technical seminar - 2 nd part - emc & thd power electronics r&d 20 th february2011

TECHNICAL SEMINAR - 2 nd PART - EMC & THD POWER ELECTRONICS R&D 20 th February2011

01 Electromagnetic Compatibility (EMC) 02 Total Harmonic Distortion (THD) Index

01. ELECTROMAGNETIC COMPATIBILITY (EMC) Index > CONDUCTED NOISE > INPUT - RFI- EMC Input filter > OUTPUT - Common Mode Ferrites - dV/dt Filter - Sinusoidal/ LC Filter > INTRODUCTION > STANDARDS & REGULATIONS > Directiva OMC 2004/108/CE > IEC/EN 61800-3 > IEEE 519-1992 > COMPETITORS

01. ELECTROMAGNETIC COMPATIBILITY (EMC) Introduction EMC Electromagnetic Compatibility EMI Electromagnetic Interference EMS Electromagnetic Susceptibility Maximum Emission level Minimum Immunity level Device Immunity level Device emission level COMPATIBILITY MARGIN ENVIRONMENT CLASS Frequency spectrum Amplitude value

01. ELECTROMAGNETIC COMPATIBILITY (EMC) Introduction EMC Electromagnetic Compatibility Low frequency F Z> 150 kHz THD Flicker EMI Electromagnetic Interference EMS Electromagnetic Susceptibility Medium Frequency 150 kHz< f < 30MHz Conduced High Frequency f < 30MHz Radiated Radio Frequency Conduced Radiated Surges Electrical fast transients Electrostatic discharges THD Voltage dips and interruptions IEC61800-3 EMC 2004/108/CE IEEE 519-1992

01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Radiated & Conduced It is necessary to deal with two kind of emissions: The electric noise is produced by the inverter bridge. It is due to the interruption of the current signal when the thyristors commutate their status (switch over ON and OFF and vice versa). For this reason the electric noise is a high frequency current signal which is coupled to the current that is flowing in the drive to the motor and that additionally can be emitted.

RADIATED The RADIATED electric noise will be attenuated considering: The use of metallic conductions. The use of shielded wires. The own metallic cabinet of the drive will help to minimize this effect. NOT NEEDED 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Radiated

Noise coupled to the INPUT SIGNAL of the drive 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Input Recommended use of RFI Input Filters (Radio Frequency Interferences) as well called EMC Filters (Electro-Magnetic Compatibility). Regulation which controls the selection of these filters is UNE-EN 61800-3/A11:2002. See details on Annex I.

Noise coupled in the CURRENT FLOWING TO THE MOTOR - OUTPUT Output Common Mode Ferrites, in case of the couple noise is common mode noise, that means, noise signal coupled to the capacitances existing between the phases and the earth and also between the motor windings and the earth. This noise is the responsible of the bearing damages. Sinusoidal / LC filters, deals with the problem by converting the chopped signal into a sinusoidal signal reducing the noise. dV/dt Output Filters, in case of the coupled noise is differential noise, that means, noise signal coupled to the capacitances existing between phases. This noise will produce isolation drillings and additionally will increase the dV/dt factor. These filters can be: Output Inductance (output coils in series, one per phase) Iron Dust Toroids, in all output phases. 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Output

It is possible to observe that the output waveform of the drive is as follow: This is the result of the inverter bridge action. Show film 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Output

If the waveform is amplified, it is possible to observe that the angle is not 90 exactly: DrivedV/dtLosses 132kW800V/s1380W 132kW4000V/s1100W 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Output | dV/dt

By incrementing the dV/dt ramp is possible to reduce the drive losses, that allows to the drives to dissipate less power and consequently they can be smaller. DrivedV/dtLosses 132kW800V/s1380W 132kW4000V/s1100W The main disadvantage of this method is the appearance of brusque over-impulses in the drive output which will be higher at motor input. It is possible to check this in the measurement realized using a competitor drive: Actual measurement on competitor drive of 200A on load 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Output | dV/dt

To solve this problem, Power Electronics works over the gate resistor of the IGBTs, guaranteeing that those over-impulses do not overcome a concrete value. Actual measurement on a drive of 200A on load: COMPETITOR Rg is the gate resistor and it controls the load of the capacitor which conform the IGBT. Actual measurement on a drive of 200A on load: POWER ELECTRONICS 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Output | dV/dt

01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | CONDUCED | Output | dV/dt filter SD700 dV/dt Filter | Iron Dust Toroids

Power Electronics for 690V drives integrates the CLAMP system. 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Conduced | Output | dV/dt This circuit injects the commutation peak voltage that occurs in the IGBTs due to the inductance caused by the output cable and the motor. This system avoids IGBTs and motor damage and reduce the dv/dt filter overheat.

