CN215934513U - AC/DC redundant power supply device suitable for industrial control system - Google Patents
AC/DC redundant power supply device suitable for industrial control system Download PDFInfo
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- CN215934513U CN215934513U CN202121600373.4U CN202121600373U CN215934513U CN 215934513 U CN215934513 U CN 215934513U CN 202121600373 U CN202121600373 U CN 202121600373U CN 215934513 U CN215934513 U CN 215934513U
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Abstract
The utility model discloses an alternating current-direct current redundant power supply device suitable for an industrial control system, which is characterized in that any one direct current power supply in the traditional two direct current power supply is replaced by an alternating current power supply, the alternating current power supply is converted into a direct current power supply to be output through a power switch, an isolation transformer and an inverter circuit, and then the direct current power supply is merged into a diode to realize the two direct current power supply redundant power supply. The power supply redundancy mode of changing the traditional two-way direct current power supply into the common power supply of direct current and alternating current to direct current ensures the safe redundant power supply of the power supply, realizes the physical isolation of the two ways of power supplies, and ensures that the grounding of one way of power supply does not influence the normal power supply of the other way of power supply. The power supply configuration is optimized, power loss caused by other grounding points is prevented, and the stability and the anti-interference capability of the direct-current power supply system are improved.
Description
Technical Field
The utility model relates to the field of industrial measurement and control, in particular to an alternating current-direct current redundant power supply device suitable for an industrial control system.
Background
The Main Fuel Trip (MFT) is the core technical content for ensuring the safe operation of the boiler, and when any dangerous condition occurs in the safe operation process of the boiler, the main fuel trip acts, and all the advantages and beauty entering a hearth are quickly cut off so as to ensure the safety of the boiler, avoid accidents or prevent further expansion of the accidents.
The turbine Emergency Trip System (ETS) is a safe and reliable protection device equipped for the operation of large-scale power plants, which enables the turbine to be automatically shut down to protect the safety of the plant in the presence of conditions that may cause damage to the plant.
In order to effectively improve the reliability of the MFT/ETS action, the MFT/ETS is designed into soft and hard redundancy. When the tripping condition is met, the MFT/ETS operates related equipment through software, and simultaneously sends signals to other systems through hardware, namely a tripping relay board, in order to reduce misoperation and prevent behavior, the MFT/ETS signals take 2 out of 3 on the hardware, and the equipment in the whole plant is protected to the maximum extent. When the MFT/ETS occurs, the relay acts, and the related equipment trips through hard wiring, so that the power supply of the MFT/ETS relay needs to be reliable, once a fault occurs, the related equipment cannot be tripped in time, the safe operation of a unit is directly influenced, and major damage is caused to the main equipment and the auxiliary equipment.
According to the requirements of twenty-five counter measures for preventing electric power production accidents, a power supply used by a trip circuit for protecting a machine furnace of a thermal power plant is reliable so as to ensure that the protection is not subjected to malfunction and misoperation. Most generator set MFT/ETS loops adopt two direct current power supplies to run in parallel through diodes, for example, two electrical 125VDC power supplies are connected in parallel to supply power, as shown in figure 1, the anodes of the two power supplies are respectively connected in series with a diode, the cathodes of the two power supplies are respectively connected in series with a diode in reverse phase with the anode, and one power supply is output after the diodes are automatically selected in a high-speed mode. According to the working characteristics of the diodes, one of the two direct current power supplies is always in a working state under normal conditions, when the power supply fails, the diode of the other power supply is conducted for a short time to enter the working state, undisturbed switching is realized, and the uninterrupted thermal control power supply is ensured.
The traditional two-way direct-current power supply redundancy configuration mode is shown in fig. 2, the positive poles of the direct-current power supplies are connected together through diodes and the positive poles of 125VDC of the two-way electric direct-current power supplies are connected together through reversed phase diodes, the two-way direct-current power supplies form a loop due to the system structure, no physical isolation device exists between the two-way power supplies and no potential hazards exist in the safe operation of a unit. When the grounding point occurs, two DC power supplies interfere with each other, and the electric grounding line selection device cannot correctly judge the position of the grounding point, thereby bringing great difficulty to the work of fault finding and accident handling. Meanwhile, in the process of searching the grounding point, the thermal control power supply has the risk of total loss, more serious consequences can be caused, and the safe operation of the unit is seriously threatened.
SUMMERY OF THE UTILITY MODEL
Aiming at the defects in the technology, the utility model provides the alternating current-direct current redundant power supply device suitable for the industrial control system, which not only ensures the safe redundant power supply of the power supply, but also realizes the physical isolation of two paths of power supplies, and ensures that the grounding of one path of power supply does not influence the normal power supply of the other path of power supply.
