Park Transformation Research Articles

A synthesised framework of eco‐industrial park transformation and stakeholder interaction

AbstractEco‐industrial parks (EIPs) combine the concepts and principles of industrial ecology (IE) and industrial symbiosis (IS) to enable environmentally‐friendly industrial manufacturing capacity. The current reality is that many EIPs are developed from ageing industrial parks (IPs). However, how such EIP transformation projects are managed by diverse public and private stakeholders is largely unknown. This study summarises the results of a systematic literature review (n = 61) to identify a five‐stage process of EIP transformation. Five key stakeholders and influencing factors are identified, and drawing on process theory, a framework is developed that highlights how these stakeholders work together over time. While this study serves as an overview of the body of knowledge on the business and social aspect of EIP transformation, the main contribution of this work is the propositions on the interactions and order of stakeholders embedded in the framework, which can guide future research especially on the early stages of EIP transformation. In practice, EIP project managers can judge the stage of the project based on the project status and work back from actions entities undertake to progress the project systematically.

Creative Destruction Path Selection for Industrial Park Transformation and Upgrading under the Concept of Character Town in the Era of Big Data

With the reshuffle of the global industrial structure, some industrial parks in China are facing problems such as unclear industrial positioning, unclear agglomeration effect, and lack of impetus for independent innovation. It is urgent to seek a way of transformation and upgrading. The arrival of the era of big data also provides new opportunities for the transformation of China’s industrial parks. In this context, the model of “character towns” proposed by Zhejiang Province provides a new concept for breaking the bottleneck of industrial park transformation and also provides a platform and space for the application of data technology and digital governance in the era of big data. Based on the theory of creative destruction and self-organization, this paper holds that the essence of industrial park transformation under the concept of character towns is the self-organization process of creative destruction and high-quality reconstruction. After sorting out the development process of parks in China, this paper divides industrial parks into production-oriented parks, consumption-oriented parks, and trade-oriented parks according to the economic activities classified by classical economics. By constructing a six-stage creative destruction model, this paper analyzes the path selection of transformation and upgrading of three types of parks under the concept of character towns and proposes that industrial structure replacement for the production-oriented parks, upgrading the consumption structure for the consumption-oriented parks, and change of trade control points for the trade-oriented parks are the possible transformation paths for the three types of parks.

Benefits of Fuzzy Logic on MPPT and PI Controllers in the Chain of Photovoltaic Control Systems

This paper presents a comparative study between two maximum power point tracking (MPPT) algorithms, the incremental conductance algorithm (InC) and the fuzzy logic controller (FLC). The two algorithms were applied to a low photovoltaic power conversion system, and they both use different PI controllers and grid synchronization techniques. Moreover, both InC and FLC methods have Clarke and Park Transformation. To some extent, the incremental conductance and fuzzy logic controller approaches are similar, but their control loops are different. Therefore, the InC has classic Proportional Integrative (PI) controllers with simple phase-locked loops (PLL). At the same time, the FLC works with fuzzy logic PI controllers linked with the Second Order Generalized Integrator (SOGI). The proposed techniques examine the solar energy conversion performance of the photovoltaic (PV) system under possible irradiance changes and constant temperature conditions. Finally, a performance comparison has been made between InC and FLC, which demonstrates the effectiveness of the fuzzy controller over the incremental conductance algorithm. FLC turns to convert photovoltaic power easily, decreasing fluctuations, and it offers a quick response to the variation of solar irradiance (shading effect). The simulation results show a superior performance of the controller with fuzzy logic, which helps the inverter convert over 99% of the power generated by the photovoltaic panels. In comparison, the incremental conductance algorithm converts around 80%.

Phase Lead-Lag Synchronous Reference Frame Phase-locked loop for Grid Synchronization of a Single-Phase Inverter

In this study, a phase lead-lag synchronous reference frame phase-locked loop (SRF-PLL) is proposed for the grid connection of a single-phase inverter. A tuned filter is employed to enable the phase of the input voltage to be advanced or delayed by ±45 degrees with respect to the grid voltage. The generated orthogonal signals are fed into Park's transformation. Only the quadrature-phase signal is regulated to zero using a PI controller. Its output determines the estimated frequency. The phase angle is obtained by integrating the estimated frequency. The linearized model of the proposed SRF-PLL is developed and stability analysis is discussed. The viability of the proposed method is tested under computer simulation using MATLAB/Simulink. The method is then implemented on a 32-bit microcontroller and tested with a programmable AC source. The results positively confirm the effectiveness of the method.

