CN202221885U - Protection device of DC low voltage breaker - Google Patents
Protection device of DC low voltage breaker Download PDFInfo
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- CN202221885U CN202221885U CN2011202751011U CN201120275101U CN202221885U CN 202221885 U CN202221885 U CN 202221885U CN 2011202751011 U CN2011202751011 U CN 2011202751011U CN 201120275101 U CN201120275101 U CN 201120275101U CN 202221885 U CN202221885 U CN 202221885U
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Abstract
The utility model discloses a protection device of a DC low voltage breaker, comprising at least one shunt in series connection in a DC system, at least one signal filter and amplification circuit, at least one A/D conversion circuit, at least one digital isolation circuit, a microprocessor and a power supply isolation circuit used for supplying power connected orderly. The shunt is used to sample a DC signal, the voltage drops at the two ends of the shunt are inputted in the signal filter and amplification circuit and are transmitted to the A/D conversion circuit after low pass filter and amplification to transform an analog signal into a digital signal, and then the digital signal is inputted to the digital isolation circuit to carry out electrical isolation between an input signal and an output signal, and finally is transmitted to the microprocessor to be computed and judged. The protection device of the DC low voltage breaker enables the electrical isolation between the input signal and the output signal to be realized, is low in cost and has a generality.
Description
Technical field
The utility model relates to a kind of dc low-voltage breaker protection device, belongs to the low-voltage electrical apparatus field.
Background technology
Owing to be the unsustainable property of master's energy general layout at present with the fossil energy; The global energy general layout just progressively makes the transition under the promotion of energy and environment crisis; Regenerative resource is expected to replace the main body that oil, colliery etc. become the energy; With photovoltaic generation and wind power generation is in master's the new energy field, generally all adopts direct current system, needs dc circuit breaker protection.
Compare with the AC low-tension circuit breaker; The dc low-voltage circuit breaker is different to the sample mode of dc current signal; Direct current system sample mode commonly used has DC current transformer, shunt, Hall element at present; The three respectively has characteristics, and wherein: the advantage of DC current transformer is simple in structure, and shortcoming is to be subject to magnetic interference, fragile, poor linearity; The advantage of Hall element be simple in structure, precision is high, shortcoming is to be subject to influence of magnetic field, needs shielding harness, cost high.According to above pluses and minuses; Adopt shunt to carry out the preferred version of dc current signal sampling becoming all big enterprises; The advantage of shunt is that simple in structure, measuring range greatly, is not influenced by external magnetic field, does not electricly isolate, exports a little less than the signal but shunt and major loop directly link to each other.
To adopting shunt to carry out the shortcoming of dc current signal sampling; Publication number is CN101346863; The patent that name is called " protected location that is used for ac/dc low-voltage power supply line " provides a kind of employing isolated amplifier that the input sample signal is carried out electrical isolation, though the influence of just taking to isolate late-class circuit in the initial treatment stage of sampled signal input is less, because the complexity that isolated amplifier designs; Using costliness, obviously is disadvantageous for volume production.
The utility model content
The technical problem that the utility model solves provides the low and high dc low-voltage breaker protection device of protection accuracy of a kind of volume production cost.
For solving the problems of the technologies described above; A kind of dc low-voltage breaker protection device that the utility model provides; Comprise that at least one is connected on the shunt in the direct current system, at least one signal filtering and amplifying circuit, at least one A/D change-over circuit, at least one digital buffer circuit, a microprocessor and power isolation circuit that is used to supply power that connects in order; Described shunt is sampled to dc current signal; With shunt voltage pressure drop input signal filtering and amplifying circuit,, get into the A/D change-over circuit analog signal conversion is become digital signal through LPF and after amplifying; The input digit buffer circuit; Make between input signal and the output signal and carry out electrical isolation, behind the digital signal input microprocessor of isolating, calculate judgement by microprocessor, power isolation circuit is that foregoing circuit provides power supply.
Further; In a kind of dc low-voltage breaker protection of the utility model device; Also comprise a trip circuit, described trip circuit links to each other with microprocessor, and direct current system is short-circuited when causing operating electric current to surpass the protective device preset threshold; Microprocessor sends the instruction of threading off and gives trip circuit, the dc low-voltage breaker open operation in the trip circuit control direct current system.
