UPS Inverter 砞璸

UPS爵传瑈竟ぇDSPユ瑈铆溃北

DSP Control of a Half-Bridge UPS Inverter for Sinusoidal Voltage Regulation with Robust Performance

讲瓣订狶▅﹙筈莱垃

ユ硄厩 筿筿垂砞璸籔DSP北龟喷

200556

Technical Report: TR-UP08.DSP Control of a HB-Inverter for AC Voltage Regulation


Digital Control of a Half-Bridge UPS Inverter Provides Robust Performance!


Abstract

This report presents the design and implementation of a DSP-controlled half-bridge UPS inverter for sinusoidal voltage regulation under large nonlinear load variations. The half-bridge common-neutral ac-dc-ac converter is a major choice in the design of low-power single-phase double-conversion uninterruptible power supply systems due to its simple and robust hardware architecture. Several control topologies for single-phase uninterruptible power system (UPS) inverters are presented and compared, with the common objective of providing a dynamically stiff, low total harmonic distortion (THD), sinusoidal output voltage. A multiple rate digital controller generates all the PWM control signals for the power stage by using a set of synchronously detected feedback signals. Software current control scheme with nonlinear pulsewidth compensation has been developed to eliminate the nonlinearity caused by the dead-lock protected PWM converters. A full-state feedback decoupling control scheme utilizing both filter inductor current and output current feedback to augment output voltage control.  Digital control techniques have been developed to solve the control problems for voltage regulation and power factor correction under large nonlinear load variations. Experimental verifications has been carried out to evaluate the proposed control scheme. 

Index Terms: UPS inverters, digital control topology, DSP control, output impedance, total harmonic distortion, half-cycle control scheme.  


1.  Introduction 

         Uninterruptible power supplies (UPSs) are used to supply clean and uninterrupted power to critical loads, e.g., computers, medical/life support systems, communication systems, industrial controls, etc., under any normal or abnormal utility power conditions, including outages from a few milliseconds up to several hours duration. This holdup time is totally dependent upon the size of the critical load and the energy-storage capabilities built into the UPS powering this critical load. In order to supply output power in the absence of the input power, the UPS employs some form of bulk energy-storage mechanism. Most UPS systems use valve-regulated lead-acid batteries or glass matte starved electrolyte batteries for this purpose. These maintenance-free batteries are the most widely used energy storage devices because of their portability and low maintenance requirements. 

1.2 Research Background and Status 

        The marketing development of UPS can categorized as single-phase off-line and interactive UPSs for personal computers in low-power applications, single-phase on-line UPSs for servers, communication equipments, etc. in medium power applications, and three-phase on-line and line-interactive UPSs for data centers, critical manufacturing equipments in large power applications. Various UPS topologies have been developed to fit different application requirements [Karve 2000, Krishnan and Srinivasan 1993, Krishman 1995]. 

        The goal of the UPS inverters is to maintain the desired output voltage waveform over all loading conditions and transients. In the past, sinewave inverters relied on open-loop feedforward control to produce the shape of the waveform, while a relatively slow output voltage rms feedback loop regulated the magnitude. While these types of controllers could maintain a desired steady-state rms output voltage, their response to step changes in load were noticeably slow (several cycles of the output waveform), and nonlinear loads could greatly distort their output voltage waveform. Today, various modern feedback control techniques are available to control the output voltage waveform continuously, rather than on an rms basis. These so-called "instantaneous" controllers offer many performance advantages including faster (sub-cycle) transient response, better total harmonic distortion (THD), and improved disturbance rejection via lower output impedance. 

        Closed-loop regulated pulsewidth modulated (PWM) dc-ac converters have found their wide applications in various type of ac power conditioning systems, such as automatic voltage regulator (AVR) systems, uninterruptible power supply (UPS) systems, distributed power generators, stand-along PV inverters, and programmable ac source (PAS) systems. In these applications, the PWM dc-ac converters are required to maintain a sinusoidal output waveform under various type of loads and this can only be achieved by employing feedback control technique.

        Various control schemes have been developed for the UPS inverters to maintain a high-quality sinusoidal output voltage under highly nonlinear rectifier loads. The control architecture of a UPS inverter can classified as control topologies and control algorithms. The control topology is defined as the control configurations using various feed-forward and feedback controller via the reference and measured state variables. The control algorithm is defined as the control law employed in the feedback and feed-forward controllers. The development of control topologies and control algorithms for modern power electronic converters is significantly  influenced by the realization technology. The UPS controller can be realization by using conventional analog control ICs with a microcontroller, or by using a programmable logic device such as FPGA with a microcontroller, or by suing a single-chip DSP controller [Digital Realization of UPS Controllers]. Fig. 1 shows the functional block diagram of a DSP-embedded UPS controller for the digital control of a single-phase double-conversion UPS system. The DSP-embedded UPS controller consists of a single-chip DSP controller and dedicated interface hardware and software designed for the interface and control of a UPS system. This paper presents the synreport of the digital controller of the UPS inverter for the ac voltage regulation.  

