CN1184735C

CN1184735C - Frequency varying driven washer

Info

Publication number: CN1184735C
Application number: CNB001310186A
Authority: CN
Inventors: 区长钊
Original assignee: Jin Ling Electrical Co ltd
Current assignee: Jinling Electrical Co Ltd
Priority date: 2000-12-29
Filing date: 2000-12-29
Publication date: 2005-01-12
Anticipated expiration: 2020-12-29
Also published as: CN1325178A

Abstract

The present invention relates to a various frequency driven washing machine. In the washing machine, a network power supply is converted into symmetrical two-phase power supplies of which the converted frequency and the time lag are equal to 1/4 cycle, two-phase symmetrical winding motors are adopted, and the driving spaces of the motor has the difference of an electric angle of pi/2. The present invention has one scheme that the network power supply is converted into a variable frequency power supply through a rectification filtering circuit and an inverse circuit. The rectification filtering circuit is a half-wave rectification filtering circuit having a common end with a power supply loop of the network and a positive electrode and a negative electrode. The inverse circuit is a double half-wave unit. The present invention uses a motor of an original washing machine. The motor has the good performance of the symmetrical motor, but the structure is simplified, and the cost is reduced.

Description

The washing machine of frequency conversion drive

Technical field

The present invention relates to a kind of washing machine of frequency conversion drive.

Background technology

In washing machine, be converted into variable frequency power supply, drive motor from the power supply of electrical network.Frequency conversion drive is the preferable electric motor speed adjusting method of quality.For improving performance, in recent years, washing machine is developed to the frequency conversion drive threephase motor by the single-phase motor of fixed frequency driving in the past.Chinese patent application number: 98104171, publication number: CN1191909A, the applicant: Samsung Electronics Co., Ltd proposes to set up single-phase variable frequency power supply to washing machine and drives in the past single-phase capacitor operation motor.This method is fairly simple, but, weaken the speed governing quality of motor because the circuitry phase state of single-phase capacitor operation motor can not keep symmetry, and can produce bad skew because of supply frequency, particularly be unfavorable for raising the efficiency and reducing electromagnetic vibration noise, do not see in actual product so far and use.The premium properties of symmetry multiphase motor is well-known.The three-phase electronics variable frequency power supply that particularly time-honored threephase motor and developed recently get up has mature technology, is extensive use of on industrial equipment.So, go out present stage three phase variable frequency drive system on the washing machine product.As seen its latest development is published in " household electrical appliance science and technology " the 9th phase in 2000 " converter technique " special column " exploitation of rotary drum washing machine frequency-changing control system and application " and articles such as " energy-saving washer control system-DSP microcontroller ", and its characteristics have:

1, in this washing machine, be converted into the three phase mains of frequency conversion from the power supply of electrical network, be generally symmetrical threephase source.

2, washing machine motor is a threephase motor, comprises induction motor or permanent magnet brushless electromotor.

3, inverter circuit is bridge-type Unit 6.

As widely used typical frequency changing driving system on the industrial equipment, be used for the much smaller relatively washing machine of power, promptly have following aspect to be worth improving:

1, the unit number of inverter circuit is on the high side, is the principal element that influences cost.

2, for induction motor, threephase motor single-phase motor relatively in the past, due to the groove number that needs many phases, fluting seems on the high side; The many phase planes of winding, rule complicates; The automatic rule equipment of two-phase type that in the past was used to make the motor of washing machine can not use, and influences cost.Permanent magnet brushless electromotor then is to adapt to the novel motor that frequency conversion drive is introduced, and structure and technology are all than induction motor complexity, and cost is also high.

3, in bridge inverter main circuit, two units in series cross-over connections up and down of each brachium pontis are in DC power supply, when accidental interference or false triggering so that during conducting simultaneously, i.e. low-impedance path at two unit forms the shoot through of big electric current, so that burn element, be the weak link of system.Usually need select for use more outstanding unit elements, or complicated protective circuit is set,,, obviously influence cost for washing machine so that use the higher Intelligent Power Module (IPM) of price etc. to this.