Further, in a kind of dc low-voltage breaker protection of the utility model device, comprise also showing and alarm module that said demonstration links to each other with microprocessor with alarm module that microprocessor shows relevant information and output alarm signal through showing with alarm module.
Further; In a kind of dc low-voltage breaker protection of the utility model device; Also comprise selective circuit of measuring range; Said selective circuit of measuring range links to each other with amplifying circuit, A/D change-over circuit with signal filtering respectively, and the signal after will passing through LPF and amplifying is transferred to measuring range and the precision that selective circuit of measuring range enlarges signal, is transferred to the A/D change-over circuit again and carries out analog-to-digital conversion.
Further, in a kind of dc low-voltage breaker protection of the utility model device, also comprise communication module, said communication module links to each other with microprocessor, realizes Long-distance Control and communicates by letter.
Further; In a kind of dc low-voltage breaker protection of the utility model device; Also comprise the power that can increase direct current system, the voltage sample modulate circuit that energy calculates and the shunt temperature rise sampling processing circuit of monitoring the shunt safe operation, said voltage sample modulate circuit, shunt temperature rise sampling processing circuit link to each other with the A/D change-over circuit.
The utility model compared with prior art; Have following conspicuousness advantage: (1) the utility model adopts the instrument amplifier or the differential amplifier of high cmrr that the voltage drop at shunt two ends is sampled; Can gather faint differential voltage signal accurately, certainty of measurement height and measuring range are big; (2) the utility model dc low-voltage breaker protection device and direct current system electrical isolation make operator safety operate; (3) the utility model can storage failure information and warning message, helps custom system and safeguards with line fault and investigate; (4) the utility model adopts temperature sensor to carry out temperature measurement and alarm signal is provided, and helps monitoring safety, the reliability service of direct current system and shunt; (5) the utility model greatly reduces the cost of volume production owing to the digital buffer circuit that adopts.
Description of drawings
Below in conjunction with accompanying drawing and embodiment the utility model is described in further detail.
Fig. 1 is the utility model embodiment 1 block diagram.
Fig. 2 is the utility model embodiment 2 block diagrams.
Fig. 3 is the utility model embodiment 3 block diagrams.
Fig. 4 is the utility model embodiment 4 block diagrams.
Fig. 5 is the utility model embodiment 5 block diagrams.
Fig. 6 is signal filtering and an amplifying circuit schematic diagram in the utility model.
Fig. 7 is an A/D change-over circuit schematic diagram in the utility model.
Fig. 8 is a digital buffer circuit schematic diagram in the utility model.
Fig. 9 is a microprocessor schematic diagram in the utility model.
Figure 10 shows and the warning circuit schematic diagram in the utility model; Figure 10 a is that LED reports to the police and the failure indicating circuit schematic diagram; Figure 10 b is the keyboard circuit schematic diagram; Figure 10 c is the liquid crystal display circuit schematic diagram.
Figure 11 is a trip circuit schematic diagram in the utility model.
Figure 12 is a power isolation circuit schematic diagram in the utility model.
Embodiment
The utility model adopts digital buffer circuit to make protective device and direct current system electrical isolation; Digital data transmission after isolating is calculated judgement to microprocessor, shows relevant warning message through showing with warning circuit thereby send the instruction of threading off simultaneously to trip circuit.
As shown in Figure 1, a kind of dc low-voltage breaker protection device comprises shunt, signal filtering and amplifying circuit, A/D change-over circuit, digital buffer circuit, microprocessor, demonstration and the warning circuit, trip circuit, the power isolation circuit that are connected in the direct current system; Shunt is sampled to dc current signal, and signal filtering and amplifying circuit are connected the two ends of shunt, with shunt voltage pressure drop input signal filtering and amplifying circuit; Through LPF and after amplifying; Get into the A/D change-over circuit analog signal conversion is become digital signal, the input digit buffer circuit makes between input signal and the output signal and carries out electrical isolation; Behind the digital signal input microprocessor of isolating, calculate judgement by microprocessor; When direct current system is short-circuited when causing operating electric current to surpass the protective device preset threshold, microprocessor sends the instruction of threading off and gives trip circuit, the dc low-voltage breaker open operation in the trip circuit control direct current system; Microprocessor is through showing and warning circuit; Show relevant information and output alarm signal, can carry out the inquiry of relevant information records simultaneously, power isolation circuit is that foregoing circuit provides power supply.
