Sunnanmuutoksia. Luova, innovatiivinen ja hyvinvoiva Etelä-Karjala

Suunnanmuutoksia -raporttiin on koottu hankkeen tuloksia sekä aiemmissa Etelä-Karjala-instituutin hankkeissa syntynyttä tietoa. Raportti on tiivis lukupaketti, joka sisältää seitsemän artikkelia maakunnan kannalta keskeisistä aiheista. Jokaisen ytimekkään artikkelin lopussa on toimenpide-ehdotuksia, jotka on laadittu aluekehitystä silmälläpitäen. Raportissa pohditaan kestävän rakennemuutoksen mahdollisuuksia, maakunnan identiteetin ja median suhdetta, Saimaata ja veden merkitystä, yliopiston asemaa maakunnassa, venäläisten maahanmuuttoa ja monikulttuurisuutta, matkailun kehittämistä sekä kulttuurin merkitystä maakunnan hyvinvoinnille. Etelä-Karjalassa on tehty paljon työtä hyvinvoinnin eteen ja kirjoitettu runsaasti erilaisia strategioita. Strategioiden toteuttajia ei tunnu kuitenkaan olevan tarpeeksi. Maakunta on ikään kuin odottavassa tilassa ja toivoo, että jostakin löytyisi veturi, joka tulisi vetämään maakuntaa eteenpäin. Suunnanmuutoksia -raportin kirjoittajat esittävät, että Etelä-Karjalan on aika siirtyä veturin odottamisesta malliin, jossa kaikki toimijat ottavat vastuuta oma-aloitteisina toimijoina. Luovuus ei synny siitä, että yksi vetää muita perässään kohti tiettyä päämäärää, vaan siitä, että kukin toimija ottaa vastuun omasta hyvinvoinnistaan ja kulkee luovasti sitä kohti. Suunnanmuutoksia -raportti päättyy toivomukseen maakunnallisesta flow-ilmiöstä, keskittymisen, osaamisen ja onnistumisen kautta saavutetusta onnellisuuden tunteesta. Sen alkua ja suuntaa on mahdoton ennustaa, mutta aika on kypsä entistä radikaaleimmille innovaatioille. Näiden tekeminen vaatii flowta; halua ja rohkeutta tavoitella jotakin sellaista, joka on arkipäiväisyyden yläpuolella. Raportti on suunnattu kaikille Etelä-Karjalan tulevaisuudesta ja kehittämisestä kiinnostuneille. Raportin kirjoittaneet Etelä-Karjala-instituutin tutkijat toivovat etenkin kuntien päättäjien ja aluekehittäjien ottavan sen työkalukseen.

SÍNTESE E PROPRIEDADES DE SÍLICAS HÍBRIDAS CONTENDO SURFACTANTES CETILTRIALQUILAMÔNIO

This work presents the synthesis of silicas containing cetyltrialkylammoniun surfactants in their mesopores. Initially, the aqueous dispersions of these surfactants were characterized by small-angle X-ray scattering (SAXS). The hybrid silicas obtained from these dispersions were evaluated by X-ray diffractometry (XRD) and nitrogen physisorption. The XRD showed that, increasing the head size, there is a shift of the peak corresponding to the (100) diffraction plane to smaller 2θ angles, which indicates an increase in the silicas porous diameter. The increasing of the silicas porous diameter was confirmed by nitrogen physisorption. The base catalytic properties of these hybrid silicas were evaluated in the transesterification reaction showing that those containing the cations C16Et3+ and C16Pr3+ showed better performance.

