] In this embodiment, the upper AC power switch S1 and the upper AC normally open auxiliary contact 6 are both located in the first AC / DC distribution cabinet 8. The AC power supply circuit is connected to the first AC / DC distribution cabinet 8 through the upper AC normally open auxiliary contact 6 and obtains external input AC power from it.
[0030] The upper DC power switch S2 and the upper DC normally open auxiliary contact 7 are both located in the second AC / DC distribution cabinet 9. The DC power supply circuit is connected to the second AC / DC distribution cabinet 9 through the upper DC normally open auxiliary contact 7 and obtains external DC power input therefrom.
[0031] like Figure 1 As shown, the first power isolation contactor and the second power isolation contactor in this embodiment are the key to preventing the inverter power module 1 from reverse power transmission; wherein: the first power isolation contactor also has a first excitation coil KM1, and the lower-level AC power switch S3 is connected to the connection line between the lower-level AC normally open auxiliary contact 3 and the first make contact 2 through the first excitation coil KM1. The lower-level AC normally open auxiliary contact 3 has two output terminals, and both output terminals are connected to the two corresponding input terminals of the first make contact 2; among the two output terminals of the lower-level AC normally open auxiliary contact 3, one of the output terminals is also connected to the first excitation coil KM1, the lower-level AC power switch S3 and the upper-level AC power switch S1 in sequence, and then connected to the other output terminal.
[0032] The second power isolation contactor also has a second excitation coil KM2, and the lower DC power switch S4 is connected to the connection line between the lower DC normally open auxiliary contact 5 and the second make contact 4 through the second excitation coil KM2. The lower DC normally open auxiliary contact 5 has a positive output terminal and a negative output terminal, and the positive output terminal and the negative output terminal are both connected to the two corresponding input terminals of the second make contact 4; the negative output terminal is also connected to the second excitation coil KM2, the lower DC power switch S4 and the upper DC power switch S2 in sequence, and then connected to the positive output terminal.
[0033] Finally, as a perfection of the relevant structure, the inverter power supply module 1 has an AC input interface 11, a DC input interface 12 and an AC output interface 13 to realize its proper functions. The first make contact 2 is connected to the AC input interface 11, the second make contact 4 is connected to the DC input interface 12; the AC output interface 13 is connected to the useful power load 10.
[0034] In this embodiment, the inverter power supply module 1, the first power isolation contactor, the second power isolation contactor, the downstream AC power switch S3, the downstream DC power switch S4, the downstream AC normally open auxiliary contact 3, the downstream DC normally open auxiliary contact 5 and the power load 10 are all arranged in the main cabinet 14 of the ultrasonic flow measuring device.
[0035] In this embodiment, a power isolation contactor is added between the two input power supplies of the inverter power module 1 in the main cabinet 14 of the ultrasonic flow measurement device and the lower switch. The power isolation contactor can be an electromagnetic type, a dynamic contactor with a clear breaking point. After the dynamic contact of the power isolation contactor is connected to the AC and DC input channels of the lower power switch and the inverter power module 1, the excitation coil driving power is taken from the lower power switch outlet of the corresponding power supply circuit, and the normally open auxiliary contacts of the upper and lower power switches are connected in series.
[0036] When any of the following conditions is met: the AC or DC circuit loses power, the upper power switch is disconnected, or the lower power switch is disconnected, the contactor of the corresponding circuit may trip due to power loss, thereby reliably isolating the corresponding input end of the inverter power module 1 from the power outage circuit switch, cables, wires, etc., to prevent leakage at the input end of the inverter power module 1, avoid reverse power supply to the power outage circuit, and thus avoid electric shock accidents.
[0037] Example 2
[0038] Based on Example 1, this example introduces the specific working scenarios and principles of the circuit structure for preventing the inverter power module from sending power in reverse. The following four situations are introduced respectively:
[0039] 1. Under normal circumstances, the power supply of the AC power supply circuit is first supplied, and the action sequence is: the upper AC power switch S1 (including its upper AC normally open auxiliary contact 6) is closed, and the lower AC power switch S3 (including its lower AC normally open auxiliary contact 3) is closed; at this time, the first excitation coil KM1 of the first power isolation contactor is energized, and the corresponding first moving contact 2 is energized, and the AC power supply is connected to the inverter power module 1. After inversion, an AC power is output for use by the ultrasonic flow measurement device industrial computer, switching power supply and other power loads in the water motor group.
[0040] 2. In order to prevent the AC power supply from being unstable due to the switching of the power supply of the hydropower plant or the failure of the AC power supply, and to prevent the power supply of the ultrasonic current measuring device of the hydropower unit from being affected during the maintenance of the AC power supply circuit, a DC power supply is introduced from another AC / DC distribution board of the hydropower plant. After the AC power supply is put into use, the DC power supply is sent, and the action sequence is as follows: the upper DC power supply switch S2 (including its upper DC normally open auxiliary contact 7) is closed, and the lower DC power supply switch S4 (including its lower DC normally open auxiliary contact 5) is closed; at this time, the second excitation coil KM2 of the second power isolation contactor is energized, and the corresponding second moving contact 4 is energized, and the DC power supply is connected to the inverter power module 1, and used as a backup power supply for the AC power supply.
