This paper describes two methods of representation of voltages and currents in electric circuits： in the vector form and in the shape of oscillations, represented as diagrams in the plane. The appropriate power compo...This paper describes two methods of representation of voltages and currents in electric circuits： in the vector form and in the shape of oscillations, represented as diagrams in the plane. The appropriate power components are discussed depending on the representation of voltages and currents. Special attention is paid to the instantaneous power peculiarities for diverse loads and non-sinusoidal conditions. A case study of power calculations in an electric circuit with a pluggable capacitor is presented. For these types of transient modes, the instantaneous power is represented in the form of active and reactive components. Calculation of active, reactive, and exchange powers for steady-state processes is presented.展开更多
This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried o...This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried on the test in transmission field. This paper introduces in detail the structure and characteristic of DSP system, and gives a design scheme of Doubly Fed Speed Control System of motor based on this chip.展开更多
Voltage source converter high-voltage direct current （VSC-HVDC） is a new power transmission technology pref- erable in small or medium power transmission. In this paper we discuss a new control system based on space...Voltage source converter high-voltage direct current （VSC-HVDC） is a new power transmission technology pref- erable in small or medium power transmission. In this paper we discuss a new control system based on space vector modulation （SVM） without any voltage line sensors. Using direct power control （DPC） SVM and a new double synchronous reference frame phase-locked loop （DSRF-PLL） approach, the control system is resistant to the majority of line voltage disturbances. Also, the system response has accelerated by using a feed forward power decoupled loop. The operation of this control strategy was verified in a SIMULINK/MATLAB simulation environment. To validate this control system, a 5 kV.A prototype system was constructed. Compared to the original controllers, the current total harmonic distortion （THD）, the active and reactive deviations and the DC voltage overshoot were lowered by 2.5%, 6.2% and 8%, respectively. The rectifier power factor in the worst condition was 0.93 and the DC voltage settling time was 0.2 s.展开更多
文摘This paper describes two methods of representation of voltages and currents in electric circuits： in the vector form and in the shape of oscillations, represented as diagrams in the plane. The appropriate power components are discussed depending on the representation of voltages and currents. Special attention is paid to the instantaneous power peculiarities for diverse loads and non-sinusoidal conditions. A case study of power calculations in an electric circuit with a pluggable capacitor is presented. For these types of transient modes, the instantaneous power is represented in the form of active and reactive components. Calculation of active, reactive, and exchange powers for steady-state processes is presented.
文摘This paper introduces the design of doubly fed system for conveyor belt motor, the system adopts stator flux orientation vector control technology and AC-AC inverter motor speed and power factor control, and carried on the test in transmission field. This paper introduces in detail the structure and characteristic of DSP system, and gives a design scheme of Doubly Fed Speed Control System of motor based on this chip.
文摘Voltage source converter high-voltage direct current （VSC-HVDC） is a new power transmission technology pref- erable in small or medium power transmission. In this paper we discuss a new control system based on space vector modulation （SVM） without any voltage line sensors. Using direct power control （DPC） SVM and a new double synchronous reference frame phase-locked loop （DSRF-PLL） approach, the control system is resistant to the majority of line voltage disturbances. Also, the system response has accelerated by using a feed forward power decoupled loop. The operation of this control strategy was verified in a SIMULINK/MATLAB simulation environment. To validate this control system, a 5 kV.A prototype system was constructed. Compared to the original controllers, the current total harmonic distortion （THD）, the active and reactive deviations and the DC voltage overshoot were lowered by 2.5%, 6.2% and 8%, respectively. The rectifier power factor in the worst condition was 0.93 and the DC voltage settling time was 0.2 s.