In order to achieve the above object, the present invention provides an ac/dc redundant power supply device suitable for an industrial control system, including a first power supply, a second power supply, an isolation circuit and four diodes, where the first power supply is a dc power supply, the second power supply is an ac power supply, the isolation circuit is connected in series in the second power supply, the ac power supply outputs a dc power after passing through the isolation circuit, the positive electrode of the dc power after being output by the ac power supply and the positive electrode of the dc power supply are respectively connected in series with one diode, and the negative electrode of the dc power after being output by the ac power supply and the negative electrode of the dc power supply are respectively connected in series with one diode opposite to the positive electrode.
Preferably, the isolation circuit comprises a power switch, an isolation transformer and an inverter circuit, the power switch, the isolation transformer and the inverter circuit are sequentially connected in series in the second power supply, and the alternating current power supply outputs direct current after passing through the power switch, the isolation transformer and the inverter circuit.
Preferably, the isolation transformer is a 3KVA isolation transformer.
Preferably, the inverter circuit comprises an inverter bridge, a PWM control circuit, a field effect transistor, a capacitor and a filter capacitor, the ac power is input to the input terminal of the isolation transformer, the input terminal of the inverter bridge is connected to the output terminal of the isolation transformer, a connection point between one end of the capacitor and the output terminal of the inverter bridge is connected to the drain of the field effect transistor, the gate of the field effect transistor is connected to one end of the PWM control circuit, the source of the field effect transistor is connected to one end of the filter capacitor, and a connection point between the other end of the capacitor, the other end of the filter capacitor and the other end of the PWM control circuit is grounded; the alternating current power supply is rectified and filtered by the inverter bridge, the capacitor, the PWM control circuit, the field effect tube and the filter capacitor and then outputs direct current.
The utility model has the beneficial effects that: compared with the prior art, the alternating current-direct current redundant power supply device suitable for the industrial control system, provided by the utility model, is characterized in that any one direct current power supply in two direct current power supply of the MFT/ETS relay panel is replaced by an alternating current power supply, the alternating current power supply is converted into direct current power supply output through the switching power supply, the isolation transformer and the inverter circuit, and then the direct current power supply is merged into the diode to realize the redundant power supply of the two direct current power supplies. The MFT/ETS control cabinet power supply is changed into a power supply redundancy mode of common power supply of direct current and alternating current to direct current, so that the safe redundant power supply of the power supply is ensured, the physical isolation of two paths of power supplies is realized, and the condition that the normal power supply of the other path of power supply is not influenced when one path of power supply is grounded is ensured. The power supply configuration is optimized, the power supply of the ETS/MFT disk is prevented from being lost due to other grounding points, so that the main protection of a boiler and a turbine is lost, and the stability and the anti-interference capability of a unit direct-current power supply system are improved.
Drawings
Fig. 1 is a schematic diagram of a conventional MFT protection trip circuit;
FIG. 2 is a schematic circuit diagram of a conventional two-way DC power supply redundancy configuration;
FIG. 3 is a schematic diagram of a 220VAC to 125VDC power isolation switch of the present invention;
fig. 4 is a circuit schematic diagram of a dc + ac dc power supply redundancy configuration mode of the present invention.
Detailed Description
In order to more clearly describe the present invention, the present invention will be further described with reference to the accompanying drawings.
Referring to fig. 3, the present invention includes a first power source and a second power source, wherein the first power source is a dc power source, and a relay JR1 is connected between the positive pole and the negative pole of the first power source; the second power supply is an alternating current power supply, the alternating current power supply is converted into direct current through the isolation circuit and then output, and a relay JR2 is connected between the anode and the cathode of the output direct current; the positive pole of the direct current output by the second power supply and the positive pole of the direct current power supply of the first power supply are respectively connected with the cathodes of two diodes in V2, and the anodes of the two diodes in V2 are connected together to output the positive poles of the two power supplies; the negative electrode of the direct current output by the second power supply and the negative electrode of the direct current power supply of the first power supply are respectively connected with the anodes of two diodes in V1, and the cathodes of two diodes in V1 are connected together to output the negative electrodes of the two power supplies; and a DC and AC-to-DC power supply redundancy configuration mode is formed, so that the safe redundant power supply of the power supply is ensured.