Wet oxidation of recalcitrant lignin waters: Experimental and kinetic studies

The dissertation is based on four articles dealing with recalcitrant lignin water purification. Lignin, a complicated substance and recalcitrant to most treatment technologies, inhibits seriously pulp and paper industry waste management. Therefore, lignin is studied, using WO as a process method for its degradation. A special attention is paid to the improvement in biodegradability and the reduction of lignin content, since they have special importance for any following biological treatment. In most cases wet oxidation is not used as a complete ' mineralization method but as a pre treatment in order to eliminate toxic components and to reduce the high level of organics produced. The combination of wet oxidation with a biological treatment can be a good option due to its effectiveness and its relatively low technology cost. The literature part gives an overview of Advanced Oxidation Processes (AOPs). A hot oxidation process, wet oxidation (WO), is investigated in detail and is the AOP process used in the research. The background and main principles of wet oxidation, its industrial applications, the combination of wet oxidation with other water treatment technologies, principal reactions in WO, and key aspects of modelling and reaction kinetics are presented. There is also given a wood composition and lignin characterization (chemical composition, structure and origin), lignin containing waters, lignin degradation and reuse possibilities, and purification practices for lignin containing waters. The aim of the research was to investigate the effect of the operating conditions of WO, such as temperature, partial pressure of oxygen, pH and initial concentration of wastewater, on the efficiency, and to enhance the process and estimate optimal conditions for WO of recalcitrant lignin waters. Two different waters are studied (a lignin water model solution and debarking water from paper industry) to give as appropriate conditions as possible. Due to the great importance of re using and minimizing the residues of industries, further research is carried out using residual ash of an Estonian power plant as a catalyst in wet oxidation of lignin-containing water. Developing a kinetic model that includes in the prediction such parameters as TOC gives the opportunity to estimate the amount of emerging inorganic substances (degradation rate of waste) and not only the decrease of COD and BOD. The degradation target compound, lignin is included into the model through its COD value (CODligning). Such a kinetic model can be valuable in developing WO treatment processes for lignin containing waters, or other wastewaters containing one or more target compounds. In the first article, wet oxidation of "pure" lignin water was investigated as a model case with the aim of degrading lignin and enhancing water biodegradability. The experiments were performed at various temperatures (110 -190°C), partial oxygen pressures (0.5 -1.5 MPa) and pH (5, 9 and 12). The experiments showed that increasing the temperature notably improved the processes efficiency. 75% lignin reduction was detected at the lowest temperature tested and lignin removal improved to 100% at 190°C. The effect of temperature on the COD removal rate was lower, but clearly detectable. 53% of organics were oxidized at 190°C. The effect of pH occurred mostly on lignin removal. Increasing the pH enhanced the lignin removal efficiency from 60% to nearly 100%. A good biodegradability ratio (over 0.5) was generally achieved. The aim of the second article was to develop a mathematical model for "pure" lignin wet oxidation using lumped characteristics of water (COD, BOD, TOC) and lignin concentration. The model agreed well with the experimental data (R2 = 0.93 at pH 5 and 12) and concentration changes during wet oxidation followed adequately the experimental results. The model also showed correctly the trend of biodegradability (BOD/COD) changes. In the third article, the purpose of the research was to estimate optimal conditions for wet oxidation (WO) of debarking water from the paper industry. The WO experiments were' performed at various temperatures, partial oxygen pressures and pH. The experiments showed that lignin degradation and organics removal are affected remarkably by temperature and pH. 78-97% lignin reduction was detected at different WO conditions. Initial pH 12 caused faster removal of tannins/lignin content; but initial pH 5 was more effective for removal of total organics, represented by COD and TOC. Most of the decrease in organic substances concentrations occurred in the first 60 minutes. The aim of the fourth article was to compare the behaviour of two reaction kinetic models, based on experiments of wet oxidation of industrial debarking water under different conditions. The simpler model took into account only the changes in COD, BOD and TOC; the advanced model was similar to the model used in the second article. Comparing the results of the models, the second model was found to be more suitable for describing the kinetics of wet oxidation of debarking water. The significance of the reactions involved was compared on the basis of the model: for instance, lignin degraded first to other chemically oxidizable compounds rather than directly to biodegradable products. Catalytic wet oxidation of lignin containing waters is briefly presented at the end of the dissertation. Two completely different catalysts were used: a commercial Pt catalyst and waste power plant ash. CWO showed good performance using 1 g/L of residual ash gave lignin removal of 86% and COD removal of 39% at 150°C (a lower temperature and pressure than with WO). It was noted that the ash catalyst caused a remarkable removal rate for lignin degradation already during the pre heating for `zero' time, 58% of lignin was degraded. In general, wet oxidation is not recommended for use as a complete mineralization method, but as a pre treatment phase to eliminate toxic or difficultly biodegradable components and to reduce the high level of organics. Biological treatment is an appropriate post treatment method since easily biodegradable organic matter remains after the WO process. The combination of wet oxidation with subsequent biological treatment can be an effective option for the treatment of lignin containing waters.

