CN201726147U - Low-voltage digital capacity circuit - Google Patents

Abstract

The utility model relates to a capacity circuit, in particular to a low-voltage digital capacity circuit used in a low-voltage power-free system, which comprises a three-phase power, a mircoprocessor, a phase voltage information feedback circuit, a voltage current signal input circuit, a relay control circuit, a temperature acquisition circuit, an upper computer connecting circuit and a key display circuit, wherein the phase voltage information feedback circuit comprises a digital signal processor, a capacitor and a relay circuit which are manually matched and connected. The utility model is directly applied in the low-voltage power-free system, has high measurement precision, flexible configuration, good compensation effect, perfect protection function, long service life, high reliability, small size and high performance cost, is convenient for installing and debugging, improves the power factor of low-voltage power networks, improves the power utilization quality of the power networks, reduces the power loss, and saves the electric power.

Description

Low pressure digital capacitance circuit

Technical field

The utility model is a kind of condenser network, particularly a kind of low pressure digital capacitance circuit that is used for low-voltage reactive power rate system.

Background technology

Condenser network in the prior art in the power capacitor, general certainty of measurement is not high, and real-time and dynamic and intelligent compensates slow, the defencive function imperfection, volume is big, and Installation and Debugging are safeguarded inconvenient.

Chinese patent CN1581637 discloses a kind of condenser network, comprises charge circuit, discharge loop and self discharge loop; Described charge circuit comprises current-limiting charge resistance and the anti-drop electric capacity that is serially connected with between the input power supply; Described discharge loop comprises a discharge diode, and this discharge diode is parallel to described current-limiting charge resistance two ends; Described self discharge loop comprises self discharge control circuit and self discharge resistance, described self discharge resistance and described charge circuit two ends are connected in parallel, described self discharge control circuit is in order to control the break-make that is connected of described self discharge resistance and anti-drop electric capacity, at input voltage just often, the two is disconnected connects, when input voltage falls and interrupts in short-term, make the two keep connecting.Electric capacity condenser network described in this invention, though the compensation of a timing can be provided, the speed of compensation is slow, and this condenser network volume ratio is bigger.

Summary of the invention

The utility model mainly is to solve the deficiencies in the prior art, and a kind of low pressure digital capacitance circuit that is directly used in reactive power compensation is provided.

Above-mentioned technical problem of the present utility model is mainly solved by following technical proposals:

A kind of low pressure digital capacitance circuit, comprise three phase mains and microprocessor, also comprise phase voltage feedback information circuit, the voltage and current signal input circuit, control relay circuit, temperature collection circuit, host computer connecting circuit and button display circuit, phase voltage feedback information circuit comprises digital signal processor, capacitor and relay circuit, described three phase mains is connected with digital information processor is single-phase, capacitor is connected with digital information processor is single-phase, digital signal processor is connected with relay circuit is single-phase, and digital signal processor is connected by the I/O end with microprocessor; Described voltage and current signal input circuit comprises current signal end and analog signal preprocessor, and described current signal end is connected with the analog signal preprocessor is single-phase, and the analog signal preprocessor is connected by the AD end with microprocessor; Control relay circuit comprises relay circuit, relay and capacitor, and microprocessor is connected by the I/O end with relay circuit, and relay circuit is connected with relay is single-phase, and relay is connected with capacitor is single-phase; Temperature collection circuit comprises protractor, and protractor is connected by the I1C end with microprocessor; Described host computer connecting circuit comprises the host computer interface, and the host computer interface is connected by the UART end with microprocessor; Described button display circuit comprises button and LCD display, and described button is connected by the I2C end with microprocessor with LCD display; Described phase voltage feedback information circuit, voltage and current signal input circuit, control relay circuit, temperature collection circuit, host computer connecting circuit and button display circuit interconnect and form.

The current signal end is PT and CT, sending into analog signal processing circuit after the analog signals such as replacement voltage and current handles, signal after the processing is sent into the high-speed AD input in the microprocessor, calculate digitized data such as voltage, electric current, meritorious, idle, power factor, phase angle, harmonic wave by software FFT, Temperature sampler IC sends on the microprocessor I bus and obtains temperature information; The phase information of power supply ABC three-phase and the information of voltage of low voltage power capacitor are sent into the digital information processing circuit simultaneously, have obtained the phase place of ABC three-phase and the real-time switching of low voltage power capacitor; According to voltage, electric current, power factor, the phase place of ABC three-phase, the information of voltage of low voltage power capacitor is in time made the whether order of output control relay, pass through the phase-splitting phase place of ABC three-phase when dropping into low voltage power capacitor, the information of voltage of low voltage power capacitor split-phase capacitor is accurately calculated the operate time of output relay, the moment that makes input voltage and the branch phase voltage of power supply equally (the isobaric input) on the split-phase capacitor, and when excision low voltage power capacitor split-phase capacitor, accurately calculate operate time of output relay, the moment that makes excision, the electric current by split-phase capacitor was zero (zero passage excision), in input and excision process, follow the tracks of pull up time simultaneously, guarantee the accuracy that drops into and excise.Do like this in the time of both can avoiding with controllable silicon as the switching major component owing to impact, surge and withstand voltage problem cause that controllable silicon burns and trigger bigger fault, can save more manufacturing cost again, reduce the fault point, improve stability, produce the impact surge current of high power when also having avoided selecting for use contactor and shorten useful life of low voltage power capacitor as the major component of switching, drop into because voltage is isobaric during switching capacitance, the current over-zero excision, so the time of dynamic switching is short, speed is fast.Timely excision low voltage power capacitor when in actual motion, noting abnormalities as situations such as overcurrent, overvoltage, under-voltage, phase shortage, excess temperature, imbalances, guarantee the stable of power supply, can normally come into operation again as the power up digital capacitance, when having fault, the digital capacitance built in self testing also in time excises low voltage power capacitor, guaranteed the fault point indiffusion, digital capacitance excises the electric capacity that has dropped into when the unexpected power down of power supply, avoided when power supply powers on again the electric capacity impact of shoving.Drop into because voltage is isobaric during switching capacitance, the current over-zero excision, so dynamically the time of switching is short, speed is fast, described man-machine interface button links to each other by the I2C bus with microprocessor with LCD display, intuitively and clearly know low voltage power capacitor running status and electric power data such as voltage, electric current, reactive power, power factor, temperature, operation information, self check information etc., described 485 interfaces are the host computer interface just, link to each other with the UART of microprocessor, the built-in digital capacitance communication protocol of microprocessor, after many digital capacitance networkings, the communication network that can form an intelligence, when being connected with host computer by 485 interfaces, the digital capacitance group is subjected to PC control to carry out switching, transmits the running status of digital capacitance group and data message simultaneously to host computer, during many digital capacitance parallel kinematics, can produce main control system automatically in the digital capacitance group in parallel, idle in the intelligent coordinated compensates electric network.Modular design directly inserts in the low voltage electric network digital capacitance, and Rational structure design makes the miniaturization of digital capacitance volume, and flexible configuration, installation and maintenance are easy to use in actual use to make it.