Figure 1.1  DSP-embedded UPS controller for the digital control of a single-phase double-conversion UPS. 

Progress of DSP Controller

        The innovation of DSP control into power electronic designs is an excellent example of the advantages provided by major technological advances. By replacing classic analog control with DSP-based digital control, the primary advantages are achieved by replacing hardware with flexible software. The advantages are even more dramatic because they donˇt just extend to reducing cost and increasing performance over classic designs. By using the DSP-based software control technologies, many advantages can be obtained such as cost reduction due to software replacement of hardware components, standardization of design procedures across an entire product line, reutilization of software intellectual properties, and increased performance.

        In order to achieve real time digital control of UPS systems, designers turned to high-speed digital signal processors (DSPs) now capable of executing over 30 million instructions per second (MIPS). In operation, DSPs compare software reference signals with actual readings from the inverter, and then perform high-speed calculations to produce output values for PWM inverter control. There are many advantages in using a DSP to replace analog circuitry including stable system parameters free from the effects of aging and temperature drift. In addition, control system upgrades can be implemented in software, making the latest features available to any compatible UPS without changes to the hardware.

        The control software also provides users with more complete operating and historical data in the form of clear read-out monitors. The UPS operating information can also be accessed remotely by modem or control panel for monitoring, adjustment of operating parameters, diagnostics and software-based repairs. Finally, lower maintenance costs can be realized due to self-calibration features and remote servicing.

Development of Control Topology

        The control topology or control configuration of a closed-loop controlled system plays an important role in the synreport of the controller. Several control topologies have been developed to solve the control problem for a single-phase PWM inverter with an LC output filter. Reference  [Ryan 1997] has made an evaluation of four state feedback control topologies. Two basic feedback topologies are explored: 1) filter inductor and load current sensing and 2) filter capacitor current sensing, where both approaches use a full-state command structure. For the case of inductor current feedback, two methods of load current decoupling will be considered. In the case of capacitor current feedback, a Luenberger-style observer for capacitor current will also be considered in lieu of a current sensor. All controllers presented employ active decoupling of both the dc bus and the "back-EMF" of the output voltage. The output dynamic stiffness (inverse of output impedance) of each controller is evaluated and compared on a single plot. Experimental results reveal that the capacitor current feedback controller topology can achieve a highest dynamic stiffness performance. 

        Although frequency-domain based analog control schemes are predominantly used in compensator design of power converters, there are several drawbacks that hinder the performance of analog controllers, such as temperature drift, aging effect, complexity in component adjustment, and susceptibility to EMI. With the rapid progress in microelectronics technology, digital control of power converters using advanced microcontroller and digital signal processor (DSP) becomes an active research area [Modern Digital Control Schemes].

Development of Control Schemes for UPS Inverter

        During the past several years, various closed-loop control schemes for the PWM inverter with instantaneous feedback by using analog techniques have been proposed to achieve both good dynamic response and low harmonic distortion. These control schemes can be classified as analog and digital control schemes due to their realization method. Because the advantages provided by using digital control scheme with modern DSP realization, the digital control scheme has become a predominated choice for the control of a modern UPS system. In the followings, we made a review of the development of conventional analog and modern digital control schemes for the closed-loop regulation of UPS inverters. 

Conventional Analog Control Schemes

        The instantaneous feedback control with adaptive hysteresis regulates the PWM inverter with direct current and voltage feedback [Kawamura and Hoft 1984]. This control scheme changes the hysteresis width as a function of the voltage reference, but its dynamic responses to large loads change or rectifier types of load are left unsolved. Instantaneous voltage feedback with an inner adaptive hysteresis-band current loop controller was also developed for the control of PWM inverters [Bose 1990]. This control scheme can reduce the excessive current ripples produced by the conventional fixed hysteresis-band current controller. The realization of the adaptive hysteresis-band current controller requires a microcontroller to generate a analog output to modify the hysteresis band of an analog hysteresis comparator. 

