有源电力滤波器APF(active power filter)是一种动态抑制谐波、补偿无功的电力电子装置,能够对不同大小和频率的谐波进行快速实时跟踪补偿,有效降低电力系统的谐波含量。但APF长期处于高频通断的工作状态,造成较高的功率损耗和故障率,...有源电力滤波器APF(active power filter)是一种动态抑制谐波、补偿无功的电力电子装置,能够对不同大小和频率的谐波进行快速实时跟踪补偿,有效降低电力系统的谐波含量。但APF长期处于高频通断的工作状态,造成较高的功率损耗和故障率,降低了经济性和工作可靠性。针对高功损和高故障率的问题,分析传统滞环电流控制策略的不足,提出一种新型滞环电流控制策略,合理控制APF开关器件的通断,进而降低开关频率,同时提升谐波补偿效果,使APF工作可靠性和谐波补偿性能提高。最后仿真和实验结果验证了该控制策略的可行性与有效性。展开更多
A highly efficient and re liable topology-dual buck half bridge inverter (DBI) is introduced. The existenc e of discontinuous conduction mode (DCM) operation state requires the bias of in du ctor current for DBI imple...A highly efficient and re liable topology-dual buck half bridge inverter (DBI) is introduced. The existenc e of discontinuous conduction mode (DCM) operation state requires the bias of in du ctor current for DBI implemented with linear controllers like ramp comparison SP WM (RCSPWM) controllers. A novel operation scheme for DBI and a hysteresis curre nt controlled dual buck half bridge inverter (HCDBI) are proposed. The bias curr ent required by RCSPWM DBI is eliminated and conduction losses are dramatically reduced. HCDBI has greatly improved the modulation performance in DCM region for the benefit of its excellent command tracking capability. The operational schem e and control strategy are presented. Power losses of the conventional half brid ge inverter (CHBI) and HCDBI are compared with mathematical computation, and exp erimental verification is also executed. Both calculational and experimental res ults verify that HCDBI has a superior switching performance over CHBI. Its exce llent high frequency operational capacity provides another access to realize high fre quency operation of inverters.展开更多
In the conventional cascade control structure of aerospace electrically powered actuators, the current（or electromagnetic torque） loop plays a critical role in realizing a rapid response for a digitally controlled B...In the conventional cascade control structure of aerospace electrically powered actuators, the current（or electromagnetic torque） loop plays a critical role in realizing a rapid response for a digitally controlled Brush Less Direct Current（BLDC） motor. Hysteresis Current Control（HCC） is an effective method in improving the performance of current control for a BLDC motor.Nevertheless, the varying modulating frequency in the traditional HCC causes severe problems on the safety of power devices and the electromagnetic compatibility design. A triangular carrier-based fixed-frequency HCC strategy is expanded by relaxing the constraints on the rising and descending rates of the winding current to advance the capability of HCC to realize fixed-frequency modulation in the steady state. Based on that, a new flexible-bound-size quasi-fixed-frequency HCC is proposed, and the range feasible to realize fixed-frequency modulation control can cover the entire running process in the steady state. Meanwhile, a corresponding digital control strategy is designed,and four digitalization rules are proposed to extend the capacity to achieve fixed-frequency modulation control to the unsteady working state, that is, a novel fixed-frequency modulation is realized.Simulation and experimental results prove the effectiveness of this improved fixed-frequency HCC strategy.展开更多
文摘有源电力滤波器APF(active power filter)是一种动态抑制谐波、补偿无功的电力电子装置,能够对不同大小和频率的谐波进行快速实时跟踪补偿,有效降低电力系统的谐波含量。但APF长期处于高频通断的工作状态,造成较高的功率损耗和故障率,降低了经济性和工作可靠性。针对高功损和高故障率的问题,分析传统滞环电流控制策略的不足,提出一种新型滞环电流控制策略,合理控制APF开关器件的通断,进而降低开关频率,同时提升谐波补偿效果,使APF工作可靠性和谐波补偿性能提高。最后仿真和实验结果验证了该控制策略的可行性与有效性。
文摘A highly efficient and re liable topology-dual buck half bridge inverter (DBI) is introduced. The existenc e of discontinuous conduction mode (DCM) operation state requires the bias of in du ctor current for DBI implemented with linear controllers like ramp comparison SP WM (RCSPWM) controllers. A novel operation scheme for DBI and a hysteresis curre nt controlled dual buck half bridge inverter (HCDBI) are proposed. The bias curr ent required by RCSPWM DBI is eliminated and conduction losses are dramatically reduced. HCDBI has greatly improved the modulation performance in DCM region for the benefit of its excellent command tracking capability. The operational schem e and control strategy are presented. Power losses of the conventional half brid ge inverter (CHBI) and HCDBI are compared with mathematical computation, and exp erimental verification is also executed. Both calculational and experimental res ults verify that HCDBI has a superior switching performance over CHBI. Its exce llent high frequency operational capacity provides another access to realize high fre quency operation of inverters.
基金supported by the National Natural Science Foundation of China (Nos.51275021,61327807)
文摘In the conventional cascade control structure of aerospace electrically powered actuators, the current（or electromagnetic torque） loop plays a critical role in realizing a rapid response for a digitally controlled Brush Less Direct Current（BLDC） motor. Hysteresis Current Control（HCC） is an effective method in improving the performance of current control for a BLDC motor.Nevertheless, the varying modulating frequency in the traditional HCC causes severe problems on the safety of power devices and the electromagnetic compatibility design. A triangular carrier-based fixed-frequency HCC strategy is expanded by relaxing the constraints on the rising and descending rates of the winding current to advance the capability of HCC to realize fixed-frequency modulation in the steady state. Based on that, a new flexible-bound-size quasi-fixed-frequency HCC is proposed, and the range feasible to realize fixed-frequency modulation control can cover the entire running process in the steady state. Meanwhile, a corresponding digital control strategy is designed,and four digitalization rules are proposed to extend the capacity to achieve fixed-frequency modulation control to the unsteady working state, that is, a novel fixed-frequency modulation is realized.Simulation and experimental results prove the effectiveness of this improved fixed-frequency HCC strategy.
