Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

What is a PLC?PLC stands for “Programmable Logic Controller.” A PLC is a computer specially designed to operate reliably in harsh industrial environments, such as extreme temperatures and wet, dry, and/or dusty conditions. PLCs are used to automate industrial processes such as a manufacturing plant’s assembly line, an ore processing plant, or a wastewater treatment plant.PLCs share many features of the personal computer you have at home. They both have a power supply, a CPU (Central Processing U

What is Steady State Error?Steady-state error is defined as the difference between the desired value and the actual value of a system output in the limit as time goes to infinity (i.e. when the response of the control system has reached steady-state).Steady-state error is a property of the input/output response for a linear system. In general, a good control system will be one that has a low steady-state error.First, we will discuss the steady-state error in a first-order transfer function by an

What is a Transfer Function?A transfer function describes the relationship between the output signal of a control system and the input signal. A block diagram is a visualization of the control system that uses blocks to represent the transfer function and arrows representing the different input and output signals. Transfer Function The transfer function is a convenient representation of a linear time-invariant dynamical system. Mathematically the transfer function is a function of complex v

What is Rise Time?Rise time is defined as the time taken for a signal to cross from a specified low value to a specified high value. In analog and digital electronics, the specified lower value and specified higher value are 10% and 90% of the final or steady-state value. So the rise time is typically defined as how long it takes for a signal to go from 10% to 90% of its final value.The rise time is an essential parameter in analog and digital systems. It describes the time taken for the output

A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications, especially under grid voltage disturbance conditions. Moreover, stability issues related to the grid-connec

In this paper, an overall individual dc voltage (including high-voltage and low-voltage dc-link voltages) balance strategy is proposed for the electronic power transformer with separated dc-link topology. The strategy adjusts active powers flowing through the isolation and output stages in different power modules to enhance the dc voltage balance capability. Through the strategy, the high-voltage and low-voltage dc-links can be well balanced when unbalance occurs among different power modules

This paper proposes and analyzes a two-stage dc-dc isolated converter for electric vehicle charging applications, where high efficiency over a wide range of battery voltages is required. The proposed conversion circuit comprises a first two-output isolation stage with CLLC resonant structure and a second two-input buck regulator. The transformer of the first stage is designed such that its two output voltages correspond, ideally, to the minimum and maximum expected voltage to be supplied to th

Grid-forming (GFM) inverters are recognized as a viable solution to increase the penetration of renewable energy in bulk power systems. However, they are physically different from synchronous generators in terms of overcurrent capability. To protect the power semiconductor devices and support the power grid under severe symmetrical disturbances, the GFM control systems should be able to achieve the following requirements: current magnitude limitation, fault current contribution, and fault reco

A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications, especially under grid voltage disturbance conditions. Moreover, stability issues related to the grid-connected