CN2807593Y

CN2807593Y - Transducer capable of filtering common mode and differential mode voltage change rate

Info

Publication number: CN2807593Y
Application number: CN 200520020750
Authority: CN
Inventors: 姜艳姝; 徐殿国; 刘宇; 赵洪; 高俊山
Original assignee: Harbin University of Science and Technology
Current assignee: Harbin University of Science and Technology
Priority date: 2005-04-30
Filing date: 2005-04-30
Publication date: 2006-08-16
Anticipated expiration: 2015-04-30

Abstract

The utility model relates to a pulsewidth modulation type transducer. The transducer which can filter the voltage change rate of a common mode and a differential mode comprises a rectifier 1, an inverter 2, a flat wave capacitance C4, a first inductance LI, a second inductance LII, a third inductance LIII, a fourth inductance LIV, a fifth inductance LV, a sixth inductance LVI, a seventh inductance LVII, a first capacitance C1, a second capacitance C2, a third capacitance C3 and a resistor R. One end of first inductance LI, one end of the second inductance LII one end of the third inductance LIII are respectively connected with the inverter 2. The other end of the first inductance LI is connected with one end of the fourth inductance LIV and one end of the first capacitance C1. The other end of the second inductance LII is connected with one end of the fifth inductance LV and one end of the second capacitance C2. The third inductance LIII is connected with one end of the sixth inductance LVI and one end of the third capacitance C3. The other end of the first capacitance C1 is connected with one end of the resistor R, the other end of the second capacitance C2 and the other end of the third capacitance C3. The other end of the resistor R is connected with one end of the seventh inductance LVII. The other end of the seventh inductance LVII is connected with an input terminal of a negative pole or a positive pole of the inverter 2. The fourth inductance LIV, the fifth inductance LV, the sixth inductance LVI and the seventh inductance LVII are identically coiled on the same ring-shaped iron core T in phase. Therefore, the harm for the power quality of an electric motor and an electric network from dv or dt can be eliminated by eliminating the dv or the dt.

Description

But the frequency converter of filtering common mode and differential mode voltage rate of change

Technical field:

The utility model relates to a kind of pulse-width modulation that contains passive filter (PWM) type frequency converter that is used for systems such as Electric Traction and Electric Drive.

Background technology:

Frequency control is a high efficiency, good, the widely used A/C transmission control technology of performance.As realize frequency control control device---frequency converter has been widely used in every field such as industry, agricultural and national defence, will play the part of more and more important role in future world.Yet, frequency converter energy-conservation, improve human habitat, reduce production costs, improve the quality of products and improve and also produced some significant negative effects when huge contribution is made in aspects such as industrial automatization.The develop rapidly of modern power electronic device makes device for power switching, can reach tens kHz as the switching frequency of insulated gate bipolar transistor IGBT, and its quick turn-on and turn-off characteristic makes the output of frequency converter produce very high dv/dt (voltage change ratio).Dv/dt is too high will to produce a series of harm to the frequency converter drive system, can be summarized as follows: (1) is during the high speed break-make of device for power switching, the dv/dt of high frequency can encourage eddy current to cause thermal losses in the electric machine iron core lamination, also can make the copper cash winding of motor consume more energy by kelvin effect, the thermal losses of aggravation motor, cause the power of motor loss to increase, efficient reduces, thereby influences motor performance.When the natural mode shape of the frequency that the high-frequency electromagnetic that produces when frequency converter vibrates and the parts of motor is close, can lure that mechanical resonance and noise take place for it into.Power circuit exists distributed capacitance and motor internal to have parasitic capacitance during (2) owing to high frequency, will produce charging and discharging currents I _1g(I _1gBe called leakage current, this electric current is proportional to dv/dt), flow into ground wire, leakage current is crossed the misoperation that senior general causes motor protective circuit.(3) during the voltage type PWM frequency converter drive motors of high carrier frequency, when the dv/dt of high frequency acts on the motor internal parasitic capacitance, not only can produce charging and discharging currents, but also can be because the cumulative function of electric capacity make armature spindle voltage raise.The two can cause that all lubricating oil film punctures, and produces the spark machined effect, thereby causes the motor bearings premature damage, increases the maintenance cost of motor, influences the normal operation of system; (4) leakage current of frequency from 100kHz to several million range flow back into the three phase mains of system through ground wire, produce high-frequency electromagnetic and disturb (EMI), higher harmonic current forms the harmonic wave pressure drop on line impedance, produce meritorious and reactive loss, influence the power supply grid quality of power supply, cause power supplying efficiency to descend; Also can make protective relaying device because of being disturbed misoperation, influence the normal operation of other electronic equipment on the electrical network, even can cause the damage of equipment; (5) when adopting long line transmission cable between motor and the frequency converter inevitably, as in oil exploitation, papermaking, fields such as mining industry, distributed inductance and distributed capacitance owing to long cable exists will produce the reflected wave phenomenon, and motor side dv/dt is doubled.The dv/dt of common-mode voltage doubles to make above-mentioned harm further to increase the weight of.