01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| CONDUCED | Output | Sinusoidal/LC filter L C Converts the chopped signal into a sinusoidal signal

For higher cable lengths additional filters must be used. See next pages. 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC | Competitors SUPPLIER A

DRIVE SUPPLIER A 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| Competitors

SUPPLIER A 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| Competitors

For higher cable lengths additional output chokes must be used. For further details, see next page. SUPPLIER B 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| Competitors

SUPPLIER B 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| Competitors

SUPPLIER C 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| Competitors

Input chokes (as standard) Output dV/dt filters (as standard) Electronic control of the dV/dt of the IGBT Supply Voltage400Vac (-20% to +10%) Frames1234567891011 Screened (m) 150 Unscreened (m) 300 Mechanical construction Design of PCBs Supply Voltage550Vac to 690Vac (-20% to +10%) Frames34567891011 Screened (m) 100 Unscreened (m) 200 For higher cable length contact with Power Electronics SD700 SERIES 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| SD700

Admissible Peak voltage limit curves in AC motors terminals: 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| SD700

One sample of the tests to the SD700. 01. ELECTROMAGNETIC COMPATIBILITY (EMC) OMC| SD700

01. ELECTROMAGNETIC COMPATIBILITY (EMC) Standards & Regulations IEC61800-3 The CE certification for Variable Speed Drive requires compliance with directive : EMC 2004/108/CE IEC61800-3 compliance

WHERE? Classifying CriteriaApplication Limit First environment Non restricted distributionC1 Restricted distributionC2 Second environment Input current 100A C3 Input current > 100AC4 First Environment: Includes domestic or residential use. It includes also, places directly connected, without intermediate transformers, to a power supply distribution system of low energy which additionally gives supply to buildings used for domestic uses (cinemas, theatres, shopping centres, hospitals,). Second Environment: (Named also industrial). It includes all places different from those which are directly connected to a power supply distribution system of low energy which additionally gives supply to buildings used for domestic uses (factories and facilities supplied with transformer of medium voltage to low voltage). 01. ELECTROMAGNETIC COMPATIBILITY (EMC) Standards & Regulations | 61800-3 IEC61800-3/A11

WHERE? Classifying CriteriaApplication Limit First environment Non restricted distributionC1 Restricted distributionC2 Second environment Input current 100A C3 Input current > 100AC4 Non-Restricted Distribution: Marketing modality where the power supply of the drive does not depend on the customer or user regarding to EMC issues for the application of operation. Restricted Distribution: Marketing modality where the manufacturer limits the supplying of the drive to those customers or users which, in an independent or together way, have technical competence on the EMC requirements for the application of operation. IEC61800-3/A11 01. ELECTROMAGNETIC COMPATIBILITY (EMC) Standards & Regulations | 61800-3

EMC PLAN I < 100A I > 100A RADIATED 01. ELECTROMAGNETIC COMPATIBILITY (EMC) Standards & Regulations | 61800-3 CONDUCTED C1 C2 C4C3 1 st Environment 2 nd Environment Quasi pick value Average value

01 Electromagnetic Compatibility (EMC) 02 Total Harmonic Distortion (THD) Index

> Basic principles > Measurement > Effects > Standards & Regulations > Solutions - Passive Filters - FREEMAQ - Active Filters - Multipulses drives > Competitors TOTAL HARMONIC DISTORTION 02 TOTAL HARMONIC DISTORTION Index

02 TOTAL HARMONIC DISTORTION Basic Principles | What is the Harmonic Distortion? It can be demonstrate that any periodic waveform (squared, triangular, ) can be represented as the sum of several sinusoidal waves with different frequencies and phases. All those waves constitute the harmonic spectrum of the wave.

