DC‐side fault detection for photovoltaic energy conversion system using fractional‐order dynamic‐error‐based fuzzy Petri net integrated with intelligent meters

Technol Econ Smart Grids Sustain Energy

et al. 2018

To reduce peak loads, direct and indirect load control are common strategies used to change demand during peak hours. Voltage dependent demand response (DR) is a direct load control for changing loads in a DC mircogrid. The characteristics of electronic loads can be controlled with a switch-mode DC boost or buck converter. They have faster response to maintain stable output voltage under the fluctuating load condition and heavy load condition. Applying a fast load step to voltage regulator can maintain a well regulated voltages and load currents. The increased load resistance will cause voltage drop when load current is increased during heavy loads. Thus, their adjustable internal load impedances can change the absorbed currents by regulating the duty ratio. In this study, a screening model is employed to estimate the virtual internal impedances of power electronic loads. Then, the desired duty ratio can be determined to perform the DR program, while the boost converter acts to step-up or step-down the load voltages using the PID (proportional-integral-derivative) controller. For a DC microgrid, simulation results show the feasibility of the proposed methods: (1) exact control of load voltage at both the power source side and load sides and (2) regulation of absorbed currents to modify load voltages and reduce line voltage drops and line losses during heavy loads.

Section: The Procedures Of Electronic Load Demand Responsesmentioning

confidence: 99%

Section: The Procedures Of Electronic Load Demand Responsesmentioning

confidence: 99%

Direct Electronic Load Control for Demand Response in a DC Microgrid Using a Virtual Internal Impedance Screening Model and PID Controller

Lin

Chen

Technol Econ Smart Grids Sustain Energy

et al. 2018

“…Therefore, the maximum output power (MOP) of each PV panel, P q,est , and total MOP, P est , can be estimated as LGF / UGF) [6,[11][12][13]. When any fault occurs in a PV panel, voltage, current, and power meters can be employed to measure the output power, P q,mea , of each panel, as seen in the measurement system in Figure 2(b).…”

Section: Maximum Output Power Estimation and Fault Feature Extractionmentioning

confidence: 99%

“…Previous studies [6][7] have proposed that use of the MPPT algorithm may prevent faults during periods of lower solar radiation and night-to-day transition, as the algorithm can locate the reference value at the maximum power point. When the measured output power is degraded, based on the electrical property, faults such as grounded faults, line-to-line faults, and open circuit faults can be identified [6,[11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Multiple Fault Location in a Photovoltaic Array Using Bidirectional Hetero-Associative Memory Network in Micro-distribution Systems

Chang¹,

Pai²,

Chou³

et al. 2018

Preprint

Abstract:In manual maintenance inspections of large-scaled photovoltaic (PV) or rooftop PV systems, several days are required to survey the entire PV field. To improve reliability and shorten the amount of time involved, this study proposes an electrical examination based method for locating multiple faults in the PV array. The maximum power point tracking (MPPT) algorithm is used to estimate the maximum power of each PV panel; this is then compared with metering the output power of PV array. Power degradation indexes are parameterized to quantify the degradation between maximum power and metered output power. Bidirectional hetero-associative memory (BHAM) networks are then used to locate multiple faults within the entire PV field. For a rooftop PV system with two strings, experimental results demonstrate that the proposed model has computational efficiency for real-time applications and that its algorithm is easily implemented in a mobile intelligent vehicle.

“…Traditionally, the differential or integral of the integer order has often been used in physical phenomenon or for the control of a system. For example, speed can be obtained through displacing the displacement, the curve can be integrated to obtain the area, and fuzzy PD or PID controllers are often applied in the control system, thereby providing good effects [3,6,8,9].…”

Section: Introductionmentioning

confidence: 99%

Visual servo control for the underwater robot station-keeping

Chang

2017 International Conference on Applied Electronics (AE)

et al. 2017

This paper presents a visual servo and fuzzy-PID controller to enable underwater robot stationkeeping. Movements of underwater robots are easily disturbed by water flow or external factors in a deepwater environment. In this study, control systems are used to adjust the underwater robot's propeller, which reduces chattering of the robot's postures, and visual target feedback and an accelerometer are employed to control its station-keeping. Results of a station-keeping test confirm the applicability and effectiveness of the proposed controller.