Summary of the invention

Task of the present invention is at the little characteristics of washing machine power, propose one and both had the premium properties of symmetrical multiphase motor compared with the prior art, but the system that advises to be driven in the frequency conversion that structure and cost reduce.Comprise:

1, reduces the unit number of frequency changer circuit;

2, can use in the past single-phase motor structure;

3, can eliminate the short circuit Low ESR of inverter circuit cross-over connection in DC power supply.

A kind of washing machine of frequency conversion drive, in this washing machine, power supply from electrical network is converted into variable frequency power supply, drive motor, it is characterized in that: the variable frequency power supply that is converted to is the symmetrical two-phase power supply that time lag equaled for 1/4 cycle, and institute's drive electric motor is the two-phase symmetric winding motor that the space differs the pi/2 electrical degree.Described variable frequency power supply is converted through current rectifying and wave filtering circuit and inverter circuit, current rectifying and wave filtering circuit is made up of one group of positive half wave current rectifying and wave filtering circuit and one group of negative halfwave rectifier filter circuit of a common port with the electric power loop from electrical network, forms positive and negative each one group of DC power supply of supplying with frequency changer circuit; Inverter circuit is two half-wave Unit 4, and per two unit are one group, and what DC power supply was modulated to frequency conversion equals the symmetrical two-phase power supply in 1/4 cycle with time lag, and each group is to a power supply mutually of motor.Described motor is the two-phase symmetric winding squirrel-cage induction motor that a kind of space differs the pi/2 electrical degree.

Its symmetrical two-phase power supply provides two polyphase sources that amplitude is identical, time lag equals the alternating voltage in 1/4 cycle; Its motor is the two-phase symmetric winding motor that the space differs the pi/2 electrical degree.Though three-phase system is outstanding for the high-power electric system advantage, and become power supply network unique polyphase source except that single phase poaer supply, symmetrical quarter-phase system is then comparatively simple for small-power electric power system, only to go into the inconvenient use of power supply easily for want of.In the research of single-phase condenser motor, proposed principle with symmetrical two-phase motor as analysis means, and proposed to develop out the required symmetrical two-phase power supply of development test with three phase mains.At the symmetrical two-phase power supply that the washing machine of single phase power supply can not be set up and use in the past, be when the power source conversion from electrical network becomes variable frequency power supply, to form in the present invention.

About the variable frequency power supply in the such scheme, a solution of the present invention is that variable frequency power supply is converted through current rectifying and wave filtering circuit and inverter circuit from the power supply of electrical network.Current rectifying and wave filtering circuit is made up of one group of positive half wave current rectifying and wave filtering circuit and one group of negative halfwave rectifier filter circuit of a common port from the electric power loop of electrical network, forms each one group of DC power supply of positive and negative of supplying with inverter circuit; Inverter circuit is two half-wave Unit 4, and per two unit are one group, and what DC power supply was modulated to frequency conversion equals the symmetrical two-phase power supply in 1/4 cycle with time lag.Each group is to a power supply mutually of motor.The solution of the present invention, the rectifier cell number reduces 1/2nd than bridge rectifier; Unit number in the inverter circuit has reduced 1/3rd than three-phase circuit; Each unit is through motor inductance series connection power supply, can avoid big short circuit current that false triggering causes so that burn element, improves reliability, thereby can simplify protective circuit and select more common element for use.