Improving demand forecasting practices in the industrial context

Demand forecasting is one of the fundamental managerial tasks. Most companies do not know their future demands, so they have to make plans based on demand forecasts. The literature offers many methods and approaches for producing forecasts. When selecting the forecasting approach, companies need to estimate the benefits provided by particular methods, as well as the resources that applying the methods call for. Former literature points out that even though many forecasting methods are available, selecting a suitable approach and implementing and managing it is a complex cross-functional matter. However, research that focuses on the managerial side of forecasting is relatively rare. This thesis explores the managerial problems that are involved when demand forecasting methods are applied in a context where a company produces products for other manufacturing companies. Industrial companies have some characteristics that differ from consumer companies, e.g. typically a lower number of customers and closer relationships with customers than in consumer companies. The research questions of this thesis are: 1. What kind of challenges are there in organizing an adequate forecasting process in the industrial context? 2. What kind of tools of analysis can be utilized to support the improvement of the forecasting process? The main methodological approach in this study is design science, where the main objective is to develop tentative solutions to real-life problems. The research data has been collected from two organizations. Managerial problems in organizing demand forecasting can be found in four interlinked areas: 1. defining the operational environment for forecasting, 2. defining the forecasting methods, 3. defining the organizational responsibilities, and 4. defining the forecasting performance measurement process. In all these areas, examples of managerial problems are described, and approaches for mitigating these problems are outlined.

Pienten osakeyhtiöiden verosuunnittelu - empiirinen tutkimus

Tutkimuksen aiheeksi valittiin pienten osakeyhtiöiden verosuunnittelu. Tutkimuksen teoreettinen viitekehys perustui aiempaan laskentatoimen empiiriseen verotutkimukseen sekä laskentatoimen kontingenssiteoreettiseen pk-yritystutkimukseen. Tutkimusaineistoa kerättiin kyselytutkimuksella sekä tilinpaatostietokannasta Voitto+. Kyselytutkimukseen valittiin satunnaisotannalla osakeyhtiötä Etelä Suomen läänistä, joiden liikevaihto oli välillä 1 10 milj. euroa. Kyselytutkimukseen vastasi 216 yritystä, jolloin vastausprosentiksi saatiin 21,3. Kerättyä tutkimusaineistoa analysoitiin kvantitatiivisin menetelmin. Pääasiallisina analysointimenetelminä käytettiin pääkomponentti-, klusteri- ja regressioanalyysiä. Tutkimuksen tavoitteeksi asetettiin kokonaiskuvan muodostaminen pienten osakeyhtiöiden verosuunnittelusta, verosuunnittelun asemointi osaksi yrityksen taloushallintoa sekä yritysten erilaisia verosuunnittelustrategioita selittävien tekijöiden tunnistaminen. Tutkimusaineistosta kyettiin tunnistamaan pääkomponenttianalyysillä neljä erilaista verosuunnitteluorientaatiota: valistunut, resursseja panostava, veroa minimoiva sekä vastuuta ulkoistava. Verosuunnitteluorientaatioita kuvaavien muuttujien avulla yritykset jaettiin klusterianalyysilla neljään ryhmään. Yritykset nimettiin ryhmien luonteidensa mukaisesti verosuunnittelun osalta vastuun ulkoistajiksi, veron minimoijiksi, veroneutraaleiksi sekä valistuneiksi. Verosuunnitteluvastuuta ulkoistavien yritysten ryhmään kuului n. 57 % kyselyyn vastanneista yrityksistä. Tulos osoittaa sen, että yritykset ovat verosuunnittelun osalta paljolti riippuvaisia taloushallinnon sidosryhmistä, tilitoimistoista sekä tilintarkastajista. Tulosta voidaan tulkita myös niin, että taloushallinnon sidosryhmien ammattitaito verosuunnittelun osalta on keskeisessä roolissa, kun arvioidaan, miten yritysten välinen tasapuolisuus verotuksen osalta käytännössä toteutuu. Yritysten erilaisia verosuunnitteluorientaatioita, jotka kuvasivat yritysten verosuunnittelustrategioita, ei kyetty kvantitatiivisilla analyyseilla selittämään samoilla muuttujilla kuin yritysten erilaisia johdon laskentatoimen käytänteitä. Tätä havaintoa tulkittiin siten, että vaikka verosuunnittelu on selkeästi osa yrityksen taloushallintoa, sen asema ei ole johdon laskentatoimen käytänteiden tavoin taloushallinnon ytimessä. Tutkimuksessa kyettiin tuottamaan tuloksia, jotka kontribuoivat aiempia laskentatoimen empiirisiä verotutkimuksia, ja joilla on uutuusarvoa käytännön toimijoiden näkökulmasta.