The utility model content:

But the utility model provides the frequency converter of a kind of filtering common mode and differential mode voltage rate of change, can eliminate the dv/dt of differential mode voltage and the dv/dt of common-mode voltage simultaneously, thereby eliminates the harm of dv/dt to the motor and the electrical network quality of power supply.It comprises rectifier 1, inverter 2 peaceful ripple capacitor C 4, the end of flat wave capacitor C4 connects the cathode output end of rectifier 1 and the electrode input end of inverter 2, the other end of flat wave capacitor C4 connects the cathode output end of rectifier 1 and the negative input of inverter 2, it also comprises the first inductance L I, the second inductance L II, the 3rd inductance L III, the 4th inductance L IV, the 5th inductance L V, the 6th inductance L VI, the 7th inductance L VII, first capacitor C 1, second capacitor C 2, the 3rd capacitor C 3 and resistance R, the end of the first inductance L I, the end of the end of the second inductance L II and the 3rd inductance L III is connected on the three-phase output end of inverter 2, the other end of the first inductance L I connects the end of the 4th inductance L IV and an end of first capacitor C 1, the other end of the second inductance L II connects the end of the 5th inductance L V and an end of second capacitor C 2, the 3rd inductance L III connects the end of the 6th inductance L VI and an end of the 3rd capacitor C 3, the other end of first capacitor C 1 connects the other end of second capacitor C 2, one end of the other end of the 3rd capacitor C 3 and resistance R, the other end of resistance R connects the end of the 7th inductance L VII, the other end of the 7th inductance L VII connects the negative input or the electrode input end of inverter, the 4th inductance L IV, the 5th inductance L V, the 6th inductance L VI and homophase identical with the 7th inductance L VII is wound on the same annular core T, first capacitor C 1, the capacitance of second capacitor C 2 and the 3rd capacitor C 3 equates, the first inductance L I, the second inductance L II is identical with the 3rd inductance L III.LIV during the utility model work, the other end of LV and LVI is connected on respectively on the three-phase power input end of motor, LI, LII, LIII, C1, C2 and C3 constitute the dv/dt that differential mode filter is used for the filtering differential mode voltage, C1, C2, C3, R, LI, LII, LIII, LIV, LV, LVI and LVII constitute the dv/dt that common-mode filter is used for the filtering common-mode voltage, filter in the utility model frequency converter can filtering dv/dt, avoided the harm of dv/dt to the motor and the electrical network quality of power supply, and because the 4th inductance L IV, the 5th inductance L V, identical and the homophase of the number of turn of the 6th inductance L VI and the 7th inductance L VII is wound on the same annular core T, the influence that not changed by frequency converter frequency to the inhibitory action of common-mode voltage dv/dt.Reasonable in design, the reliable operation of the utility model has bigger promotional value.

Description of drawings:

Fig. 1 is an electrical block diagram of the present utility model, Fig. 2 is the 4th inductance L IV, the 5th inductance L V, the 6th inductance L VI, the 7th inductance L VII and annular core T coiling connection diagram, Fig. 3 is the motor side common-mode voltage schematic diagram that does not have filter, Fig. 4 is the motor side common-mode voltage schematic diagram of having used behind the filter of the present utility model, Fig. 5 is the motor side differential mode voltage schematic diagram that does not have filter, and Fig. 6 is the motor side differential mode voltage schematic diagram of having used behind the filter of the present utility model.