02 TOTAL HARMONIC DISTORTION Basic Principles | What is the Harmonic Distortion? If g 50Hz or 60 Hz If 5rd 5 f g If 7th 7 f g I T = I 1 + I 5 ..+I n

Wave Fourier Transform THDi Value 02 TOTAL HARMONIC DISTORTION Meassurement

In variable speed drives applications both the harmonic current distortion and the harmonic voltage distortion are of interest. The harmonic current and voltage distortion have different effects on the power system and it is therefore important to separate them. The harmonic current distortion is caused by the rectifier part of the variable speed drive, typically a 6-pulse diode rectifier. The harmonic currents can be described as a reactive current adding to the active current. Consequently the harmonic current distortion is increasing the RMS current and if not taking into account can result in overheating of components such as the supply transformer or cables. The amount of harmonic current distortion is often described in percent of the fundamental current also known as the total harmonic current distortion (THID). 02 TOTAL HARMONIC DISTORTION Meassurement

The harmonic current is normally flowing from the harmonic current generator (e.g. the diode rectifier) into the mains. The voltage drop caused by the harmonic currents over the supply impedance causes then the harmonic voltage distortion. I.e. the harmonic voltage distortion is a product of the harmonic current distortion and the supply impedance, where a grid with the largest impedance yields the highest voltage distortion. The harmonic voltage distortion can interfere with equipment connected to the same line such as direct on-line motors or electronic equipment and eventually cause this equipment to fail. The amount of harmonic voltage distortion is often described in percent of the fundamental voltage also known as the total harmonic voltage distortion (THVD). 02 TOTAL HARMONIC DISTORTION Meassurement

1) Electrical Grid and Power Transformer overload and heating. 2) Reduction of the Motor Efficiency, non sinusoidal waveforms increases internal heating lost. 3) Resonance effects and power capacitors banks overload, the power factor corrections systems do not work properly increasing the energy bill. 4) Electronic and computers underperformance. Low consumption and single phase devices could be affected and do not work properly. 02 TOTAL HARMONIC DISTORTION Effects

The legislation applicable for drives is that described in the international regulation IEC61800- 3. Included in that general regulation, there are some others regulations which refer to harmonics such us IEC61000-2-4 (Class 3: THD=10%) or IEC61000-2-2 (THD=8%) Literal description extracted from regulation IEC61800-3: The immunity levels used for the design regarding the THD of voltage and the individual harmonics orders will be as minimum equal to the permanent compatibility levels at the IEC61000-2-2 (class 3: THD=10%) or IEC61000-2-4 (THD=8%), for those situations in permanent service. For transient situations (duration less than 15 seconds), the immunity levels used for the design will be minimum 1.5 times the permanent levels. 02 TOTAL HARMONIC DISTORTION Standards & Regulations

NORMSDESCRIPTION IEC61000-2-4 The norm establishes the electromagnetic compatibility levels for low frequency conducted distortions at industrial installations. IEC61000-2-2 The norm establishes the electromagnetic compatibility levels for low frequency distortions at public low voltage supply systems. IEC61000-2-12 The norm established the electromagnetic compatibility levels for low frequency distortions at public medium voltage supply systems. 02 TOTAL HARMONIC DISTORTION Standards & Regulations

This regulation refers to conducted distortions at frequency ranges from 0kHz to 9kHz. It establishes the numeric values of compatibility levels for industrial supply distribution systems and no publics at nominal voltages up to 35kV and nominal frequencies of 50Hz or 60Hz. ELECTROMAGNETIC ENVIRONMENT CLASSES CLASS 1 To protected distribution systems and has compatibility levels lower than the public power supply systems. It is related to the use of the equipments very sensible to the supply distribution distortions, as the electric instruments of technological laboratories, some kind of automatic equipments and protection equipments, some computers, etc CLASS 2 This class is generally applied to PCC and PCI in industrial supply distribution systems and some others no public supply systems. The compatibility levels are generally identical to the corresponding to public supply systems. For that reason, the equipments (in our case the VSD) designed to be used in public power supply systems could also be used in this class in industrial environment CLASS 3 This class is applicable only for PCI at industrial environment. There should be considered under the following conditions: Most par of the load is supplied with converters, there are welding machines, the big motors are often started, the load varies quickly. 02 TOTAL HARMONIC DISTORTION Standards & Regulations | IEC61000-2 -4