Therefore, the utility model provides low pressure digital capacitance circuit, directly applies in the low-voltage reactive power system; the certainty of measurement height, flexible configuration, compensation effect is good; defencive function is perfect, long service life, reliability height; device volume is little; the cost performance height, Installation and Debugging are easy to maintenance, improved the power factor of low voltage electric network; improve the electricity quality of using of electrical network, reduced power consumption and saved electric supply.

Description of drawings

Fig. 1 is a circuit schematic flow sheet of the present utility model.

Embodiment

Below by embodiment, and in conjunction with the accompanying drawings, the technical solution of the utility model is described in further detail.

Embodiment: as shown in Figure 1, a kind of low pressure digital capacitance circuit, comprise three phase mains 10 and microprocessor 5, also comprise phase voltage feedback information circuit, the voltage and current signal input circuit, control relay circuit, temperature collection circuit, host computer connecting circuit and button display circuit, phase voltage feedback information circuit comprises digital signal processor, capacitor and relay circuit, described three phase mains 10 and 7 single-phase connections of digital information processor, capacitor 11 and 7 single-phase connections of digital information processor, digital signal processor 7 and 8 single-phase connections of relay circuit, digital signal processor 7 is connected by the I/O end with microprocessor 5; Described voltage and current signal input circuit comprises current signal end 1 and analog signal preprocessor 2, described current signal end 1 and 2 single-phase connections of analog signal preprocessor, and analog signal preprocessor 2 is connected by the AD end with microprocessor 5; Control relay circuit comprises relay circuit 8, relay 9 and capacitor 11, and microprocessor 5 is connected relay circuit 8 and 9 single-phase connections of relay, relay 9 and 11 single-phase connections of capacitor with relay circuit 8 by the I/O end; Temperature collection circuit comprises protractor 3, and protractor 3 is connected by the I1C end with microprocessor 5; Described host computer connecting circuit comprises host computer interface 4, and host computer interface 4 is connected by the UART end with microprocessor 5; Described button display circuit comprises button and LCD display 6, and described button is connected by the I2C end with microprocessor 5 with LCD display 6; Described phase voltage feedback information circuit, voltage and current signal input circuit, control relay circuit, temperature collection circuit, host computer connecting circuit and button display circuit interconnect and form.

Claims (1)

1. low pressure digital capacitance circuit, comprise three phase mains (10) and microprocessor (5), it is characterized in that: also comprise phase voltage feedback information circuit, the voltage and current signal input circuit, control relay circuit, temperature collection circuit, host computer connecting circuit and button display circuit, phase voltage feedback information circuit comprises digital signal processor, capacitor and relay circuit, described three phase mains (10) and single-phase connection of digital information processor (7), capacitor (11) and single-phase connection of digital information processor (7), digital signal processor (7) and single-phase connection of relay circuit (8), digital signal processor (7) is connected by the I/O end with microprocessor (5); Described voltage and current signal input circuit comprises current signal end (1) and analog signal preprocessor (2), described current signal end (1) and single-phase connection of analog signal preprocessor (2), analog signal preprocessor (2) is connected by the AD end with microprocessor (5); Control relay circuit comprises relay circuit (8), relay (9) and capacitor (11), microprocessor (5) is connected by the I/O end with relay circuit (8), relay circuit (8) and single-phase connection of relay (9), relay (9) and single-phase connection of capacitor (11); Temperature collection circuit comprises protractor (3), and protractor (3) is connected by the I1C end with microprocessor (5); Described host computer connecting circuit comprises host computer interface (4), and host computer interface (4) is connected by the UART end with microprocessor (5); Described button display circuit comprises button and LCD display (6), and described button is connected by the I2C end with microprocessor (5) with LCD display (6); Described phase voltage feedback information circuit, voltage and current signal input circuit, control relay circuit, temperature collection circuit, host computer connecting circuit and button display circuit interconnect and form.

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