Modern Digital Control Schemes

Deadbeat Control

        Microprocessor-based deadbeat control technique has been applied to the closed-loop regulation of PWM inverters for UPS applications [Gokhale 1985, Kawamura 1988]. Five different schemes for digital feedback control of PWM inverter are proposed, and compared through simulations and experiments [Kawamura 1990]. These five are 1) resistive load based DB (deadbeat) control, 2) disturbance observer based deadbeat control I, 3) disturbance observer based deadbeat control II, 4) internal model principle based pole placement, and 5) digital PI control. It is found in this study that the control law of internal model principle based pole placement control scheme was unstable for non-linear load and is infeasible for practical applications. The resistive load based deadbeat control scheme will result a larger fundamental voltage in case of no load due to the assumption of a constant resistive load. Another demerits of the control scheme is the output voltages becomes unbalanced for unbalanced load. The disturbance observer based dead-beat control scheme has the best performance among these five control schemes, especially under no load and unbalanced load conditions. However, the output voltage waveform is still seriously distorted.

        The deadbeat control theory is based on the inverse discrete model of the plant to be controlled to reach a response with a zero steady-state error within a finite settling-time interval to a specific reference input. However, the designed deadbeat controller based state feedback or observer by using pole placement technique for specific reference regulation system is usually not suitable for tracking system with arbitrary reference. Another demerit of the deadbeat control scheme is that excessive actuating signal may be required in order to reach a deadbeat response. This results high ratings for the power devices. The deadbeat controller for a power converter is also very sensitive to parameter variations of the load and saturation limits of the power device. Therefore, in practical situations, the deadbeat controller is usually tuned to get a relaxed deadbeat response. Further investigations of applications of deadbeat control schemes to closed-loop regulation on PWM inverters have been studied [Kawamura and K. Ishihara 1988, Yokoyama 1994, Koga 1994, Hua 1995, Malesani 1999, Kukrer 1999]. In summary, the deadbeat control scheme can reach the fastest dynamic response, however, it also has the disadvantages of highly sensitive to parameter and load variations and requiring large peak-to-average ratio of control signals to achieve deadbeat effect. For the inner current loop control of the PWM inverter, there only exists one system parameter, the filter inductance. This filter inductance is a known parameter and if the inductor is kept not saturated it is usually within 10% ranges due to temperature and flux variations. If other related system variables can be measured, such the dc-link voltage, inductor current, and output filter capacitor voltage, the deadbeat control scheme is very suited for the current loop control to reach a robust deadbeat response.

Voltage Variation Compensation Control

        The deadbeat control scheme of a UPS inverter for ac voltage regulation is to control the output voltage of the next sampling instant to reach a deadbeat response. In these control schemes, the output voltage for the next sampling instant is compensated, but the inclination of voltage at the sampling instant is not considered. To minimize the cost of the inverter, the output LC filter component should be small, but an extreme small output LC filter causes the output voltage ripple. In reference [Yokoyama 2000], a voltage variation compensation method has been proposed to control not only the output voltage but also the derivative of the output voltage. This control scheme has advantage of elimination of the beat phenomena of the inverter output voltage when the output LC filter is very small. However, this control scheme also requires a sampling frequency of double the inverter PWM carrier frequency, which results higher computation load for the microprocessor implementation.

Multi-loop Real-Time Control & Predictive Control

        Real-time instantaneous control schemes based on the discretization of conventional instantaneous analog control schemes have also been developed for the closed-loop regulation of PWM inverters. Reference [Kawamura 1990] developed a digital PI control scheme by sampling two state variables (output voltage and load current) and with an inductor current estimator to generate PWM duties for output voltage regulation. The proposed control scheme is verified on a single-phase 115V, 60 Hz, 2KVA UPS with a dc-libk voltage of 170 V and a switching frequency of 20 kHz. The sampling frequency is set as the same as the PWM switching frequency and the proposed controller is realized by using the TMS320C14. Very low THD of the output voltage under rated rectifier load has been obtained. 

        Reference [Jung 1997, Tzou 1998] proposed a multi-loop control scheme by using the instantaneous feedback of the inductor current and output voltage with a feedforward contoller. The multiloop digital controller consists of a current controller, a voltage controller, and a feedforward controller. A software current control scheme has been developed to achieve fast current control of the PWM inverter and decouple the inductor of the output filter. This control scheme can achieve fast dynamic response for step load changes and has low output voltage THD under rectifier loads.

        Further investigations on applications of discretization of conventional analog control techniques with computation delay compensation or predictive control modification have been studied [Buso 2001, Mihalache 2002, Jiang 1998, Zargari 1995, Ito 1995, Sun1995, Kubo 1991]. In summary, these control schemes have advantages of using familiar analog design approach with digital realization while they also suffer from a high sampling rate and need to devise compensation scheme for the sampling and computation delay.