Compatibility levels for Total Harmonic Distortions CLASS 1CLASS 2CLASS 3 Total Harmonic Distortion (THD) 5%8%10% Note: In case of one part of the power supply system is used for important non linear loads, the compatibility levels of class 3 for this par of the supply distribution could be 1,2 times the above mentioned values. Then it is necessary to take caution for those equipments there connected. Nevertheless, in the CCP (public supply distribution system) the values offered in norms IEC61000-2-2 and IEC61000-2-12 will prevail. 02 TOTAL HARMONIC DISTORTION Standards & Regulations | IEC61000-2 -4

This norm refers to the conducted distortions in the frequency range from 0kHz to 9kHz, with amplified option to 148kHz for signals transmission system to the supply distribution system. These numerical values are offered for compatibility levels in case of public supply distribution system of low voltage with nominal voltage of 420V single-phase or 690V 3-phase and nominal frequency of 50Hz or 60Hz. Compatibility levels for individual harmonics voltages in low voltage distribution systems. Odd harmonics not multiple of 3 Odd harmonics multiple of 3 (note) Even harmonics Order of harmonic (h) Voltage of harmonic (%) Order of harmonic (h) Voltage of harmonic (%) Order of harmonic (h) Voltage of harmonic (%) 563522 7591,541 113,5150,460,5 133210,380,5 17 h 492,27 x (17/h)-0,2721 h 450,210 h 500,25 x (10/h)+0,25 Note: The levels indicated through odd harmonics multiples of three are applied to the homopolar harmonics. So this, in a 3-phase distribution line without neutral cable with no load connected between a phase and ground, the value of the harmonics order 3 and 9 can be lower enough than compatibility levels, depending on the distribution line imbalance. 02 TOTAL HARMONIC DISTORTION Standards & Regulations | IEC61000-2-2

This norm refers to the conducted distortions in the frequency range from 0kHz to 9kHz, with amplified option to 148,5kHz for signals transmission system to the supply distribution system. These numerical values are offered for compatibility levels in case of public supply distribution system of low voltage with nominal voltage between 1kV and 35kV and nominal frequency of 50Hz or 60Hz. The compatibility levels are specified for electromagnetic distortion of those types that can be expected in the public power supply distribution systems of medium voltage, with the target of helping to define the following: a)The limits to be established for distortions emissions (in our case of study, harmonics) in the public power supply distribution systems. b)The immunity limits to be established by products committees or for other devices which support conducted emissions in the public power supply distribution lines. The medium voltage systems covered by this norm are public power supply distribution systems that supply to: a)Particular installations where devices are connected directly or through transformers. b)Sub-stations that supply to low voltage public power supply distribution lines. 02 TOTAL HARMONIC DISTORTION Standards & Regulations | IEC61000-2-12

Compatibility levels for individual harmonic voltages in distribution lines of medium voltage. Odd harmonic not multiples of 3 Odd harmonics multiples of 3 (note) Even harmonics Harmonic order (h) Harmonic voltage (%) Harmonic order (h) Harmonic voltage (%) Harmonic order (h) Harmonic voltage (%) 563522 7591,541 113,5150,460,5 133210,380,5 17 h 492,27 x (17/h)-0,2721 h 450,210 h 500,25 x (10/h)+0,25 Note: The levels indicated through even harmonics multiples of three are applied to the homopolar harmonics. So this, in a 3-phase distribution line without neutral cable with no load connected between a phase and ground, the value of the harmonics order 3 and 9 can be lower enough than compatibility levels, depending on the distribution line imbalance. 02 TOTAL HARMONIC DISTORTION Standards & Regulations | IEC61000-2-12

SUMMARY It is necessary to clarify that in order to fulfill standard regulations, it is required to fulfil the following norms:IEC61000-2-2, IEC61000-2-4 or IEC61000-2-12 depending on the location where the equipments are connected. If those regulations above mentioned are fulfilled and the THD values in current are above the specified ones in document IEEE-519, then it is possible to state that both the installation and the equipments are have compliance with the norms. Special applications General system Dedicated system THD (voltage) 3%5%10% Maximum harmonic current distortion Order of each harmonic Isc/IL

PASSIVE FILTERS Input Coils - Choke Inductances Passive 5 th & 7 th Notch Filter HIGH INPUT IMPEDANCE NOTCH FILTER Low Harmonic FREEMAQ ACTIVE FILTERS. Controller bridge rectifier - Active filter VSD Active Front End MULTIPULSES DRIVES Low voltage 12, 18, 24 pulses drives Medium Voltage Multipulse Drive 02 TOTAL HARMONIC DISTORTION Solutions

