Speed regulator dual power supply circuit capable of simultaneously inputting alternating current and direct current in hydraulic power plant

Abstract

The utility model discloses a speed regulator dual power supply circuit capable of simultaneously inputting alternating current and direct current in a hydraulic power plant, and relates to the technical field of dual power supply. The circuit comprises a DC power supply input loop, an AC power supply input loop, a parallel connection and power supply filtering loop and a switching power supply input loop. The beneficial effects of the utility model are that the AC 220V power supply and the DC 220V power supply are input at the front end for isolation and parallel connection, and then are input into the switching power supply, and only one switching power supply is adopted, so that the cost is low, and the occupied space is small; the output end does not need parallel connection of diodes, so that voltage reduction is avoided, and low-voltage output loops of 12V and the like are facilitated; the circuit adopts a public switching power supply, and an output loop is simpler.

Description

Technical Field

[0001] The utility model relates to the technical field of dual power supply, in particular to a dual power supply circuit for a speed regulator with AC and DC simultaneous inputs in a hydropower plant. Background Art

[0002] The turbine speed governor is the core equipment of the hydroelectric power plant. It is responsible for regulating the speed, frequency and output of the turbine. If the equipment is powered off, it will cause major accidents such as unit shutdown and power outage in the power plant. Therefore, its power supply is crucial. Generally, the power plant adopts 220V AC and DC dual power supply. One 220V AC comes from the power plant's plant power, and the other 220V DC comes from the DC battery system of the power plant. The two power supplies are input at the same time and switch the working mode without disturbance. The electrical control cabinet and hydraulic operation cabinet of the speed governor are required to meet the input requirements of AC and DC dual power supply. The speed governor control cabinet generally uses a switching power supply to output DC as the internal equipment power supply system, such as DC24V, 12V, -12V, etc., and generally can only accept one 220V input. Therefore, it is necessary to rectify, filter, and parallel the two AC and DC power supplies at the front end before inputting the switching power supply.

[0003] At present, the AC and DC power supply of hydropower plants mainly adopts Figure 1 The AC 220V is input into the switching power supply 1 through the isolation transformer, and the DC 220V is input into the switching power supply 2. The DC24V outputs of the switching power supply 1 and the switching power supply 2 are connected in parallel through diodes, and the DC24V outputs are directly connected to the ground, finally forming a DC24V redundant power supply system. Some power stations may also need a DC12V power supply system. Generally, a multi-channel output switching power supply can be selected. The output 12V of the two switching power supplies is connected in parallel through diodes to form a DC12V power supply system (see Figure 1 The power ground can be connected directly.

[0004] The main disadvantages of the existing power supply method are as follows: (1) Two switching power supplies are required. The power of the switching power supply is generally 250W, which is expensive and takes up a lot of space. (2) When diodes are connected in parallel, the diodes will produce a 0.7V voltage drop, and the output 24V voltage will drop to 23.3V, which is slightly different from the rated voltage. (3) Some power plants require multiple power outputs, such as 24V, 12V, -12V, etc. In this case, the parallel connection of two switching power supplies requires multiple diodes in parallel, which makes the output more complicated, and the voltage drop has a greater impact on the low-voltage 12V power supply. Utility Model Content

[0005] The purpose of this section is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and utility model name of this application to avoid blurring the purpose of this section, specification abstract and utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0006] Therefore, the problem to be solved by the utility model is how to realize the AC and DC dual power supply of the speed regulator equipment of the hydropower plant.

[0007] In order to solve the above technical problems, the utility model provides the following technical solutions: a dual power supply circuit of a speed regulator with simultaneous AC and DC input in a hydropower plant, comprising a DC power input circuit, including a first rectifier bridge, respectively connected to the positive and negative poles of a 220V DC power supply; an AC power input circuit, including a second rectifier bridge, respectively connected to the L pole and N pole of the output end of an isolation transformer; a parallel and power filter circuit, wherein the positive output ends of the first rectifier bridge and the second rectifier bridge are connected in parallel at point A, and the negative output ends are connected in parallel at point B, and then input into a power filter; a switching power input circuit, including a power switch and a switching power supply, wherein the switching power supply is connected to the output end of the power filter through the power switch, and the output end of the switching power supply outputs a 24V or 12V DC power supply.