Because shunt is connected in the direct current system; Therefore be to have the over the ground common-mode voltage identical with the filtering of shunt voltage pressure drop input signal during with amplifying circuit with direct current system; This common-mode voltage often reaches several hectovolts even goes up kilovolt; If do not consider the electrical isolation of signal input part and late-class circuit, late-class circuit is easy to damage so.Therefore; Between microprocessor and A/D change-over circuit, inserted digital isolator spare; The specified insulation operating voltage of this digital isolator spare is greater than the common mode high voltage of direct current system; Can make microprocessor, demonstration and warning circuit, trip circuit and the direct current system electrical isolation of back level effectively, in addition, also adopt power isolation circuit; The specified insulation operating voltage of this power isolation circuit is greater than the common mode high voltage of direct current system; External power source input power isolation circuit, power isolation circuit the output supply voltage of mutual electrical isolation are respectively given signal filtering and amplifying circuit, A/D change-over circuit, digital buffer circuit input stage and digital buffer circuit output stage, microprocessor, demonstration and warning circuit, trip circuit, and power supply is imported also with the direct current system electrical isolation in the outside of power isolation circuit in addition.
As shown in Figure 2; A kind of dc low-voltage breaker protection device comprises shunt, signal filtering and amplifying circuit, range circuit, A/D change-over circuit, digital buffer circuit, microprocessor, demonstration and the warning circuit, trip circuit, the power isolation circuit that are connected in the direct current system, and shunt is sampled to dc current signal; Signal filtering and amplifying circuit are connected the two ends of shunt; With shunt voltage pressure drop input signal filtering and amplifying circuit, through LPF with amplify after, get into measuring range that range circuit enlarges dc current signal effectively and precision after entering A/D change-over circuit analog signal conversion is become digital signal; The input digit buffer circuit; Make input signal and output carry out electrical isolation between the signal, behind the digital signal input microprocessor of isolating, calculate and judge, when direct current system is short-circuited when causing operating electric current above the protective device preset threshold by microprocessor; Microprocessor sends the instruction of threading off and gives trip circuit; Dc low-voltage breaker open operation in the trip circuit control direct current system, microprocessor shows relevant information and output alarm signal through showing and warning circuit; Simultaneously can carry out the inquiry of relevant information records, power isolation circuit is that foregoing circuit provides power supply.
As shown in Figure 3, a kind of dc low-voltage breaker protection device comprises shunt, signal filtering and amplifying circuit, A/D change-over circuit, digital buffer circuit, microprocessor, demonstration and the warning circuit, trip circuit, telecommunication circuit, the power isolation circuit that are connected in the direct current system; Shunt is sampled to dc current signal, and signal filtering and amplifying circuit are connected the two ends of shunt, with shunt voltage pressure drop input signal filtering and amplifying circuit; Through LPF and after amplifying; Get into the A/D change-over circuit analog signal conversion is become digital signal, the input digit buffer circuit makes between input signal and the output signal and carries out electrical isolation; Behind the digital signal input microprocessor of isolating, calculate judgement by microprocessor; When direct current system is short-circuited when causing operating electric current to surpass the protective device preset threshold, microprocessor sends the instruction of threading off and gives trip circuit, the dc low-voltage breaker open operation in the trip circuit control direct current system; Microprocessor is through showing and warning circuit; Show relevant information and output alarm signal, can carry out the inquiry of relevant information records simultaneously, power isolation circuit is that foregoing circuit provides power supply; Microprocessor is connected with telecommunication circuit; Can realize long-range remote regulating, remote measurement, remote signalling, distant control function, telecommunication circuit can be based on the RS485 interface, based on the wire communication of Ethernet interface or other interface, also can be ZigBee, GPRS or other communication.
As shown in Figure 4; A kind of dc low-voltage breaker protection device; The embodiment 4 of the utility model, a kind of dc low-voltage breaker protection device has increased by one tunnel sampling to dc current signal again on the basis of embodiment 1; This road sampling channel not only with the direct current system electrical isolation, and with other one road sampling channel also be electrical isolation.Certainly, the described protective device of the utility model not only is confined to two-way to the sampling channel of dc current signal, can be more than two-way, but every Lu Jiyu direct current system electrical isolation, and electrical isolation each other again.
