CN210380683U - Direct current power supply - Google Patents
Direct current power supply Download PDFInfo
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- CN210380683U CN210380683U CN201920969636.5U CN201920969636U CN210380683U CN 210380683 U CN210380683 U CN 210380683U CN 201920969636 U CN201920969636 U CN 201920969636U CN 210380683 U CN210380683 U CN 210380683U
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Abstract
The utility model discloses a DC power supply connects three-phase DC output side, include: the low-voltage protection circuit, the low-voltage soft start circuit, the voltage regulator, the phase-shifting transformer, the high-voltage soft start circuit and the energy supplementing valve unit are arranged on the power supply unit; the input end of the low-voltage protection circuit is connected with the three-phase direct current output side, the output end of the low-voltage protection circuit, the low-voltage soft start loop and the input end of the voltage regulator are sequentially connected in series, the output end of the voltage regulator is connected with the primary side of the phase-shifting transformer, and the secondary side of the phase-shifting transformer is connected with the energy supplementing valve unit through the high-voltage soft start loop. Short-circuit protection, overload protection and fault protection of the whole direct current source are achieved through the low-voltage protection circuit, dependence on a high-voltage side direct current contactor or a semiconductor switch is reduced, and protection design of a high-voltage part is simplified. And can suppress short-circuit current when an external circuit is short-circuited. The device is safely output, the direct-current voltage fluctuation caused by pulse load is reduced, the stress of a loop device is reduced, and the manufacturing cost is low.
Description
Technical Field
The utility model relates to a high voltage direct current transmission field, specificly relate to a direct current power supply.
Background
GB/T33348-2016 high voltage source converter valve electrical test for high voltage direct current transmission requires that the tested valve section has the requirements of maximum continuous operation load test, maximum transient overload operation test and the like. Such a pulsed load presents challenges to both the functional implementation and the protection of the test platform.
The specific mode for realizing the platform function is to design a direct-current power supply, and the output power and voltage fluctuation of the direct-current power supply need to meet the load requirement; the existing direct current power supply has large voltage fluctuation and high manufacturing cost after being loaded, and meanwhile, the protection function of the direct current power supply is not comprehensive enough.
SUMMERY OF THE UTILITY MODEL
In order to solve the above problems, the present invention provides a dc power supply with small voltage fluctuation, low cost and comprehensive protection function.
The utility model adopts the technical proposal that:
a dc power supply connected to a three-phase dc output side, comprising: the low-voltage protection circuit, the low-voltage soft start circuit, the voltage regulator, the phase-shifting transformer, the high-voltage soft start circuit and the energy supplementing valve unit are arranged on the power supply unit;
the input end of the low-voltage protection circuit is connected with the three-phase direct current output side, the output end of the low-voltage protection circuit, the low-voltage soft start loop and the input end of the voltage regulator are sequentially connected in series, the output end of the voltage regulator is connected with the primary side of the phase-shifting transformer, the secondary side of the phase-shifting transformer is connected with the input end of the high-voltage soft start loop, and the output end of the high-voltage soft start loop is used for being connected with a load.
Furthermore, a filter circuit is arranged between the low-voltage protection circuit and the low-voltage soft start loop.
Furthermore, the low-voltage protection circuit comprises a fuse and a circuit breaker which are sequentially connected in series, and the circuit breaker is connected with a low-voltage soft start circuit.
Further, the low-voltage soft start circuit comprises a current-limiting resistor R1, a low-voltage contactor KM1 and a low-voltage contactor KM2, wherein the current-limiting resistor is connected with the low-voltage contactor KM1 in series, and a branch formed by the current-limiting resistor R1 and the low-voltage contactor KM1 is connected with the low-voltage contactor KM2 in parallel.
Furthermore, the secondary side of the phase-shifting transformer comprises a plurality of secondary side windings, the plurality of secondary side windings are respectively connected with corresponding secondary side units, each secondary side unit comprises a rectifier bridge, a voltage-sharing resistor and a voltage-sharing capacitor which are connected in parallel, the single secondary side unit outputs a single direct-current voltage, and the plurality of secondary side units are connected in series to output a total direct-current voltage.
Further, the high-voltage soft start loop comprises a current-limiting resistor R3, a high-voltage alternating current vacuum contactor KM3 and a high-voltage alternating current vacuum contactor KM4, wherein the high-voltage alternating current vacuum contactor KM3 is connected with the current-limiting resistor R3 in series, and the high-voltage alternating current vacuum contactor KM4 is connected with the current-limiting resistor R3 and the high-voltage alternating current vacuum contactor KM3 in parallel.
Furthermore, the current limiting resistor R3 is connected with a load through a tapped load reactor.