Embodiment:

Embodiment one: specify present embodiment below in conjunction with Fig. 1 to Fig. 6.Present embodiment is by rectifier 1, inverter 2 peaceful ripple capacitor C 4, the end of flat wave capacitor C4 connects the cathode output end of rectifier 1 and the electrode input end of inverter 2, the other end of flat wave capacitor C4 connects the cathode output end of rectifier 1 and the negative input of inverter 2, it also comprises the first inductance L I, the second inductance L II, the 3rd inductance L III, the 4th inductance L IV, the 5th inductance L V, the 6th inductance L VI, the 7th inductance L VII, first capacitor C 1, second capacitor C 2, the 3rd capacitor C 3 and resistance R, the end of the first inductance L I, the end of the end of the second inductance L II and the 3rd inductance L III is connected on the three-phase output end of inverter 2, the other end of the first inductance L I connects the end of the 4th inductance L IV and an end of first capacitor C 1, the other end of the second inductance L II connects the end of the 5th inductance L V and an end of second capacitor C 2, the 3rd inductance L III connects the end of the 6th inductance L VI and an end of the 3rd capacitor C 3, the other end of first capacitor C 1 connects the other end of second capacitor C 2, one end of the other end of the 3rd capacitor C 3 and resistance R, the other end of resistance R connects the end of the 7th inductance L VII, the other end of the 7th inductance L VII connects the negative input or the electrode input end of inverter, the 4th inductance L IV, the 5th inductance L V, the 6th inductance L VI and homophase identical with the 7th inductance L VII is wound on the same annular core T, first capacitor C 1, the capacitance of second capacitor C 2 and the 3rd capacitor C 3 equates, the first inductance L I, the second inductance L II is identical with the 3rd inductance L III.Comprise positive and negative preface component (being differential mode voltage) and zero-sequence component (being common-mode voltage) in the output voltage of three-phase voltage type PWM frequency converter, promptly usually said line voltage and phase voltage.

Claims

1, but the frequency converter of filtering common mode and differential mode voltage rate of change, it comprises rectifier (1), inverter (2) and flat wave capacitor (C4,) end of flat wave capacitor (C4) connects the cathode output end of rectifier (1) and the electrode input end of inverter (2), the other end of flat wave capacitor (C4) connects the cathode output end of rectifier (1) and the negative input of inverter (2), it is characterized in that it also comprises first inductance (LI), second inductance (LII), the 3rd inductance (LIII), the 4th inductance (LIV), the 5th inductance (LV), the 6th inductance (LVI), the 7th inductance (LVII), first electric capacity (C1), second electric capacity (C2), the 3rd electric capacity (C3) and resistance (R), one end of first inductance (LI), one end of one end of second inductance (LII) and the 3rd inductance (LIII) is connected on the three-phase output end of inverter (2), the other end of first inductance (LI) connects an end of the 4th inductance (LIV) and an end of first electric capacity (C1), the other end of second inductance (LII) connects an end of the 5th inductance (LV) and an end of second electric capacity (C2), the 3rd inductance (LIII) connects an end of the 6th inductance (LVI) and an end of the 3rd electric capacity (C3), the other end of first electric capacity (C1) connects the other end of second electric capacity (C2), one end of the other end of the 3rd electric capacity (C3) and resistance (R), the other end of resistance (R) connects an end of the 7th inductance (LVII), the other end of the 7th inductance (LVII) connects the negative input or the electrode input end of inverter, the 4th inductance (LIV), the 5th inductance (LV), the 6th inductance (LVI) and homophase identical with the 7th inductance (LVII) is wound on the same annular core (T), first electric capacity (C1), the capacitance of second electric capacity (C2) and the 3rd electric capacity (C3) equates, first inductance (LI), second inductance (LII) is identical with the 3rd inductance (LIII).