[0008] As a preferred solution for the dual power supply circuit of the speed regulator with simultaneous AC and DC input in the hydropower plant described in the utility model, the DC power supply input circuit also includes a first power supply indication circuit, which is connected in series between the positive and negative poles of the 220V DC power supply, and the first power supply indication circuit includes a first resistor and a first light-emitting diode connected in series.

[0009] As a preferred solution of the dual power supply circuit of the speed regulator with AC and DC simultaneous input in the hydropower plant of the utility model, wherein: the first rectifier bridge includes the fifth diode, the sixth diode, the seventh diode and the eighth diode which are completely the same;

[0010] The positive pole of a 220V DC power supply is connected between the fifth diode and the sixth diode, and the negative pole of a 220V DC power supply is connected between the seventh diode and the eighth diode;

[0011] The fifth diode and the seventh diode are connected to point A, and the sixth diode and the eighth diode are connected to point B.

[0012] As a preferred solution for the dual power supply circuit of the speed regulator with simultaneous AC and DC input in the hydropower plant described in the utility model, the L pole and N pole of the input end of the isolation transformer are respectively connected to the live wire and the neutral wire of the 220V AC power supply.

[0013] As a preferred solution for the dual power supply circuit of the speed regulator with simultaneous AC and DC input in the hydropower plant described in the utility model, the AC power input circuit also includes a second power indication circuit, which is connected in series between the L pole and the N pole of the output end of the isolation transformer, and the second power indication circuit includes a second resistor and a second light-emitting diode connected in series.

[0014] As a preferred solution of the dual power supply circuit of the speed regulator with AC and DC simultaneous input in the hydropower plant of the utility model, wherein: the second rectifier bridge includes the first diode, the second diode, the third diode and the fourth diode which are all identical;

[0015] A 220V AC power supply L pole is connected between the first diode and the second diode, and a 220V AC power supply N pole is connected between the third diode and the fourth diode;

[0016] The first diode and the third diode are connected to point A, and the second diode and the fourth diode are connected to point B.

[0017] As a preferred solution for the dual power supply circuit of the speed regulator with simultaneous AC and DC input in the hydropower plant described in the utility model, the power supply filter includes a front-stage π-type filter and a rear-stage π-type filter, the front-stage π-type filter is composed of a first electrolytic capacitor, a second electrolytic capacitor and a first conjugate inductor, and the rear-stage π-type filter is composed of a second electrolytic capacitor, a third electrolytic capacitor and a second conjugate inductor.

[0018] As a preferred solution for the dual power supply circuit of the speed regulator with simultaneous AC and DC input in the hydropower plant described in the utility model, the power supply filter includes a front-stage π-type filter and a rear-stage π-type filter, the front-stage π-type filter is composed of a first electrolytic capacitor, a second electrolytic capacitor and a first conjugate inductor, and the rear-stage π-type filter is composed of a second electrolytic capacitor, a third electrolytic capacitor and a second conjugate inductor.

[0019] As a preferred solution for the dual power supply circuit of the speed regulator with simultaneous AC and DC inputs in the hydropower plant described in the utility model, the switching power supply input circuit also includes a third power supply indication circuit, the third power supply indication circuit is connected in series between the positive and negative poles of the power supply filter output terminal, and the third power supply indication circuit includes a third resistor and a third light-emitting diode connected in series.

[0020] As a preferred solution of the dual power supply circuit of the speed regulator with AC and DC simultaneous input in the hydropower plant described in the utility model, wherein: the switching power supply also outputs a power ground.

[0021] The utility model has the beneficial effects of the dual power supply circuit of the speed regulator with AC and DC simultaneous input in the hydropower plant: the AC 220V power supply and the DC 220V power supply input are isolated and connected in parallel at the front end, and then input into the switching power supply, and only one switching power supply is used, which is low in cost and occupies less space; the output end does not need to connect diodes in parallel, which will not cause voltage reduction, which is beneficial for low-voltage output circuits such as 12V; this circuit uses a common switching power supply, and the output circuit is simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0023] Figure 1 It is a schematic diagram of AC and DC power supply in the prior art;

[0024] Figure 2 It is an overall schematic diagram of a dual power supply circuit of a speed regulator with simultaneous AC and DC inputs in a hydropower plant according to the utility model;

[0025] Figure 3 It is a detailed schematic diagram of a dual power supply circuit of a speed regulator with AC and DC simultaneous inputs in a hydropower plant according to the utility model;

