CN2346107Y

CN2346107Y - Single-phase inductive load power-factor compensator

Info

Publication number: CN2346107Y
Application number: CN 98218163
Authority: CN
Inventors: 孙福林; 严红缨
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-08-10
Filing date: 1998-08-10
Publication date: 1999-10-27
Anticipated expiration: 2008-08-10

Abstract

The utility model relates to a single phase inductive load power factor compensator. The utility model comprises a compensation capacitor (C). The utility model is characterized in that a single phase alternating current circuit is connected with a load sensing control circuit in series, and the load sensing control circuit is formed by that the output terminals of full wave bridge rectifier circuits (D1, D2, D3, and D4) is connected with a current relay (LJ) in a bridge connection mode; the relay contact (LJ1) of the current relay (LJ) is connected with a compensation capacitor (C) in series and is connected with the single phase alternating current circuit in parallel. The automatic tracking compensation can be realized by that the current relay (LJ) controls the switch of the compensation capacitor (C).

Description

Single-phase inductive load power-factor compensator

The utility model relates to inductive load power factor compensation device in a kind of alternating current circuit, inductive load is followed power factor compensation device automatically in particularly a kind of single phase alternating current circuit, is applicable to perceptual household electrical appliance such as air-conditioning, refrigerator, refrigerator-freezer are carried out power factor compensation.

Along with the raising of people's living standard, household electrical appliance such as air-conditioning, refrigerator, refrigerator-freezer enter Modern Family in a large number.Because these household electrical appliance all are inductive loads, so power factor is lower, generally have only 0.7-0.8, what that is to say that the electric energy of 20%-30% does is idle work, is wasted in vain.This numeral is not very big for a concrete family, but has been exactly an astronomical figure for the country with several hundred million families.At present, China's electric administrative department has only been made concrete regulation to the power factor of industrial and mining enterprises' electric power system, the power factor of general household electricity is not made concrete requirement as yet.Therefore, engineers and technicians only pay attention to the development of industrial and mining enterprises' power equipment power-factor compensator, still do not have the upright factor compensator of monophase machine merit and come out.Patent Office of the People's Republic of China's Granted publication on January 21st, 1998 a kind of " automatically control compensation formula motor high-efficiency electricity-saving appliance " utility model patent (notification number is CN2273073Y), this utility model is the circuit complexity not only, and only is applicable to the power factor compensation of three phase electric machine.

In view of the present technique exist in above-mentioned still unsolved technical problem, the purpose of this utility model is to disclose the simple single-phase inductive load power-factor compensator of a kind of circuit.

Above-mentioned purpose of the present utility model is achieved in that a kind of single-phase inductive load power-factor compensator, comprise building-out capacitor, it is characterized in that being in series with in the single phase alternating current (A.C.) loop load-transducing control circuit, this load-transducing control circuit is that output cross-over connection one current relay at full-wave bridge rectifier circuit constitutes, and is connected in parallel in the single phase alternating current (A.C.) loop behind the relay contact series compensation capacitance of described current relay.

Above-mentioned technical solution of the present utility model has following outstanding advantage:

1. circuit is simple, and element is few, can be directly installed in supply socket or the plug;

2. by the input or the disengagement of load-transducing control circuit control compensation electric capacity, promptly follow compensation automatically, the overcompensation when avoiding causing zero load;

3. the utility model can make single-phase inductive load power factor bring up to 0.99, and power saving rate can reach 20%-30%.

In conjunction with the accompanying drawings and embodiments the utility model is explained in further detail,, grasps better and implement technological means of the present utility model so that the public fully understands technical solution described in the utility model.

Description of drawings:

Figure of description is the electrical schematic diagram of a specific embodiment of utility model, and what dotted line connected among the figure is motor M.

Embodiment

Referring to accompanying drawing, first important additional technical feature of the present utility model is to be parallel with the compensation indicating circuit on the described building-out capacitor C.This indicating circuit is made up of divider resistance R1, the R2 of two series connection and the LED that is connected in parallel on the resistance R 2.After load motor M starts, the relay contact LJ1 closure of current relay LJ, LED is lighted luminous, shows building-out capacitor C input compensation operation.

Referring to accompanying drawing; second important additional technical feature of the present utility model is that the input (A-B two ends among the figure) in single phase alternating current (A.C.) loop establishes by overcurrent and overvoltage crowbar, this protective circuit be in the single phase alternating current (A.C.) loop behind the series connection fuse FUS pressure cell VR in parallel again constitute.Described pressure cell VR is that diode is protected in piezo-resistance or overvoltage, and its breakover voltage is decided on the civil power rated voltage, is 220V as China's regulation line voltage, and can select breakover voltage for use is piezo-resistance or the overvoltage protection diode of 270V.In use, when load short circuits or building-out capacitor puncture, fuse RD promptly is blown, and can avoid taking place to use electrification; When the civil power superpressure, pressure cell VR is instantaneous short-circuit just, and fuse RD promptly is blown, and the protection household electrical appliance are avoided infringement.Another effect of described pressure cell VR be can the filtering civil power in harmful spike, avoid motor overheating, improve motor working efficiency.

Referring to accompanying drawing, full-wave bridge rectifier circuit described in the utility model is made up of four rectifier diode D1, D2, D3, D4, be connected across the specified attract current of the current relay LJ of this full-wave bridge rectifier circuit output, as long as reach the 70%-80% of load rating operating current, because the starting current of perceptual household electrical appliance (as motor) is bigger, starting current is enough to make current relay LJ adhesive.Surpass or equal the rated operational current of motor as the specified attract current of selected current relay LJ, during the motor operate as normal, the pressure drop on the current relay LJ excessive (surpassing sustaining voltage) must consume more electric energy so.

Referring to accompanying drawing, when motor M starts, civil power is through four rectifier diode D1, D2, D3, D4 rectification, current relay LJ is got, the relay contact LJ1 adhesive of current relay LJ, building-out capacitor C is connected in parallel on (being two of motor M) in the single phase alternating current (A.C.) loop, changes the load characteristic of motor M, the power factor of small electromotor M.Otherwise the relay contact LJ1 of current relay LJ throws off, and building-out capacitor C is withdrawed from the single phase alternating current (A.C.) loop, has avoided the overcompensation after motor M stops.

Claims

1. single-phase inductive load power-factor compensator, comprise building-out capacitor (C), it is characterized in that being in series with in the single phase alternating current (A.C.) loop load-transducing control circuit, this load-transducing control circuit is that output cross-over connection one current relay (LJ) at full-wave bridge rectifier circuit (D1, D2, D3, D4) constitutes, and is connected in parallel in the single phase alternating current (A.C.) loop behind relay contact (LJ1) series compensation capacitance (C) of described current relay (LJ).

2. a kind of single-phase inductive load power-factor compensator according to claim 1 is characterized in that being parallel with on the described building-out capacitor (C) compensation indicating circuit (R1, R2, LED).

3. a kind of single-phase inductive load power-factor compensator according to claim 1 and 2; the input that it is characterized in that the single phase alternating current (A.C.) loop is established by overcurrent and overvoltage crowbar, and this protective circuit is to connect in the single phase alternating current (A.C.) loop that pressure cell in parallel again (VR) constitutes behind the fuse (FUS).