New! View global litigation for patent families

USRE37126E1 - Multilevel cascade voltage source inverter with seperate DC sources - Google Patents

Multilevel cascade voltage source inverter with seperate DC sources Download PDF

Info

Publication number
USRE37126E1
USRE37126E1 US09167287 US16728798A USRE37126E US RE37126 E1 USRE37126 E1 US RE37126E1 US 09167287 US09167287 US 09167287 US 16728798 A US16728798 A US 16728798A US RE37126 E USRE37126 E US RE37126E
Authority
US
Grant status
Grant
Patent type
Prior art keywords
inverter
voltage
phase
dc
cascade
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US09167287
Inventor
Fang Zheng Peng
Jih-Sheng Lai
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lockheed Martin Energy Systems Inc
Original Assignee
Lockheed Martin Energy Systems Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date

Links

Images

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483Converters with outputs that each can have more than two voltages levels
    • H02M7/49Combination of the output voltage waveforms of a plurality of converters
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18Arrangements for adjusting, eliminating, or compensating reactive power in networks
    • H02J3/1821Arrangements for adjusting, eliminating, or compensating reactive power in networks using shunt compensators
    • H02J3/1835Arrangements for adjusting, eliminating, or compensating reactive power in networks using shunt compensators with stepless control
    • H02J3/1842Arrangements for adjusting, eliminating, or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
    • H02J3/1857Arrangements for adjusting, eliminating, or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters wherein such bridge converter is a multilevel converter
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/483Converters with outputs that each can have more than two voltages levels
    • H02M2007/4835Converters with outputs that each can have more than two voltages levels comprising a plurality of cells, each including a switchable capacitor, the capacitors having a nominal charge voltage which corresponds to a given fraction of the input voltage, the capacitors being selectively connected in series to determine the instantaneous output voltage
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GASES [GHG] EMISSION, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy
    • Y02E10/56Power conversion electric or electronic aspects
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GASES [GHG] EMISSION, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/10Flexible AC transmission systems [FACTS]
    • Y02E40/12Static VAR compensators [SVC], static VAR generators [SVG] or static VAR systems [SVS], including thyristor-controlled reactors [TCR], thyristor-switched reactors [TSR] or thyristor-switched capacitors [TSC]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GASES [GHG] EMISSION, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/20Active power filtering [APF]
    • Y02E40/26Active power filtering [APF] using a multilevel or multicell converter

Abstract

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

Description

This application is a RE of 08/527,995, filed on Sep. 14, 1995, now U.S. Pat. No. 5,642,275.

This invention was made with Government support under contract DE-AC05-84OR21400 awarded by the U.S. Department of Energy to Lockheed Martin Energy Systems, Inc. and the Government has certain rights in this invention.

FIELD OF THE INVENTION

The present invention relates to a multilevel voltage source inverter with separate DC sources, and more particularly to a multilevel voltage source inverter with separate DC sources including an apparatus and a method for use in flexible AC transmission system (FACTS) applications such as compensating reactive power and voltage balancing.

BACKGROUND

With long distance electrical power transmission and load growth, active control of reactive power (VAR) is indispensable with regard to stabilizing power systems and maintaining supply voltages. Static VAR generators (SVGs) using voltage-source inverters have been widely accepted as the next generation of reactive power controllers for power systems replacing conventional VAR compensators such as Thyristor Switched Capacitors (TSCs) and Thyristor Controlled Reactors (TCRs).

Delivering power from a power generating station to the ultimate power consumers over long transmission lines can be very costly for an electric utility. The electric utility passes on these costs to the ultimate consumers as higher electricity bills. Inductive and capacitive losses affect a reactive component of power which is measured in volt-ampere-reactive (VAR) units. These reactive power (VAR) losses may be compensated using a static VAR compensator to more economically transmit thereby reducing overall electricity bills as well as stabilizing the supplied voltage to the end user.

The state of the art VAR compensating approach uses transformer coupling voltage source inverters. A transformer coupling voltage source inverter comprising eight six-pulse converters connected in either a zig-zag, wye or delta configuration has a 48-pulse or a 48-step staircase inverter output voltage waveform which dramatically reduces harmonics. The major problem of using this transformer coupling approach resides in the transformer as a function of harmonic neutralizing magnetics. The transformer with the inherent harmonic neutralizing magnetics deficiency:

(a) is the most expensive equipment in the system;

(b) produces approximately 50% of the total system losses;

(c) occupies approximately 40% of the system layout; and

(d) causes difficulties in system control due to DC magnetizing and surge overvoltage problems resulting from saturation of the transformers on the transient state.

In recent years, a relatively new type of inverter, a multilevel voltage source inverter, has attracted the attention of many researchers. The transformerless multilevel inverter can reach high voltage and minimize induced harmonics as a function of inverter structure.

A multilevel, referred to as M-level, diode clamped inverter can reach high performance without the benefit of transformers. This inverter does, however, require the implementation of additional clamping diodes. The number of diodes required is equal to (M−1)*(M−2)*3 for an M-level inverter. For example, if M=51, for direct connection to a 69 kV power system, then the number of required clamping diodes will be 7350. These clamping diodes not only increase the cost of the system but also cause packaging/layout problems and introduce parasitic inductances into the system. Thus, for practicality, the number of levels of a conventional multilevel diode clamped inverter is typically limited to seven or nine levels.

A relatively new inverter structure, the multilevel flying capacitor inverter has the capability to solve the voltage balance problems and aforementioned problems associated with the multilevel diode clamped inverters. The required number of flying capacitors for an M-level inverter, provided that the voltage rating of each capacitor used is the same as the main power switches is determined by the formula, (M−1)*(M−2)*3/2+(M−1). Using the assumption of having capacitors with the same voltage rating, an M-level diode clamped inverter requires only (M−1) capacitors. Therefore, the flying capacitor inverter requires capacitors of substantial size compared with the conventional inverter. In addition, control is very complicated and higher switching frequency is required to balance the voltages between each capacitor in the inverter.

A multilevel cascade inverter with separate DC sources for reactive power compensation in AC power systems which is directed toward overcoming and is not susceptible to the above limitations and disadvantages is described herein. The multilevel voltage source inverter having separate DC sources eliminates the excessively large number of transformers required by conventional multipulse inverters, clamping diodes required by multilevel diode-clamped inverters and flying capacitors required by multilevel flying-capacitor inverters. The multilevel voltage source inverter having separate DC sources also has the following features:

(a) the multilevel voltage source inverter having separate DC sources is more suitable to high voltage, high power applications than conventional inverters;

(b) the multilevel voltage source inverter having separate DC sources generates a multistep staircase voltage waveform with the switching of each device only once per line cycle, thus reaching a nearly sinusoidal output voltage approximation by increasing the number of voltage levels;

(c) since the multilevel voltage source inverter having separate DC sources consists of cascade connections of a plurality of single-phase full bridge inverters fed with a separate DC source, neither voltage balancing nor voltage matching of switching devices is required; and

(d) system packaging and layout is streamlined due to the simplicity and symmetry of structure as well as the minimization of component count.

Thus, a need for a multilevel cascade voltage source inverter with separate DC sources for reactive power compensation in AC power systems is clearly evident.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the present invention to provide a new and improved multilevel cascade voltage source inverter and more specifically a multilevel cascade voltage source inverter for connecting to an AC high voltage, high power system.

It is another object to provide a wye configured multilevel voltage source inverter for FACTS applications such as VAR compensation and voltage balancing of AC power systems.

It is another object to provide a delta configured multilevel voltage source inverter for FACTS applications such as VAR compensation and voltage balancing of AC power systems.

It is another object to provide a multilevel voltage source inverter for connecting to an AC high voltage, high power system for a variety of applications such as fuel cells, photovoltaic utility interface systems.

It is another object to provide a method for controlling the multilevel voltage source inverter to supply a sinusoidal approximation power waveform to an AC high voltage, high power system for a variety of applications from a plurality of DC voltage sources.

Further and other objects of the present invention will become apparent from the description contained herein.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a multiple voltage source inverter for connecting to an AC power system comprising a plurality of full bridge inverters having a primary node and a secondary node, each of the full bridge inverters having a positive node and a negative node, each of the full bridge inverters having a voltage supporting device electrically connected in a parallel relationship between the positive node and the negative node; at least one cascade inverter phase, each of the cascade inverter phases having a plurality of the full bridge inverters, each of the cascade inverter phases having a consistent number of the full bridge inverters with respect to each phase, each of the full bridge inverters in each cascade inverter phase interconnected in a series relationship with the secondary node of one of the full bridge inverters connected to the primary node of another full bridge inverter, the series interconnection defining a first full bridge inverter and a last full bridge inverter, each of the phases having an input node at the primary node of the first full bridge inverter and an output node at the secondary node of the last full bridge inverter; a control means connected in an operable relationship with each of the full bridge inverters to emit a square wave signal for a prescribed period therefrom; whereby, a nearly sinusoidal voltage waveform approximation is generated by the controlled, alternate activation and deactivation of the full bridge inverters by the control means.

This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting, voltage balancing, and fuel cell and photovoltaic utility interface systems.

In accordance with another aspect of the present invention, the multiple voltage source inverter may be configured in either a wye-connected or a delta-connected embodiment to address the requirements of multiple phase systems.

Yet another aspect of the present invention provides a method for inverting a plurality of DC voltage signals to approximate a sinusoidal voltage waveform comprising the steps of detecting the DC voltage levels of a plurality of DC voltage sources; averaging the DC voltage levels; comparing the average with a reference DC voltage; generating a first error signal from the comparison of the average with a reference DC voltage; comparing the average with the detected DC voltage levels; generating a second error signal from the comparison of the average with the detected DC voltage levels; generating a phase shift offset signal from the second error signal; generating an average phase shift signal from the first error signal; summing the phase shift offset signal and the average phase shift signal; detecting an AC line voltage having a period; generating a phase reference signal directly related to the period of the AC line voltage; generating a plurality of firing reference signals for a plurality of full bridge inverters using the phase reference signal and the sum of the phase shift offset signal and the average phase shift signal; determining a modulation index; providing a reference table for the modulation index; generating a plurality of firing angle signals for the plurality of full bridge inverters using the firing reference signal and the reference table; whereby, the alternate activation of a plurality of gate turnoff devices in the full bridge inverters may be controlled to construct an output voltage waveform having a sinusoidal approximation for use by an AC load.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawing:

FIG. 1 is a schematic representation of a full bridge inverter.

FIG. 2 is a schematic representation of the single-phase embodiment of the multilevel DC voltage source inverter.

FIG. 3 is a graphical representation of the output voltage waveforms with respect to the input signals, vC1, vC2, vC3 and vC4.

FIG. 4 is a schematic representation of the multiphase wye connected embodiment of the multilevel voltage source inverter.

FIG. 5 is a schematic representation of the multiphase delta connected embodiment of the multilevel voltage source inverter.

FIG. 6 is a control block diagram of a static VAR generatorcompensation system employing a three-phase multilevel cascade inverter having separate DC sources.

FIG. 7a is a waveform representation wherein vS is the source voltage, iC is the current flowing into the inverter and vC is the inverter output voltage of the multilevel voltage source inverter used with the control system of FIG. 6.

FIG. 7b is a waverform representation wherein vCi is the input wavform, shifted ahead by ΔαCi, a full bridge inverter of the multilevel voltage source inverter used with the control system of FIG. 6.

FIG. 8 contains the experimental voltage waveforms showing the phase voltage results of the inverter and the line current waveform in the system of FIG. 6 at +1 kVAR output.

FIG. 9 contains the experimental voltage waveforms showing the phase voltages of the AC source and of the inverter and the line current waveform in the system of FIG. 6 at +1 kVAR output.

FIG. 10 contains the experimental voltage waveforms showing the line-to-line voltages of the AC source and of the inverter and the line current waveform of in the system of FIG. 6 at +1 kVAR output.

FIG. 11 contains the experimental voltage waveforms showing the phase voltages of the inverter and the line current in the system of FIG. 6 at 0 kVAR output.

FIG. 12 contains the experimental voltage waveforms showing the phase voltages of the inverter and the line current in the system of FIG. 6 at −1 kVAR output.

FIG. 13 contains the experimental voltage waveforms showing the line-to-line voltages of the AC source and the inverter and the line current in the system of FIG. 6 at −1 kVAR output.

