scholarly journals Coordinated Recovery Strategy for Multi-infeed HVDC Systems Based on MIESCR

2021 ◽  
Vol 256 ◽  
pp. 01003
Author(s):  
Li Xiaobin ◽  
Hu Shihao ◽  
Huang Haoyu
Keyword(s):  
Reactive Power ◽  
Power Transmission ◽  
Pi Controller ◽  
Simulation Software ◽  
Recovery Strategy ◽  
Hvdc System ◽  
Dc System ◽  
Type Definition ◽  
Electromagnetic Transient Simulation ◽  
Definition Of

A coordinated recovery strategy, based on MIESCR, is proposed for the converters Excessive dynamic reactive power demand and the low speed of power transmission recovery in multi-infeed HVDC system in this paper. Firstly, the article deduces the consistency of two type definition of MIESCR, and uses the respective advantages of the definition to improve the physical meaning of MIESCR; and then it elaborates the role of MIESCR played in in MIDC system voltage and power-angle stability Third, this pages put forward MIESCR as the fundamental to distinguish the strength of AC system, and use the size of MIESCR to arrange the recovery order of DC systems. Furthermore, the parameter of PI controller is used to realize the control of each DC system current. There is a great method to ensure coordinate control of PI controller. The last, a double infeed HVDC system simulation model, based on two actual DC system of China Southern Power Grid, is built on Electromagnetic transient simulation software of PSCAD/EMTDC to confirm the validity of this method proposed in this paper.

scholarly journals Placement of shunt reactors in high-voltage network using fuzzy constraints

2019 ◽  
Vol 139 ◽  
pp. 01052
Author(s):  
Arif Hashimov ◽  
Huseyngulu Guliyev ◽  
Aytek Babayeva
Keyword(s):  
High Voltage ◽  
Reactive Power ◽  
Power Transmission ◽  
Operation Mode ◽  
Ease Of Use ◽  
Electrical Network ◽  
Control Voltage ◽  
Fuzzy Constraints ◽  
Definition Of ◽  
Shunt Reactors

In recent years, controlled shunt reactors (CSR) relevant to the class of FACTS facilities have been widely used to control voltage modes and reactive power flows in the high-voltage electrical network. The selection of location, as well as the definition of the law of CSR control in the conditions of stochastic variability of the operation mode of high-voltage power transmission, are associated with numerous technical and economic factors. At the same time, such constraint conditions as ease of use, performance efficiency, purpose and location in the system, as well as the period of commissioning should be taken into account. In the proposed procedure these factors are considered as fuzzy constraints. The procedure of CSR placement in the 330 kV electrical network of Azerenergy system for control of reactive power flows taking into account the mentioned fuzzy constraints is proposed. The obtained simulation results confirm the advantage of the proposed procedure.

scholarly journals A Novel Overcurrent Suppression Strategy during Reclosing Process of MMC-HVDC

2019 ◽  
Vol 9 (9) ◽  
pp. 1737 ◽  
Author(s):  
Bin Jiang ◽  
Yanfeng Gong
Keyword(s):  
Transmission Lines ◽  
Short Circuit ◽  
Current Method ◽  
Short Circuit Current ◽  
Simulation Software ◽  
Fault Current ◽  
Overhead Lines ◽  
Hvdc System ◽  
Electromagnetic Transient Simulation ◽  
Current Calculation

A modular multilevel converter based high-voltage DC (MMC-HVDC) system has been the most promising topology for HVDC. A reclosing scheme is usually configured because temporary faults often occur on transmission lines especially when overhead lines are used, which often brings about an overcurrent problem. In this paper, a new fault current limiter (FCL) based on reclosing current limiting resistance (RCLR) is proposed to solve the overcurrent problem during the reclosing process. Firstly, a mesh current method (MCM) based short-circuit current calculation method is newly proposed to solve the fault current calculation of a loop MMC-HVDC grid. Then the method to calculate the RCLR is proposed based on the arm current to limit the arm currents to a specified value during the reclosing process. Finally, a three-terminal loop MMC-HVDC test grid is constructed in the widely used electromagnetic transient simulation software PSCAD/EMTDC and the simulations prove the effectiveness of the proposed strategy.

scholarly journals Mal-Operation of Mho Relay In Transmission Line Due To Presence of TCSC

2019 ◽  
Vol 8 (3) ◽  
pp. 4328-4333
Keyword(s):  
Transmission Line ◽  
Fault Location ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission System ◽  
Simulation Software ◽  
Normal Operation ◽  
Distance Protection ◽  
Voltage Profile ◽  
Angle Variation

Distance protection is simple and it provides fast response to clear the fault. Distance protection is also providing primary and remote backup function depending upon distance of transmission line. Distance protection uses various relays like mho relay/admittance relay, impedance relay and reactance relay. In power transmission system, Flexible AC Transmission System (FACTS) controllers are used to increase power transfer capability and reactive power control, but distance relay get affected due to presence of FACTS devices. This may create the stability issues, security and it may affect on voltage profile. The changes in impedance level would affect the accuracy of distance protection. This paper represents the effect of TCSC on operation of mho relay in transmission line. The work presented here emphasis on the interaction of TCSC on distance protection and their performances under different condition i.e., load angle variation, variation of SCL, different fault location. Design and control performance of MHO relay during normal operation as well as during variation in different condition is verified by using PSCAD simulation software.

scholarly journals Steady State and Transient Analysis of FSIG and DFIG Integration to Grid for Different Penetration Levels using VSC-HVDC

2020 ◽  
Vol 8 (6S) ◽  
pp. 53-59
Keyword(s):  
Power System ◽  
Wind Energy ◽  
Wind Power ◽  
Reactive Power ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Simulation Software ◽  
System Stability ◽  
Induction Generator ◽  
Hvdc System

Among all the Renewable Energy Sources Wind energy is the fastest growing energy source over the last decade mainly due to crucial developments of technology in wind energy. Nowadays, the penetration of wind energy is increasing in many countries in the world including India. The power system stability with large penetration of wind power is a concern for many electrical utilities. The common technical issues with increased penetration of wind energy are voltage and reactive power control, frequency control and Low Voltage Ride Through (LVRT) capability. The VSC-HVDC system with its benefit of independent control of active and reactive power promises to enhance the system stability at high penetration levels. The maximum wind penetration levels in to the grid is analysed for Fixed Speed Induction Generator (FSIG) & Doubly Fed Induction Generator (DFIG). The penetration levels are further enhanced by considering the evacuation of wind power with VSC-HVDC system without losing system stability. Different controllers for VSC-HVDC system are used to improve the stability and LVRT capability. Standard Benchmark System is considered, and the simulations are performed by using power system simulation software SIMPOW. Results shows that wind power evacuated through VSC-HVDC system has better stability and LVRT Capability compared to AC system at high wind penetration levels.

Electromagnetic - Electromechanical Transient Hybrid Simulation of Deyang-Baoji HVDC System Based on ADPSS

2013 ◽  
Vol 805-806 ◽  
pp. 935-940
Author(s):  
Fan Tang ◽  
Guo Liang Su ◽  
Dong Xiang Li ◽  
Yu Hong Wang
Keyword(s):  
Large Scale ◽  
Hybrid Simulation ◽  
Simulation Software ◽  
Transient Simulation ◽  
Power System Simulation ◽  
Electromagnetic Transient ◽  
Hvdc System ◽  
Simulation Speed ◽  
Electromagnetic Transient Simulation ◽  
Scale Grid

three kinds of digital programs used in power system simulation are summarized in this paper. The electromagnetic and electromechanical transient simulation software ADPSS is introduced. Electromagnetic transient simulation, electromechanical transient simulation and electromagnetic-electromechanical transient hybrid simulation are performed respectively on Deyang-Baoji ±500KV HVDC system. The simulation result shows that the electromagnetic-electromechanical transient hybrid simulation has the advantage of electromagnetic transient simulation and electromechanical transient simulation. It can effectively analyze the process of the local electromagnetic transient in large-scale grid. The simulation speed is fast and the result is accurate and reliable.

scholarly journals Transient Performance Analysis of Reactive Power Compensators at LCC-HVDC Station Feeding Weak AC System

2021 ◽  
Vol 40 (4) ◽  
pp. 835-841
Author(s):  
Atiq Ur Rehman ◽  
Mehr Gul ◽  
Talha Mir ◽  
Syed Mudassir Hussain ◽  
Zahid Rauf
Keyword(s):  
Performance Analysis ◽  
Reactive Power ◽  
Short Circuit ◽  
Dynamic Performance ◽  
Poor Performance ◽  
Voltage Regulation ◽  
Comparative Performance ◽  
Dc System ◽  
Electromagnetic Transient Simulation ◽  
Bus Voltage