Sliding Mode Control

        Discrete sliding mode control (DSMC) technique has been developed for the regulation of PWM inverters [Jezernik 1990, Carpita 1993, Pinheiro 1994, Jung 1996, Muthu 1998, Tai 2002]. The main advantage of the DSMC scheme is its insensitivity to parameter variations and load disturbances, which leads to invariant steady-state response in the ideal case, while its disadvantages are that it is not easy to find an appropriate sliding surface and its performance will be degraded with a limited sampling rate. Another drawback of the sliding mode control scheme is the chattering phenomena when tracking a variable reference which degrades the overall system efficiency.

Repetitive Control

        In most ac power conditioning systems, phase controlled nonlinear loads are major sources of waveform distortion. Due to the periodic characteristics in voltage regulation, this type of nonlinear load results in periodic distortion in its output waveform. Repetitive control theory [Nakano and Hara 1986, Hara 1988, Tomizuka1988], which originates from the internal model principle [Francis and  Wonham 1975], provides a solution to eliminate periodic errors in a nonlinear dynamic system. A number of modified repetitive control schemes have been developed for use in various industrial applications. Repetitive control theory has also been applied to a PWM inverter employed in UPS systems to generate high quality sinusoidal output voltage [Haneyoshi, Kawamura, and Hoft 1988]. Reference [Tzou 1997] presented a two-layer repetitive control scheme to minimize the periodic distortion induced by the rectifier-type loads of a programmable ac power source. The proposed two-layer controller consists of a tracking controller and a repetitive controller. Pole assignment with state feedback has been employed in designing the tracking controller for transient response improvement and a repetitive control scheme was developed in synthesizing the repetitive controller for steady-state response improvement. Experimental verification has been carried out on a 2 kVA PWM inverter system. Total harmonic distortion (THD) below 1.4% for a 60 Hz output voltage under a bridge-rectifier RC load with a current crest factor of 3 has been obtained. Experimental results show that the DSP-based fully digital-controlled PWM inverter can achieve both good dynamic response and low harmonics distortion.

        Reference [Rech 2003] proposed a model reference controller with a repetitive control action for uninterruptible power supply (UPS) applications. The model reference controller modifies the structure of the plant so that the closed-loop transfer function is equal to a chosen reference model transfer function, whereas the repetitive control action minimizes periodic distortions caused by unknown periodic disturbances.

1.3 Research Motivations

        This research is based on the following motivations to solve the digital control problems of dc-ac converters used in high-performance UPS systems.

  1. Consider the Half-Bridge Inverter as a Basic Power Conversion Module 

  2. Develop a Design Criterion Based on Voltage THD Specification

  3. Construct a Systematic Design and Realization Procedure 

 These design and realization issues are further addressed as followings.

Half-Bridge Inverter as a Intelligent Inverter Module

        The half-bridge ac-dc converter plays a very important role in utility-interface and ac supplying power converters. The half-bridge inverter has inherent bidirectional power flow capability and can be used for both interface interface and ac & dc power supplying. The half-bridge inverter with double-switch can be constructed as a programmable and configurable basic power conversion module. Digital control and monitoring functions can be developed based on a single-DSP controller and integrated with the power semiconductor devices to form an intelligent inverter module. High-side gate drives and current sensors can be integrated with the power modules to simplify the system integration and reduce electromagnetic interference. High-speed serial interface using ring network communication protocols with optical isolation can be developed for the integration of these intelligent inverter modules to construct more sophisticated high-power converters. This paper develops the digital control techniques for the control of the inverter bridge for high-performance programmable power sources.

Low THD with Low-Switching Frequency Control Scheme 

        There have been some research on the digital control of PWM inverters for ac voltage regulation, while theoretical analysis and realization of the digital controller still need a further study. Digital control techniques can be used to improve the dynamic responses as well as the minimization of the switching losses and electromagnetic interference. 

        Control of the UPS inverter switching is important to minimize the harmonic content of the output voltage. The difficulty in successful switching control operation stems from the output impedance of the inverter filter. Much attention has been focused on providing a near zero output impedance inverter stage which in theory would provide near zero distortion of the output voltages, independent of the load conditions. Low output filter impedance can be realized via a high inverter switching frequency. However, in high power applications the switching frequency is limited to 1-2 kHz, which precludes the capability of lowering the filter output impedance.

        Thus, modem UPS systems minimize the harmonic content of the inverter output voltage through the use of complex filtering schemes employing large passive components. In addition, a number of PWM techniques have been investigated to compensate for the filter output impedance and reduce the output voltage distortion. Real time PWM control of the inverter output voltages provides the ability to dynamically adapt to changing load conditions. Digital random PWM control techniques can be developed to smooth high frequency spectra induced by the switching frequency.