Modeling the synchronous permanent magnet generator with RLC load

This paper is concerned with the modeling of the three-phase permanent magnet synchronous generator (PMSG) and its load in the dq0 reference system. The generator was considered to be directly connected to a balanced three-phase load. The loads under consideration were R and RLC type loads. The connection to the R load can be simulated using the standard PMSG dq model and Park transformations, but the connection to the RLC load requires the modeling of the system as a whole. LabVIEW simulations of these models were used in order to study the behavior of the PMSG under various load conditions (R, RL and RC). These models can be used to simulate the behavior of the PMSG in a conventional (natural gas, coal, etc.) or renewable (wind energy, hydropower, etc.) energy conversion system. They can also be used in designing the control of the energy conversion system (MPPT control, Droop control, etc.).

Design and lumped parameter magnetic network model of hybrid excited consequent pole flux switching machine

PurposeThe purpose of this paper is to analyze electromagnetic performance and develop an analytical approach to find the suitable coil combination and no-load flux linkage of the proposed hybrid excited consequent pole flux switching machine (HECPFSM) while minimizing the drive storage and computational time which is the main problem in finite element analysis (FEA) tools.Design/methodology/approachFirst, a new HECPFSM based on conventional consequent pole flux switching permanent machine (FSPM) is proposed, and lumped parameter magnetic network model (LPMNM) is developed for the initial analysis like coil combination and no-load flux linkage. In LPMNM, all the parts of one-third machine are modeled which helps in reduction of drive storage, computational complexity and computational time without affecting the accuracy. Second, self and mutual inductance are calculated in the stator, and dq-axis inductance is calculated using park transformation in the rotor of the proposed machine. Furthermore, on-load performance analysis, like average torque, torque density and efficiency, is done by FEA.FindingsThe developed LPMNM is validated by FEA via JMAG v. 19.1. The results obtained show good agreement with an accuracy of 96.89%.Practical implicationsThe proposed HECPFSM is developed for high-speed brushless AC applications like electric vehicle (EV)/hybrid electric vehicle (HEV).Originality/valueThe proposed HECPFSM offers better flux regulation capability with enhanced electromagnetic performance as compared to conventional consequent pole FSPM. Moreover, the developed LPMNM reduces drive storage and computational time by modeling one-third of the machine.

Combined voltage oriented control and direct power control based on backstepping control for four-leg PWM rectifier under unbalanced conditions

The present paper proposes a combined voltage-oriented control and direct power control (VOC-DPC) method associated with the backstepping control technique for a three-phase four-wire grid-connected four-leg rectifier in the synchronous rotating frame without using phase locked loop (PLL) and Parks transformation under balanced and unbalanced load and grid conditions. This control method is proposed in order to remove the drawbacks of the conventional VOC based on the PLL technique .The proposed control method is able to enhance the control performance and dynamic responses of the system when considering slow dynamics and instability issues of the PLL in several cases and can decrease the computational burden due to the absence of PLL and Park transformation. In addition, the performance of the proposed VOC-DPC method is enhanced by using backstepping control (BSC) based on Lyabonov theory for both the input currents and DC-bus voltage loops. As a consequence, constant DC-bus voltage, unit power factor, sinusoidal input currents, and neutral current minimization can be accurately carried out under both DC-bus voltage and load variations. Furthermore, robustness against filter inductance variations can also be achieved. The effectiveness, superiority, and performance of the proposed control method for a four-leg rectifier based on BSC in the dq0-frame are validated by several processor-in-the-loop (PIL) co-simulation tests sing the STM32F407 discovery development board.