FIG. 14 is a block diagram of a typical application of a multiphase, multilevel cascade inverter with separate DC sources connected to an AC load.

For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the above-described drawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in detail to the drawings wherein like parts are designated by like reference numerals throughout, there is illustrated in FIG. 1 a schematic representation showing the primary building block of the preferred embodiment of the apparatus of the present invention, a single-phase, full-bridge inverter (FBI) unit 50. A FBI unit comprises a primary node 1 and a secondary node 2 and an inverting means therebetween. The inverting means comprises four switching means further comprising gate turn-off devices 10, 20, 30 and 40 and anti-parallel diodes 15, 25, 35 and 45 connected in an operable, oppositely biased, parallel relationship by conductors 17, 18, 27, 28, 37, 38, 47 and 48, respectively. The gate turn-off devices may be any of the components capable of switching such as gate turn-off thyristors, insulated gate bipolar transistors, power MOSFETs, MOSFET controlled thyristors, bipolar junction transistors, static induction transistors, static induction thyristors or MOSFET turn-off thyristors. The first switching means is connected to the second switching means by conductors 22 and 24 through positive node 26. The second and third switching means are connected by conductors 23 and 33 through secondary node 2. The third and fourth switching means are connected by conductors 32 and 34 through negative node 36. The first and fourth switching means are connected by conductors 11 and 12 through primary node 1. A voltage supporting device 5, most commonly a capacitor, is connected between positive node 26 and negative node 36 by conductors 6 and 7, respectively. The voltage supporting device 5 may be any device, such as a DC voltage source or a capacitor, capable of maintaining a DC voltage for a sufficient period of time.

The FBI unit 50 can generate three level outputs; +VDC, 0 and −VDC at the respective primary node 1. This is permitted by connecting the DC source 5 to the AC side of the FBI unit 50 via the four switching devices 10, 20, 30 and 40. Each switching device 10, 20, 30 and 40 is switched, wherein switching is defined by the activation and deactivation of the respective switching device, only once per power line cycle in an alternating fashion commonly known to one of ordinary skill in the art to produce the +VDC, 0 and −VDC output voltages across the primary node 1 and the secondary node 2. The switching action is generally controlled by an external control means using either analog or digital control signals in a manner commonly known to one of ordinary skill in the art.

SINGLE-PHASE EMBODIMENT

FIG. 2 shows the single-phase embodiment 100 of the multilevel cascade inverter having separate DC voltage sources. The single-phase embodiment 100 comprises n FBI units 60, 70, 80 and 90 wherein n is determined by: n = ( M - 1 ) 2 ( Eq . 1 )

Figure USRE037126-20010403-M00001

wherein M is the number of output voltage levels generated by the multilevel cascade inverter during a half fundamental cycle.

FBI units 60 and 70 are interconnected between primary node 75 and secondary node 66 by conductor 51. FBI units 70 and 80 are interconnected between primary node 85 and secondary node 76 by conductor 52. FBI units 80 and 90 are interconnected between primary node 95 and secondary node 86 by conductor 53. The primary node 65 of the first FBI unit 60 in the multilevel cascade inverter functions as the output of the cascade inverter single-phase embodiment 100. The secondary node 96 of the last FBI unit 90 in the multilevel cascade inverter functions as the reference of the cascade inverter single-phase embodiment 100. The FBI units are provided with separate DC voltage sources 63, 73, 83 and 93.

The schematic represented in FIG. 2 shows the M level, single phase cascade inverter 100 wherein M=9. FIG. 3 shows the waveform response of the circuit shown in FIG. 2 wherein a DC voltage input was injected by independent voltage sources 63, 73, 83 and 93. The waveform vCp is measured between node 65 and node 96 using the output waveforms shown as vC1, vC2, vC3 and vC4, injected by 60, 70, 80 and 90, respectively. It is obvious to one of ordinary skill in the relevant art that vCp as shown in FIG. 3 with reference to vCn may be accurately described by: v Cp = v C1 + v C2 + v C3 + v C4 ( Eq . 2 )

Figure USRE037126-20010403-M00002

wherein vC1, vC2, vC3 and vC4 are the respective voltage output levels of the each FBI unit in the single phase cascade inverter 100 as shown in FIG. 2.

THREE-PHASE, WYE CONNECTED EMBODIMENT

FIG. 4 shows the three-phase, wye connected embodiment 250 of the multilevel cascade inverter having separate DC voltage sources. The wye connected embodiment 250 comprises three distinct phases 110, 160 and 210, each phase having a multilevel cascade inverter comprising a plurality of FBI units. Each multilevel cascade is constructed as previously described in the single-phase embodiment discussion. The primary nodes 115, 165 and 215 of the first FBI units 120, 170 and 220 in each phase of the multilevel cascade is the phase output for each of the respective phases 110, 160 and 210. The secondary nodes 125, 175 and 225 of the last FBI units 130, 180 and 230 in each phase of the multilevel cascade are electrically connected to create a common node 200 therebetween.

The operative aspects of the three-phase, wye connected embodiment of the multilevel cascade inverter having separate DC sources are identical to the single-phase embodiment as previously discussed.

THREE-PHASE, DELTA CONNECTED EMBODIMENT

FIG. 5 shows the three-phase, delta connected embodiment 400 of the multilevel cascade inverter having separate DC voltage sources. The delta connected embodiment 400 comprises three distinct phases 260, 310 and 360, each phase having a multilevel cascade inverter comprising a plurality of FBI units. Each multilevel cascade is constructed as previously described in the single-phase embodiment. The primary nodes 265, 315 and 365 of the first FBI units 270, 320 and 370 in each phase of the multilevel cascade is the phase output for the respective phases 260, 310 and 360. The primary node 265 of FBI unit 270 is electrically connected to the secondary node 375 of the FBI unit 380 by conductor 285. The primary node 315 of FBI unit 320 is electrically connected to the secondary node 275 of the FBI unit 280 by conductor 290. The primary node 365 of FBI unit 370 is electrically connected to the secondary node 325 of the FBI unit 330 by conductor 295.

The operative aspects of the three-phase, delta connected embodiment of the multilevel cascade inverter having separate DC sources are identical to the single-phase embodiment as previously discussed.

SYSTEM CONFIGURATION AND CONTROL SCHEME FOR SVGs

FIG. 6 shows a control block diagram of a SVG 405 employing a three-phase multilevel cascade inverter 410 having separate DC sources as described herein. In FIG. 6, vs represents the source voltage, Ls the source impedance and LC the inverter interface impedance, respectively. The multilevel cascade inverter discussed in this example will be the inverter previously discussed for the multilevel, wye connected embodiment 250. Variations therefrom utilizing other embodiments previously discussed will be obvious to one of ordinary skill in the relevant art. The switching pattern table 415 contains switching timing data for the multilevel cascade inverter 410 to generate the desired phase output voltage as shown in FIG. 3. The switching angles, θi, where i=1, 2, (M−1)/2, are calculated off-line by conventional methods to minimize harmonics for each modulation index, MI, described by: MI = V C * V Cmax ( Eq . 3 )

Figure USRE037126-20010403-M00003

wherein VC* is the amplitude command of the inverter output phase voltage and VCmax is the maximum obtainable amplitude, i.e., the amplitude of the phase voltage when all switching angles, θi, are equal to zero.

Since the phase current, iCa, graphically displayed in FIG. 3 is either leading or lagging the phase voltage vCan by 90 degrees, the average charge to each DC voltage supporting device is equal to zero over every half line cycle. From FIG. 3, the average charge to each DC voltage supporting device, Qi, over half cycle 0 to π can be expressed as: Q i = θ i π - θ i I cos θ θ = 0 ( Eq . 4 )

Figure USRE037126-20010403-M00004

where, i=1, 2, 3 and 4 with respect to FIB. 4 and θi to π−θi represents the interval of connecting the DC voltage supporting device to the AC side of the FBI unit and I is the magnitude of the line current iC. This configuration allows balanced DC voltages on each DC voltage supporting device in each FBI unit of each phase of the multilevel, wye connected cascade inverter due to equal charge and discharge of the voltage supporting devices.

As previously discussed, the average charge to each DC voltage supporting device will be zero if each FBI unit output voltage, vC1, is exactly 90 degrees out-of-phase with the line current, iC, as shown in FIG. 3. Therefore the DC voltage supporting device, in this case a capacitor, sees no real power. Even without real power imparted on the respective capacitors, the capacitor voltage can not be maintained due to switching device losses and capacitor losses. Therefore to maintain each DC capacitor voltage, the inverter must be controlled to allow some real power to influence the DC capacitors to maintain the DC command voltage VDC*.

The control block diagram shown in FIG. 6 includes two distinct control loops. The outer loop, defined by the influence of the DC command voltage VDC*, is to control total power flow to the FBI units, whereas the inner loop, defined by the feed back from the individual FBI units, is to offset power flow to the individual FBI units.

The control principle can be explained with the assistance of FIGS. 7a and 7 b. In FIG. 7a, vs is the source voltage, iC is the current flowing into the inverter and vC is the inverter output voltage. If vC is controlled so that vC lags vs by αC, then the total real power flowing into the inverter, Pi, is: P i = V S V C sin α c X Lc ( Eq . 5 )

Figure USRE037126-20010403-M00005

where XLc is the inductance of the interface inductor LC. Since the devices, e.g. capacitors, diodes, etc., used in the construction of the multilevel cascade inverter 410 are not ideal and therefore have varying tolerances, each DC capacitor voltage can not be exactly balanced using the outer loop only. Referring to FIGS. 7a and 7 b, if FBI unit I output voltage, vCi, is as shown by trace 520, then the average charge into the DC capacitor over each half cycle, the second shaded area 530, will nearly equal zero. However, if vCi is shifted ahead by ΔαCi as shown by trace 540, the charge shown in area 550 can be expressed as: Q i = θ i - Δ θ ci π - θ i - Δ α ci I cos θ θ = 2 I cos θ i sin Δ α ci ( Eq . 6 )

Figure USRE037126-20010403-M00006

which is proportional to ΔαCi when ΔαCi is small. Therefore, each FBI unit DC capacitor voltage can be actively controlled by slightly shifting the switching pattern. In the case for high voltage, high power applications, total power loss for the multilevel cascade inverter 410 is typically less than one percent.

The control principle can be explained with the assistance of FIGS. 7a and 7b. In FIG. 7a, V2 is the source voltage, i C is the current flowing into the inverter, and V C is the inverter output voltage. If V C is controlled so that V C lags V 2 by ∝ C , then the total real power flowing into the inverter, P i is: P i = V s V c sin α c X Lc (Eq . 5)

Figure USRE037126-20010403-M00007

where XLc is the inductance of the interface inductor L C . Since the devices, e.g., capacitors, diodes, etc., used in the construction of the multilevel cascade inverter 410 are not ideal and therefore have varying tolerances, each DC capacitor voltage can not be exactly balanced using the outer loop only. Referring to FIGS. 7a and 7b, if FBI unit I output voltage, V C1 is as shown by trace 520, then the average charge into the DC capacitor over each half cycle, the second shaded area 530, will nearly equal zero. However, if V Ci is shifted ahead by Δα Ci as shown by trace 540, the charge shown in area 550 can be expressed as: Q i = θ i - Δ α Ci π - θ i - Δ α ci I cos θ θ = 2 I cos θ i sin Δ α ci (Eq .   6)

Figure USRE037126-20010403-M00008

which is proportional to ΔαCi when Δα Ci is small. Therefore, each FBI unit DC capacitor voltage can be actively controlled by slightly shifting the switching pattern. In the case for high voltage, high power applications, total power loss for the multilevel cascade inverter 410 is typically less than one percent.