Managing regulatory risks when outsourcing network-related services in the electricity distribution sector

Deregulation of the electricity sector liberated the electricity sale and production for competitive forces while in the network business, electricity transmission and distribution, natural monopoly positions were recognised. Deregulation was accompanied by efficiencyoriented thinking on the whole electricity supply industry. For electricity distribution this meant a transition from a public service towards profit-driven business guided by economic regulation. Regulation is the primary means to enforce societal and other goals in the regulated monopoly sector. The design of economic regulation is concerned with two main attributes; end-customer price and quality of electricity distribution services. Regulation limits the costs of the regulated company but also defines the desired quality of monopoly services. The characteristics of the regulatory framework and the incentives it provides are therefore decisive for the electricity distribution sector. Regulation is not a static factor; changes in the regulatory practices cause discontinuity points, which in turn generate risks. A variety of social and environmental concerns together with technological advancements have emphasised the relevance of quality regulation, which is expected to lead to the large-scale replacement of overhead lines with underground cables. The electricity network construction activity is therefore currently witnessing revolutionary changes in its competitive landscape. In a business characterised by high statutory involvement and a high level of sunk costs, recognising and understanding the regulatory risks becomes a key success factor. As a response, electricity distribution companies have turned into outsourcing to attain efficiency and quality goals. This doctoral thesis addresses the impacts of regulatory risks on electricity network construction, which is a commonly outsourced activity in the electricity distribution network sector. The chosen research approach is characterised as an action analytical research on account of the fact that regulatory risks are greatly dependent on the individual nature of the regulatory regime applied in the electricity distribution sector. The main contribution of this doctoral thesis is to develop a concept for recognising and managing the business risks stemming from economic regulation. The degree of outsourcing in the sector is expected to increase in years to come. The results of the research provide new knowledge to manage the regulatory risks when outsourcing services.

I den symfoniska fantasin

Soitinnus: piano.

The intrinsic mechanisms of softwood fiber damage in brown stock fiber line unit operations Lappeenranta 2010

The effects of pulp processing on softwood fiber properties strongly influence the properties of wet and dry paper webs. Pulp strength delivery studies have provided observations that much of the strength potential of long fibered pulp is lost during brown stock fiber line operations where the pulp is merely washed and transferred to the subsequent processing stages. The objective of this work was to study the intrinsic mechanisms which maycause fiber damage in the different unit operations of modern softwood brown stock processing. The work was conducted by studying the effects of industrial machinery on pulp properties with some actions of unit operations simulated in laboratory scale devices under controlled conditions. An optical imaging system was created and used to study the orientation of fibers in the internal flows during pulp fluidization in mixers and the passage of fibers through the screen openings during screening. The qualitative changes in fibers were evaluated with existing and standardized techniques. The results showed that each process stage has its characteristic effects on fiber properties: Pulp washing and mat formation in displacement washers introduced fiber deformations especially if the fibers entering the stage were intact, but it did not decrease the pulp strength properties. However, storage chests and pulp transfer after displacement washers contributed to strength deterioration. Pulp screening proved to be quite gentle, having the potential of slightly evening out fiber deformations from very deformed pulps and vice versa inflicting a marginal increase in the deformation indices if the fibers were previously intact. Pulp mixing in fluidizing industrial mixers did not have detrimental effects on pulp strength and had the potential of slightly evening out the deformations, provided that the intensity of fluidization was high enough to allow fiber orientation with the flow and that the time of mixing was short. The chemical and mechanical actions of oxygen delignification had two distinct effects on pulp properties: chemical treatment clearly reduced pulp strength with and without mechanical treatment, and the mechanical actions of process machinery introduced more conformability to pulp fibers, but did not clearly contribute to a further decrease in pulp strength. The chemical composition of fibers entering the oxygen stage was also found to affect the susceptibility of fibers to damage during oxygen delignification. Fibers with the smallest content of xylan were found to be more prone to irreversibledeformations accompanied with a lower tensile strength of the pulp. Fibers poor in glucomannan exhibited a lower fiber strength while wet after oxygen delignification as compared to the reference pulp. Pulps with the smallest lignin content on the other hand exhibited improved strength properties as compared to the references.

L'Univers

1869/12/10 (Numéro 952).