Systematic Design Procedure

        With the availability of 16-bit high-performance DSP chips, most of its instructions can be accomplished in one instruction cycle, complicated control algorithms can be executed with fast speed. Realization of sophisticated digital control algorithms using advanced DSP has been a development trend for modern power electronic systems. However, there still exists many design and realization issues in application of digital control schemes. These include delay effect due to sampling delay and computation delay, quantization effect due to limited resolution of the analog-to-digital converters, rounding effect due to limited bit length, sampling noise due to switching of power devices, crossover distortion due to and dead-time protection, and DSP programming skills such as page addressing management, interrupt mechanism and scheduling, Q-format arithmetic, etc. Although some of the above mentioned design issues also exist in an analog-controlled power electronic systems, however, the analog controller is a true real-time controller, and it exhibits inherent low-pass filtering characteristics for random high frequency noises. On the other hand, although the digital controller has a higher noise rejection capability due to its digital circuitry in nature, noises coupling to the A/D converters may result large noises at the sampling frequency, and this will seriously deteriorate the digital controller performance.  

Summary 

        This report focuses on the development of a DSP-embedded UPS controller with special emphasis put on the development of digital control scheme for the PWM inverter to achieve low output impedance to minimize the total harmonic distortion (THD) of the UPS output voltage due to specified nonlinear rectifier load.  This paper describes the design and implementation of a DSP-based fully digital-controlled single-phase pulsewidth modulated (PWM) inverter for ac voltage regulation. The proposed digital controlled PWM inverter system employs a single-chip digital signal processor (DSP) to realize a multiloop control scheme with sinusoidal reference. The PWM gating signals are determined at every sampling instant by the proposed multiloop digital control scheme using a set of detected feedback signals. The development of advanced single-chip DSP controllers makes it possible to realize sophisticated control schemes. 

1.4 Report Organization 

        This report focuses on the analysis and synreport of  a robust digital control scheme for the ac voltage regulation of a half-bridge UPS inverter under large load variations and uncertainties. We propose a multiple-loop state feedback decoupling control scheme for the closed-loop regulation of PWM inverters used for high-performance double-conversion UPS. The control scheme has been realized by using a low-cost single-chip digital signal processor. The report is organized as follow. 

        Chapter one makes a description of current development status of digital control schemes for single-phase UPS inverters. Special emphasis is focused on the development of single-chip DSP controller in applications to the digital control of motor drives and power converters. The concept of DSP-embedded UPS controller is introduced. Some digital control schemes for the digital control of PWM inverters for the ac voltage regulation have been reviewed. 

        Chapter two makes an introduction to double-conversion UPS. This chapter also presents the development of common-neutral ac-dc-ac converters in applications to single-phase and three-phase UPS systems. It can observed that the half-bridge inverter form the basis among these developed common-neutral topologies. This chapter also  makes an analysis of the static and dynamic characteristics of the single-phase half-bridge inverters.  

        Chapter three makes an analysis of the half-bridge inverter used for a double-conversion UPS.  

        Chapter four makes a survey of developed control topologies and control schemes for the closed-loop control of UPS inverter for ac voltage regulation.  

        Chapter five introduces the proposed digital multiple-loop decoupling control scheme for the closed-loop regulation of a PWM inverter. 

        Chapter six makes a simulation-oriented analysis of the digital-controlled half-bridge inverter for ac voltage regulation. The output impedance is the most important performance measure of the UPS inverter. To verify the proposed control scheme, the output impedance of the UPS inverter is derived and calculated using MATLAB. The output impedance is also calculated based on a digital-controlled half-bridge inverter using PSIM.  

        Chapter seven addresses the realization issues of the proposed digital inverter control scheme using a single-chip DSP controller, the TMS320F2407A. Some practical realization issues for the digital control of PWM inverters for the ac voltage regulation have been addressed.

        Chapter eight gives some experimental results to verify the proposed digital multiple-loop decoupling control scheme. Chapter nine remarks the conclusions and makes some comments on further researching issues. 


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    D. Development of UPS Inverter Control Topologies

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    E. Conventional Analog Control Schemes  

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    F. Modern Digital Control Schemes: Deadbeat Control 

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    G. Modern Digital Control Schemes: Voltage Variation Compensation Control

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    H. Modern Digital Control Schemes: Multi-loop Real-Time Control & Predictive Control 
     

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  35. Shih-Liang Jung (篴▆) and Ying-Yu Tzou, "Multiloop control of an 1-phase PWM inverter for ac power source," IEEE PESC Conf. Rec., pp. 706-712, June 22-26, 1997. 

  36. Ying-Yu Tzou and Shih-Liang Jung, "Full control of a PWM DC-AC converter for AC voltage regulation," IEEE Trans. on Aerospace and Electronic Systems, vol. 34, no. 4, pp. 1218-1226, Oct. 1998. 