The method used to control the automatic switching of the FBIs may be best described with reference to FIG. 6. First, the voltage supporting device DC voltage levels, VCi, are detected, summed and then averaged. The average DC voltage level is then compared with a system reference DC voltage, Vdc*. Using a proportional integrator, an average phase shift signal, αC, is generated from a first error signal describing the comparison between the average DC voltage level and the system reference DC voltage, Vdc*. The average DC voltage level is also compared with the respective detected DC voltage levels, VCi. Using a proportional integrator, a phase shift offset signal, ΔαCi, is generated from a second error signal describing the comparison between the average DC voltage level and the respective detected DC voltage levels, VCi. The phase shift offset signal, ΔαCi, and said average phase shift signal, αC, are then summed. An AC line voltage, VS, having a period is detected from which a phase reference signal, α0, directly related to the period of the AC line voltage, VS, is developed by comparison with the sum of the phase shift offset signal signal ΔαCi, and said average phase shift signal, αC. Multiple firing reference signals, αCi, for the FBIs are generated by comparing the phase reference signal, α0, and the sum of phase shift offset signal, ΔαCi, and the average phase shift signal, αC. A modulation index, MI, may be selected by the user for which a corresponding reference table is provided. Firing angle signals are generated for the FBIs using the firing reference signal in view of the reference table for the given modulation index, MI, whereby, the alternate activation of a plurality of gate turn-off devices in the FBIs may be controlled to construct an output voltage waveform having a sinusoidal approximation for use by an AC load.

REQUIRED CAPACITANCE OF DC CAPACITANCE

Since each phase of the multilevel cascade inverter described herein has independent DC capacitors, the required capacitance calculation of each FBI unit DC capacitor is straightforward. With reference to FIG. 3, the required capacitance, Ci, can be expressed as: C i = Δ Q i Δ V d c = θ i ( t ) T / 4 2 I cos t t 2 εV dc = 2 I ( 1 - sin θ i ) 2 ∞εV dc ( Eq . 7 )

Figure USRE037126-20010403-M00009

where I is the current rating of the inverter, ε is the given regulation factor of the DC voltage and θi is the switching timing angle of FBI unit I as shown in FIG. 3. Note that:

 I=ISVG  (Eq. 8)

for the wye connected embodiment and: I = I SVC 3 ( Eq . 9 )

Figure USRE037126-20010403-M00010

for the delta connected embodiment. The total required capacitance for a three-phase M-level converter, C, may be expressed as C = 3 i = 1 ( M - 1 ) / 2 C i ( Eq . 10 )

Figure USRE037126-20010403-M00011

As previously discussed, θi is calculated for each MI value. To generate ±QVAR reactive power, MI would change between MImin and MImax, wherein the SVG produces +QVAR when MI=MImax and produces −QVAR for MI=MImin. For MI=MImax, θi becomes minimum and for MI=MImin, θi becomes maximum. Therefore, θilat MI=MImax may be used in equation 6 to calculate the required capacitance to maintain the DC voltage ripple below the given regulation, ε, for all loads.

EXAMPLE

A SVG system as shown in FIG. 6 having an 11-level wye-connected cascade inverter with 5 FBI units per phase was constructed having the system parameters shown in Table 1. The switching timing angles, θi, wherein i=1, 2. 3, 4, 5), shown in Table 2, were specifically calculated for minimizing voltage harmonics, below the 25th order, and stored in the switching pattern table 415 shown in FIG. 6.

TABLE 1
System Parameters of Experimental Prototype
System Parameter Value
Source Voltage Rating, Vs 240 V
VAR Rating, QVAR ±1 kVAR
Current Rating, I 2.4 A
DC Voltage, Vdc 40 V
DC Voltage Regulation, ε ±5%
Interface Inductance, LC 20% (32 mH)
Source Impedance, LS 3%
Modulation Index, MImin, MImax 0.615, 0.915

TABLE 2
Switching Pattern Table of 11-Level Cascade Inverter
Modulation Index Switching Timing Angles (rad.)
MI θ1 θ2 θ3 θ4 θ5
0.615 0.4353 0.7274 0.8795 1.0665 1.2655
. . . . . . . . . . . . . . . . . .
0.915 0.0687 0.1595 0.3124 0.4978 0.7077

Using the parameters of Tables 1 and 2 and Equations 7 and 10, the following values may be calculated:

C1=2.1 mF;

C2=1.89 mF;

C3=1.56 mF;

C4=1.18 mF; and

 C5=0.79 mF.

The total capacitance is calculated:

C=22.56 mF.

As the number of inverter cascade levels is increased for high voltage applications, the required capacitance of the cascade inverter, C, will approach that of a conventional multipulse inverter, Cdc, wherein the ratio C/Cdc will approach one as a limit.

EXAMPLE

An SVG system using the delta connected embodiment of a 21-level cascade inverter having 10 FBI units per phase is connected directly to a 13 kV distribution system. The SVG capacity is ±50 MVAR. ISVG=2.22 kA, I=1.282 kA, LC=3%, MImin=0.6385, MImax=0.8054, Vdc=2 kV and ε=±5%. At the rated load of +50 MVAR, [θ1, θ2. . . θi]=[0.0334, 0.1840, 0.2491, 0.3469, 0.4275, 0.5381, 0.6692, 0.8539, 0.9840, 1.1613] rad. For this SVG system, the total required capacitance of DC capacitors can be calculated as C=370 mF. The required capacitance for a comparable conventional multipulse inverter will be Cdc=332 mF. Therefore, the ratio C/Cdc approached unity at 1.11.

SIMULATION AND EXPERIMENTAL RESULTS

To demonstrate the validity of the multilevel cascade inverter described herein, an SVG prototype using an 11-level wye-connected cascade inverter was built. FIG. 6 and Tables 1 and 2 show the experimental configuration and the corresponding parameters. For the DC voltage control loops, only the voltages of C1 and C5 of phase “a” are detected and controlled directly. The control voltages for C2, C3 and C4 uses interpolating values of ΔαC1 and ΔαC5.

FIGS. 8, 9 and 10 show the experimental results when the SVG generates +1 kVAR reactive power. FIG. 11 shows experimental results at zero VAR output. FIGS. 12 and 13 show the case of generating −1 kVAR reactive power.

From FIGS. 8, 9 and 10 it is demonstrated that the inverter output phase voltage is an 11-level steplike waveform and the line-to-line voltage is a 21-level steplike waveform over a half cycle. Each step has the same span, which means the voltage of each DC capacitor is well controlled and balanced. The DC voltage command, Vdc*, was 40 V, and the modulation index was the maximum, MI=0.915, in this case.

It is well known to those of ordinary skill in the art that either the modulation index or the DC voltage or both may be controlled to regulate the output voltage. FIG. 12 shows the experimental waveforms to generate zero reactive power or zero current with a different DC voltage and the same modulation index as that of FIGS. 8, 9 and 10. In this case, the DC voltage of each DC capacitor was controlled to be 34 V, Vdc*=34 V.

In FIGS. 12 and 13, M1=0.615 and Vdc*=40 V. The inverter generates −1 kVAR of reactive power, that is, the current, ICa, is lagging the voltage, VSa, by 90 degrees.

These experimental results show that the voltages of the DC capacitors are well balanced. The results also show that pure sinusoidal current has been obtained with only 20% impedance on the AC side of the inverter. Using the delta-connected embodiment of the cascade inverter can compensate for a balanced or unbalanced three-phase load reactive power.

APPLICATIONS FOR CASCADE INVERTERS WITH SEPARATE DC SOURCES

Applications for the multilevel cascade voltage source inverters with separate DC sources are not limited to static VAR compensation or power system applications. These multilevel cascade inverters may also be used for providing clean AC power to AC loads with separate DC sources. FIG. 14 shows a circuit diagram having a multiphase, multilevel cascade inverter with separate DC sources 701 connected to an AC load 790 through smoothing inductors 760, 770 and 780. Typically, this circuit contains a set of separate DC voltage sources 710, 720, 730 and 740 which feed through a multilevel cascade inverter 701 to produce a step-like AC output voltage waveform. The voltage is then filtered by small smoothing inductors 760, 770 and 780 to produce a pure sinusoidal wave for an AC load 790. If the specific application is for AC motors, then the smoothing inductors 760, 770 and 780 may be removed from the circuit because the load motor has sufficient inductance to filter the input current. Examples of typical loads comprise motor drives, actuators and appliances. The DC voltage sources 710, 720, 730 and 740 may be obtained from any type conventional voltage source such as batteries, capacitors, photocells, fuel cells and biomass.

While there has been shown and described what is at present considered the preferred embodiments of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention deformed by the appended claims.

Claims (36)