As shown in Figure 5; A kind of dc low-voltage breaker protection device; On the basis of embodiment 1, increased sampling processing, after the A/D conversion, isolated the entering microprocessor processes through numeral to direct current system voltage; Owing to added the sampling of d. c. voltage signal, protective device can increase the calculating of power to direct current system, energy etc.In addition, in order to monitor the safe operation of shunt, can adopt the measurement of temperature sensor to the shunt temperature rise.
As shown in Figure 6, signal filtering of the utility model and amplifying circuit, the voltage signal of two ends output inserts signal filtering and amplifying circuit on the shunt, and the sampled signal of obtaining on the shunt is carried out inputing to A/D converter after the processing and amplifying.Resistance R 1, R2 and capacitor C 1, C2, C3 form common mode, differential mode filter circuit.N1 is a differential operational amplifier, and C4, C5 are decoupling capacitor, and R3 is for regulating the resistance of amplifying circuit gain.Vref1 is a reference voltage, is used for the lifting of differential operational amplifier output signal level.
As shown in Figure 7, the A/D change-over circuit of the utility model.Analog signal AIN0 input a/d converter N2 after signal filtering and amplifying circuit processing and amplifying exports digital serial signal SDO1.Vref2 is the reference voltage of A/D converter, and SCLK1 and CS1 are clock signal and chip selection signal.
As shown in Figure 8, the digital buffer circuit of the utility model, N3 and N4 are digital isolator spares, are used for digital signal is carried out electrical isolation.Chip selection signal CS2 that single-chip microcomputer N5 sends and clock signal SCLK2 isolate the CS1 and the SCLK1 that generate through digital isolator spare N3 conversion and offer A/D converter N2.After digital isolator spare N4 isolates, convert signal SDO2 to through the digital serial signal SDO1 that A/D converter N2 produces and deliver to single-chip microcomputer N5 processing.Power supply VCC and VCC-ISO+ are electrical isolation.
As shown in Figure 9, the microprocessor of the utility model, N5 are single-chip microcomputer, are responsible for all data processing, control output; Crystal oscillator G1, capacitor C 13, the capacitor C 14 common outer clock circuits of forming.Reset chip N6 and resistance R 4, the capacitor C 12 common reset circuits of forming.Signal DB0 ~ DB7, RESET, RS, CS, RD, WR is connected with LCD MODULE LCD, is used for the operation of single-chip microcomputer N5 to LCD MODULE LCD.The demonstration of light-emitting diode in signal LED1 ~ LED8 control external LED warning and the failure indication module circuit.Signal K1 ~ K5 reads keyboard input signal.SCLK2 and CS2 are that SDO2 is the digital serial signal from digital isolator spare N4 to the clock and the chip selection signal of digital isolator spare N3 output.Trip is a trip signal, is used to drive outside trip circuit.
Shown in Figure 10, Figure 10 a, Figure 10 b, Figure 10 c, demonstration of the utility model and warning circuit show with warning circuit and are reported to the police and failure indicating circuit by LED that keyboard circuit and liquid crystal display circuit are formed.In LED warning and failure indicating circuit, comprise triode V1 ~ V8, resistance R 5 ~ R20 is through the demonstration of single-chip microcomputer N5 control LED 1 ~ LED8.In the keyboard circuit, comprise button AN1 ~ AN5, resistance R 21 ~ R25, single-chip microcomputer N5 reads push button signalling through the I/O mouth.In the liquid crystal display circuit, comprise the LCD LCD MODULE, single-chip microcomputer N5 is through WR, RS, and RD, CS, control signal such as RESET and data-signal DB0 ~ DB7 operate the LCD LCD MODULE.
Shown in figure 11, the trip circuit of the utility model, N7 is for driving the MOS device of relay K 1 action, and the trip signal Trip that sends through single-chip microcomputer N5 drives relay K 1 action, the external shunt release of relay K 1 output contact.The reverse high voltage that diode VD1 produces when being used for protecting MOS device N7 to avoid relay K 1 releasing contact is broken.