These passive filters can be placed in the rectifier bridge input, realizing a double mission: First of all, they protect to the rectifier from voltage variation of the mains. On the other hand, they filter the produced harmonics making softer the sinusoidal wave of current. SD700 Frame 1 & 2 SD700 Frames 3 on They can also be placed in the DC bus. The rectifier bridge will not be as protected as in the previous configuration, but this is always a low cost option. Passive Filter Input Coils Choque Inductances 02 TOTAL HARMONIC DISTORTION Solutions | Passive filter

Zg L1 C1 1) LC Filters designed for an Specific Harmonic and Grid Impedance ( Zg) 2) Variation on Zg Increase THDi 3) Variation on Zg May cause Resonance 4) Valid for original installations, not compatible with new Grid Loads f 5th f 7th 1 st 5 th 7 th 1 st 5 th 7 th Grid Impedance (Zg) Variation L2 C2 02 TOTAL HARMONIC DISTORTION Solutions | Passive filter | 5th & 7th Notch Filter)

Zg L1 C1 L2 L3 1) LCL Filters designed for General Harmonic attenuation and Independent from the Grid Impedance ( Zg) 2) Variation on Zg Do NOT affect to THDi. Z L1 >> Zg 3) Built in with robust electric components 4) Never cause resonance 1 st 5 th 7 th 02 TOTAL HARMONIC DISTORTION Solutions | Low Harmonics FREEMAQ

Zg C1 L1 L2 CONTROLLED BRIDGE RECTIFIER 1) Works as a Current source. 2) LCL Filter in Parallel. 3) Smaller size of L1 and L2, designed for switching frequency. 4) Built in with Semiconductors and control software - reduce robustness 02 TOTAL HARMONIC DISTORTION Solutions | Active Filter - Controller bridge rectifier -(AAF)

Zg L1 C1 L2 1) Regenerates the braking energy 4 quadrants drive. Increase the overall efficiency 2) Serie LCL Filter 3) Smaller size of L1 and L2, designed for switching frequency. 4) Built in with Semiconductors and control software - reduce robustness 02 TOTAL HARMONIC DISTORTION Solutions | Active Filter | VSD Active Front End (AFE)

The 12, 18, 24 pulses drive have two, three or four rectifier bridges and the input voltage of each rectifier bridge is 30 / 15 / 7,5 diphase each other PULSESTHDi (%) 6 < 40 % 12 < 15 % 18 < 9 % 24 < 5% To do that, it is needed a special transformer with multiple secondary windings is required. 02 TOTAL HARMONIC DISTORTION Solutions | Active Filter | Multipulses

12 PULSES ELECTRIC SCHEME 02 TOTAL HARMONIC DISTORTION Solutions | Active Filter | Multipulses

12 PULSES RECTIFYING BRIDGE We can suppose a quasi ideal system applied to the rectifier, considering squared wave signal as reference. Having into consideration that the double secondary, explained before, enters a 30 phase shift in the currents applied to each rectifier, the result is a waveform much more sinusoidal in the inverter bridge: 02 TOTAL HARMONIC DISTORTION Solutions | Active Filter | Multipulses

(*): Depending on the Grid Impedance Zg. Notch filter Re-design for grid load changes. FILTER TECHNOLOGY LOAD 60% LOAD 75% LOAD 100% Passive 5th & 7th Notch Filter 7% (*) 6% (*) 5% (*) Low Harmonic FREEMAQ 6.5%5%5% Active Filter 10%8%5% VSD Active Front End 10%8%5% 02 TOTAL HARMONIC DISTORTION Solutions | THDi variation with load

FILTER TECHNOLOGY LOAD 60% LOAD 75% LOAD 100% Passive 5th & 7th Notch Filter 96.5 97 97.5 Low Harmonic FREEMAQ 96.5 97 Active Filter 96.5 97 VSD Active Front End 96 96.5 97 02 TOTAL HARMONIC DISTORTION Solutions | Efficiency variation with load