What is claimed is:
1. A multiple DC voltage source inverter for connecting to an AC power system, comprising:
a. a plurality of full bridge inverters having a primary node and a secondary node, each of said full bridge inverters having a positive node and a negative node, each of said full bridge inverters having a voltage supporting device electrically connected in a parallel relationship between said positive node and said negative node;
b. at least one cascade inverter phase, each cascade inverter phase having a plurality of said full bridge inverters, each cascade inverter phase having a consistent number of said full bridge inverters with respect to each phase, each of said full bridge inverters in each cascade inverter phase interconnected in a series relationship with said secondary node of one of said full bridge inverters connected to said primary node of another full bridge inverter, said series interconnection defining a first full bridge inverter and a last full bridge inverter, each phase having an input node at said primary node of said first full bridge inverter and an output node at said secondary node of said last full bridge inverter;
c. a control means connected in an operable relationship with each of said full bridge inverters to emit a square wave signal for a prescribed period therefrom; whereby, detect a period and a reference signal associated with the AC power system and to alternate activation and deactivation of each of said full bridge inverters in response to the reference signal to create a nearly sinusoidal voltage waveform approximation is generated by the controlled, alternate activation and deactivation of said full bridge inverters by said control means having substantially the same period as the AC power system and having a desired phase shift defined with respect to the reference signal.
2. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 1 having three cascade inverter phases.
3. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 2 having a plurality of phase connectors, one of said phase connectors electrically connected between said input node of the first of said cascade inverter phases and said output node of the third of said cascade inverter phases, another of said phase connectors electrically connected between said input node of the third of said cascade inverter phases and said output node of the second of said cascade inverter phases, another of said phase connectors electrically connected between said input node of the second of said cascade inverter phases and said output node of the first of said cascade inverter phases.
4. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 3 further comprising each of said full bridge inverters having a first switching pair and a second switching pair, each of said switching pairs having a plurality of switching means for controllably regulating electrical current flow, each of said switching means having a first end and a second end, said first switching pair having a plurality of switching means electrically connected at said first end at said positive node of said full bridge inverter, said second end of one of said switching means of said first switching pair electrically connected to said primary node, said second end of another of said switching means of said first switching pair electrically connected to said secondary node, said second switching pair having a plurality of switching means electrically connected at said second ends at said negative node of said full bridge inverter, said first end of one of said switching means of said second switching pair electrically connected to said primary node, said first end of another of said switching means of said second switching pair electrically connected to said secondary node.
5. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 4 wherein said switching means comprises a gate turn-off device and an anti-parallel device connected in parallel and oppositely biased with respect to one another.
6. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 5 wherein said gate turn-off device is a component selected from the group consisting of a gate turn-off thyristor, an insulated gate bipolar transistor, a power MOSFET, a MOSFET controlled thyristor, a bipolar junction transistor, a static induction transistor, a static induction thyristor and a MOSFET turn-off thyristor.
7. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 5wherein said anti-parallel device is a diode.
8. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 1 wherein each of said voltage supporting devices is a component selected from the group consisting of capacitors, fuel cells, photovoltaic cells and biomass ceils cells.
9. A multiple DC voltage source inverter for connecting to an AC power system having a plurality of phases, comprising:
a. a plurality of full bridge inverters having a primary node and a secondary node, each of said full bridge inverters having a positive node and a negative node, each of said full bridge inverters having a voltage supporting device electrically connected in a parallel relationship between said positive node and said negative node;
b. a plurality of cascade inverter phases, each of said cascade inverter phases corresponding to one of the phases of the AC power system and having a plurality of said full bridge inverters, each of said cascade inverter phases having a consistent number of said full bridge inverters with respect to each phase, each of said full bridge inverters in each cascade inverter phase interconnected in a series relationship with said secondary node of one of said full bridge inverters connected to said primary node of another full bridge inverter, said series interconnection defining a first full bridge inverter and a last full bridge inverter, each of said phases having an input node at said primary node of said first full bridge inverter and an output node at said secondary node of said last full bridge inverter;
c. a common node defined by the electrical interconnection of said output nodes of each of said cascade inverter phases; and
d. a control means connected in an operable relationship with each of said full bridge inverters to emit a square wave signal for a prescribed period therefrom;
whereby, cascade inverter phase to detect a period and a phase reference signal associated with a corresponding phase of the AC power system and to alternate activation and deactivation of each of the full bridge inverters of the cascade inverter phase in response to the phase reference signal to create a nearly sinusoidal voltage waveform approximation is generated by the controlled, alternate activation and deactivation of said full bridge inverters by said control means having substantially the same period as the corresponding phase of the AC power system and having a desired phase shift defined with respect to the phase reference signal.
10. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 9 further comprising each of said full bridge inverters having a first switching pair and a second switching pair, each of said switching pairs having a plurality of switching means for controllably regulating electrical current flow, each of said switching means having a first end and a second end, said first switching pair having a plurality of switching means electrically connected at said first end at said positive node of said full bridge inverter, said second end of one of said switching means of said first switching pair electrically connected to said primary node, said second end of another of said switching means of said first switching pair electrically connected to said secondary node, said second switching pair having a plurality of switching means electrically connected at said second ends at said negative node of said full bridge inverter, said first end of one of said switching means of said second switching pair electrically connected to said primary node, said first end of another of said switching means of said second switching pair electrically connected to said secondary node.
11. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 10 wherein said switching means comprises a gate turn-off device and an anti-parallel device connected in parallel and oppositely biased with respect to one another.
12. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 11 wherein said gate turn-off device is a component selected from the group consisting of a gate turn-off thyristor, an insulated gate bipolar transistor, a power MOSFET, a MOSFET controlled thyristor, a bipolar junction transistor, a static induction transistor, a static induction thyristor and a MOSFET turn-off thyristor.
13. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 11wherein said anti-parallel device is a diode.
14. A multiple DC voltage source inverter for connecting to an AC power system as described in claim 9 wherein each of said voltage supporting devices is a component selected from the group consisting of capacitors, fuel cells, photovoltaic cells and biomass cells.
15. A multiple DC voltage source inverter for connecting to a AC power system as described in claim 9 having three cascade inverter phases.
16. A method for inverting a plurality of DC voltage signals to approximate a sinusiodal sinusoidal voltage waveform comprising the following steps:
a. detecting the DC voltage levels of a plurality of DC voltage sources;
b. averaging said DC voltage levels;
c. comparing said average with a reference DC voltage;
d. generating a first error signal from said comparison of said average with a reference DC voltage;
e. comparing said average with said detected DC voltage levels;
f. generating a second error signal from said comparison of said average with said detected DC voltage levels;
g. generating a phase shift offset signal from said second error signal;
h. generating an average phase shift signal from said first error signal;
i. summing said phase shift offset signal and said average phase shift signal;
j. detecting an AC line voltage having a period;
k. generating a phase reference signal directly related to said period of said AC line voltage;
l. generating a plurality of firing reference signals for a plurality of full bridge inverters using said phase reference signal and said sum of said phase shift offset signal and said average phase shift signal;
m. determining a modulation index;
n. providing a reference table for said modulation index;
o. generating a plurality of firing angle signals for said plurality of full bridge inverters using said firing reference signal and said reference table;
whereby, the alternate activation of a plurality of gate turn-off devices in said full bridge inverters may be controlled to construct an output voltage waveform having a sinusoidal approximation for use by an AC load.
17. The multiple DC voltage source inverter of claim 1, wherein:
the phase shift is selected to generate a desired level of positive or negative reactive power delivered to the AC power system while generating sufficient real power to offset losses incurred within the full bridge inverters.
18. The multiple DC voltage source inverter of claim 1, further comprising a smoothing inductor connected in series between the cascade inverter phase and the AC power system.
19. The multiple DC voltage source inverter of claim 1, wherein:
the phase shift is selected to perform a flexible AC transmission operation selected from the group including static VAR generation, power line conditioning, series compensation, phase shifting, voltage balancing, and generator interfacing.
20. The multiple DC voltage source inverter of claim 2, wherein the AC power system includes three phases corresponding to the three cascade inverter phases, further comprising three smoothing inductors, one of the smoothing inductors connected in series between each cascade inverter phase and a corresponding phase of the AC power system.
21. The multiple DC voltage source inverter of claim 10, wherein:
the phase shift for each cascade inverter phase is selected to generate a desired level of positive or negative reactive power delivered to the corresponding phase of the AC power system while generating sufficient real power to offset losses incurred within the cascade inverter phase.
22. The multiple DC voltage source inverter of claim 10, further comprising a smoothing inductor connected in series between each of the cascade inverter phases and a corresponding phase of the AC power system.
23. The multiple DC voltage source inverter of claim 10, wherein:
the phase shift for each cascade inverter phase is selected to perform a flexible AC transmission operation selected from the group including static VAR generation, power line conditioning, series compensation, phase shifting, voltage balancing, and generator interfacing.
24. A multiple DC voltage source inverter for connecting to an AC power system, comprising:
at least one cascade inverter phase including a plurality of full bridge inverters connected in a series relationship;
a control means connected in an operable relationship with each of said full bridge inverters to detect a period and a reference signal associated with the AC power system and to alternate activation and deactivation of each of said full bridge inverters in response to the reference signal to create a nearly sinusoidal voltage waveform approximation having substantially the same period as the AC power system and having a desired phase shift defined with respect to the phase reference signal; and
a smoothing inductor connected in series between the cascade inverter phase and the AC power system.
25. The multiple DC voltage source inverter of claim 24, wherein the control means further comprises:
a first control loop for controlling the power flow to the cascade inverter phase; and
a second feed-back control loop for offsetting the power flow to each of the full bridge inverters of the cascade inverter phase.
26. The multiple DC voltage source inverter of claim 24, wherein the control means further comprises:
a switching pattern table containing switching timing data for generating the nearly sinusoidal voltage waveform approximation in response to a reference output voltage signal and a desired phase angle;
means for calculating the reference output voltage signal;
a phase detector for determining the reference signal; and
means for determining the desired phase angle in response to the reference signal and a feedback signal produced by the first and second control loops.
27. The multiple DC voltage source inverter of claim 26, wherein:
the AC power system includes three phases;
the cascade inverter includes three phases, one cascade inverter phase corresponding to each phase of the AC power system;
the cascade inverter includes three smoothing inductors, one smoothing inductor connected in series between each cascade inverter phase and each phase of the AC power system; and
the control means includes for each cascade inverter phase,
a first control loop for controlling the power flow to the cascade inverter phase,
a second feed-back control loop for offsetting the power flow to each of the full bridge inverters of the cascade inverter phase,
a switching pattern table containing switching timing data for generating the nearly sinusoidal voltage waveform approximation in response to a reference output voltage signal and a desired phase angle for the cascade inverter phase,
means for calculating the reference output voltage signal for the cascade inverter phase,
a phase detector for determining a phase reference signal associated with a corresponding phase of the AC system, and
means for determining the desired phase angle for the cascade inverter phase in response to the phase reference signal and a feedback signal produced by the first and second control loops for the cascade inverter phase.
28. The multiple DC voltage source inverter of claim 27, wherein:
each of said full bridge inverters includes a primary node and a secondary node, each of said full bridge inverters includes a positive node and a negative node, each of said full bridge inverters includes a voltage supporting device electrically connected in a parallel relationship between said positive node and said negative node; and
each cascade inverter phase includes a plurality of said full bridge inverters, each cascade inverter phase having a consistent number of said full bridge inverters with respect to each phase, each of said full bridge inverters in each cascade inverter phase interconnected in a series relationship with said secondary node of one of said full bridge inverters connected to said primary node of another full bridge inverter, said series interconnection defining a first full bridge inverter and a last full bridge inverter, each phase having an input node at said primary node of said first full bridge inverter and an output node at said secondary node of said last full bridge inverter.
29. The multiple DC voltage source inverter of claim 28, wherein:
the phase shift for each cascade inverter phase is selected to generate a desired level of positive or negative reactive power delivered to the corresponding phase of the AC power system while generating sufficient real power to offset losses incurred within the cascade inverter phase.
30. The multiple DC voltage source inverter of claim 28, wherein:
the phase shift for each cascade inverter phase is selected to perform a flexible AC transmission operation selected from the group including static VAR generation, power line conditioning, series compensation, phase shifting, voltage balancing, and generator interfacing.
31. The multiple DC voltage source inverter of claim 30 having a plurality of phase connectors, one of said phase connectors electrically connected between said input node of the first of said cascade inverter phases and said output node of the third of said cascade inverter phases, another of said phase connectors electrically connected between said input node of the third of said cascade inverter phases and said output node of the second of said cascade inverter phases, another of said phase connectors electrically connected between said input node of the second of said cascade inverter phases and said output node of the first of said cascade inverter phases.
32. The multiple DC voltage source inverter of claim 30, further comprising each of said full bridge inverters having a first switching pair and a second switching pair, each of said switching pairs having a plurality of switching means for controllably regulating electrical current flow, each of said switching means having a first end and a second end, said first switching pair having a plurality of switching means electrically connected at said first end at said positive node of said full bridge inverter, said second end of one of said switching means of said first switching pair electrically connected to said primary node, said second end of another of said switching means of said first switching pair electrically connected to said secondary node, said second switching pair having a plurality of switching means electrically connected at said second ends at said negative node of said full bridge inverter, said first end of one of said switching means of said second switching pair electrically connected to said primary node, said first end of another of said switching means of said second switching pair electrically connected to said secondary node.
33. The multiple DC voltage source inverter of claim 32, wherein said switching means comprises a gate turn-off device and an anti-parallel device connected in parallel and oppositely biased with respect to one another.
34. The multiple DC voltage source inverter of claim 33, wherein said gate turn-off device is a component selected from the group consisting of a gate turn-off thyristor, an insulated gate bipolar transistor, a power MOSFET, a MOSFET controlled thyristor, a bipolar junction transistor, a static induction transistor, a static induction thyristor and a MOSFET turn-off thyristor.
35. The multiple DC voltage source inverter of claim 34, wherein said anti-parallel device is a diode.
36. The multiple DC voltage source inverter of claim 35, wherein each of said voltage supporting devices is a component selected from the group consisting of capacitors, fuel cells, photovoltaic cells and biomass cells.
US09167287 1995-09-14 1998-10-06 Multilevel cascade voltage source inverter with seperate DC sources Expired - Fee Related USRE37126E1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US08527995 US5642275A (en) 1995-09-14 1995-09-14 Multilevel cascade voltage source inverter with seperate DC sources
US09167287 USRE37126E1 (en) 1995-09-14 1998-10-06 Multilevel cascade voltage source inverter with seperate DC sources

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09167287 USRE37126E1 (en) 1995-09-14 1998-10-06 Multilevel cascade voltage source inverter with seperate DC sources

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US08527995 Reissue US5642275A (en) 1995-09-14 1995-09-14 Multilevel cascade voltage source inverter with seperate DC sources

Publications (1)

Publication Number Publication Date
USRE37126E1 true USRE37126E1 (en) 2001-04-03

Family

ID=24103826

Family Applications (2)

Application Number Title Priority Date Filing Date
US08527995 Expired - Lifetime US5642275A (en) 1995-09-14 1995-09-14 Multilevel cascade voltage source inverter with seperate DC sources
US09167287 Expired - Fee Related USRE37126E1 (en) 1995-09-14 1998-10-06 Multilevel cascade voltage source inverter with seperate DC sources

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US08527995 Expired - Lifetime US5642275A (en) 1995-09-14 1995-09-14 Multilevel cascade voltage source inverter with seperate DC sources

Country Status (1)

Country Link
US (2) US5642275A (en)