Differing the two-phase symmetric winding motor of pi/2 electrical degree about the space of such scheme, can be induction motor or permanent magnet brushless electromotor, reluctance motor and tape motor.A scheme of the present invention is to adopt a kind of induction motor one space to differ the two-phase symmetric winding squirrel-cage motor of pi/2 electrical degree.It is exactly the single-phase capacitor operation motor that in the past uses on the washing machine, but by symmetrical two-phase power supply power supply, saves original motor capacitor; Efficient that is significantly improved and torque, thereby can save the electromagnetic material of motor; The rotating magnetic field of motor is circular, thereby obviously reduces electromagnetic vibration noise.Compare with the threephase motor that is symmetrical motor equally, the groove number of the few phase of stator, for the minor diameter iron core of small power motor, fluting seems preferably; The few phase plane of winding, rule is simplified, and can continue to use so that make the automatic rule equipment of two-phase type of the motor of washing machine in the past.The structure of other motor in addition and technology are all than induction motor complexity, and is unfavorable in reliability and cost, and the serviceability difference in washing machine is little.

Below in conjunction with the description of drawings embodiments of the invention.

Description of drawings

Fig. 1 is the electrical diagram of frequency changing driving system of the present invention.

Embodiment

Steel ladle rotation is provided with the washing tube that is provided with impeller freely in the inner bottom part rotation dehydration barrel of holding concurrently freely, hangs in body of the washing machine by suspender.Reducing gear is located at the bottom of steel ladle, transmission of power to impeller and the washing tube dehydration barrel of holding concurrently.The bottom of reducing gear is provided with motor.Water system supplies water in washing tube is held concurrently dehydration barrel, and the draining valve system is the discharges such as washings in the washing and dewatering bucket.This is a kind of typical case's formation of impeller type washing machine.But do not limit is impeller type washing machine, also can be the agitator type washing machine drum type washing machine.Also be not limited in addition need reducing gear or/and the structure of the same through-drive of diagram motor and each rotary body, for example can adopt by belt the transmission of power of motor to the structure of reducing gear, in washing process, power is directly delivered to the direct Drive Structure of impeller or/and do not establish reducing gear.

The control device of motor 6 comprises: by from the AC power 1 of for example 220V50HZ of electrical network be connected in its output and AC power 1 rectification and the current rectifying and wave filtering circuit 2 of transform direct voltage, the DC power supply 3 of formation; The inverter circuit 4 that connects at the output of DC power supply.Output at inverter circuit is connecting motor 6.In addition, inverter circuit 4 is connected in controlling organization 5, and controlled by it.This is the control device of typical A C-DC-AC indirect conversion mode, but is not limited thereto, and also can be the control device of not establishing the AC-AC Direct Transform mode of current rectifying and wave filtering circuit.

Fig. 1 represents the circuit diagram of motor 6 and control device in the embodiment of the invention.In the present embodiment, current rectifying and wave filtering circuit 2 comprises: the current rectifying and wave filtering circuit of the positive supply of being made up of diode D1 and capacitor C1; The current rectifying and wave filtering circuit of the negative supply of forming by diode D2 and capacitor C2.The zero-potential point of the current rectifying and wave filtering circuit of two groups of power supplys links to each other with an output line (being generally the neutral line) of power supply 1.The double half-wave rectification filter circuit that this proposes for the embodiment of the invention.But be not limited to this, when needs are higher than the variable frequency power supply of line voltage, can use all-wave and/or voltage multiplying rectifier filter circuit.

Inverter circuit 3 has two the hot side unit corresponding with Wb with two phase winding Wa of motor 6 (each drive circuit K1a that is being connected with its input of switch element V1a, V1b, the combination of K1b), with two low potential side unit (each drive circuit K2a that is being connected with its input of switch element V2a, V2b, the combination of K2b).The emitter and collector of switch element V1a, V1b, V2a and V2b respectively is parallel with sustained diode 1a, D1b, D2a and D2b; But being not limited to this, also can be in parallel or/and the protective circuit that the suitable resistance of connecting, electric capacity, inductance and semiconductor device are formed.Above-mentioned switch element can use the module that comprises 4 or 2 IGBT, perhaps discrete IGBT element; Circuit.Above-mentioned switch element can use the module that comprises 4 or 2 IGBT, perhaps discrete IGBT element; Also can use the power component except IGBT, for example power-type MOSFET, GTR (BJT) and GTO etc.In addition, also can be the integrated power module that above-mentioned all unit add protective circuit encapsulation one, as IPM etc.