[0026] Figure 4 The utility model is a schematic diagram of the internal circuit of the power filter of the dual power supply circuit of the speed regulator with simultaneous AC and DC input in the hydropower plant. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0030] Example 1

[0031] Reference Figure 2-3 , is the first embodiment of the utility model, which provides a dual power supply circuit for a speed regulator with AC and DC simultaneous input in a hydropower plant, including a DC power input circuit 100, including a first rectifier bridge 101, which is respectively connected to the positive and negative poles of a 220V DC power supply; an AC power input circuit 200, including a second rectifier bridge 201, which is respectively connected to the L pole and N pole of the output end of an isolation transformer TR; a parallel and power filter circuit 300, in which the positive output ends of the first rectifier bridge 101 and the second rectifier bridge 201 are connected in parallel at point A, and the negative output ends are connected in parallel at point B, and then input into a power filter FL; a switching power input circuit 400, including a power switch F1 and a switching power supply PWR, the switching power supply PWR is connected to the output end of the power filter FL through the power switch F1, and the output end of the switching power supply PWR outputs a 24V or 12V DC power supply.

[0032] The DC power input circuit 100 further includes a first power indication circuit 102, which is connected in series between the positive and negative electrodes of the 220V DC power supply. The first power indication circuit 102 includes a first resistor R1 and a first light emitting diode LED1 connected in series.

[0033] The first rectifier bridge 101 includes completely identical fifth diodes D5, sixth diodes D6, seventh diodes D7 and eighth diodes D8; the positive pole of the 220V DC power supply is connected between the fifth diode D5 and the sixth diode D6, and the negative pole of the 220V DC power supply is connected between the seventh diode D7 and the eighth diode D8; the point A is connected between the fifth diode D5 and the seventh diode D7, and the point B is connected between the sixth diode D6 and the eighth diode D8.

[0034] The L pole and N pole of the input end of the isolation transformer TR are connected to the live wire and the neutral wire of the 220V AC power supply respectively.

[0035] The AC power input circuit 200 further includes a second power indication circuit 202, which is connected in series between the L pole and the N pole of the output end of the isolation transformer TR. The second power indication circuit 202 includes a second resistor R2 and a second light emitting diode LED2 in series.

[0036] The second rectifier bridge 201 includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4 that are all identical; the L pole of a 220V AC power supply is connected between the first diode D1 and the second diode D2, and the N pole of a 220V AC power supply is connected between the third diode D3 and the fourth diode D4; the point A is connected between the first diode D1 and the third diode D3, and the point B is connected between the second diode D2 and the fourth diode D4.

[0037] The capacity of the isolation transformer matches the subsequent switching power supply, which is generally 15% larger than the switching power supply capacity. The transformation ratio is generally 1:0.9.

[0038] The present invention can realize the simultaneous input of AC and DC 220V power supplies, and is equipped with a special power supply filter. The disappearance of any power supply does not affect the normal power supply of the switching power supply, and the power failure and power-on of any power supply do not cause output voltage fluctuations. By processing the two-way input signals of AC and DC 220V, redundant power supply of the equipment in the electrical control cabinet and the mechanical operation cabinet of the hydropower station speed regulator is finally realized, and the reliability of the speed regulator equipment is guaranteed.

[0039] Example 2

[0040] Reference Figure 4 , which is the second embodiment of the utility model, and is different from the first embodiment in that: the power supply filter FL includes a front-stage π-type filter and a rear-stage π-type filter, the front-stage π-type filter is composed of a first electrolytic capacitor CX1, a second electrolytic capacitor CX2 and a first conjugate inductor L1, and the rear-stage π-type filter is composed of a second electrolytic capacitor CX2, a third electrolytic capacitor CX3 and a second conjugate inductor L2.

[0041] The input terminal of the power filter FL is L / N and is connected to point A and point B respectively.

[0042] Because the signal waveform after AC rectification still has pulsations and needs to be smoothed and filtered, a power filter is introduced. A standard integrated device can be used for the power filter.

[0043] The power filter FL also includes a parallel resistor R, which is mainly used to suppress input interference.

[0044] Example 3

[0045] Reference Figure 2 and 3 , which is the third embodiment of the utility model. It is different from the previous two embodiments in that this embodiment provides a switching power supply input circuit 400, and also includes a third power supply indication circuit 401. The third power supply indication circuit 401 is connected in series between the positive and negative poles of the output terminal of the power supply filter FL. The third power supply indication circuit 401 includes a third resistor R3 and a third light-emitting diode LED3 connected in series.