Shown in figure 12; The power isolation circuit of the utility model; DC/DC conversion chip N8 is used for external DC24V power source conversion is become VCC; VCC offers single-chip microcomputer N5 circuit, LED warning and failure indicating circuit etc. on the one hand, generates isolation voltage VCC-ISO+ through isolated from power chip N9 on the other hand, and VCC-ISO+ passes through DC/DC conversion chip N10 again; N11; N12 generates VCC-ISO-, reference voltage V ref1, reference voltage V ref2 respectively, and the above-mentioned various voltage signal correspondences that produce through isolated from power chip N9 offer differential operational amplifier N1, A/D converter N2, digital isolator spare N3, digital isolator spare N4, and capacitor C 16 ~ C25 is used for supply voltage filtering.
Claims (6)
1. dc low-voltage breaker protection device; Be characterised in that: comprise that at least one is connected on the shunt in the direct current system, at least one signal filtering and amplifying circuit, at least one A/D change-over circuit, at least one digital buffer circuit, a microprocessor and power isolation circuit that is used to supply power that connects in order; Said shunt is sampled to dc current signal; With shunt voltage pressure drop input signal filtering and amplifying circuit,, get into the A/D change-over circuit analog signal conversion is become digital signal through LPF and after amplifying; The input digit buffer circuit; Make between input signal and the output signal and carry out electrical isolation, behind the digital signal input microprocessor of isolating, calculate judgement by microprocessor, said power isolation circuit is that foregoing circuit provides power supply.
2. a kind of dc low-voltage breaker protection device according to claim 1; It is characterized in that: also comprise a trip circuit; Said trip circuit links to each other with microprocessor; Direct current system is short-circuited when causing operating electric current to surpass the protective device preset threshold, and microprocessor sends the instruction of threading off and gives trip circuit, the dc low-voltage breaker open operation in the trip circuit control direct current system.
3. a kind of dc low-voltage breaker protection device according to claim 1 and 2; It is characterized in that: also comprise showing and alarm module; Said demonstration links to each other with microprocessor with alarm module, and microprocessor shows relevant information and output alarm signal through showing with alarm module.
4. a kind of dc low-voltage breaker protection device according to claim 1 and 2; It is characterized in that: also comprise selective circuit of measuring range; Said selective circuit of measuring range links to each other with amplifying circuit, A/D change-over circuit with signal filtering respectively; Signal after will passing through LPF and amplifying is transferred to measuring range and the precision that selective circuit of measuring range enlarges signal, is transferred to the A/D change-over circuit again and carries out analog-to-digital conversion.
5. a kind of dc low-voltage breaker protection device according to claim 1 and 2, it is characterized in that: also comprise communication module, said communication module links to each other with microprocessor, realizes Long-distance Control and communicates by letter.
6. a kind of dc low-voltage breaker protection device according to claim 1 and 2; It is characterized in that: also comprise the power that can increase direct current system, the voltage sample modulate circuit that energy calculates and the shunt temperature rise sampling processing circuit of monitoring the shunt safe operation, said voltage sample modulate circuit, shunt temperature rise sampling processing circuit link to each other with the A/D change-over circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202751011U CN202221885U (en) | 2011-08-01 | 2011-08-01 | Protection device of DC low voltage breaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011202751011U CN202221885U (en) | 2011-08-01 | 2011-08-01 | Protection device of DC low voltage breaker |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202221885U true CN202221885U (en) | 2012-05-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011202751011U Expired - Lifetime CN202221885U (en) | 2011-08-01 | 2011-08-01 | Protection device of DC low voltage breaker |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202221885U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102255275A (en) * | 2011-08-01 | 2011-11-23 | 常熟开关制造有限公司(原常熟开关厂） | DC low voltage circuit breaker protection device |
| CN113125847A (en) * | 2021-04-21 | 2021-07-16 | 广东电网有限责任公司广州供电局 | Method and device for processing direct current signal |
-
2011
- 2011-08-01 CN CN2011202751011U patent/CN202221885U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102255275A (en) * | 2011-08-01 | 2011-11-23 | 常熟开关制造有限公司(原常熟开关厂） | DC low voltage circuit breaker protection device |
| CN113125847A (en) * | 2021-04-21 | 2021-07-16 | 广东电网有限责任公司广州供电局 | Method and device for processing direct current signal |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20120516 |