  37. Simone Buso, Sandro Fasolo, and Paolo Mattavelli, "Uninterruptible power supply multiloop control employing digital predictive voltage and current regulators," IEEE Trans. on Ind. Appli., vol. 37, no. 6, pp. 1846-1853, Nov./Dec. 2001.

  38. Liviu Mihalache, "DSP control method of single-phase inverters for UPS applications," IEEE APEC Conf. Rec., pp. 590-596, 2002.

  39. H. J. Jiang, Y. Qin, S. S. Du, Z. Y. Yu, and S. Choudhury, "DSP based implementation of a digitally-controlled single phase PWM inverter for UPS," IEEE INTELEC Conf. Rec., pp. 221-224, 1998.

  40. N. R. Zargari, P. D. Ziogas, and G. Joos, "A two switch high performance current regulated DC/AC converter module," IEEE Transactions on Industry Applications, vol. 31, no. 3, pp. 583-589, May-June 1995.  

  41. Y. Ito and S. Kawauchi, "Microprocessor-based robust digital control for UPS with three-phase PWM inverter," IEEE Trans. on Power Electron., pp. 196-204, vol. 10, no. 2, March 1995.

  42. Y. S. Sun, C. H. Kim, J. W. Lee, Y. H. Kim, and Y. S. Yoo, "Fully digitalized high frequency link DC/AC converter," IEEE Intelec. Conf. Rec., pp. 659-663, 1995.

  43. I. Kubo, Y. Ozawa, R. Nakatsuka, and A. Shimizu, "A fully digital controlled UPS using IGBT's," IEEE IAS Annual Meeting Conf. Rec., pp. 1042-1046, 1991. 

    I. Modern Digital Control Schemes: Sliding Mode Control 

  44. K. Jezernik and D. Zadravec, "Sliding mode controller for a single phase inverter," IEEE APEC Conf. Rec., pp. 185-190, May 1990.

  45. M. Carpita, P. Farina, and S. Tenconi, "A single phase, sliding mode controlled inverter with three levels output voltage for UPS or power conditioning applications," Fifth European Conference on Power Electronics and Applications, pp. 272-277, Sept. 1993.

  46. H. Pinheiro, A. S. Martins, and J. R. Pinheiro, "A sliding mode controller in single phase voltage source inverters," IEEE IECON Conf. Rec., pp. 394-398, Sept. 1994.

  47. S. L. Jung and Y. Y. Tzou, "Discrete sliding-mode control of a PWM inverter for sinusoidal output waveform synreport with optimal sliding curve," IEEE Trans. Power Electron., vol. 11, pp. 567577, July 1996. 

  48. S. Muthu and J. M. S. Kim "Discrete-time sliding mode control for output voltage regulation of three-phase voltage source inverters," IEEE APEC Conf. Rec., 1998.

  49. Tsang-Li Tai and Jian-Shiang Chen, "UPS inverter design using discrete-time sliding-mode control scheme," IEEE Trans. on Ind. Electron., vol. 49, no. 1, pp. 67-75, Feb. 2002.

    J. Modern Digital Control Schemes: Repetitive Control 

  50. B. A. Francis and W. M. Wonham, "The internal model principle for linear multivariable regulators," Appl. Math. Opt., vol. 2, pp. 170-194, 1975.

  51. N. Nakano and S. Hara, Chap. 14: Microprocessor-based repetitive control of Microprocessor-based Control Systems, D. Reidel Publishing Company, Amsterdam, The Netherlands, Reidel, 1986. [PEMCLAB Technical Report TR-DC10: Microprocessor-Based Repetitive Control]

  52. S. Hara, Y. Yamamoto, T. Omata, and M. Nakano, "Repetitive control systems: a new type servo system for periodic exogenous signals," IEEE Trans. Auto. Control, vol. 33, no. 7, pp. 659-668, July 1988.

  53. M. Tomizuka, T. C. Tsao, K. K. Chew, "Discrete-time domain analysis and synreport of repetitive controller," Amer. Contr. Conf. Rec., pp. 860-866, 1988.

  54. T. Haneyoshi, A. Kawamura, and R. G. Hoft, "Waveform compensation of PWM inverter with cyclic fluctuating loads", IEEE Trans. on Ind. Appli. vo1. 24, no.4, pp. 582-589, July, 1988. [First appears in IEEE IAS Annual Meeting Conf. Rec., pp. 744-751, 1986.]

  55. Ying-Yu Tzou, Rong-Shyang Ou (稼篴不), Shih-Liang Jung (篴▆), and Meng-Yueh Chang (眎幅┄), "High-performance programmable ac power source with low harmonic distortion using DSP-based repetitive control technique," IEEE Trans. on Power Electronics, vol. 12, no. 4, pp. 715-725, July, 1997. 

