Mitigation of Negative Impedance Instabilities in a DC/DC Buck-Boost Converter with Composite Load
01 May 2016-Journal of Power Electronics (The Korean Institute of Power Electronics)-Vol. 16, Iss: 3, pp 1046-1055
TL;DR: In this article, a controller to mitigate the destabilizing effect of constant power load (CPL) is proposed for a DC/DC buck-boost converter, where the load profile has been considered to be predominantly of CPL type.
Abstract: A controller to mitigate the destabilizing effect of constant power load (CPL) is proposed for a DC/DC buck–boost converter. The load profile has been considered to be predominantly of CPL type. The negative incremental resistance of the CPL tends to destabilize the feeder system, which may be an input filter or another DC/DC converter. The proposed sliding mode controller aims to ensure system stability under the dominance of CPL. The effectiveness of the controller has been validated through real-time simulation studies and experiments under various operating conditions. The controller has been demonstrated to be robust with respect to variations in supply voltage and load and capable of mitigating instabilities induced by CPL. Furthermore, the controller has been validated using all possible load profiles, which may arise in modern-day DC-distributed power systems.
Citations
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TL;DR: In this paper, the authors provide a comprehensive review of the major concepts associated with the μgrid, such as constant power load (CPL), incremental negative resistance or impedance (INR/I), and its dynamic behaviors on the μ-grid, and power system distribution.
Abstract: This paper provides a comprehensive review of the major concepts associated with the μgrid, such as constant power load (CPL), incremental negative resistance or impedance (INR/I) and its dynamic behaviours on the μgrid, and power system distribution (PSD). In general, a μgrid is defined as a cluster of different types of electrical loads and renewable energy sources (distributed generations) under a unified controller within a certain local area. It is considered a perfect solution to integrate renewable energy sources with loads as well as with a traditional grid. In addition, it can operate with a conventional grid, for example, by energy sourcing or a controllable load, or it can operate alone as an islanding mode to feed required electric energy to a grid. Hence, one of the important issues regarding the μgrid is the constant power load that results from the tightly designed control when it is applied to power electronic converters. The effect of CPL is incremental negative resistance that impacts the power quality of a power system and makes it at negative damping. Also, in this paper, a comprehensive study on major control and compensation techniques for μgrid has been included to face the instability effects of constant power loads. Finally, the merits and limitations of the compensation techniques are discussed.
101 citations
Cites background or methods from "Mitigation of Negative Impedance In..."
...The μgrid was introduced as an efficient solution to guarantee the reliable operation of distribution generating (DG) when DGs operate in connected mode or islanded mode [6,25,29,30]....
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...The development of electronic switch devices has led to penetrations of power electronic applications in a power system [1,2], advanced control approaches, and more renewable energy sources [3], and on the other hand an increase in energy demands that has consequently led to increased environmental problems such as greenhouse gases being emitted from non-renewable energy sources [4,5]; all these factors have contributed to the appearance of new applications in power systems and have taken many forms in modern life [6]....
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TL;DR: The output voltage regulation problem of a buck–boost converter feeding a CPL is addressed and an immersion and invariance parameter estimator is proposed to compute online the extracted load power, which is difficult to measure in practical applications.
Abstract: Rapid developments in power distribution systems and renewable energy have widened the applications of dc–dc buck–boost converters in dc voltage regulation. Applications include vehicular power systems, renewable energy sources that generate power at a low voltage, and dc microgrids. It is noted that the cascade connection of converters in these applications may cause instability due to the fact that converters acting as loads have a constant power load (CPL) behavior. In this brief, the output voltage regulation problem of a buck–boost converter feeding a CPL is addressed. The construction of the feedback controller is based on the interconnection and damping assignment control technique. In addition, an immersion and invariance parameter estimator is proposed to compute online the extracted load power, which is difficult to measure in practical applications. It is ensured through the design that the desired operating point is (locally) asymptotically stable with a guaranteed domain of attraction. The approach is validated via computer simulations and experimental prototyping.
39 citations
TL;DR: An adaptive passivity-based controller for output voltage regulation of DC–DC buck–boost converter with an unknown constant power load is developed and is amenable for the addition of an outer-loop PI that improves its transient and disturbance rejection performances.
31 citations
Cites background from "Mitigation of Negative Impedance In..."
...shown in [8], which exhibit a very poor performance....
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TL;DR: In this article, an adaptive interconnection and damping assignment passivity based control that incorporates the immersion and invariance parameter estimator for the load power is proposed to solve the problem of regulating the output voltage of a DC-DC buck-boost converter feeding a constant power load.
Abstract: This paper addresses the problem of regulating the output voltage of a DC-DC buck-boost converter feeding a constant power load,which is a problem of current practical interest. Designing a stabilising controller is theoretically challenging because its average model is a bilinear second order system that, due to the presence of the constant power load,is non- minimum phase with respect to both states.Moreover,to design a high performance controller, the knowledge of the extracted load power, which is difficult to measure in industrial applications, is required. In this paper, an adaptive interconnection and damping assignment passivity based control that incorporates the immersion and invariance parameter estimator for the load power is proposed to solve the problem. Some detailed simulations are provided to validate the transient behaviour of the proposed controller and compare it with the performance of a classical PD scheme.
31 citations
TL;DR: In this paper , the authors proposed a super twisting-based second-order sliding mode control (SOSMC) for regulating the output voltage of a DC/DC buck converter feeding CPL.
