Study On High Performance Emergency Power Supply With One-cycle Control

The dependence on electric power is becoming more and more in the human society with the rapid development of industry and science technology. The sudden power failure will affect people's natural life, seriously can make great accident and economy loss, especially in the time that our country's electric power supply is being in tension. So standby power supply is requirement. The Emergency Power Supply (EPS) is a sort of new type standby power supply. Comparatively with the conventional diesel generating set, EPS is provided with dependable performance, convenient management, safety, longevity of service and flexible design. EPS has been broadly used in the standby power supply design of building electricity and industry electricity.The system of Emergency Power Supply mostly forms from commutated charger, accumulator battery, inverter and automatic switching set. The inverter is the core of EPS, its output directly choose the performance of EPS. But the quality of inverter output voltage depends on the inverse control technique. The one-cycle control is a great signal nonlinear control technique firstly proposed by Keyue M.Smedley and Slobodan at 1991. Compared with the method of constant frequency PWM control, one-cycle control has simple structure, fast response speed, good stability, beautiful robustness, no steady error and transient error. It can adapt the control requirement of high precision, high speed and high against disturbance.For the aim that EPS needs rapid dynamic response, high quality output voltage and strong antijamming ability, the One-cycle control technique is applied into the control system of the Emergency Power Supply. Based on the one-cycle control theory, three key problems when one-cycle control used in the inverse circuit are resolved. The first problem that the integrator needs to be reset instantaneously is resolved by using dual channel integrator with reset. Secondly, by added dc offset voltage, an automatic switching-error correction scheme is developed for the instability problem. The last, the steady error problem caused by autoecious parameters is resolved by added PI control with feedforward. By using of one-cycle control technique, this paper gives the simulation details of the single-phase full-bridge EPS inverter, whose simulation results compare with the EPS inverter based on the SPWM. Simulation results show that the one-cycle control technique gets better performance than the SPWM technique at the ability of against DC source, load disturbance and dead-zone affection. This paper simply shows the simulation results of three-phase half-bridge EPS inverter. At the last, this paper gives experiment research on the single-phase full-bridge EPS inverter and also gives some experiment results.