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6556461B1 (en) * 2001-11-19 2003-04-29 Power Paragon, Inc. Step switched PWM sine generator
US20050127853A1 (en) * 2003-12-12 2005-06-16 Gui-Jia Su Multi-level dc bus inverter for providing sinusoidal and pwm electrical machine voltages
US20090102288A1 (en) * 2007-10-17 2009-04-23 Edwin Arthur Blackmond Modular Power Supply
US20090302682A1 (en) * 2008-05-30 2009-12-10 Siemens Energy & Automation, Inc. Method and system for reducing switching losses in a high-frequency multi-cell power supply
US20100142234A1 (en) * 2008-12-31 2010-06-10 Mehdi Abolhassani Partial regeneration in a multi-level power inverter
US20100213921A1 (en) * 2009-02-26 2010-08-26 Mehdi Abolhassani Pre-Charging An Inverter Using An Auxiliary Winding
US7830681B2 (en) 2008-09-24 2010-11-09 Teco-Westinghouse Motor Company Modular multi-pulse transformer rectifier for use in asymmetric multi-level power converter
US20110019449A1 (en) * 2009-07-21 2011-01-27 Shuji Katoh Power converter apparatus
US20110235376A1 (en) * 2010-03-25 2011-09-29 Feng Frank Z Multi-level parallel phase converter
US8130501B2 (en) 2009-06-30 2012-03-06 Teco-Westinghouse Motor Company Pluggable power cell for an inverter
US20120081939A1 (en) * 2009-06-18 2012-04-05 Jean-Philippe Hasler Arrangement For Exchanging Power
US20120092906A1 (en) * 2009-06-18 2012-04-19 Jean-Philippe Hasler Arrangement for exchanging power
US20120212065A1 (en) * 2011-02-15 2012-08-23 George Shu-Xing Cheng Scalable and redundant mini-inverters
US8254076B2 (en) 2009-06-30 2012-08-28 Teco-Westinghouse Motor Company Providing modular power conversion
US8279640B2 (en) 2008-09-24 2012-10-02 Teco-Westinghouse Motor Company Modular multi-pulse transformer rectifier for use in symmetric multi-level power converter
US8536734B2 (en) 2010-04-14 2013-09-17 East Coast Research And Development, Llc Apparatus for inverting DC voltage to AC voltage
US8575479B2 (en) 2009-06-30 2013-11-05 TECO—Westinghouse Motor Company Providing a transformer for an inverter
US8601190B2 (en) 2011-06-24 2013-12-03 Teco-Westinghouse Motor Company Providing multiple communication protocols for a control system having a master controller and a slave controller
US20140016380A1 (en) * 2012-07-16 2014-01-16 Delta Electronics, Inc. Multi-level voltage converter
US8711530B2 (en) 2009-06-30 2014-04-29 Teco-Westinghouse Motor Company Pluggable power cell for an inverter
US20140252862A1 (en) * 2013-03-07 2014-09-11 Cyboenergy, Inc. Maximizing Power Production at Low Sunlight by Solar Power Mini-Inverters
US8976526B2 (en) 2009-06-30 2015-03-10 Teco-Westinghouse Motor Company Providing a cooling system for a medium voltage drive system
US9257916B2 (en) 2009-07-16 2016-02-09 Cyboenergy, Inc. Power inverters with multiple input channels
US9294003B2 (en) 2012-02-24 2016-03-22 Board Of Trustees Of Michigan State University Transformer-less unified power flow controller
US9318974B2 (en) 2014-03-26 2016-04-19 Solaredge Technologies Ltd. Multi-level inverter with flying capacitor topology
US9331488B2 (en) 2011-06-30 2016-05-03 Cyboenergy, Inc. Enclosure and message system of smart and scalable power inverters
US20160134201A1 (en) * 2014-11-06 2016-05-12 Delta Electronics, Inc. Control method and control device for inverter system
EP2667279A4 (en) * 2011-01-18 2016-12-21 Tokyo Inst Tech Power converter and method for controlling same
US9941813B2 (en) 2013-03-14 2018-04-10 Solaredge Technologies Ltd. High frequency multi-level inverter