XMV660 is multi-cell VFD with series multi-cell VFD with series-connect units, high voltage input, high voltage output. VFD is composed of transformer, power cells and control system. Communication between power cells and control system is performed by optic fibre that can handle the problem of separation between heavy current and light current as well as electric magnetic harassment. 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Each power cell is AC-DC-AC voltage source and low voltage transformer with 3-phase input, single phase output. The rectifying side of power cell is rectified by diode 3-phase full bridge in the mode of not-controllable full wave. Electrolytic capacitor is used to filter wave and store energy in the middle, the output side is formed by 4 pieces of IGB in the form of H bridge. Diode does not control rectification, power factor of single power cell is 0.97. Capacitor can buffer power supply impact. Equipment can keep on working in case of insufficient voltage or power off within short time. Structure and power cell working principle 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

At any moment, there are 3 types of possible output voltage. If A+ is on with B-, the output voltage from U to V is +Ud, if B+ is on with A, output voltage from U to V is Ud, if A+ is on with B+ or A- is on with B-, output voltage from U to V is 0V. In the end, equal amplitude PWM wave form can be obtained from U, V output terminal through control on/off on the IGBT A+ A- B+ B-. Control over Output Voltage of Power Cell 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Frequency of output voltage of power cell is changed by altering the cycled period between positive voltage and negative voltage of PWM wave form. Size of AC basic wave of output voltage from the power cell is changed by altering duty ratio between positive and negative voltage of PWM wave form. Forma de onda salida PWM durante Frecuencia de Alta Conmutacin Forma de onda de salida PWM durante Frecuencia de Baja Conmutacin Frequency and Voltage Varying principle of Power Cell 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Output of neighboring power cells are connected in series in Y form, which can realize high voltage output. Each power cell undertakes 1/n phase voltage, 100% motor current, 1/3n output efficiency. For 6KV VFD, if 5 steps in each phase are connected in series, each power cell can output 693V, phase voltage is 3464V, wire voltage is 6000V. Unit DC Bus voltage is lower than 980V. IGBT resisting 1700V can be adopted. Output Connection of Power Cell 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

En cualquier momento, la tensin de salida que cada clula puede ofrecer es: Tensin= +600V en caso de que Q1 y Q4 estn en ON. Tensin= -600V en caso de que Q2 y Q3 estn en ON. Tensin= 0V en caso de que Q1 y Q3 estn en ON si Q2 y Q4 estn en ON. Q1 Q2 Q3 Q4 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Detail Level 1 : Power cell A2 offers 600V at the output, power cells A1 and A3 offer 0V. Therefore, the voltage is +600V. Multi-level Signal Generation 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Multi-level Signal Generation Detail Level 2: Power cells A1 and A3 offer 600V at the output, power cell A2 offers 0V. Therefore, the voltage is +1200V.. 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Multi-level Signal Generation Detail Level 3: The three power cells A1, A2 and A3 offer 600V at the output each one. Therefore, the voltage is +1800V.. 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Power cell in the same phase outputs basic wave voltage with the same amplitude and phase position. But the carrier wave of serial connected cells are separated at certain electric angle. Phase shifting of triangle carrier wave is 360 /n electric angle of carrier wave. Producing mechanism of Multi-cell and Phase-shifting PWM 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

Wave form of phase voltage and wire voltage (take 3 grade as example). As for n grade system, there are 2n+1 cells in the phase voltage and 4n+1 cells in the wire voltage. If the modulating frequency of power cell is f, the equivalent on/off frequency of output wire voltage is 2nf. The on/off frequency of IGBT is smaller (the on/off loss is also small), the equivalent on/off frequency of output is very high. As there is wave filtration of induction in the motor, current content of output harmonic is very low. Phase Voltage and wire Voltage of Multi-cell Phase shifting Output 02 TOTAL HARMONIC DISTORTION Solutions | Multipulses | MV

SUPPLIER A 1.DC CHOKES. 38% of drives standard built in 62% of drives external option 2.LINE CHOKES. 100% of drives external option DRIVE OTHER SUPPLIER 02 TOTAL HARMONIC DISTORTION Competitors

SUPPLIER B 1.DC CHOKES. 100% of drives external option 2.LINE CHOKES. 100% of drives external option 02 TOTAL HARMONIC DISTORTION Competitors

FILTER SUPPLIER C 1.DC CHOKES. 100% of drives external option 2.LINE CHOKES. 100% of drives external option 02 TOTAL HARMONIC DISTORTION Competitors

technical seminar - 2 nd part - emc & thd power electronics r&d 20 th february2011

Documents

noise signal

coupled noise

noise input rfi

radiated electric noise

common mode noise

couple noise

input signal

radiated radio frequency