CN201601605U - Control system for restraining common-mode voltage of two-stage matrix converter - Google Patents

Abstract

The utility model discloses a control system for restraining common-mode voltage of a two-stage matrix converter. The two-stage matrix converter forms a rectifier stage via a bidirectional switch and forms an inverter stage via an IPM module. The control system is characterized in that the control system of the two-stage matrix converter comprises a voltage capture unit, an over-current and IPM fault detecting unit, a TMS320LF2407 main controller, an EPM1270 auxiliary controller and a driving circuit. Aiming to problems of common-mode voltage when the two-stage matrix converter drives an asynchronous motor, the control system for restraining common-mode voltage of the two-stage matrix converter utilizes an improving double space vector modulation method including distributing inverter-stage zero vector again, and can effectively reduce common-mode voltage of the two-stage matrix converter while guaranteeing rectifier-stage zero-current commutation.

Description

Be used to suppress the control system of common-mode voltage of dual stage matrix converter

Technical field

The common-mode voltage that the utility model belongs to asynchronous motor suppresses the field, and the common-mode voltage when especially adopting dual stage matrix converter to drive suppresses the field.

Background technology

Matrix converter has good frequency conversion performance because of it, from being born is one of research focus of power electronics so far always, yet seldom have product to come out so far, the bottleneck that restricts its development is the four safe changes of current of step of matrix converter complexity and the reliability that modulator approach has reduced system.Calendar year 2001, the novel matrix converter that constitutes main circuit by rectification stage and inverse cascade that is proposed by American scholar Lixiang Wei and Thomas.ALipo is a dual stage matrix converter, except good input-output characteristic with matrix converter, also have the simple zero current change of current and clamp circuit, and control method is also simpler, becomes a kind of friendship-friendship Direct Power converter that development potentiality is arranged at present very much.

When matrix converter drives asynchronous motor, the common-mode voltage of high frequency, high dv/dt will be produced, the harm of common-mode voltage is to produce electric current by the stator and rotor of asynchronous motor and the coupling channels such as distributed capacitance between the air gap: when this electric current flows through asynchronous motor bearing generation shaft current, will cause damage to the bearing of asynchronous motor; When flowing through ground wire, this excessive electric current will cause the misoperation of asynchronous motor ground protection; Because the common-mode voltage of high dv/dt will form very strong electromagnetic interference, the normal operation of installing is impacted simultaneously.So the reduction common-mode voltage is used for the engineering of matrix converter has very important and practical meanings.

The common-mode voltage that suppresses matrix converter at present mainly contains two kinds of methods of hardware and software: F Yue, people such as P W Wheeler adopted hardware in 2005 in paper " Cancellation of 3rd Common-mode Voltage Generated by MatrixConverter.IECON 2005; 31st Annual Conference of IEEE. " (eliminating 3 common-mode voltages that matrix converter produces), promptly by common mode transformer, do not control rectifier bridge and single-phase bridge type inverter and constitute the common-mode voltage arrester, eliminate 3 subharmonic of common-mode voltage, yet adopt this method to increase the hardware cost of system and the complexity of design; And reduce the hardware cost that common-mode voltage can reduce system from software, H J Cha, P N Enjeti studied suppressing common-mode voltage on the modulator approach in the paper " Anapproach to reduce common mode voltage in matrix converter.2002; 37th IAS Annual Meeting " (a kind of method that reduces the matrix converter common-mode voltage) in 2002, and low energy is reduced to common-mode voltage original

The common-mode voltage of matrix converter suppresses thought and is fit to dual stage matrix converter equally, yet, at present the common-mode voltage that suppresses dual stage matrix converter is studied also seldom.Document " Common-Mode Voltages ofSpace-Vector Modulated Matrix Converters Compared to Three-Level Voltage SourceInverter.PESC ' 06; 37th IEEE " (based on the common-mode voltage comparative study of the matrix converter and the three level voltage type inverters of space vector modulation) relates to adjusts the common-mode voltage that zero vector reduces dual stage matrix converter, but what adopt in the literary composition is the indirect space vector modulating method of matrix converter, and shortcoming is that the rectification stage bidirectional switch can not be realized the zero current change of current.

The utility model content

The utility model is for avoiding above-mentioned existing in prior technology weak point, a kind of control system that is used to suppress common-mode voltage of dual stage matrix converter being provided, and when guaranteeing the change of current of rectification stage zero current, reduces the common-mode voltage amplitude of dual stage matrix converter.