Families Citing this family (166)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5889668A (en) * 1997-09-05 1999-03-30 Electric Power Research Institute, Inc. Three-phase DC-to-AC power inverter with three-level poles
US6005788A (en) * 1998-02-13 1999-12-21 Wisconsin Alumni Research Foundation Hybrid topology for multilevel power conversion
US6075350A (en) * 1998-04-24 2000-06-13 Lockheed Martin Energy Research Corporation Power line conditioner using cascade multilevel inverters for voltage regulation, reactive power correction, and harmonic filtering
US6031738A (en) * 1998-06-16 2000-02-29 Wisconsin Alumni Research Foundation DC bus voltage balancing and control in multilevel inverters
US6072707A (en) * 1998-10-23 2000-06-06 Siemens Power Transmission & Distribution, Inc. High voltage modular inverter
WO2001005022A1 (en) * 1999-07-09 2001-01-18 Green Global, S.A. High performance system for generating alternating current from direct current
ES2189702B1 (en) * 1999-07-09 2004-11-16 Green Global, S.A. System to generate alternating current from direct current high performance.
US6205042B1 (en) 1999-10-27 2001-03-20 General Electric Company Indirect calculation of bus voltage for voltage source inverter
US6503649B1 (en) 2000-04-03 2003-01-07 Convergence, Llc Variable fuel cell power system for generating electrical power
EP1364450A1 (en) * 2001-02-07 2003-11-26 Asea Brown Boveri Ab A converter device and a method for the control thereof
CN100413199C (en) 2001-02-28 2008-08-20 艾默生网络能源有限公司 Pulse width modulation control method for multistage superposed high-voltage frequency converter
EP1253706B1 (en) * 2001-04-25 2013-08-07 ABB Schweiz AG Power electronic circuit and process to transfer active power
DE10233443A1 (en) * 2002-07-23 2004-01-29 Still Gmbh Industrial truck with an electric drive
US7040391B2 (en) * 2003-06-30 2006-05-09 Baker Hughes Incorporated Low harmonic diode clamped converter/inverter
US20060241880A1 (en) * 2003-07-18 2006-10-26 Forth J B Methods and apparatus for monitoring power flow in a conductor
US20070230226A1 (en) * 2003-11-25 2007-10-04 Jih-Sheng Lai Multilevel intelligent universal auto-transformer
US6954366B2 (en) * 2003-11-25 2005-10-11 Electric Power Research Institute Multifunction hybrid intelligent universal transformer
US7050311B2 (en) * 2003-11-25 2006-05-23 Electric Power Research Institute, Inc. Multilevel converter based intelligent universal transformer
US20070223258A1 (en) * 2003-11-25 2007-09-27 Jih-Sheng Lai Multilevel converters for intelligent high-voltage transformers
CN100384045C (en) * 2004-03-24 2008-04-23 盈正豫顺电子股份有限公司 Virtual work compensating device
US7972749B2 (en) * 2004-06-24 2011-07-05 GM Global Technology Operations LLC Low voltage power tap on high voltage stack
US7433216B2 (en) * 2005-11-14 2008-10-07 Hamilton Sundstrand Corporation Voltage control and harmonic minimization of multi-level converter
US7230837B1 (en) * 2006-03-27 2007-06-12 North Carolina State University Method and circuit for cascaded pulse width modulation
CN100553106C (en) 2006-06-29 2009-10-21 上海交通大学 Solar grid-connected electricity-generation energy output maximization circuit structure
CN100449923C (en) 2006-07-12 2009-01-07 哈尔滨九洲电气股份有限公司 Frequency transformer capable of continuously operating during power-off
US7808125B1 (en) 2006-07-31 2010-10-05 Sustainable Energy Technologies Scheme for operation of step wave power converter
CN1929278B (en) 2006-08-16 2010-05-12 南京航空航天大学 Cascading multiple electrical level double decompression semi-bridge converter
DE102007018343A1 (en) * 2007-04-16 2008-10-30 Siemens Ag Active filter with a multi-level topology
CN101790827B (en) * 2007-06-04 2013-06-12 可持续能源技术公司 Prediction scheme for step wave power converter and inductive inverter topology
KR101392117B1 (en) 2008-01-08 2014-05-07 에이비비 테크놀로지 아게 Voltage source converter control method, and a voltage conversion device
DE102008007659A1 (en) * 2008-02-06 2009-02-19 Siemens Aktiengesellschaft Indirect voltage converter, has upper and lower valve branches of each phase module of load-sided multi-phase power inverter with two-pole subsystem, and multi-phase network-guided power inverter provided as network-sided power inverter
KR101225322B1 (en) * 2008-03-20 2013-01-23 에이비비 리써치 리미티드 A voltage source converter
US7719864B2 (en) * 2008-04-02 2010-05-18 Array Converter, Inc. Pulse amplitude modulated current converter
US7929324B1 (en) * 2008-04-02 2011-04-19 Array Converter Inc. Blade architecture array converter
EP2277258B1 (en) * 2008-05-07 2013-12-04 ABB Technology AG A voltage source converter
CA2727112C (en) 2008-06-09 2015-10-13 Abb Technology Ag A voltage source converter
KR101191694B1 (en) * 2008-06-12 2012-10-16 에이비비 테크놀로지 아게 A plant for transmitting electric power
DE102008032813A1 (en) * 2008-07-11 2010-01-21 Siemens Aktiengesellschaft Grid connection of solar cells
WO2010040388A1 (en) * 2008-10-07 2010-04-15 Abb Technology Ag Multilevel converter and method for compensating active and reactive power in a high voltage network
FR2937477B1 (en) * 2008-10-21 2011-02-25 Areva T & D Sa System and method for controlling at least one voltage converter has a plurality of cells in series
EP2342808B1 (en) 2008-11-07 2014-10-29 ABB Technology AG Chain-link converter, method for starting chain-link converter and static compensator system
EP2368316A1 (en) * 2008-12-19 2011-09-28 Areva T&D Uk Ltd Current source element
WO2010069399A1 (en) * 2008-12-19 2010-06-24 Abb Technology Ag A voltage source converter
US8144491B2 (en) 2008-12-31 2012-03-27 Drs Power & Control Technologies, Inc. Cascaded flying capacitor modular high voltage inverters
DE102009007476A1 (en) * 2009-01-30 2010-08-05 Siemens Aktiengesellschaft A method of balancing the DC voltages in a self-commutated multilevel Blindstromkompensator and a self-commutated multilevel Blindstromkompensator
EP2244363A1 (en) * 2009-04-23 2010-10-27 Mitsubishi Electric R&D Centre Europe B.V. Method and an apparatus for controlling the output voltage of a boost converter
DE102009023626A1 (en) 2009-05-27 2010-12-02 Siemens Aktiengesellschaft An apparatus for compensating harmonics
CN101599708B (en) 2009-06-26 2011-01-26 华中科技大学 Method for controlling power balance of DC side of cascaded multilevel inverter
DE102009031574A1 (en) 2009-06-30 2011-01-05 Siemens Aktiengesellschaft Building a multi-level inverter of the electric power supply
US8482156B2 (en) * 2009-09-09 2013-07-09 Array Power, Inc. Three phase power generation from a plurality of direct current sources
US8395280B2 (en) * 2010-02-16 2013-03-12 Infineon Technologies Ag Circuit arrangement including a multi-level converter
FR2956529B1 (en) * 2010-02-17 2012-03-16 Inst Polytechnique Grenoble Balancing system by magnetic coupling of an association serie of elements of generation or electric power storage
JP5163673B2 (en) * 2010-03-11 2013-03-13 オムロン株式会社 Control circuit, a power conditioner including the control circuit and photovoltaic systems,
DE102010013862A1 (en) 2010-04-01 2011-10-06 Gottfried Wilhelm Leibniz Universität Hannover Transformerless cyclo
DE102010027856A1 (en) * 2010-04-16 2011-10-20 Sb Limotive Company Ltd. Battery with an integrated pulse-controlled inverter
DE102010018970A1 (en) 2010-04-27 2011-10-27 Siemens Aktiengesellschaft Sub module for a modular Mehrstufenumrichter
US8772965B2 (en) * 2010-06-29 2014-07-08 General Electric Company Solar power generation system and method
CN102013691A (en) * 2010-07-22 2011-04-13 荣信电力电子股份有限公司 Battery energy storage topology structure without transformer based on MMC modularized multi-level inverter
CN102013685A (en) * 2010-07-22 2011-04-13 荣信电力电子股份有限公司 Transformerless STATCOM (Static Compensator) topological structure based on MMC (Modular Multilevel Converter)
WO2012016285A1 (en) * 2010-08-04 2012-02-09 Kevin Stephen Davies Solar power conversion system
US8872384B2 (en) 2010-08-18 2014-10-28 Volterra Semiconductor Corporation Switching circuits for extracting power from an electric power source and associated methods
DE102010046142A1 (en) 2010-09-15 2012-03-15 Converteam Gmbh Modular switch for an electric drive, electric drive and method for operating an electric drive
DE102010041068A1 (en) 2010-09-20 2012-03-22 Robert Bosch Gmbh System for charging an energy storage device and method for operating the charging system
DE102010041065A1 (en) 2010-09-20 2012-03-22 Robert Bosch Gmbh System for charging an energy storage device and method for operating the charging system
DE102010064301A1 (en) 2010-12-29 2012-07-05 Robert Bosch Gmbh battery cell
DE102010064303A1 (en) 2010-12-29 2012-07-05 Robert Bosch Gmbh battery module
EP2695291A4 (en) 2011-01-17 2017-05-24 Kent Kernahan Idealized solar panel
DE102011003778A1 (en) * 2011-02-08 2012-08-09 Robert Bosch Gmbh A method of operating a control system for an electrical machine and system for controlling an electrical machine
DE102011003810A1 (en) * 2011-02-08 2012-08-09 Robert Bosch Gmbh Controllable energy storage device and method of operating a controllable energy store
WO2012130296A1 (en) 2011-03-30 2012-10-04 Siemens Aktiengesellschaft Hybrid converter and method for controlling said hybrid converter
DE102011006761A1 (en) 2011-04-05 2012-10-11 Robert Bosch Gmbh Switching matrix of switching system, has switching devices that are arranged to switch supply terminals with respect to output ports in response to control signals to form series/parallel/bridging circuit with power sources
DE102011006762A1 (en) 2011-04-05 2012-10-11 Robert Bosch Gmbh Batteriedirektumrichter in ring configuration
DE102011075376A1 (en) * 2011-05-06 2012-11-08 Sb Limotive Company Ltd. A method of controlling a battery and a battery for carrying out the method
DE102011076199A1 (en) * 2011-05-20 2012-11-22 Siemens Aktiengesellschaft tension adjustment
DE102011076515A1 (en) 2011-05-26 2012-11-29 Robert Bosch Gmbh Energy storage device and system with energy storage device
DE102011076571A1 (en) 2011-05-27 2012-11-29 Robert Bosch Gmbh Power supply device for inverter circuits
DE102011077270A1 (en) 2011-06-09 2012-12-13 Robert Bosch Gmbh Energy storage device system with energy storage device and method for generating a supply voltage of an energy storage device
DE102011077264A1 (en) * 2011-06-09 2012-12-13 Robert Bosch Gmbh Heating means for energy storage device and method for heating energy of an energy storage device cells
US9124136B1 (en) * 2011-06-10 2015-09-01 The Florida State University Research Foundation, Inc. System and method for single-phase, single-stage grid-interactive inverter
EP2732527A4 (en) 2011-07-11 2015-10-07 Sinewatts Inc Systems and methods for solar photovoltaic energy collection and conversion
CN103875147B (en) 2011-10-14 2017-08-25 Abb技术有限公司 And a multi-level converter for controlling a multi-level converter comprises a cell voltage balancing method
DE102011084698A1 (en) 2011-10-18 2013-04-18 Sb Limotive Company Ltd. Converter unit for an asynchronous
US9112430B2 (en) 2011-11-03 2015-08-18 Firelake Acquisition Corp. Direct current to alternating current conversion utilizing intermediate phase modulation
DE102011086545A1 (en) 2011-11-17 2013-05-23 Robert Bosch Gmbh Energy storage device system with energy storage device and method for driving an energy storage device
US9071164B2 (en) * 2011-12-09 2015-06-30 General Electric Company Multi-phase converter system and method
US9143056B2 (en) 2011-12-16 2015-09-22 Empower Micro Systems, Inc. Stacked voltage source inverter with separate DC sources
US9263971B2 (en) * 2011-12-16 2016-02-16 Empower Micro Systems Inc. Distributed voltage source inverters
US9099938B2 (en) 2011-12-16 2015-08-04 Empower Micro Systems Bi-directional energy converter with multiple DC sources
DE102011089312A1 (en) 2011-12-20 2013-06-20 Robert Bosch Gmbh System and method for charging the energy storage cells of an energy storage device
DE102011089309A1 (en) 2011-12-20 2013-06-20 Robert Bosch Gmbh System and method for driving an energy storage device
DE102011089297A1 (en) 2011-12-20 2013-06-20 Robert Bosch Gmbh Energy storage device system with energy storage device and method for driving an energy storage device
DE102011089648A1 (en) * 2011-12-22 2013-06-27 Robert Bosch Gmbh Energy storage device system with energy storage device and method for driving an energy storage device
KR101255959B1 (en) * 2011-12-28 2013-04-23 주식회사 효성 Protection circuit for protecting voltage source converter
KR101221159B1 (en) * 2011-12-30 2013-01-10 연세대학교 산학협력단 Multilevel converter controlling method
DE102012200577A1 (en) * 2012-01-17 2013-07-18 Robert Bosch Gmbh Motor vehicle battery and method for controlling a battery
KR101422905B1 (en) * 2012-01-30 2014-07-23 엘에스산전 주식회사 Meduim voltage inverter control apparatus and meduim voltage inverter system
DE102012202868A1 (en) 2012-02-24 2013-08-29 Robert Bosch Gmbh Direct voltage tapping arrangement for battery direct inverter for electrically operated vehicle, has step-up-chopper providing direct voltage to tapping terminals based on potential between half bridge circuit and reference terminal
DE102012202853A1 (en) 2012-02-24 2013-08-29 Robert Bosch Gmbh Charging circuit for energy storage device of e.g. electric drive system in wind-power plant, has transducer throttle coupled between supply node and supply circuit, and semiconductor switch coupled between supply node and supply circuit
DE102012202856A1 (en) 2012-02-24 2013-08-29 Robert Bosch Gmbh Circuit for charging lithium ion battery of electrical propulsion system of e.g. electric car, has supply circuit coupled with input terminals of buck converter, and temporarily providing charging direct voltage for buck converter
DE102012202855A1 (en) 2012-02-24 2013-08-29 Robert Bosch Gmbh Direct voltage tap assembly for energy storage device for electrical propulsion system, has boost converter located between half-bridge circuits based on potential difference between circuits and direct current voltage
DE102012202867A1 (en) 2012-02-24 2013-08-29 Robert Bosch Gmbh Charging circuit for energy storage device for electrical propulsion system used for e.g. electric car, has choke transformer and switching element controller which receive direct current for charging energy storage modules
DE102012205119A1 (en) 2012-03-29 2013-10-02 Robert Bosch Gmbh A method for heating energy storage cells of an energy storage device and heatable energy storage device
DE102012205109A1 (en) 2012-03-29 2013-10-02 Robert Bosch Gmbh Energy storage device with cooling elements and method for cooling power storage cells
US9444320B1 (en) 2012-04-16 2016-09-13 Performance Controls, Inc. Power controller having active voltage balancing of a power supply
US8619446B2 (en) 2012-04-27 2013-12-31 Rockwell Automation Technologies, Inc. Cascaded H-bridge (CHB) inverter level shift PWM with rotation
US8982593B2 (en) 2012-04-27 2015-03-17 Rockwell Automation Technologies, Inc. Cascaded H-Bridge (CHB) inverter level shift PWM with rotation
DE102012209179A1 (en) 2012-05-31 2013-12-05 Robert Bosch Gmbh Energy storage device i.e. lithium-ion battery for producing power supply voltage for electric machine that is utilized e.g. electric car, has switch switching cell modules in power supply lines to provide supply voltage to output terminal
DE102012209392A1 (en) 2012-06-04 2013-12-05 Robert Bosch Gmbh A method of dynamically setting a short circuit condition in an energy storage device
DE102012209652A1 (en) * 2012-06-08 2013-12-12 Robert Bosch Gmbh A method for determining an ohmic internal resistance of a battery module, the battery management system and motor vehicle
DE102012210010A1 (en) 2012-06-14 2013-12-19 Robert Bosch Gmbh Energy storage device for producing power supply voltage for e.g. synchronous machine in hybrid car, has module intermediate circuit coupled with conversion circuit for selectively switching or bridging in supply strands
DE102012212262A1 (en) * 2012-07-13 2014-01-16 Robert Bosch Gmbh Driving device and method for charging an electrical energy accumulator
CN103580517A (en) 2012-08-08 2014-02-12 Abb 技术有限公司 Method for operating power electronics circuit
US9425705B2 (en) 2012-08-13 2016-08-23 Rockwell Automation Technologies, Inc. Method and apparatus for bypassing cascaded H-bridge (CHB) power cells and power sub cell for multilevel inverter
US9007787B2 (en) 2012-08-13 2015-04-14 Rockwell Automation Technologies, Inc. Method and apparatus for bypassing Cascaded H-Bridge (CHB) power cells and power sub cell for multilevel inverter
CN102832841B (en) * 2012-08-27 2014-09-17 清华大学 Modularized multi-level converter with auxiliary diode
DE102012215743A1 (en) 2012-09-05 2014-03-06 Robert Bosch Gmbh Control device and method for determining the state of charge of energy storage cells of an energy storage device
DE102012216469A1 (en) 2012-09-14 2014-03-20 Robert Bosch Gmbh Energy supply system and method for controlling coupling means an energy storage device
CN102857136B (en) * 2012-10-10 2015-04-08 范家闩 Converter for converting high-voltage direct current into alternating current
DE102012220376A1 (en) * 2012-11-08 2014-05-08 Robert Bosch Gmbh Apparatus and method for charging an electrical energy storage device from an AC voltage source
JP6139111B2 (en) * 2012-11-15 2017-05-31 株式会社東芝 Reactive power compensation device
DE102012222333A1 (en) 2012-12-05 2014-06-05 Robert Bosch Gmbh Energy storage device for e.g. battery direct converter circuitry to supply power to switched reluctance machine in electrical propulsion system of hybrid car, has energy storage modules selectively switched or bypassed in supply branches
DE102012222343A1 (en) 2012-12-05 2014-06-05 Robert Bosch Gmbh A method for providing a supply voltage and electric drive system
CN104467397B (en) * 2012-12-13 2017-01-11 国网山东省电力公司蒙阴县供电公司 Correcting the power factor improving transformer efficiency svg chain means
CN103036238B (en) * 2012-12-24 2015-02-04 珠海万力达电气自动化有限公司 Control structure and method of chain-type active power filter (FAPF) linkage unit bypass
CN103066871A (en) * 2013-01-15 2013-04-24 中国矿业大学(北京) High power cascade type diode H-bridge unit power factor rectifier
DE102013202652A1 (en) 2013-02-19 2014-08-21 Robert Bosch Gmbh Charging circuit for an energy storage device and method for charging an energy storage device
DE102013202650A1 (en) 2013-02-19 2014-08-21 Robert Bosch Gmbh Internal power supply of energy storage modules for an energy storage device and energy storage device with such
US9450274B2 (en) 2013-03-15 2016-09-20 Design Flux Technologies, Llc Method and apparatus for creating a dynamically reconfigurable energy storage device
DE102013204541A1 (en) * 2013-03-15 2014-09-18 Robert Bosch Gmbh Battery cell unit with the battery cell and ultra-fast discharge circuit and method for monitoring a battery cell
US9240731B2 (en) 2013-03-18 2016-01-19 Rockwell Automation Technologies, Inc. Power cell bypass method and apparatus for multilevel inverter
DE102013205562A1 (en) 2013-03-28 2014-10-02 Robert Bosch Gmbh Energy storage device and system with an energy storage device
US9246407B2 (en) 2013-03-29 2016-01-26 General Electric Company Voltage balancing system and method for multilevel converters
DE102013206942A1 (en) * 2013-04-17 2014-10-23 Robert Bosch Gmbh Battery system disposed in a battery string battery modules and methods for determining at least one operating parameter of a battery module of the battery system
DE102013208338A1 (en) 2013-05-07 2014-11-13 Robert Bosch Gmbh Drive system with energy storage device and transverse flux machine and method for operating a transverse flux machine
JP2014233126A (en) * 2013-05-28 2014-12-11 株式会社東芝 Power converter
JP6149516B2 (en) * 2013-06-03 2017-06-21 ミツミ電機株式会社 Optical scanning device, the optical scanning controller and an optical scanning unit
WO2014194968A1 (en) * 2013-06-07 2014-12-11 Abb Technology Ltd A converter arrangement for power compensation and a method for controlling a power converter
DE102013211094A1 (en) 2013-06-14 2014-12-18 Robert Bosch Gmbh Energy storage module for an energy storage device and energy storage device with such
US9083230B2 (en) 2013-06-20 2015-07-14 Rockwell Automation Technologies, Inc. Multilevel voltage source converters and systems
DE102013212682B4 (en) 2013-06-28 2017-03-02 Robert Bosch Gmbh Energy storage device with DC voltage supply circuit and method for providing a DC voltage from an energy storage device
DE102013212716A1 (en) 2013-06-28 2014-12-31 Robert Bosch Gmbh Energy storage device with DC voltage supply circuit and method for providing a DC voltage from an energy storage device
DE102013212692A1 (en) 2013-06-28 2014-12-31 Robert Bosch Gmbh Energy storage device with DC power supply circuit
DE102013218081A1 (en) * 2013-09-10 2015-03-12 Robert Bosch Gmbh Battery module device and method for determining a complex impedance of a battery module arranged in a device battery module
CN105723607A (en) * 2013-09-23 2016-06-29 西门子公司 New four-level converter cell topology for cascaded modular multilevel converters
DE102013221830A1 (en) 2013-10-28 2015-04-30 Robert Bosch Gmbh Charging circuit for an energy storage device and method for charging an energy storage device
DE102013224511A1 (en) 2013-11-29 2015-06-03 Robert Bosch Gmbh Electric propulsion system with charging circuit for an energy storage device and method for operating an energy storage device
EP2881811A1 (en) * 2013-12-06 2015-06-10 Alstom Technology Ltd A control apparatus for a power converter comprising a redundent control system of two controllers
US9520800B2 (en) 2014-01-09 2016-12-13 Rockwell Automation Technologies, Inc. Multilevel converter systems and methods with reduced common mode voltage
US9325252B2 (en) 2014-01-13 2016-04-26 Rockwell Automation Technologies, Inc. Multilevel converter systems and sinusoidal pulse width modulation methods
DE102014201363A1 (en) * 2014-01-27 2015-07-30 Robert Bosch Gmbh Method and circuit arrangement for determining the coulomb efficiency of battery modules
DE102014201365A1 (en) * 2014-01-27 2015-07-30 Robert Bosch Gmbh Method and circuit arrangement for determining the coulomb efficiency of battery modules
DE102014201711A1 (en) 2014-01-31 2015-08-06 Robert Bosch Gmbh Energy storage device system with energy storage device and method for driving an energy storage device
EP3138176A1 (en) * 2014-05-22 2017-03-08 Siemens Aktiengesellschaft Converter for symmetrical reactive power compensation, and a method for controlling same
US9819286B2 (en) 2014-06-13 2017-11-14 Siemens Aktiengesellschaft Converter for outputting reactive power, and method for controlling said converter
US9667164B2 (en) * 2014-06-27 2017-05-30 Alstom Technology, Ltd. Voltage-source converter full bridge module IGBT configuration and voltage-source converter
WO2016008003A1 (en) * 2014-07-14 2016-01-21 Davies Alexander Phillip Method for controlling a power conversion system
DE102014218063A1 (en) 2014-09-10 2016-03-10 Robert Bosch Gmbh Energy storage device and method for operating an energy storage device
JP2016063610A (en) * 2014-09-17 2016-04-25 株式会社東芝 Power converter
US9611836B2 (en) 2014-11-26 2017-04-04 Siemens Aktiengesellschaft Wind turbine power conversion system
US9559541B2 (en) 2015-01-15 2017-01-31 Rockwell Automation Technologies, Inc. Modular multilevel converter and charging circuit therefor
US9748862B2 (en) 2015-05-13 2017-08-29 Rockwell Automation Technologies, Inc. Sparse matrix multilevel actively clamped power converter
US20160380556A1 (en) * 2015-06-26 2016-12-29 Board Of Trustees Of Michigan State University System and method for optimizing fundamental frequency modulation for a cascaded multilevel inverter
CN105024574B (en) * 2015-07-22 2017-09-08 上海交通大学 mmc capacitor voltage sub-module Ping Heng control method is applied to the phase shift modulation of the carrier
WO2017033069A1 (en) 2015-08-24 2017-03-02 Imperix Sa Distributed modulation system and method for power electronic applications
CN105470978B (en) * 2016-01-12 2017-10-13 国电南瑞科技股份有限公司 A static var compensator group coordinated control method
US9812990B1 (en) 2016-09-26 2017-11-07 Rockwell Automation Technologies, Inc. Spare on demand power cells for modular multilevel power converter

Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3581212A (en) 1969-07-31 1971-05-25 Gen Electric Fast response stepped-wave switching power converter circuit
US3867643A (en) 1974-01-14 1975-02-18 Massachusetts Inst Technology Electric power converter
US4052658A (en) 1976-10-18 1977-10-04 Sundstrand Corporation Inverter circuit for producing synthesized sinusoidal waveforms
US4052657A (en) 1976-04-22 1977-10-04 Rockwell International Corporation Distribution system for a. c. electrical energy derived from d. c. energy sources
FR2349231A1 (en) 1976-04-23 1977-11-18 Thomson Csf Variable frequency high power signal generator - produces four control signals for four transistors in each of several bridge circuits across load
US4470005A (en) 1982-11-02 1984-09-04 Westinghouse Electric Corp. Static VAR generator having a thyristor circuit arrangement providing reduced losses
US4571535A (en) 1984-11-15 1986-02-18 Westinghouse Electric Corp. VAR Generator having controlled discharge of thyristor switched capacitors
US5270657A (en) 1992-03-23 1993-12-14 General Electric Company Split gradient amplifier for an MRI system
US5311419A (en) 1992-08-17 1994-05-10 Sundstrand Corporation Polyphase AC/DC converter
US5329221A (en) 1992-08-12 1994-07-12 Electric Power Research Institute Advanced static var compensator control system
US5345375A (en) 1991-12-16 1994-09-06 Regents Of The University Of Minnesota System and method for reducing harmonic currents by current injection
US5424627A (en) 1991-12-13 1995-06-13 Electric Power Research Institute Modular thyristor controlled series capacitor control system
US5481448A (en) 1990-09-14 1996-01-02 Hitachi, Ltd. Multilevel inverter having voltage dividing capacitors distributed across multiple arms
US5532575A (en) 1994-01-08 1996-07-02 Gec Alsthom Limited Multilevel converter with capacitor voltage balancing
US5535114A (en) 1991-10-22 1996-07-09 Hitachi, Ltd. Power converter
US5644483A (en) * 1995-05-22 1997-07-01 Lockheed Martin Energy Systems, Inc. Voltage balanced multilevel voltage source converter system

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3581212A (en) 1969-07-31 1971-05-25 Gen Electric Fast response stepped-wave switching power converter circuit
US3867643A (en) 1974-01-14 1975-02-18 Massachusetts Inst Technology Electric power converter
US4052657A (en) 1976-04-22 1977-10-04 Rockwell International Corporation Distribution system for a. c. electrical energy derived from d. c. energy sources
FR2349231A1 (en) 1976-04-23 1977-11-18 Thomson Csf Variable frequency high power signal generator - produces four control signals for four transistors in each of several bridge circuits across load
US4052658A (en) 1976-10-18 1977-10-04 Sundstrand Corporation Inverter circuit for producing synthesized sinusoidal waveforms
US4470005A (en) 1982-11-02 1984-09-04 Westinghouse Electric Corp. Static VAR generator having a thyristor circuit arrangement providing reduced losses
US4571535A (en) 1984-11-15 1986-02-18 Westinghouse Electric Corp. VAR Generator having controlled discharge of thyristor switched capacitors
US5481448A (en) 1990-09-14 1996-01-02 Hitachi, Ltd. Multilevel inverter having voltage dividing capacitors distributed across multiple arms
US5535114A (en) 1991-10-22 1996-07-09 Hitachi, Ltd. Power converter
US5424627A (en) 1991-12-13 1995-06-13 Electric Power Research Institute Modular thyristor controlled series capacitor control system
US5345375A (en) 1991-12-16 1994-09-06 Regents Of The University Of Minnesota System and method for reducing harmonic currents by current injection
US5270657A (en) 1992-03-23 1993-12-14 General Electric Company Split gradient amplifier for an MRI system
US5329221A (en) 1992-08-12 1994-07-12 Electric Power Research Institute Advanced static var compensator control system
US5311419A (en) 1992-08-17 1994-05-10 Sundstrand Corporation Polyphase AC/DC converter
US5532575A (en) 1994-01-08 1996-07-02 Gec Alsthom Limited Multilevel converter with capacitor voltage balancing
US5644483A (en) * 1995-05-22 1997-07-01 Lockheed Martin Energy Systems, Inc. Voltage balanced multilevel voltage source converter system

Non-Patent Citations (29)

* Cited by examiner, † Cited by third party
Title
"A Comparison of Different Circuit Configurations for an Advanced Static VAR Compensator (ASVC)," by D. Wuest, H. Stemmler & G. Scheuer in IEEE Power Electronics Specialists Conference, Toledo, Spain, Jun. 29-Jul. 3, 1992 (PESC '92 Record) vol. 1, pp. 521-529.
"A New N-Level High Voltage Inversion System," by Young-Seok Kim, Beom-Seok Seo & Dong-Seok Hyun, in IEEE Doc No 0-7803-0891-3/93, pp. 1252-1258.
"A Novel Multilevel Structure for Voltage Source Inverter," by M. Carpita, S. Tenconi, & M. Fracchia in EPE Firenze, 1991, pp. 1-090 through 1-094.
"A Static VAR Generator Using a Staircase Waveform Multilevel Voltage-Source Converter," by Fang Zheng Peng & Jih-Sheng Lai in Power Quality, Sep. 1994 Proceedings, pp. 58-66.
"A Study of Active Power Filters Using Quad-Series Voltage-Source PWM Converters for Harmonic Compensation," by Fang-Zhang Peng, Hirofumi Akagi & Akira Nabae in IEEE Transactions on Power Electronics, vol. 5, No. 1, Jan. 1990, pp. 9-15.
"Active AC Power Filters," by L. Gyugyi & E.C. Strycula, in IAS '76 Annual, 19-C, pp. 529-535.
"Advanced Static Compensation Using a Multilevel GTO Thyristor Inverter," by R.W. Menzies & Yiping Zhuang, in IEEE Transactions on Power Delivery, vol. 10, No. 2, Apr. 1995, pp. 732-738.
"An Active Power Quality Conditioner for Reactive Power and Harmonics Compensation," by N.R. Raju, S.S. Venkata, R.A. Kagalwala, & V. V. Sastry, in an unidentified publication, on Dec. 6, 1995, pp. 209-214.
"Analysis and Design of a Three-Phase Current Source Solid-State V Ar Compensator," by Luis T. Moran, Phoivos D. Ziogas, & Geza Joos in IEEE Transactions on Industry Applications, vol. 25, No. 2, Mar./Apr. 1989, pp. 356-365.
"Analysis of GTO-Based Static VAR Compensators," by D.R. Trainer, S.B. Tennakoon, & R.E. Morrison in IEEE Proceedings-Electric Power Applications, vol. 141, No. 6, Nov. 1994, pp. 293-302.
"Analysis of GTO-Based Static VAR Compensators," by D.R. Trainer, S.B. Tennakoon, & R.E. Morrison in IEEE Proceedings—Electric Power Applications, vol. 141, No. 6, Nov. 1994, pp. 293-302.
"Comparison of Multilevel Inverters for Static VAr Compensation," by Clark Hochgraf, Robert Lasseter, Deepak Divan, & T.A. Lipo, in IEEE Doc. No. 0-7803-1993-1/94, pp. 921-928.
"Control Strategy of Active Power Filters Using Multiple Voltage-Source PWM Converters," by Hirofumi Akagi, Akira Nabae, & Satoshi Atoh, in IEEE Transactions on Industry Applications, vol. 1A-22, No. 3, May/Jun. 1986, pp. 460-465.
"Controlling a Back-to-Back DC Link to Operate as a Phase Shift Transformer," by D.A. Woodford & R.W. Menzies, paper 14-202 in CIGRE 1994.
"Development of a ±100 MVAR Static Condenser for Voltage Control of Transmission Systems," by C. Schauder, M. Gernhardt, E. Stacey, T. Lemak, L. Gyugyi, T.W. Cease & A. Edris, a paper presented at the IEEE/PES 1994 Summer Meeting, San Francisco, California, Jul. 24-28, 1994.
"Development of a Large Static V Ar Generator Using Self-Commutated Inverters for Improving Power System Stability," by Shosuke Mori, Masatoshi Takeda et al. in IEEE Transactions on Power Systems, vol. 8, No. 1, Feb. 1993, pp. 371-377.
"Experimental Investigation of an Advanced Static VAr Compensator," by J.B. Ekanayake, N. Jenkins, & C.B. Cooper in IEEE Proceedings-Generation, Transmission and Distribution, vol. 142, No. 2, Mar. 1995, pp. 202-210.
"Experimental Investigation of an Advanced Static VAr Compensator," by J.B. Ekanayake, N. Jenkins, & C.B. Cooper in IEEE Proceedings—Generation, Transmission and Distribution, vol. 142, No. 2, Mar. 1995, pp. 202-210.
"Force-Commutated Reactive-Power Compensator," by Loren H. Walker, in IEEE Transactions on Industry Applications, vol. 1A-22, No. 6, Nov./Dec. 1986, pp. 1091-1104.
"High-Performance Current Control Techniques for Applications to Multilevel High-Power Voltage Source Inverters," by Mario Marchesoni, in IEEE Transactions on Power Electronics, vol. 7, No. 1, Jan. 1992, pp. 189-204.
"Modeling Analysis and Control of Static VAr Compensator Using Three-Level Inverter," by Guk C. Cho, Nam S. Choi, Chun T. Rim & Gyu H. Cho, in Conference Record of the IEEE Industry Applications Society Annual Meeting, Houston, Texas, Oct. 4-9, 1992, vol. 1, pp. 837-843.
"Modeling and Analysis of a Multilevel Voltage Source Inverter Applied as a Static VAr Compensator," by Nam S. Choi, Guk C. Cho, & Gyu H. Cho, in International Journal of Electronics, 1993, vol. 75, No. 5, 1015-1034.
"Modeling and Analysis of a Static VAr Compensator Using Multilevel Voltage Source Inverter," by Nam S. Choi, Guk C. Cho & Gyu H. Cho, in Conference Record of the 1993 IEEE Industry Applications Conference, 28th IAS Annual Meeting, Toronto, Canada Oct. 1993, pp. 901-908.
"Naturally Commutated Thyristor-Controlled High-Pulse VAr Compensator," by J. Arrillaga, R.D. Brough, & R.M. Duke, in IEEE Proceedings-Generation, Transmission & Distribution, vol. 142, No. 2, Mar. 1995, pp. 219-224.
"Naturally Commutated Thyristor-Controlled High-Pulse VAr Compensator," by J. Arrillaga, R.D. Brough, & R.M. Duke, in IEEE Proceedings—Generation, Transmission & Distribution, vol. 142, No. 2, Mar. 1995, pp. 219-224.
"Principles and Applications of Static Thyristor-Controlled Shunt Compensators," by L. Gyugyi, R.A. Otto, & T.H. Putman, in IEEE Transactions on Power Apparatus and Systems, vol. PAS-97, No. 5, Sep./Oct. 1978, pp. 1935-1945.
"Simulation and Experimental Study of a Reactively Loaded PWM Converter as a Fast Source of Reactive Power," by Jacobus D. Van Wyk, Dirk Adrian Marshall & Septimus Boshoff in IEEE Transactions on Industry Applications, vol. 1A-22, No. 6, Nov./Dec. 1986, pp. 1082-1090.
"Which is Better at a High Power Reactive Power Compensation System: High PWM Frequency or Multiple Connections?" by Nagataka Seki & Hiroshi Uchino, IEEE Doc No. 0-7803-1993-1/94, pp. 946-953.
Japanese article "Static Type Reactive Power Generator (SVG) of Shinbiwajima Transformer Station," by Shigeru Nakajima and Ichibei Komori in Tetsudo to Denki Gijutsu("Railroad and Electric Technology") vol. 5 No. 6 (1994) pp. 41-45 (w/translation).