Inverter circuit is two half-wave Unit 4, per two unit are one group, under the control of controlling organization 5, what DC power supply was modulated to frequency conversion equals the symmetrical two-phase power supply in 1/4 cycle with time lag: switch element V1a, V2a form one group of two half-wave inverter circuit, power to a of motor phase winding; Switch element V1b, V2b form the two half-wave inverter circuits of another group, power to the b of motor phase winding.About the mode of Frequency-variable Modulation, present embodiment is voltage-type pulse-width modulation (PWM, the SPWM etc.) mode of prior art, but also can be for current mode or/and modes such as pulse-ampli tude modulations; And, can also be to carry out voltage modulated when carrying out Frequency-variable Modulation for better speed adjusting performance is arranged.

Controlling organization 5 contains the PWM output mechanism, and constitutes in microcomputer, and according to washing machine service performance required intrinsic setting and the dynamically requirement of adjustment, the power supply of exporting except that the control inverter circuit is the symmetrical two-phase, also controls its frequency, voltage and waveform.Inner can being provided with the periphery of microcomputer is present embodiment circuit protection, control and electromagnetic compatibility required peripheral circuit and element.In addition, microcomputer can comprise that also the washing machine of present embodiment carries out the program of the required washing of work, rinsing and dehydration and processing to relevant sensing and controlled function.These all belong to prior art.

Present embodiment motor 6 is directly selected for use and is met the motor that the industry standard JB/T3758-1996 of the People's Republic of China (PRC) " washing machine motor general technical specifications " requires, and looks the load capacity of washing machine and selects suitable power grade.Such motor has been the two-phase symmetric winding structure that the space differs the pi/2 electrical degree usually, only because of being used for single phase poaer supply, wherein being called one of parafacies and being mutually to connect and in parallelly with principal phase again behind the phase shifting capacitor be access to power supply, thereby work in asymmetric state.At present embodiment, since the raising of motor symmetrical operation efficient, used motor on the relative washing machine in the past, and selected power grade can reduce by one grade at least; Noise requirements also can decrease.And, owing to be that unified standardized motor can adapt to the line voltage frequency because of the different situation in region, helps international trade by the variable frequency power supply power supply.

The present invention has reached the use converter technique and has improved washing machine, can reach the structure of the frequency changing driving system of simplifying prior art and the purpose that reduces cost.

Claims

1, the washing machine of frequency conversion drive, in this washing machine, comprise that the power supply from electrical network is converted into variable frequency power supply, drive motor, it is characterized in that: the variable frequency power supply of being changed is the symmetrical two-phase power supply that time lag equaled for 1/4 cycle, and described variable frequency power supply is formed by connecting by DC power supply and inverter circuit; DC power supply is made up of AC power and current rectifying and wave filtering circuit, and the output of AC power connects the input of current rectifying and wave filtering circuit, and the output of current rectifying and wave filtering circuit connects the input of inverter circuit; Inverter circuit equals two groups of power supplys of symmetry in 1/4 cycle, the power input that its output is connected motor to what DC power supply was modulated to frequency conversion with time lag; Institute's drive electric motor is the two-phase symmetric winding motor that the space differs the pi/2 electrical degree.

2, the washing machine of frequency conversion drive according to claim 1, it is characterized in that: current rectifying and wave filtering circuit with from the electric power loop of electrical network by a common port, formed by one group of positive half wave current rectifying and wave filtering circuit and one group of negative halfwave rectifier filter circuit, form positive and negative respectively one group of DC power supply of supplying with frequency changer circuit; Inverter circuit is two half-wave Unit 4, and per two unit are one group, described frequency conversion equal each group in two groups of power supplys of symmetry in 1/4 cycle to a power supply mutually of motor with time lag.

3, the motor of frequency conversion drive according to claim 1 is characterized in that: described motor is a kind of squirrel-cage induction motor.