Comparative analysis of unit template, SRF and the modified SRF technique for DSTATCOM-based distribution system

This paper introduces a new hybrid control strategy called the modified synchronous reference frame theory (modified SRF theory) for power quality improvement of a DSTATCOM-based distribution system. This control strategy makes use of both synchronous reference frame (SRF) as well as unit template technique to generate the reference supply currents which are then compared with the sensed supply currents and fed to the hysteresis/PWM current controller to generate the necessary switching signals for switches of the voltage source converter (VSC) of the DSTATCOM for a three-phase, three-wire system. The proposed algorithm eliminates the need of a complex reverse Park's transformation and results in the most efficient harmonic diminution confirming to IEEE-519 standard. The proposed control algorithm is compared with the unit template-based algorithm and the SRF theory to mitigate a variety of problems such as low power factor, voltage regulation, current unbalance and harmonics in the system. The proposed algorithm is proved efficient and reliable when compared with conventional algorithms reported in the literature.

Sliding mode control with observer for permanent magnet synchronous machine drives

<span lang="EN-US">This <span>paper aims to develop the sliding mode control (SMC) scheme in sensorless permanent magnet synchronous machine (PMSM) drives to replace conventional proportional integral (PI) speed control. The SMC is formulated based on the integral sliding surface of the speed error. And the error is corrected based on the concept of Lyapunov stability. The SMC is designed with the load torque observer so that the disturbance can be estimated as feedback to the controller. The vector control technique which is also known as field-oriented control (FOC) is also used to split the stator current into the magnetic field generating part which is the direct axis and the torque generating part which is the quadrature axis. This can be done by using Park and Clarke transformations. The performance of the proposed SMC is tested under changes in load-torque and without load for different speed commands. The results prove that the SMC produces robust performances under variations of speeds and load disturbances. The effectiveness of the proposed method is verified and simulated by using MATLAB/SIMULINK </span>software.</span>

A Systematic and Comprehensive Geometric Framework for Multiphase Power Systems Analysis and Computing in Time Domain

This paper presents a new framework for a systematic and thorough generalization of the most well-known instantaneous transformations used in electrical engineering for power systems analysis and computing through geometric principles based on the language of Geometric Algebra. By introducing the concepts of Kirchhoff Vector and Kirchhoff Subspace, a new generalized transformation is presented. Thus, it is shown how the Clarke, Park or Hyper-Space vector transformations (widely used in electrical engineering) are particular cases of this unifying framework. Moreover, a generalization to an arbitrary number of phases is achieved. In order to be as close as possible to the geometrical intuition, all the underlying ideas are presented by means of spatial-like conceptualizations, substantiated by their corresponding algebraic formulation. This proposal has potential uses in a wide range of power system applications such as electrical machines, current compensation, power quality, electronic converters or transmission lines. Preliminary results show the superior efficiency of the method compared to matrix methods. Some real-world examples have been included to highlight the potential use of the method.

A Fixed-Frame Positive-Sequence Extractor: An Alternative to the MAF-Based Park-Filter

Park-filters based on moving average filters (MAF) are a popular technique to extract the fundamental positive sequence component with zero-phase-shift from electrical three-phase signals, which is used to build references for power converters' controllers, as well as to help in grid synchronization tasks. Their implementation is, however, computationally burdensome, as it requires mapping the signals from the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\alpha \beta$</tex-math></inline-formula> -fixed reference frame coordinates to the synchronous frame coordinates, where they are processed using the moving average filter, and the result is finally transformed back to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\alpha \beta$</tex-math></inline-formula> -fixed reference frame coordinates. To overcome this issue, the present paper proposes and experimentally tests an alternative filter that directly operates on the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\alpha \beta$</tex-math></inline-formula> -fixed reference frame, thus avoiding the Park transformations. This considerably reduces the computational burden to almost one fifth. The proposed filter comprises a comb-filter cascaded with a second order harmonic oscillator. The proposed filter, referred to as CF-SOHO, guarantees the extraction of the fundamental positive sequence component with unitary gain and without phase-shift from unbalanced and harmonic-distorted signals, i.e., all harmonics (including DC components) contained in the incoming signals are fully suppressed. It can also cope with typical electrical stationary and dynamic disturbances.