The beneficial effects of the utility model reside in that:
according to the technical scheme, short-circuit protection, overload protection and fault protection of the whole direct current source are realized through the low-voltage protection circuit, dependence on a high-voltage side direct current contactor or a semiconductor switch is greatly reduced, and the protection design of a high-voltage part is simplified. And the short-circuit current in the short circuit of the external circuit can be restrained, and the influence of the short-circuit current on a valve section device, a high-voltage side vacuum contactor in a test system and a high-voltage side soft start resistor is avoided. The device realizes safe output, reduces direct-current voltage fluctuation caused by pulse load, reduces stress of the loop device and has low manufacturing cost by a step-by-step soft start mode of the low-voltage soft start loop and the high-voltage soft start loop.
Drawings
Fig. 1 is a power circuit topology diagram of the dc power supply of the present invention;
fig. 2 is a schematic diagram showing the flow of the fault current when KM3 is abnormally closed.
Detailed Description
In order to explain the technical content, the objects and the effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.
As shown in fig. 1, the present invention provides a dc power supply, which connects a three-phase dc output side, and includes: the low-voltage protection circuit, the low-voltage soft start circuit, the voltage regulator T1, the phase-shifting transformer T2 and the high-voltage soft start circuit; the input of low pressure protection circuit connects the three-phase direct current output side, and the output of low pressure protection circuit, the soft return circuit that opens of low pressure, the input of voltage regulator establish ties in proper order, and phase shift transformer's primary side is connected to voltage regulator T1, and the vice limit of phase shift transformer T2 passes through the soft return circuit that opens of high pressure and links to each other with the load, and the load is the complementary energy valve unit in this embodiment, and the load can be selected wantonly in the practical application, is provided with filter circuit between the soft return circuit that opens of low pressure protection circuit and low pressure.
The low-voltage protection circuit comprises a three-phase low-voltage fuse FU and a low-voltage circuit breaker Q which are sequentially connected in series, short-circuit protection is realized by the three-phase low-voltage fuse FU, overload protection and fault protection are realized by the low-voltage circuit breaker Q, and when a system breaks down, an electric operating mechanism on the control system can control the low-voltage circuit breaker Q to trip and break down the fault. The filter circuit is used to improve the system power factor, and in this embodiment, the filter circuit is composed of a filter inductor L, or may be composed of a combination of a filter inductor and a filter capacitor.
The low-voltage soft start circuit comprises a current-limiting resistor R1, a low-voltage contactor KM1 and a low-voltage contactor KM2, wherein the current-limiting resistor is connected with the low-voltage contactor KM1 in series, a branch consisting of the current-limiting resistor R1 and the low-voltage contactor KM1 is connected with the low-voltage contactor KM2 in parallel, and a soft start mode of connecting the resistor R1 in series is used for the voltage regulator T1, so that the low-voltage soft start circuit is low; after the voltage regulator T1 is excited normally, the output voltage is gradually increased to realize the soft start of the phase-shifting transformer T2.
When the high-voltage alternating-current vacuum contactor KM3 is closed, the soft start of the phase-shifting transformer T2 is carried out simultaneously with the charging of the load capacitor.
When the high-voltage alternating-current vacuum contactor KM3 is disconnected, the phase-shifting transformer T2 is firstly soft started; after the soft start is completed and normal output is achieved, the load capacitor charging can be started by closing the high-voltage alternating-current vacuum contactor KM 3.
The secondary side of the phase-shifting transformer T2 is a multi-winding secondary side, the multi-path secondary side windings are respectively connected with corresponding secondary side units, each secondary side unit comprises a rectifier bridge, a voltage-sharing resistor and a voltage-sharing capacitor which are connected in parallel to output a single-path direct-current voltage, and the plurality of secondary side units are connected in series to output a total direct-current voltage.
The high-voltage soft start loop comprises a current-limiting resistor R3, a high-voltage alternating current vacuum contactor KM3 and a high-voltage alternating current vacuum contactor KM4, wherein the high-voltage alternating current vacuum contactor KM3 is connected with the current-limiting resistor R3 in series, and the high-voltage alternating current vacuum contactor KM4 is connected with the current-limiting resistor R3 and the high-voltage alternating current vacuum contactor KM3 in parallel.
The energy supplementing valve unit comprises a first energy supplementing valve F1, a second energy supplementing valve F2, a third energy supplementing valve F3 and a fourth energy supplementing valve F4, the first energy supplementing valve F1 is connected with the second energy supplementing valve F3 in series, the third energy supplementing valve F2 is connected with the fourth energy supplementing valve F4 in series, the first energy supplementing valve F1 and the second energy supplementing valve F2 are connected with a current limiting resistor R3 through tapped load reactors respectively, one end of a load capacitor of the third energy supplementing valve F3 and one end of a load capacitor of the fourth energy supplementing valve F4 are connected with a secondary side of the phase-shifting transformer, and the other end of the load capacitor of the third energy supplementing valve F3 is connected with a high-voltage alternating current vacuum contactor KM 4.