The utility model technical solution problem adopts following technical scheme:

The utility model is used to suppress the control system of common-mode voltage of dual stage matrix converter, and its dual stage matrix converter is to be constituted rectification stage, constituted inverse cascade by the IPM module by bidirectional switch; Its design feature is that the control system of described dual stage matrix converter comprises voltage capturing unit, overcurrent and IPM fault detection unit, TMS320LF2407 master controller, EPM1270 assistant controller and drive circuit;

Catch the zero crossing information of net side power input voltage with described voltage capturing unit, and send into the TMS320LF2407 master controller, determining the initial phase of input voltage, and the rectification stage duty cycle signals during the unit input power factor;

Detect the instantaneous net side power supply and the overcurrent information of asynchronous motor with described overcurrent and IPM fault detection unit, and instantaneous IPM fault message, and send into the EPM1270 assistant controller;

The input current sector auxiliary information of exporting rectification stage with described TMS320LF2407 master controller is in real time judged the state of parity of sector to described EPM1270 assistant controller; The output line voltage information of given dual stage matrix converter in described TMS320LF2407 master controller, adopt rectification stage and inverse cascade duty cycle signals after the double space vector modulation method obtains coordinated control in real time, and outputing to the EPM1270 assistant controller, output voltage sector and the synchronizing signal of exporting inverse cascade simultaneously arrive the EPM1270 assistant controller;

With described EPM1270 assistant controller electric current sector, voltage sector, duty cycle signals and the synchronizing signal of the output of TMS320LF2407 master controller are decoded, when the input current sector is odd number, at inverse cascade zero vector U ₀Replace all zero vector U ₇When the input current sector is even number, at inverse cascade zero vector U ₇Replace all zero vector U ₀, obtain rectification stage switching signal and inverse cascade switching signal respectively;

Finish the rectification stage switching signal and the inverse cascade switching signal outputs to rectification stage and inverse cascade respectively with described drive circuit.

Compared with the prior art, the utility model beneficial effect is embodied in:

1, the utility model adopts improved double space vector modulation method, and when guaranteeing the change of current of rectification stage zero current, the utility model can be reduced to the common-mode voltage amplitude of dual stage matrix converter original

2, the utility model has reduced the hardware cost of system, is easy to realize the system reliability height.

Description of drawings

Fig. 1 is the main circuit structure figure of the utility model dual stage matrix converter;

Fig. 2 is the control system block diagram of the utility model dual stage matrix converter;

Input voltage input current sector division figure when Fig. 3 (a) imports unity power factor for the utility model rectification stage;

Fig. 3 (b) is the utility model inverse cascade output line voltage space vector distribution map;

Fig. 4 is the double space vector distribution map of dual stage matrix converter in the prior art;

Fig. 5 is the double space vector distribution map of the utility model dual stage matrix converter.

Below pass through embodiment, and in conjunction with the accompanying drawings the utility model be described further:

Embodiment

Figure 1 shows that the main circuit structure figure of the utility model dual stage matrix converter, be made of input net side power supply, input filter, dual stage matrix converter, clamp circuit, the load of output asynchronous motor, dual stage matrix converter is to be constituted rectification stage, constituted inverse cascade by the IPM module by bidirectional switch.

Figure 2 shows that the control system block diagram of the utility model dual stage matrix converter, comprise voltage capturing unit, overcurrent and IPM fault detection unit, TMS320LF2407 master controller, EPM1270 assistant controller and drive circuit.

Catch the zero crossing information of net side power input voltage with the voltage capturing unit, and send into the TMS320LF2407 master controller, determining the initial phase of input voltage, and the rectification stage duty cycle signals during the unit input power factor.

Initial phase adds the rotating vector angle of rectification stage input current, the space vector phase angle that obtains input current in real time is to determine the sector, input voltage input current sector division figure when Fig. 3 (a) is depicted as the input unity power factor, division rule is that a phase voltage absolute value maximum, other the two-phase polarity of voltage of each sector among the figure is opposite with it, is that example provides duty ratio d with the 3rd sector ₁And d ₂:

${\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="H2009202995790E00011.png"\; state="\{\{state\}\}">d</figure-callout>}}_1=-\frac{u_a}{u_b}=-\frac{\cos \left({\mathrm{\&theta;}}_a\right)}{\cos \left({\mathrm{\&theta;}}_b\right)},{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="H2009202995790E00022.png"\; state="\{\{state\}\}">d</figure-callout>}}_2=-\frac{u_c}{u_b}=-\frac{\cos \left({\mathrm{\&theta;}}_c\right)}{\cos \left({\mathrm{\&theta;}}_b\right)}---\left(1\right)$

In the formula: u _a, u _bAnd u _cBe net side power supply a, b and c phase voltage, θ _a, θ _bAnd θ _cBe respectively the phase angle of a, b and c phase voltage.

Detect the instantaneous net side power supply and the overcurrent information of asynchronous motor with overcurrent and IPM fault detection unit, and instantaneous IPM fault message, and send into the EPM1270 assistant controller.

The input current sector auxiliary information of exporting rectification stage in real time with the TMS320LF2407 master controller is judged the state of parity of sector to the EPM1270 assistant controller; The output line voltage information of given dual stage matrix converter in the TMS320LF2407 master controller, adopt rectification stage and inverse cascade duty cycle signals after the double space vector modulation method obtains coordinated control in real time, and outputing to the EPM1270 assistant controller, output voltage sector and the synchronizing signal of exporting inverse cascade simultaneously arrive the EPM1270 assistant controller.

The dc voltage u of dual stage matrix converter _DcBe a pulsating quantity, for obtaining constant output voltage vector amplitude, inverse cascade index of modulation m _vNeed revise to offset u _DcPulsation, Fig. 3 (b) is depicted as inverse cascade output line voltage space vector distribution map, formula (2) has provided revised duty ratio computing formula:

In the formula: m _vBe the revised inverse cascade index of modulation, θ _SvSector angle for output line voltage.

Because DC side is at 1 T _SBe made of two sections line voltages in cycle, so inverse cascade needs to coordinate control under two sections line voltages, Fig. 4 has provided the double space vector distribution map of coordinating control back dual stage matrix converter, among the figure: d _{1 α}=d ₁d _α, d _{1 β}=d ₁d _β, d ₁₀=d ₁d ₀d _{2 α}=d ₂d _α, d _{2 β}=d ₂d _β, d ₂₀=d ₂d ₀

The TMS320LF2407 master controller is exported in real time: electric current sector, voltage sector, duty cycle signals and synchronizing signal.

When dual stage matrix converter drives asynchronous motor, common-mode voltage u is arranged when the output current symmetry by Fig. 1 _NO:

$u_{\mathrm{NO}}=\frac{1}{3}(u_{\mathrm{AO}}+u_{\mathrm{BO}}+u_{\mathrm{CO}})---\left(3\right)$

Input current is an example in the 1st sector during with net side input unity power factor in conjunction with Fig. 2 and Fig. 3, when output voltage during in the 1st sector, calculates dual stage matrix converter at 1 T by formula (3) _SInterior u _NOAnd the regularity of distribution of maximum amplitude is as shown in table 1, as can be known 1 T _SInterior u _NOMaximum u _NO-max=U _Im, there is identical conclusion other voltage sector.With should u being arranged input current when the 2nd sector _NO-max=-U _ImSo, the u of dual stage matrix converter _NO-maxThe regularity of distribution suc as formula (4):

Table 11 T _SThe common-mode voltage regularity of distribution of interior dual stage matrix converter

Know the u of dual stage matrix converter when the input current sector is odd number from table 1 _NO-max=U _ImAppear at zero vector U ₇In time period, and zero vector U ₀ $u_{\mathrm{NO}}-\sqrt{3}/2U_{\mathrm{im}}$ Less relatively, in order to reduce u _NO-max, at inverse cascade zero vector U ₀Replace all U ₇When in like manner being even number in the electric current sector at inverse cascade zero vector U ₇Replace all U ₀, the u after can improving _NOThe maximum amplitude regularity of distribution suc as formula (5), coordinate after the control be improved dual stage matrix converter double space vector distribution map as shown in Figure 5, do not change the position of inverse cascade zero vector among Fig. 5, so the utility model in the rectification stage zero current change of current that guarantees dual stage matrix converter, can effectively reduce the common-mode voltage amplitude of dual stage matrix converter.

With the EPM1270 assistant controller electric current sector, voltage sector, duty cycle signals and the synchronizing signal of the output of TMS320LF2407 master controller are decoded, when the input current sector is odd number, at inverse cascade zero vector U ₀Replace all zero vector U ₇When the input current sector is even number, at inverse cascade zero vector U ₇Replace all zero vector U ₀, obtain rectification stage switching signal and inverse cascade switching signal respectively.

Finish the rectification stage switching signal and the inverse cascade switching signal outputs to rectification stage and inverse cascade respectively with drive circuit.

Claims (1)

1. be used to suppress the control system of common-mode voltage of dual stage matrix converter, described dual stage matrix converter is to be constituted rectification stage, constituted inverse cascade by the IPM module by bidirectional switch; The control system that it is characterized in that described dual stage matrix converter comprises voltage capturing unit, overcurrent and IPM fault detection unit, TMS320LF2407 master controller, EPM1270 assistant controller and drive circuit;

Catch the zero crossing information of net side power input voltage with described voltage capturing unit, and send into the TMS320LF2407 master controller, determining the initial phase of input voltage, and the rectification stage duty cycle signals during the unit input power factor;

Detect the instantaneous net side power supply and the overcurrent information of asynchronous motor with described overcurrent and IPM fault detection unit, and instantaneous IPM fault message, and send into the EPM1270 assistant controller;

The input current sector auxiliary information of exporting rectification stage with described TMS320LF2407 master controller is in real time judged the state of parity of sector to described EPM1270 assistant controller; The output line voltage information of given dual stage matrix converter in described TMS320LF2407 master controller, adopt rectification stage and inverse cascade duty cycle signals after the double space vector modulation method obtains coordinated control in real time, and outputing to the EPM1270 assistant controller, output voltage sector and the synchronizing signal of exporting inverse cascade simultaneously arrive the EPM1270 assistant controller;

With described EPM1270 assistant controller electric current sector, voltage sector, duty cycle signals and the synchronizing signal of the output of TMS320LF2407 master controller are decoded, when the input current sector is odd number, at inverse cascade zero vector U ₀Replace all zero vector U ₇When the input current sector is even number, replace all zero vector U with zero vector U7 at inverse cascade ₀, obtain rectification stage switching signal and inverse cascade switching signal respectively;

Finish the rectification stage switching signal and the inverse cascade switching signal outputs to rectification stage and inverse cascade respectively with described drive circuit.

Images