  56. Cassiano Rech, Humberto Pinheiro, Hilton Abílio Gründling, Hélio Leães Hey, and José Renes Pinheiro, "A modified discrete control law for UPS applications," IEEE Trans. on Power Electronics, vol. 18, no. 5, pp. 1138-1145, Sept. 2003.

  57. Cassiano Rech, Humberto Pinheiro, Hilton Abílio Gründling, Hélio Leães Hey, and José Renes Pinheiro, "Comparison of digital control techniques with repetitive integral action for low cost PWM inverters," IEEE Trans. on Power Electronics, vol. 18, no. 1, pp. 401-410, Jan. 2003.  

    K. Modeling of the PWM Inverters  

  58. Ying-Yu Tzou, "DSP-based fully digital control of a PWM dc-ac converter for ac voltage regulation," IEEE PESC Conf. Rec., pp. 138-144, June 1995. 

  59. Liviu Mihalache, "DSP control method of single-phase inverters for UPS applications," IEEE APEC Conf. Rec., pp. 590-596, 2002. [This paper presents the derivation of the discrete model of the PWM inverters.]

  60. M. J. Ryan, R. D. Lorenz, and R. W. De Doncker, "Modeling of sinewave inverters - a geometric approach," IEEE IECON Conf. Rec., pp. 396-401, 1998. 

  61. A. Kawamura, "Sampled-data model of power electronics system driven by a PWM inverter," Conf. Rec. of JIEE (in Japanese), pp. 636-637, 1987. 

    L. Inverter Output Filter Design  

  62. Byoungwoo Ryu, Jaesik Kim, Jaeho Choi, and Changho Choi, "Design and analysis of output filter for 3-phase UPS inverter," Proceedings of the Power Conversion Conference, PCC Osaka, pp. 941-946, 2-5 April 2002. 

  63. S. Dewan and P. Ziogas, "Optimum filter design for a single phase solid-state UPS system," IEEE Trans. Ind. Appl., vol. IA-15, no. 6, pp. 664-669, 1979.

  64. T. G. Habetler and D. M. Divan, "Rectifier/Inverter reactive component minimization," IEEE IAS Annual Meeting, pp. 648-657, 1987.

  65. A. Kusko, D. Galler, and N. Medora, "Output impedance of PWM UPS inverter-feedback vs. filters," IEEE IAS Annual Meeting, pp. 1044-1048, 1990.

  66. J. Kim, J. Choi and F. Blaabjerg, "Design and analysis of output filter for UPS," EPE Conf. Rec., 2001.

  67. J. Kim, Design of output filter and controller for UPS inverter, Ph. D report in Chungbuk National University, 2001. 

    M. Inverter Output Impedance  

  68. D. Stanojevic and M. Stefanovic, "A UPS inverter with zero output impedance," IEEE IECON Conf. Rec., pp. 469-472, 5-9 Sept. 1994.

  69. S. Vukosavic, L. Peric, E. Levi, and V. Vuckovic, "Reduction of the output impedance of PWM inverters for uninterruptible power supplies," IEEE PESC Conf. Rec., San Antonio, TX, 1990, pp. 757762. 

  70. M. A. Boost and P. D. Ziogas, "Towards a zero-output impedance UPS system," IEEE Transactions on Industry Applications, vol. 25, no. 3, pp. 408-418, May-June 1989.

  71. G. K. Schoneman and D. M. Mitchell, "Output impedance considerations for switching regulators with current-injected control," IEEE Transactions on Power Electronics, vol. 4, no. 1, pp. 25-35, Jan 1989.  

    O. Development of Single-Chip DSP Controllers

  72. Analog Devices, Single-Chip, DSP-Based High Performance Motor Controller ADMC401, 2001.

  73. Texas Instruments, TMS320LF/LC240xA DSP Controllers System & Peripherals Reference Guide (SPRU357B) (Rev. C) (SPRZ015C, 44 KB - Updated: 07/09/2002).

  74. Microchip, dsPIC30F High Performance Digital Signal Controllers - Motor Control and Power Conversion Family, 2002.

  75. Motorola, 56F801 16-bit Hybrid Controller, Feb. 2004.

  76. Texas Instruments, TMS320F2812 32-bit DSP Controller, TMS320F2810, TMS320F2812 Digital Signal Processors, Literature Number: SPRS174H, April 2001  Revised March 2003.

    P. Realization of Real-Time Multi-Tasking Control System

  77. Burns and Wellings, ¨Real-Time Systems and Programming Languages〃, 3rd Edition, 2001.

    Q. Realization of Digital Controller

  78. B. K. Bose, "Introduction to microcomputer control," from Microcomputer Control of Power Electronics and Drives, IEEE Press, pp. 3-22, 1987. 