Cited By (48)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6556461B1 (en) * 2001-11-19 2003-04-29 Power Paragon, Inc. Step switched PWM sine generator
USRE41040E1 (en) 2001-11-19 2009-12-15 Power Paragon, Inc. Step switched PWM sine generator
US20050127853A1 (en) * 2003-12-12 2005-06-16 Gui-Jia Su Multi-level dc bus inverter for providing sinusoidal and pwm electrical machine voltages
US6969967B2 (en) * 2003-12-12 2005-11-29 Ut-Battelle Llc Multi-level dc bus inverter for providing sinusoidal and PWM electrical machine voltages
US20090102288A1 (en) * 2007-10-17 2009-04-23 Edwin Arthur Blackmond Modular Power Supply
US7847436B2 (en) * 2007-10-17 2010-12-07 Edwin Arthur Blackmond Modular power supply
US20090302682A1 (en) * 2008-05-30 2009-12-10 Siemens Energy & Automation, Inc. Method and system for reducing switching losses in a high-frequency multi-cell power supply
US8169107B2 (en) 2008-05-30 2012-05-01 Siemens Industry, Inc. Method and system for reducing switching losses in a high-frequency multi-cell power supply
US8279640B2 (en) 2008-09-24 2012-10-02 Teco-Westinghouse Motor Company Modular multi-pulse transformer rectifier for use in symmetric multi-level power converter
US7830681B2 (en) 2008-09-24 2010-11-09 Teco-Westinghouse Motor Company Modular multi-pulse transformer rectifier for use in asymmetric multi-level power converter
US8045346B2 (en) 2008-09-24 2011-10-25 Teco-Westinghouse Motor Company Modular multi-pulse transformer rectifier for use in asymmetric multi-level power converter
US8213198B2 (en) 2008-12-31 2012-07-03 Teco-Westinghouse Motor Company Partial regeneration in a multi-level power inverter
US7940537B2 (en) 2008-12-31 2011-05-10 Teco-Westinghouse Motor Company Partial regeneration in a multi-level power inverter
US20110199033A1 (en) * 2008-12-31 2011-08-18 Mehdi Abolhassani Partial Regeneration In A Multi-Level Power Inverter
US20100142234A1 (en) * 2008-12-31 2010-06-10 Mehdi Abolhassani Partial regeneration in a multi-level power inverter
US20100213921A1 (en) * 2009-02-26 2010-08-26 Mehdi Abolhassani Pre-Charging An Inverter Using An Auxiliary Winding
US8223515B2 (en) 2009-02-26 2012-07-17 TECO—Westinghouse Motor Company Pre-charging an inverter using an auxiliary winding
US8259480B2 (en) * 2009-06-18 2012-09-04 Abb Technology Ag Arrangement for exchanging power
US20120081939A1 (en) * 2009-06-18 2012-04-05 Jean-Philippe Hasler Arrangement For Exchanging Power
US20120092906A1 (en) * 2009-06-18 2012-04-19 Jean-Philippe Hasler Arrangement for exchanging power
US8416595B2 (en) * 2009-06-18 2013-04-09 Abb Technology Ag Arrangement for exchanging power
US8130501B2 (en) 2009-06-30 2012-03-06 Teco-Westinghouse Motor Company Pluggable power cell for an inverter
US8254076B2 (en) 2009-06-30 2012-08-28 Teco-Westinghouse Motor Company Providing modular power conversion
US9220179B2 (en) 2009-06-30 2015-12-22 Teco-Westinghouse Motor Company Pluggable power cell for an inverter
US8711530B2 (en) 2009-06-30 2014-04-29 Teco-Westinghouse Motor Company Pluggable power cell for an inverter
US9609777B2 (en) 2009-06-30 2017-03-28 Teco-Westinghouse Motor Company Pluggable power cell for an inverter
US8976526B2 (en) 2009-06-30 2015-03-10 Teco-Westinghouse Motor Company Providing a cooling system for a medium voltage drive system
US8575479B2 (en) 2009-06-30 2013-11-05 TECO—Westinghouse Motor Company Providing a transformer for an inverter
US9257916B2 (en) 2009-07-16 2016-02-09 Cyboenergy, Inc. Power inverters with multiple input channels
US20110019449A1 (en) * 2009-07-21 2011-01-27 Shuji Katoh Power converter apparatus
US8547718B2 (en) * 2009-07-21 2013-10-01 Hitachi, Ltd. Power converter apparatus
US20110235376A1 (en) * 2010-03-25 2011-09-29 Feng Frank Z Multi-level parallel phase converter
US8374009B2 (en) 2010-03-25 2013-02-12 Hamilton Sundstrand Corporation Multi-level parallel phase converter
US8536734B2 (en) 2010-04-14 2013-09-17 East Coast Research And Development, Llc Apparatus for inverting DC voltage to AC voltage
EP2667279A4 (en) * 2011-01-18 2016-12-21 Tokyo Inst Tech Power converter and method for controlling same
US20120212065A1 (en) * 2011-02-15 2012-08-23 George Shu-Xing Cheng Scalable and redundant mini-inverters
US9093902B2 (en) * 2011-02-15 2015-07-28 Cyboenergy, Inc. Scalable and redundant mini-inverters
US8601190B2 (en) 2011-06-24 2013-12-03 Teco-Westinghouse Motor Company Providing multiple communication protocols for a control system having a master controller and a slave controller
US9331488B2 (en) 2011-06-30 2016-05-03 Cyboenergy, Inc. Enclosure and message system of smart and scalable power inverters
US9294003B2 (en) 2012-02-24 2016-03-22 Board Of Trustees Of Michigan State University Transformer-less unified power flow controller
US8730696B2 (en) * 2012-07-16 2014-05-20 Delta Electronics, Inc. Multi-level voltage converter
US20140016380A1 (en) * 2012-07-16 2014-01-16 Delta Electronics, Inc. Multi-level voltage converter
US20140252862A1 (en) * 2013-03-07 2014-09-11 Cyboenergy, Inc. Maximizing Power Production at Low Sunlight by Solar Power Mini-Inverters
US9331489B2 (en) * 2013-03-07 2016-05-03 Cyboenergy, Inc. Maximizing power production at low sunlight by solar power mini-inverters
US9941813B2 (en) 2013-03-14 2018-04-10 Solaredge Technologies Ltd. High frequency multi-level inverter
US9318974B2 (en) 2014-03-26 2016-04-19 Solaredge Technologies Ltd. Multi-level inverter with flying capacitor topology
US20160134201A1 (en) * 2014-11-06 2016-05-12 Delta Electronics, Inc. Control method and control device for inverter system
US9634575B2 (en) * 2014-11-06 2017-04-25 Delta Electronics, Inc. Control method and control device for inverter system

Also Published As

Publication number Publication date Type
US5642275A (en) 1997-06-24 grant

Similar Documents

Publication Publication Date Title
Liang et al. A new type of STATCOM based on cascading voltage-source inverters with phase-shifted unipolar SPWM
Kim et al. New control scheme for AC-DC-AC converter without DC link electrolytic capacitor
Ortúzar et al. Voltage-source active power filter based on multilevel converter and ultracapacitor DC link
Zhao et al. Voltage and power balance control for a cascaded H-bridge converter-based solid-state transformer
Ekanayake et al. A three-level advanced static VAr compensator
US6058031A (en) Five level high power motor drive converter and control system
Tolbert et al. A multilevel converter-based universal power conditioner
US5886888A (en) Voltage source type power converting apparatus
Ghosh et al. Compensation of distribution system voltage using DVR
Peng et al. A universal STATCOM with delta-connected cascade multilevel inverter
Mishra et al. Operation of a DSTATCOM in voltage control mode
Zhang et al. Force commutated HVDC and SVC based on phase-shifted multi-converter modules
Norouzi et al. Two control schemes to enhance the dynamic performance of the STATCOM and SSSC
Barrena et al. Individual voltage balancing strategy for PWM cascaded H-bridge converter-based STATCOM
Song et al. Multilevel optimal modulation and dynamic control strategies for STATCOMs using cascaded multilevel inverters
US7046531B2 (en) Transformerless static voltage inverter for battery systems
Khomfoi et al. Multilevel power converters
US7031176B2 (en) Inverter
US6757185B2 (en) Method and control circuitry for a three-phase three-level boost-type rectifier
US20120069610A1 (en) Converter
Aredes et al. Three-phase four-wire shunt active filter control strategies
Peng et al. Dynamic performance and control of a static var generator using cascade multilevel inverters
US6236580B1 (en) Modular multi-level adjustable supply with series connected active inputs
US20120188803A1 (en) Converter with reactive power compensation
Shukla et al. Hysteresis current control operation of flying capacitor multilevel inverter and its application in shunt compensation of distribution systems

Legal Events

Date Code Title Description
REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees