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Abstract. Traditional rectifier circuit by the diode or thyristor, work to produce a large number of harmonics. Active power factor correction (PFC) on this basis to add high-performance full-control power electronic devices, such as MOSFET and IGBT, and control the input current to make it close to the sine wave and the unit power factor. In recent years, with the requirements of the performance of electrical equipment continues to improve, this technology has become a hot spot in the field of power electronics research, and has been widely practical application.For the single-switch and DC-side Boost-type boost circuit, this paper uses the current hysteresis control strategy and PI regulator on the DC side of the fixed voltage control. Analyze the continue current mode (CCM) and the discontinue current mode (DCM). Then the harmonic analysis and switching loss analysis are carried out for the two models.Through the PSCAD simulation, total harmonic distortion (THD) of the current harmonics is low by the discrete Fourier transform (FFT) of the AC current waveforms of the two models. In this paper, we use parallel switch on the buffer circuit to simulate the switching losses, DCM control can be a good way to reduce the opening loss of the switch. IntroductionSingle-phase full-bridge controllable rectifier circuit consists of four half-controlled thyristor, by changing the trigger angle to adjust the rectifier side voltage. The disadvantage is the consumption of a large number of reactive power and produce harmonic interference, and the trigger angle adjustment range is limited, the rectifier side voltage range is too limited [1] . In order to solve the above problems, we can use PWM rectifier circuit, that is, all four thyristors replaced by full-control IGBT devices, but compared to thyristors, IGBT expensive and relatively small capacity, the higher the cost of circuit transformation. With the need to rectify the DC drive to drive a substantial increase in power equipment as well as the international restrictions on the implementation of power harmonics standards. Active power factor correction technology has become a hotspot in the field of power electronics, which can add a small amount of full control device to the sine wave current and the unit power factor on the basis of the original uncontrollable or semi-controlled rectifier circuit.As shown in Fig 1, when the controllable switch V is on, the power supply E is charged to the inductor L while the capacitor C supplies power to the load. As the value of C is large, the output voltage U0 is kept constant. When V is in the off state, E and L collectively charge the capacitor and supply energy to the load R. Boost type has been able to make the output voltage higher than the power supply voltage, the key for two reasons: First, the inductance L after the energy storage has the role of voltage pump, and second, the capacitor C can maintain the output voltage.As shown in Fig 2, in the rectifier circuit DC side by adding Boost module, you can meet the following c...

For the sake of exploring how to apply new flexible resources to power system efficiently, it is urgent to study the comprehensive value of different flexible resources in typical application scenarios of power system. In this paper, a flexible resource value comprehensive evaluation index system is established from three dimensions: technical value, economic value and application value. Combined with the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method, a comprehensive evaluation model of power system flexible resource value in typical application scenarios is constructed to evaluate the current value of flexible resources in China. The results show that the virtual power plant shows the highest flexible resource matching degree in the peak shaving and valley filling scenario and the auxiliary service scenario, and the electrochemical energy storage shows the highest flexible resource matching degree in the safety support scenario.