Abstract: Multi-converter systems used in DC microgrid feed supply constant power loads (CPL) as well as classical electrical loads. CPL has a non-linear load nature because of the negative impedance effect. This impact causes instability in converter systems within the micro-grid. This paper proposes a super twisting-based second-order sliding mode control (SOSMC) for regulating the output voltage of a DC/DC buck converter feeding CPL. The goal of this method is to suppress the chattering effect and maintaining the robustness under load variations and parametric uncertainties. With the experimental studies constructed in the laboratory and simulations executed in Matlab environment, the proposed SOSMC was compared with classical first-order SMC for the response of the buck converter feeding CPL under various conditions. The simulation and experimental results show the proposed controller has higher tracking precision and stronger robustness during any disturbance in input voltage or CPL power, as well as reducing the chattering effect.
11 citations
References
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TL;DR: A tutorial account of variable structure control with sliding mode is presented, introducing in a concise manner the fundamental theory, main results, and practical applications of this powerful control system design approach.
Abstract: A tutorial account of variable structure control with sliding mode is presented. The purpose is to introduce in a concise manner the fundamental theory, main results, and practical applications of this powerful control system design approach. This approach is particularly attractive for the control of nonlinear systems. Prominent characteristics such as invariance, robustness, order reduction, and control chattering are discussed in detail. Methods for coping with chattering are presented. Both linear and nonlinear systems are considered. Future research areas are suggested and an extensive list of references is included. >
2,884 citations
"Mitigation of Negative Impedance In..." refers background or methods in this paper
...For detailed information on the theory of sliding mode control and its prominent features see [14] and references therein....
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...The existence of the sliding mode for the proposed PWM based sliding mode controller (6) is proved based on the reaching dynamics given in [14] as follows:...
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TL;DR: The implementation of novel active-damping techniques on dc/dc converters has been shown and the proposed active- damping method is used to overcome the negative impedance instability problem caused by the CPLs.
Abstract: Multi-converter power electronic systems exist in land, sea, air, and space vehicles. In these systems, load converters exhibit constant power load (CPL) behavior for the feeder converters and tend to destabilize the system. In this paper, the implementation of novel active-damping techniques on dc/dc converters has been shown. Moreover, the proposed active-damping method is used to overcome the negative impedance instability problem caused by the CPLs. The effectiveness of the new proposed approach has been verified by PSpice simulations and experimental results.
422 citations
"Mitigation of Negative Impedance In..." refers methods in this paper
...A method based on active damping has been presented in [9] to compensate the CPL effect in dc/dc converters....
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TL;DR: A simple unified approach to the design of fixed-frequency pulsewidth-modulation-based sliding-mode controllers for dc-dc converters operating in the continuous conduction mode is presented.
Abstract: This paper presents a simple unified approach to the design of fixed-frequency pulsewidth-modulation-based sliding-mode controllers for dc-dc converters operating in the continuous conduction mode. The design methodology is illustrated on the three primary dc-dc converters: buck, boost, and buck-boost converters. To illustrate the feasibility of the scheme, an experimental prototype of the derived boost controller/converter system is developed. Several tests are performed to validate the functionalities of the system
289 citations
"Mitigation of Negative Impedance In..." refers methods in this paper
...Authors in [15], have presented an unified approach to design PWM based SMCs for dc/dc converters with a resistive load and operating in CCM, wherein the switching function is of PID form....
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20 Jun 1993
TL;DR: In this paper, a general-purpose sliding-mode controller is described, which can be applied to most DC-DC power converter topologies and provides extreme robustness and speed of response against supply, load, and parameter variations.
Abstract: A general-purpose sliding-mode controller is described, which can be applied to most DC-DC power converter topologies. It has the same circuit complexity as standard current-mode controllers, but provides extreme robustness and speed of response against supply, load, and parameter variations. Moreover, contrary to other sliding-mode techniques, the proposed solution features constant switching frequency in the steady state, synchronization to external triggers, and absence of steady-state errors in the output voltage. >
260 citations
"Mitigation of Negative Impedance In..." refers background in this paper
...The last term of the switching function ensures zero steady-state error in the output voltage [20]....
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...[19], [20]....
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TL;DR: A novel nonlinear feedback, which is called loop cancellation, is introduced and used to cancel the destabilizing effect of the constant-power loads.
Abstract: Tightly regulated closed-loop converters are problematic when used as a load since they tend to draw constant power and exhibit negative incremental resistance. This negative resistance causes stability problems for the feeder system, whether it is an input filter or another converter. In multiconverter power electronic systems, which exist in different land, sea, air, and space vehicles, including electric, hybrid, plug-in hybrid, and fuel-cell vehicles, there are many converters loaded by other converters. Therefore, the destabilizing effect of the load converters, which are called constant-power loads, is a major issue. In this paper, a novel nonlinear feedback, which is called loop cancellation, is introduced. This technique is used to cancel the destabilizing effect of the constant-power loads. Theoretically, any amount of constant-power load can be compensated by this technique, and it can identically be implemented on different types of converters. The effectiveness of the proposed technique has been verified by PSpice simulations and experimental results.
178 citations
"Mitigation of Negative Impedance In..." refers background in this paper
...Due do the intensive use of power electronic converters these systems are usually referred as multiconverter power distribution systems or dc distributed power systems [3]....
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...The use of nonlinear feedback to cancel out nonlinearity due to CPL and to stabilize the system, has been presented in [3]....
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