[0046] The switching power supply PWR also outputs a power ground.

[0047] The AC / DC 220V parallel filtered power supply is finally input into the switching power supply PWR. PWR can be selected according to the capacity of the power plant governor electrical control cabinet or hydraulic operation cabinet. It is generally configured with 250W. The output voltage can be determined according to the needs of the power plant. Generally, a single 24V output is used. For some sensors that require 12V or ±12V power supply, a multi-channel output switching power supply can also be used.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A dual power supply circuit for a speed regulator with simultaneous AC and DC input in a hydropower plant, characterized in that: include, A DC power supply input circuit (100) comprises a first rectifier bridge (101) connected to the positive electrode and the negative electrode of a 220V DC power supply respectively; An AC power input circuit (200) comprises a second rectifier bridge (201) connected to an L pole and an N pole of an output end of an isolation transformer (TR) respectively; A parallel connection and power supply filtering circuit (300), wherein the positive output terminals of the first rectifier bridge (101) and the second rectifier bridge (201) are connected in parallel at point A, and the negative output terminals are connected in parallel at point B, and then input into a power supply filter (FL); The switching power supply input circuit (400) comprises a power switch (F1) and a switching power supply (PWR), wherein the switching power supply (PWR) is connected to an output end of a power filter (FL) via the power switch (F1), and the output end of the switching power supply (PWR) outputs a 24V or 12V DC power supply.

2. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 1, characterized in that: The DC power input circuit (100) further comprises a first power indication circuit (102), the first power indication circuit (102) being connected in series between the positive electrode and the negative electrode of the 220V DC power supply, the first power indication circuit (102) comprising a first resistor (R1) and a first light emitting diode (LED1) connected in series.

3. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 2, characterized in that: The first rectifier bridge (101) comprises a fifth diode (D5), a sixth diode (D6), a seventh diode (D7) and an eighth diode (D8) which are identical; A positive electrode of a 220V DC power supply is connected between the fifth diode (D5) and the sixth diode (D6), and a negative electrode of a 220V DC power supply is connected between the seventh diode (D7) and the eighth diode (D8); The fifth diode (D5) and the seventh diode (D7) are connected to point A, and the sixth diode (D6) and the eighth diode (D8) are connected to point B.

4. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 3, characterized in that: The L pole and N pole of the input end of the isolation transformer (TR) are connected to the live wire and the neutral wire of the 220V AC power supply respectively.

5. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 4, characterized in that: The AC power input circuit (200) further comprises a second power indication circuit (202), the second power indication circuit (202) being connected in series between the L pole and the N pole of the output end of the isolation transformer (TR), the second power indication circuit (202) comprising a second resistor (R2) and a second light emitting diode (LED2) connected in series.

6. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 5, characterized in that: The second rectifier bridge (201) comprises a first diode (D1), a second diode (D2), a third diode (D3) and a fourth diode (D4) which are identical; A 220V AC power supply L pole is connected between the first diode (D1) and the second diode (D2), and a 220V AC power supply N pole is connected between the third diode (D3) and the fourth diode (D4); The first diode (D1) and the third diode (D3) are connected to point A, and the second diode (D2) and the fourth diode (D4) are connected to point B.

7. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 6, characterized in that: The power supply filter (FL) comprises a front-stage π-type filter and a rear-stage π-type filter, wherein the front-stage π-type filter is composed of a first electrolytic capacitor (CX1), a second electrolytic capacitor (CX2) and a first conjugate inductor (L1), and the rear-stage π-type filter is composed of a second electrolytic capacitor (CX2), a third electrolytic capacitor (CX3) and a second conjugate inductor (L2).

8. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 7, characterized in that: The input terminals of the power filter (FL) are L / N and are connected to point A and point B respectively.

9. The dual power supply circuit for the speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in claim 8, characterized in that: The switching power supply input circuit (400) further comprises a third power supply indication circuit (401), wherein the third power supply indication circuit (401) is connected in series between the positive and negative poles of the output terminal of the power supply filter (FL), and the third power supply indication circuit (401) comprises a third resistor (R3) and a third light emitting diode (LED3) connected in series.

10. The dual power supply circuit for a speed regulator with AC and DC simultaneous input in a hydropower plant as claimed in any one of claims 1 to 9, characterized in that: The switching power supply (PWR) also outputs a power ground.

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