Coopetitive advantage – How firms create and appropriate value by collaborating with their competitors

Collaboration between competing firms (coopetition) has emerged as an important issue forn business practice in many industries. Extant literature has examined coopetition on many levels of analysis, but lacks clarity in distinguishing it explicitly from cooperation between noncompeting organizations. Because of this, the performance implications of coopetition from the perspective of an individual firm are still ambiguous – some research suggests positive results whereas other studies suggest detrimental outcomes. The aim in this dissertation is to narrow these gaps by exploring how firms create and appropriate value through collaboration with their competitors. The dissertation is divided into two parts. The first part comprises an overview of the relevant literature, as well as the conclusions of the whole study, and the second part includes six research publications. Both qualitative and quantitative methodologies are utilized. The results suggest that coopetition embodies the distinctive logic of value creation and appropriation from the perspective of an individual firm, and thus differs in terms of performance implications from cooperation between non-competitors. The distinction comes from the fact that competitors have somewhat similar understanding, capabilities and interest related to certain markets, which is potentially both challenging and beneficial in terms of the individual firm’s competitiveness. It appears from the findings that there are distinctive firm-external and firm-specific factors affecting the success of a coopetition strategy. This study makes three main contributions. First, on the conceptual level it shows the distinction between coopetition and cooperation between non-rivals as a collaborative inter-organizational relationship. Secondly, it sets out a framework and propositions that enhance understanding of how value is created and appropriated in coopetition from the perspective of an individual firm. Thirdly, it offers empirical evidence of how coopetition affects firms’ innovation and market performance, and identifies the focal internal and external factors involved. In general terms, the thesis adds to our knowledge of how a firm can successfully utilize a coopetition strategy in its pursuit of improved performance.

Contextuality in SME Ownership – Studies on Owner-managers’ Ownership Behavior

The purpose of this study is to deepen the understanding of the meaning of ownership in the context of small and medium sized businesses. The research on ownership has increased and widened during the last few years. Ownership is treated increasingly as a psychological phenomenon and it has been noticed that it is common for SME ownermanagers to be mentally linked to their firms. Previous research is suggesting that the central role of an owner-manager in an SME is specifying the concept of SMEs, and that ownership is creating a great heterogeneity within SMEs. This study suggests that there is a variation whitin ownership behaviour of small business owners, and the variation is not totally random or irrational, but following the general patterns of business ownership and of doing business on an SME level. This study is a concept analytical in nature and it builds on the theoretical clarification of the concept of ownership. The theoretical consideration concludes with proposing a definition of ownership: Ownership means a subject’s relatively sustaining position of control in regard to an object. The empirical part of this study consists of five articles, out of which one is conceptual and four are empirical in nature. The notion of contextuality of ownership and the notions of SME characteristics form the basic premise of this study and the theoretical basis for the publications. From the owner-managers point of view, ownership relates the owner also to his or her environment and therefore also to the valuations of the owner-managers. This means that all the dimensions are not equally valued, but certain dimensions in his or her ownership are more important. The presented empirical research is supporting the claim that there is a variation whitin ownership behaviour of small business owners. When bringing the definition of ownership onto a personal and psychological level and into the SME context, it was noticed that ownership is not only a closed system phenomenon occurring between the owner and object owned, but it is also elementarily connected to the environment. Ownership - along with the psychological side of it - is a contextual phenomenon where the fundamental factor is the relatively sustaining position of control with regard to an object. As a contribution of the study, this definition is bringing a new point of view to the discussion on SMEs, SME strategic behaviour and family businesses. The study concludes with pointing out directions for future research.