Formulating the geometric foundation of Clarke, Park, and FBD transformations by means of Clifford's geometric algebra

Several of the most fundamental transformations widely used by the power engineering community are strongly based on geometrical considerations. Clifford's geometric algebra (GA) is the natural language for describing concepts in Euclidean geometry. In this work, we show how Clarke, Park, and Depenbrock's FBD transformations can be derived by imposing orthogonality on the voltage and current vectors defined in a Euclidean space by using GA. This paper presents these transformations as spatial‐like rotations and projections by means of the use of special algebraic objects named GA rotors. We prove that there is no need to use complex numbers nor matrices to perform the mentioned transformations and to provide geometrical intuition for electrical quantities and their transformations. Furthermore, power properties can be described using GA terminology by means of the proposed geometric power. The manipulation of the geometric power allows a useful current decomposition for a variety of applications such active filtering, frequency estimation, or electrical machinery. We provide in this paper an alternative approach focused on power systems under the paradigm of GA.

Noise prediction of chemical industry park based on multi-station Prophet and multivariate LSTM fitting model

With the gradual transformation of chemical industry park to digital and intelligent, various types of environmental data in the park are extremely rich. It has high application value to provide safe production environment by deeply mining environmental data law and providing data support for industrial safety and workers’ health in the park through prediction means. This paper takes the noise data of the chemical industry park as the main research object, and innovatively applies the 3σ principle to the zero-value processing of the noise data, and builds an LSTM model that integrates multivariate information based on the characteristics of the wind direction classification noise data combined with the wind speed and vehicle flow information. The Prophet model integrating multi-site noise information was adopted, and the Multi-PL model was constructed by fitting the above two models to predict the noise. This paper designs and implements a comparative experiment with Kalman filter, BP neural network, Prophet, LSTM, Prophet + LSTM weighted combination prediction model. R2 was used to evaluate the fitting effect of single model in Multi-PL, RMSE and MAE that were used to evaluate the prediction effect of Multi-PL on noise time series. The experimental results show that the RMSE and MAE of the data processed by the 3σ principle are reduced by 32.2% and 23.3% in the multi-station ordered Prophet method, respectively. Compared with the above comparison models, the Multi-PL model prediction method is more stable and accurate. Therefore, the Multi-PL method proposed in this paper can provide a new idea for noise prediction in digital chemical parks.

A Novel Experimental Method to Detect Early Rotor Faults in Induction Machines

The Induction Machines (IMs) have numerous industrial interests, as they have an uncomplicated design, strong, robust, and vulnerable to maintain. Despite that fact, a small fault in one rotor bar or a low Unbalance Rotor (UR) causes the break of this bar. Subsequently, the break of the adjacent bar because of the mechanical vibration generated by this imbalance of the rotor. This contribution proposes a new method based on the analysis of the stator line current to enhance the reliability of the monitoring system of an incipient defect in one rotor bar of the Induction Motor (IM). This new method, which combines the Electrical-Time-Synchronous-Averaging (ETSA) procedure with the Vector Park Transform (VPT) technique and Motor Current Signature Analysis (MCSA), and a Fuzzy Logic Algorithm (FLA), is performed. Indeed, an incipient rotor failure cannot be detected using the stator line current signal curve. Absolutely, in cases of the minor defect in one only rotor bar and low UR at low load. Nevertheless, the residual energy contained in each spectrum is considered as input variables for a fuzzy logic system to classify the type and the level of rotor defects. The proposed algorithm applied to the measured stator line-current has been built under the MatLab environment. The experimental obtained results confirm that the conceived algorithm can classify exactly the rotor faults.

Design of a New Duty Cycle Modulation to Improve the Energy Quality of an Insulated Production System

In this article, we propose a new strategy for controlling three-phase inverters of renewable energy sources, based on the Duty Cycle Modulatiom (DCM) control using the Park and Fortescue transformation (DCM-dq-dih). Our goals in setting and using this strategy are, on the one hand, to induce a lower harmonic rate as compared to the SPWM (Sinusoidal Pulse Width Modulation) strategy and on the other hand, this control technique enables the inverter to deliver balanced voltages, be it in the event of load unbalance. Our design is built on the basis of the known mode of DCM control of single-phase inverters. Thus, the control of our three-phase inverter is carried out by three DCM modules whose set-points come from the direct, reverse and homopolar strings reconstructed in a Park landmark. This new strategy was tested on the MATLAB Simulink environment for a load of 160 kW. The test results show a reduced Total Harmonic Distorsion (THD) of 2.7 times compared to the THD produced by the SPWM control strategy. In addition, regulation of the symmetrical components during load unbalance is ensured so that the inverter always delivers constant and balanced voltages.