When/after the first energy compensation valve F1, the third energy compensation valve F3, or the second energy compensation valve F2, the fourth energy compensation valve F4 are charged to the minimum operating voltage, the energy compensation valve unit can be switched in or out according to the charging logic. When the third energy supplementing valve F3 or the fourth energy supplementing valve F4 is charged, the high-voltage alternating-current vacuum contactor KM4 is closed, the low current impact of high-voltage soft start is realized, and the soft start control mode is beneficial to system safety.
A tapped load reactor L1 is arranged between the current limiting resistor R3 and the energy supplementing valve unit, and the tapped load reactor L1 is matched with the current limiting resistor R3 to effectively reduce short-circuit current caused by external short circuit and reduce device stress. The smaller the current-limiting resistor R3 is, the closer the charging voltage of the capacitors of the energy compensating valve units to the power supply voltage is, and the stronger the short-circuit current suppression capability of the tapped load reactor L1 is; as shown in fig. 2, when the high-voltage ac vacuum contactor KM3 is closed abnormally, a fault current flows in a direction that the loop voltage increases and the current suppression effect of the inductor increases as the number of the energy compensation valve units connected in series increases.
To sum up, the utility model discloses a low voltage protection circuit realizes to short-circuit protection, overload protection and the fault protection of whole direct current source, has reduced the reliance to high pressure side direct current contactor or semiconductor switch greatly, has simplified the protection design of high-pressure part. And the short-circuit current in the short circuit of the external circuit can be restrained, and the influence of the short-circuit current on a valve section device, a high-voltage side vacuum contactor in a test system and a high-voltage side soft start resistor is avoided. The device realizes safe output, reduces direct-current voltage fluctuation caused by pulse load, reduces stress of the loop device and has low manufacturing cost by a step-by-step soft start mode of the low-voltage soft start loop and the high-voltage soft start loop.
The above mentioned is only the embodiment of the present invention, and not the limitation of the patent scope of the present invention, all the equivalent transformations made by the contents of the specification and the drawings, or the direct or indirect application in the related technical field, are included in the patent protection scope of the present invention.
Claims (7)
1. A DC power supply connected to a three-phase DC output side, comprising: the low-voltage protection circuit, the low-voltage soft start circuit, the voltage regulator, the phase-shifting transformer and the high-voltage soft start circuit;
the input end of the low-voltage protection circuit is connected with the three-phase direct current output side, the output end of the low-voltage protection circuit, the low-voltage soft start loop and the input end of the voltage regulator are sequentially connected in series, the output end of the voltage regulator is connected with the primary side of the phase-shifting transformer, the secondary side of the phase-shifting transformer is connected with the input end of the high-voltage soft start loop, and the output end of the high-voltage soft start loop is used for being connected with a load.
2. The direct current power supply according to claim 1, wherein: and a filter circuit is arranged between the low-voltage protection circuit and the low-voltage soft start loop.
3. The direct current power supply according to claim 1, wherein: the low-voltage protection circuit comprises a fuse and a circuit breaker which are sequentially connected in series, and the circuit breaker is connected with a low-voltage soft start circuit.
4. The direct current power supply according to claim 1, wherein: the low-voltage soft start circuit comprises a current-limiting resistor R1, a low-voltage contactor KM1 and a low-voltage contactor KM2, wherein the current-limiting resistor is connected with the low-voltage contactor KM1 in series, and a branch formed by the current-limiting resistor R1 and the low-voltage contactor KM1 is connected with the low-voltage contactor KM2 in parallel.
5. The direct current power supply according to claim 1, wherein: the secondary side of the phase-shifting transformer comprises multiple secondary side windings, the multiple secondary side windings are respectively connected with corresponding secondary side units, each secondary side unit comprises a rectifier bridge, a voltage-sharing resistor and a voltage-sharing capacitor which are connected in parallel, the single secondary side unit outputs single direct-current voltage, and the multiple secondary side units are connected in series to output total direct-current voltage.
6. The direct current power supply according to claim 1, wherein: the high-voltage soft start loop comprises a current-limiting resistor R3, a high-voltage alternating current vacuum contactor KM3 and a high-voltage alternating current vacuum contactor KM4, wherein the high-voltage alternating current vacuum contactor KM3 is connected with the current-limiting resistor R3 in series, and the high-voltage alternating current vacuum contactor KM4 is connected with the current-limiting resistor R3 and the high-voltage alternating current vacuum contactor KM3 in parallel.
7. The direct current power supply of claim 6, wherein: the current limiting resistor R3 is connected with a load through a tapped load reactor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920969636.5U CN210380683U (en) | 2019-06-25 | 2019-06-25 | Direct current power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920969636.5U CN210380683U (en) | 2019-06-25 | 2019-06-25 | Direct current power supply |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210380683U true CN210380683U (en) | 2020-04-21 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920969636.5U Active CN210380683U (en) | 2019-06-25 | 2019-06-25 | Direct current power supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN210380683U (en) |
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2019
- 2019-06-25 CN CN201920969636.5U patent/CN210380683U/en active Active
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