[0041] 3. When the AC / DC distribution board corresponding to the AC power supply circuit in the hydropower station needs to be repaired, the upper end of the upper AC power switch S1 will be powered off, or the lower end outgoing cable of the upper AC power switch S1 needs regular maintenance, the upper AC power switch S1 (including its upper AC normally open auxiliary contact 6) and the lower AC power switch S3 (including its lower AC normally open auxiliary contact 3) will be disconnected; at this time, the first excitation coil KM1 of the first power isolation contactor loses power, and the corresponding first moving contact 2 is disconnected, completely isolating the AC power supply circuit from the AC input interface 11 of the inverter power module 1, preventing the DC power supply from being reversely supplied to the AC power supply circuit due to the unreliable semiconductor devices inside the inverter power module 1, thereby affecting the repair and maintenance work of the lower AC power switch S3 or the upper AC power switch S1 area.
[0042] 4. When the AC / DC distribution board corresponding to the DC power supply circuit in the hydropower station needs to be repaired, the upper end of the upper DC power switch S2 will be powered off, or the lower end outgoing cable of the upper DC power switch S2 needs regular maintenance, the upper DC power switch S2 (including its upper DC normally open auxiliary contact 7) and the lower DC power switch S4 (including its lower DC normally open auxiliary contact 5) will be disconnected; at this time, the second excitation coil KM2 of the second power isolation contactor loses power, and the corresponding second moving contact 2 is disconnected, completely isolating the DC power supply circuit from the DC input interface 11 of the inverter power module 1, preventing the unreliable semiconductor devices inside the inverter power module 1 from causing the AC power supply to reversely supply power to the DC power supply circuit, thereby affecting the repair and maintenance work of the lower DC power switch S4 or the upper DC power switch S2 area.
Claims
1. A circuit structure for preventing reverse power transmission of an inverter power module, characterized in that: The invention comprises an inverter power supply module (1), an AC power supply circuit and a DC power supply circuit, wherein the inverter power supply module (1) is connected to the AC power supply circuit and the DC power supply circuit respectively; a first power supply isolation contactor is arranged between the AC power supply circuit and the inverter power supply module (1), and a second power supply isolation contactor is arranged between the DC power supply circuit and the inverter power supply module (1); the first power supply isolation contactor has a first make contact (2), and the first make contact (2) is located between a lower-level AC normally open auxiliary contact (3) of the AC power supply circuit and the inverter power supply module (1); and the second power supply isolation contactor has a second make contact (4), and the second make contact (4) is located between a lower-level DC normally open auxiliary contact (5) of the DC power supply circuit and the inverter power supply module (1).
2. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 1, characterized in that: The AC power supply circuit also includes a lower-level AC power switch S3, which is linked and matched with the lower-level AC normally open auxiliary contact (3); the DC power supply circuit also includes a lower-level DC power switch S4, which is linked and matched with the lower-level DC normally open auxiliary contact (5).
3. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 2, characterized in that: The AC power supply circuit also includes an upper AC power switch S1, which has an upper AC normally open auxiliary contact (6) that is linked and matched with the upper AC power switch S1; the DC power supply circuit also includes an upper DC power switch S2, which has an upper DC normally open auxiliary contact (7) that is linked and matched with the upper AC power switch S2; the upper AC normally open auxiliary contact (6) is connected to the lower AC normally open auxiliary contact (3), and the upper DC normally open auxiliary contact (7) is connected to the lower DC normally open auxiliary contact (5).
4. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 3, characterized in that: The upper AC power switch S1 and the upper AC normally open auxiliary contact (6) are both located in the first AC / DC distribution cabinet (8), and the AC power supply circuit is connected to the first AC / DC distribution cabinet (8) through the upper AC normally open auxiliary contact (6); the upper DC power switch S2 and the upper DC normally open auxiliary contact (7) are both located in the second AC / DC distribution cabinet (9), and the DC power supply circuit is connected to the second AC / DC distribution cabinet (9) through the upper DC normally open auxiliary contact (7).
5. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 3, characterized in that: The first power supply isolation contactor also has a first excitation coil KM1, and the lower-level AC power switch S3 is connected to the connection line between the lower-level AC normally open auxiliary contact (3) and the first make contact (2) through the first excitation coil KM1.
6. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 5, characterized in that: The lower-level AC normally open auxiliary contact (3) has two output ends, both of which are connected to the two corresponding input ends of the first normally closed contact (2); among the two output ends of the lower-level AC normally open auxiliary contact (3), one of the output ends is also connected to the first excitation coil KM1, the lower-level AC power switch S3 and the upper-level AC power switch S1 in sequence, and then connected to the other output end.
7. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 3, characterized in that: The second power supply isolation contactor also has a second excitation coil KM2, and the lower-level DC power supply switch S4 is connected to the connection line between the lower-level DC normally open auxiliary contact (5) and the second make contact (4) through the second excitation coil KM2.
8. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 7, characterized in that: The lower-level DC normally open auxiliary contact (5) has a positive output terminal and a negative output terminal, both of which are connected to two corresponding input terminals of the second normally closed contact (4); the negative output terminal is also connected to the second excitation coil KM2, the lower-level DC power switch S4 and the upper-level DC power switch S2 in sequence, and then connected to the positive output terminal.
9. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 1, characterized in that: The inverter power supply module (1) comprises an AC input interface (11), a DC input interface (12) and an AC output interface (13); the first make contact (2) is connected to the AC input interface (11), the second make contact (4) is connected to the DC input interface (12); and the AC output interface (13) is connected to a useful electrical load (10).
10. A circuit structure for preventing reverse power transmission of an inverter power module according to claim 9, characterized in that: The inverter power supply module (1), the first power supply isolation contactor, the second power supply isolation contactor, the lower-level AC power supply switch S3, the lower-level DC power supply switch S4, the lower-level AC normally open auxiliary contact (3), the lower-level DC normally open auxiliary contact (5) and the power load (10) are all arranged in a main cabinet (14) of the ultrasonic flow measurement device.