English

Recently the use of sensitive electronic devices has increased, and the quality of energy has become an important factor in electrical power systems, where disturbances occurring in the network (harmonics, swell, voltage sag, etc.) affect consumers and lead to technical-economic damages. One of the most prominent solutions to address energy quality problems is the UPQC (Unified Power Quality Conditioner). In this paper, the unified power quality conditioner used to improve the electrical power quality in the distribution networks was discussed, where the Park transformations are used to obtain the required reference signals, and also the use of adaptive hysteresis band to generate the electronic switch pulses in both serial and shunt switches, where the pulse width is determined by dependence on fuzzy logic. The studied system was validated by simulating different distortion cases and comparing the results when using the Sinusoidal Pulse Width Modulation (SPWM) to control the two switches. The results showed improvement in the electrical power quality through the use of an adaptive hysteresis band controller, and that appeared by reducing the total distortion factor (THD%), which resulted in improving the shape of both the voltage and current waveforms.

Design and simulation of Dynamic Voltage Restorer (DVR) supported by solar panels

This work presents the design and simulation of a Dynamic Voltage Restorer (DVR) to mitigate power quality problems such as voltage sags and swells at sensitive loads to these types of disturbances, but with a compensation topology using one the most popular of the renewable energies, currently employed, which is photovoltaic solar energy. The DVR must operate with a control loop, monitoring the voltage at the load side and generating the voltage for compensation during the disturbances. The energy is obtained, from an array of solar panels for the injection of active power. The control algorithm discussed in this article is based on the Clark and Park transformations to generate the required signals for voltage compensation, these mathematical techniques allow fixing the variables and hence simplicity for the controller design. The results of the simulation in MATLAB/Simulink are used to show the performance of the proposed topology with symmetrical voltage sags in the distribution system.

An improved power control strategy for grid‐connected hybrid microgrid without park transformation and phase‐locked loop system

An improved power control strategy for <scp>grid‐connected</scp> hybrid microgrid without park transformation and phase‐locked loop system

An Enhanced Converter-based Diesel Generator Emulator for Voltage and Frequency Control Studies in Laboratory-Scale Microgrids

Diesel generator emulators (DGEs) are commonly used instead of real diesel generator units in laboratory-scale studies for their lower noise, more flexible parameters design and lower environmental pollution. This study presents a new control system in αβ framework for a DGE based on power electronic converter. The proposed control system has two parallel control paths including the frequency path and the voltage path. The voltage path consists of a PI controller that generates the amplitude of the modulation reference waveform. The frequency path consists of a transfer function in series with a droop curve to generate the angle of the modulation reference waveform. Finally, the angle and amplitude are applied to an especial space vector modulation unit for generation of the inverter gate pulses. The presented algorithm can be simply implemented in αβ framework with no need to PLL system and park transformation. It employs just one PI controller which can be easily implemented and tuned on the microcontroller. The experimental and simulation results verify the accuracy and performance of the proposed method.

Memorial Park Evolution

This article chronologically presents the genesis of memorial parks in the European civilization. It demonstrates the transformation of sacred landscape architecture into ritual facilities using the synthetic semantic of architecture and monumental art (cenotaphs, garden sculpture, fountains). Memorial parks became a means of identifying specific places and events in space, thus preserving the memories of certain times. The location of memorial parks within cities turned them into one of the key city-forming elements of the urban environment. Being an integral part of community lives, gardens and parks appeared pursuant to both the material and spiritual needs of people and became one of the attributes of civilization.The analysis of planning and dimensional-spatial methods in park construction helped classify them into types and identify their city-forming role from ancient times up to nowadays. Also, the authors could expose the memorial park transformation and adaptation processes depending on the changes to the social and economic formations.The symbol is always more important than a genuine person or thing.M. Pasturo.