Referring to fig. 4, the isolation circuit includes a power switch, an isolation transformer and an inverter circuit, wherein the isolation transformer is a 3KVA isolation transformer; the inverter circuit comprises an inverter bridge, a PWM control circuit, a field effect transistor, a capacitor and a filter capacitor, wherein an alternating current power supply is input into the input end of the isolation transformer, the input end of the inverter bridge is connected with the output end of the isolation transformer, the connection point of one end of the capacitor and the output end of the inverter bridge is connected with the drain electrode of the field effect transistor, the grid electrode of the field effect transistor is connected with one end of the PWM control circuit, the source electrode of the field effect transistor is connected with one end of the filter capacitor, and the connection point of the other end of the capacitor, the other end of the filter capacitor and the other end of the PWM control circuit is grounded; the alternating current power supply of the second power supply is input to the input end of the isolation transformer through the power switch, is output to the inverter bridge after being subjected to voltage reduction through the isolation transformer, and is output as direct current after being rectified and filtered through the inverter bridge, the field effect tube, the PWM control circuit and the filter capacitor. The isolation circuit realizes physical isolation of two power supplies and ensures that the grounding of one power supply does not influence the normal power supply of the other power supply. The power supply configuration is optimized, the power supply of the ETS/MFT disk is prevented from being lost due to other grounding points, so that the main protection of a boiler and a turbine is lost, and the stability and the anti-interference capability of a unit direct-current power supply system are improved.
The alternating current-direct current redundant power supply device suitable for the industrial control system is suitable for power supply configuration of an MFT protection circuit and an ETS protection circuit in a DCS system of a generator set, is also suitable for redundant configuration of a direct current power supply in a relay protection circuit of an electrical system, and can be widely applied to industries of aerospace, water conservancy, electric power, metallurgy, steel, petrifaction, oil refining and the like.
The utility model has the advantages that:
(1) the safe redundant power supply of the power supply is ensured;
(2) the physical isolation of two power supplies is realized, and the condition that the grounding of one power supply does not influence the normal power supply of the other power supply is ensured.
The above disclosure is only for a few specific embodiments of the present invention, but the present invention is not limited thereto, and any variations that can be made by those skilled in the art are intended to fall within the scope of the present invention.
Claims (4)
1. The utility model provides a redundant power supply unit of alternating current-direct current suitable for industrial control system, its characterized in that includes first power, second power, buffer circuit and four diodes, first power is DC power, the second power is AC power, buffer circuit establishes ties in the second power, AC power warp the output is the direct current behind the buffer circuit, the direct current after the AC power output anodal with DC power's positive pole respectively establishes ties a diode, the direct current after the AC power output negative pole with DC power's negative pole respectively establishes ties a diode reverse with the positive pole.
2. The ac-dc redundant power supply device suitable for industrial control systems according to claim 1, wherein the isolation circuit comprises a power switch, an isolation transformer and an inverter circuit, the power switch, the isolation transformer and the inverter circuit are serially connected in the second power supply, and the ac power supply outputs dc power after passing through the power switch, the isolation transformer and the inverter circuit.
3. The ac-dc redundant power supply unit suitable for use in an industrial control system of claim 2, wherein said isolation transformer is a 3KVA isolation transformer.
4. The ac-dc redundant power supply device suitable for industrial control systems according to claim 2, wherein the inverter circuit comprises an inverter bridge, a PWM control circuit, a fet, a capacitor and a filter capacitor, the input end of the isolation transformer inputs the ac power, the input end of the inverter bridge is connected to the output end of the isolation transformer, the connection point between one end of the capacitor and the output end of the inverter bridge is connected to the drain of the fet, the gate of the fet is connected to the end connected to the PWM control circuit, the source of the fet is connected to one end of the filter capacitor, and the connection point between the other end of the capacitor, the other end of the filter capacitor and the other end of the PWM control circuit is grounded; the alternating current power supply is rectified and filtered by the inverter bridge, the capacitor, the PWM control circuit, the field effect tube and the filter capacitor and then outputs direct current.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202121600373.4U CN215934513U (en) | 2021-07-14 | 2021-07-14 | AC/DC redundant power supply device suitable for industrial control system |
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| CN202121600373.4U CN215934513U (en) | 2021-07-14 | 2021-07-14 | AC/DC redundant power supply device suitable for industrial control system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113890391A (en) * | 2021-09-06 | 2022-01-04 | 华能国际电力股份有限公司丹东电厂 | Alternating current-direct current redundant power supply system suitable for industrial control system |
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2021
- 2021-07-14 CN CN202121600373.4U patent/CN215934513U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113890391A (en) * | 2021-09-06 | 2022-01-04 | 华能国际电力股份有限公司丹东电厂 | Alternating current-direct current redundant power supply system suitable for industrial control system |
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