Michael John Harrison

Three-Phase Phase-Locked Loop Control of a New Generation Power Converter

This paper describes the development of a new generation of power converter, used to power telecommunications equipment. A telecommunications converter must comply with the psophometric noise standard CCIF-1951 and the IEC1000-3-2 harmonic standard. While the IEC1000-3-2 standard is easily met with active power factor correction techniques, a high degree of effort is usually required to meet with the psophometric standard. Therefore, a control methodology utilising a three-phase phase-locked loop is introduced as a method of complying with the psophometric standard under distorted mains conditions. Simulations show that combining this with a novel feedback controller, results in an improved load step response over using a traditional proportional integral type controller

A Novel Three-Phase Software Phase-Locked Loop

This paper describes the development of a novel three-phase phase-locked loop (PLL) used to compensate for mains variations by being incorporated as part of a feedforward loop in a three-phase telecommunications power converter. A telecommunications converter must comply with industry standards, in particular the psophometric noise standard CCIF-1951; this is achieved by controlling the output voltage ripple from the dc-dc converter. It is required that psophometric compliance is maintained under expected mains variations documented in the EN50160 power quality standard. The software PLL is simulated and performance characteristics show a high degree of noise rejection while also maintaining good dynamic performance.

New generation power converter

Abstract This paper describes an initial investigation into the development of a new generation of power converter, used to power telecommunications equipment. The traditional topology for such power converters is a single-phase two-stage design, resulting in an overall reduction in efficiency. A power converter solution is sought that meets with all the requirements of the telecommunications industry, and which can be realised by a single-stage design. A new converter, which is a three-phase single-stage buck-derived topology, is proposed. Simulation shows that if this topology is combined with a three-phase phase-locked loop controller it can potentially meet the compliance standards.

A Proposal for a New Generation Power Converter With Pseudo-Derivative Control

This paper describes the development of a new generation of DC converter used to supply power to telecommunications equipment. Traditional topologies have been single-phase two-stage designs. As a consequence of having a two-stage design there are losses across both stages, resulting in a cascading effect. A new type of converter is proposed that utilizes a three-phase single-stage design and as a result, has efficiency advantages over the traditional approach. Output regulation is normally achieved by means of a PI feedback control. However, under conditions of a step load change there is considerable overshoot. A control technique, known as pseudo-derivative feedback control (PDF) is introduced, and simulation results show an improved response to a step load change

Phase locked loop control of a three-phase single-stage power converter

Abstract A three-phase single-stage power converter has been proposed and is shown to provide some benefits over the traditional single-phase two-stage telecommunication power converter designs. It has the ability to conform to all the required telecommunication standards, while only employing a single-stage design with reduced controller complexity and with the expectation of yielding efficiency advantages. An improved three-phase phase locked loop design is discussed with performance results showing its robust nature. A pseudo derivative feedback controller is introduced, with simulation results showing its ability to maintain a constant output voltage under load disturbances. Complete digital control of the three-phase single-stage power converter implementation is also detailed in the paper.