Multilevel converter modulation: implementation and analysis

Multilevel converters provide an attractive solution to bring the benefits of speed-controlled rotational movement to high-power applications. Therefore, multilevel inverters have attracted wide interest in both the academic community and in the industry for the past two decades. In this doctoral thesis, modulation methods suitable especially for series connected H-bridge multilevel inverters are discussed. A concept of duty cycle modulation is presented and its modification is proposed. These methods are compared with other well-known modulation schemes, such as space-vector pulse width modulation and carrier-based modulation schemes. The advantage of the modified duty-cycle modulation is its algorithmic simplicity. A similar mathematical formulation for the original duty cycle modulation is proposed. The modified duty cycle modulation is shown to produce well-formed phase-to-neutral voltages that have lower total harmonic distortion than the space-vector pulse width modulation and the duty cycle modulation. The space-vector-based solution and the duty cycle modulation, on the other hand, result in a better-quality line-to-line voltage and current waveform. The voltage of the DC links in the modules of the series-connected H-bridge inverter are shown to fluctuate while they are under load. The fluctuation causes inaccuracies in the voltage production, which may result in a failure of the flux estimator in the controller. An extension for upper-level modulation schemes, which changes the switching instants of the inverter so that the output voltage meets the reference voltage accurately regardless of the DC link voltages, is proposed. The method is shown to reduce the error to a very low level when a sufficient switching frequency is used. An appropriate way to organize the switching instants of the multilevel inverter is to make only one-level steps at a time. This causes restrictions on the dynamical features of the modulation schemes. The produced voltage vector cannot be rotated several tens of degrees in a single switching period without violating the above-mentioned one-level-step rule. The dynamical capabilities of multilevel inverters are analyzed in this doctoral thesis, and it is shown that the multilevel inverters are capable of operating even in dynamically demanding metal industry applications. In addition to the discussion on modulation schemes, an overvoltage in multilevel converter drives caused by cable reflection is addressed. The voltage reflection phenomenon in drives with long feeder cables causes premature insulation deterioration and also affects the commonmode voltage, which is one of the main reasons for bearing currents. Bearing currents, on the other hand, cause fluting in the bearings, which results in premature bearing failure. The reflection phenomenon is traditionally prevented by filtering, but in this thesis, a modulationbased filterless method to mitigate the overvoltage in multilevel drives is proposed. Moreover, the mitigation method can be implemented as an extension for upper-level modulation schemes. The method exploits the oscillations caused by two consecutive voltage edges so that the sum of the oscillations results in a mitigated peak of the overvoltage. The applicability of the method is verified by simulations together with experiments with a full-scale prototype.

Parallel-Operating Three-Phase Voltage Source Inverters – Circulating CurrentModeling, Analysis and Mitigation

The maximum realizable power throughput of power electronic converters may be limited or constrained by technical or economical considerations. One solution to this problemis to connect several power converter units in parallel. The parallel connection can be used to increase the current carrying capacity of the overall system beyond the ratings of individual power converter units. Thus, it is possible to use several lower-power converter units, produced in large quantities, as building blocks to construct high-power converters in a modular manner. High-power converters realized by using parallel connection are needed for example in multimegawatt wind power generation systems. Parallel connection of power converter units is also required in emerging applications such as photovoltaic and fuel cell power conversion. The parallel operation of power converter units is not, however, problem free. This is because parallel-operating units are subject to overcurrent stresses, which are caused by unequal load current sharing or currents that flow between the units. Commonly, the term ’circulatingcurrent’ is used to describe both the unequal load current sharing and the currents flowing between the units. Circulating currents, again, are caused by component tolerances and asynchronous operation of the parallel units. Parallel-operating units are also subject to stresses caused by unequal thermal stress distribution. Both of these problemscan, nevertheless, be handled with a proper circulating current control. To design an effective circulating current control system, we need information about circulating current dynamics. The dynamics of the circulating currents can be investigated by developing appropriate mathematical models. In this dissertation, circulating current models aredeveloped for two different types of parallel two-level three-phase inverter configurations. Themodels, which are developed for an arbitrary number of parallel units, provide a framework for analyzing circulating current generation mechanisms and developing circulating current control systems. In addition to developing circulating current models, modulation of parallel inverters is considered. It is illustrated that depending on the parallel inverter configuration and the modulation method applied, common-mode circulating currents may be excited as a consequence of the differential-mode circulating current control. To prevent the common-mode circulating currents that are caused by the modulation, a dual modulator method is introduced. The dual modulator basically consists of two independently operating modulators, the outputs of which eventually constitute the switching commands of the inverter. The two independently operating modulators are referred to as primary and secondary modulators. In its intended usage, the same voltage vector is fed to the primary modulators of each parallel unit, and the inputs of the secondary modulators are obtained from the circulating current controllers. To ensure that voltage commands obtained from the circulating current controllers are realizable, it must be guaranteed that the inverter is not driven into saturation by the primary modulator. The inverter saturation can be prevented by limiting the inputs of the primary and secondary modulators. Because of this, also a limitation algorithm is proposed. The operation of both the proposed dual modulator and the limitation algorithm is verified experimentally.