This paper focuses on analyzing the dynamic performance of various reactive power compensators at weak LCC-HVDC terminals. Four scenarios based on combination of active and passive reactive power compensation schemes are presented. The comparative performance analysis of various compensators in different types of AC and DC system faults are evaluated using electromagnetic transient simulation program PSCAD/EMTDC. The analysis shows that fixed capacitor has poor performance and results in reducing effective short circuit ratio of system, while STATCOM on the other hand, increases AC system strength and has significant performance in areas like immunity to commutation failure, suppression of temporary overvoltage, AC bus voltage regulation and fault recovery time.

Improving the efficiency of oilfield electric power distribution

2019 ◽  
pp. 79-87
Author(s):  
Yu. F. Yu. F. Romaniuk ◽  
О. V. Solomchak ◽  
М. V. Hlozhyk
Keyword(s):  
Power Distribution ◽  
Reactive Power ◽  
Power Transmission ◽  
Transmission Efficiency ◽  
Active Power ◽  
Oil Field ◽  
Total Power ◽  
Simultaneous Increase ◽  
Active Load ◽  
Step Down

The issues of increasing the efficiency of electricity transmission to consumers with different nature of their load are considered. The dependence of the efficiency of the electric network of the oil field, consisting of a power line and a step-down transformer, on the total load power at various ratios between the active and reactive components of the power is analyzed, and the conditions under which the maximum transmission efficiency can be ensured are determined. It is shown by examples that the power transmission efficiency depends not only on the active load, but also largely on its reactive load. In the presence of a constant reactive load and an increase in active load, the total power increases and the power transmission efficiency decreases. In the low-load mode, the schedule for changing the power transmission efficiency approaches a parabolic form, since the influence of the active load on the amount of active power loss decreases, and their value will mainly depend on reactive load, which remains unchanged. The efficiency reaches its maximum value provided that the active and reactive components of the power are equal. In the case of a different ratio between them, the efficiency decreases. With a simultaneous increase in active and reactive loads and a constant value of the power factor, the power transmission efficiency is significantly reduced due to an increase in losses. With a constant active load and an increase in reactive load, efficiency of power transmission decreases, since with an increase in reactive load, losses of active power increase, while the active power remains unchanged. The second condition, under which the line efficiency will be maximum, is full compensation of reactive power.  Therefore, in order to increase the efficiency of power transmission, it is necessary to compensate for the reactive load, which can reduce the loss of electricity and the cost of its payment and improve the quality of electricity. Other methods are also proposed to increase the efficiency of power transmission by regulating the voltage level in the power center, reducing the equivalent resistance of the line wires, optimizing the loading of the transformers of the step-down substations and ensuring the economic modes of their operation.

scholarly journals Optimal Sizing and Placement of Capacitor Banks in Distribution Networks Using a Genetic Algorithm

Electricity ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 187-204
Author(s):  
Gian Giuseppe Soma
Keyword(s):  
Genetic Algorithm ◽  
Electricity Market ◽  
Distribution Systems ◽  
Reactive Power ◽  
Electricity Consumption ◽  
Distribution Networks ◽  
Optimal Placement ◽  
Capacitor Banks ◽  
Control Pattern ◽  
Definition Of

Nowadays, response to electricity consumption growth is mainly supported by efficiency; therefore, this is the new main goal in the development of electric distribution networks, which must fully comply with the system’s constraints. In recent decades, the issue of independent reactive power services, including the optimal placement of capacitors in the grid due to the restructuring of the electricity industry and the creation of a competitive electricity market, has received attention from related companies. In this context, a genetic algorithm is proposed for optimal planning of capacitor banks. A case study derived from a real network, considering the application of suitable daily profiles for loads and generators, to obtain a better representation of the electrical conditions, is discussed in the present paper. The results confirmed that some placement solutions can be obtained with a good compromise between costs and benefits; the adopted benefits are energy losses and power factor infringements, taking into account the network technical limits. The feasibility and effectiveness of the proposed algorithm for optimal placement and sizing of capacitor banks in distribution systems, with the definition of a suitable control pattern, have been proved.

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