  79. H. Hanselmann, "Implementation of Digital Controllers -- A Survey," Automatica, vol. 23, no. 1, pp 7-32, 1987.

  80. Paul Katz, Chapter 5 Mechanization of Control Algorithms on Microcontrollers of Digital Control Using Microprocessors, Prentice-Hall, Inc., 1981.

  81. C. P. Diduch and R. Doraiswami, "Robust servomechanism controller design for digital implementation," IEEE Trans. on Ind. Electronics, vol. 34, no. 2, pp. 172-179, May 1987.

  82. Analog Devices, Implementing PI controllers with the ADMC401, Application Note: AN401-13, 1999.

    S. Selection of Sampling Rate  

  83. William S. Levine, Chapter 16. Sample-rate Selection of  The Control Handbook, CRC Press, February 23, 1996. 

  84. G. F. Franklin, J. D. Powell, and M. L. Workman, Chap. 11: Sample Rate Selection from Digital Control of Dynamic Systems, Addison-Wesley Publishing Company, 1990. 

  85. Paul Katz, Chapter 7 Selection of Sampling Rate of Digital Control Using Microprocessors, Prentice-Hall, Inc., 1981. 

    T. Decoupling Effect of the Current Loop Controllers  

  86. C. K. Taft and E. V. Slate, "Pulsewidth modulated DC motor control: a parameter variation study with current loop analysis," IEEE Trans. on IECI, vol. 26, no. 4, pp. 218-226, Nov. 1979. 

    U. Sampling of the Noise-Corrupted Ripple Currents 

  87. Gabriele Grandi, Domenico Casadei, and Ugo Reggiani, Member, "Common- and differential-Mode HF current components in AC motors supplied by voltage source inverters," IEEE Trans. on Power Electronics, vol. 19, no. 1, pp. 16-24, Jan. 2004.

  88. David M. Van de Sype, Koen De Gusseme , Alex P. Van den Bossche, and Jan A. Melkebeek, "A sampling algorithm for digitally controlled boost PFC converters," IEEE PESC Conf. Rec., pp.1693-1698, 2002. 

  89. Jinghai Zhou, Yousheng Wang, Yuancheng Ren, Zhaoming Qian, Zhengyu Lin, and Zhengyu Lu, "Novel sampling algorithm for DSP controlled 2 kW PFC converter," IEEE Transactions on Power Electronics, vol. 16, no. 2, pp. 217-222, March 2001. 

  90. S.-H. Song, J.-W. Choi, S.-K. Sul, "Current measurements in digitally controlled ac drives," IEEE Industry Applications Magazine, vol. 6, no. 4, pp. 51-62, July/August 2000. 

  91. V. Blasko, V. Kaura, W. Niewiadomski, "Sampling of discontinuous voltage and current signals in electrical drives: a system approach," IEEE Transactions on Industry Applications, vol. 34, no. 5, pp. 1123-1130, September/October 1998. 

    V. Scaling and Finite Word Length Effect

  92. C. H. Houpis and G. B. Lamont, Chap. 10: Analysis of Finite Word Length of Digital Control Systems:  Theory, Hardware, Software, McGraw Hill, 1992. 

  93. P. Katz, Chapter 6: Analysis of the Implementation of the Numerical Algorithm from Digital Control Using Microprocessors, Prentice-Hall Inc., pp. 148-155, 1982. 

  94. G. F. Franklin, J. D. Powell, and M. L. Workman, Chap. 10: Quantization Effects from Digital Control of Dynamic Systems, Addison-Wesley Publishing Company, 1990. 

    W. PFC Control of the Half-Bridge Boost AC-DC Converter

  95. Gui-Jia Su, D. J. Adams, and L. M. Tolbert, "Comparative study of power factor correction converters for single phase half-bridge inverters," IEEE PESC Conf. Rec., pp. 995-1000, 2001. 

  96. S. Bibian and Hua Jin, "Digital control with improved performance for boost power factor correction circuits," IEEE APEC Conf. Rec., pp. 137-143, 2001. 

  97. W.-L. Lu (ゅ订), S. N. Yeh (腑秤), J.-C. Hwang, and H.-P. Hsieh, "Development of a single-phase half-bridge active power filter with the function of uninterruptible power supplies," IEE Proceedings - Electric Power Applications, vol. 147, no. 4, pp. 313-319, July 2000. 


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Copyright © 1987-2004 by DigitalPowerLab, NCTU, TAIWAN

Author: Prof. Ying-Yu Tzou

Affiliation: Power Electronics IC Design and DSP Control Lab., NCTU, Hsinchu, Taiwan

TR-UP08.DSP Control of a HB-Inverter for AC Voltage Regulation

Last update: 2005/5/6