40results about How to "Less power conversion stages" patented technology

The invention discloses a DC residential energy router based on a multi-port converter and a control method thereof. The energy router is characterized in that the energy router is composed of four H bridge modules, two-way buck/boost converter modules BB1 and BB2, four external series inductors, and a high-frequency four-winding transformer; driving signals used to control on-off of full-control power devices in the converter modules BB1 and BB2 are obtained by means of pulse width modulation; and driving signals used to control on-off of full-control power devices in the H bridge modules are obtained by means of single phase shift modulation. The energy router integrates photovoltaic energy, stored energy, a power grid, and a residential load with different voltage grades. Two-way power flow between stored energy and the power grid is realized. Maximum use of renewable energy, reduction in power exchange with the power grid, charge and discharge based on stored energy, input source use priority, control on port voltages and power balance control in the system are realized.

The invention discloses a single-stage bidirectional isolation AC-DC converter, and belongs to the field of an electronic power electronic converter. The structures of three converters are each composed of single-phase AC sources, DC sources, Boost inductors, phase shift inductors, bus capacitors, transformers, primary power switch tubes, secondary power switch tubes and the like. The Boost inductors are connected to leg midpoints such that the integration of a bidirectional Boost PFC converter with a bridge type bidirectional converter is realized, through single-stage power transformation, two functions of PFC and isolation DC-DC transformation can be realized, and bidirectional flowing of energy is realized. The single-stage bidirectional isolation AC-DC converter, has the advantages of small power loss, high transformation efficiency, small switching loss, capability of realizing the bidirectional flowing of the energy, and the like, thereby being especially suitable for V2G and power network-storage battery energy storage systems.

The invention provides a full-bridge current-source high-frequency isolation-type three-level inverter. The full-bridge current-source high-frequency isolation-type three-level inverter consists of an input direct-current power supply, voltage-dividing capacitors, a full-bridge current-source high-frequency isolation-type three-level conversion unit, a cyclic wave converter, an output filter and an output alternating-current load which are sequentially connected with one another, wherein on the basis of the traditional full-bridge current-source inverter, two capacitors are connected to two ends of the input direct-current voltage source in parallel to divide the voltage, so that three levels of Ui, Ui/2, minus N1U0/N2 can be generated on the front end of a transformer, the voltage stress on a switch tube can be reduced, and the application range of the current-source high-frequency isolation inverter can be enlarged. The full-bridge current-source high-frequency isolation-type three-level inverter has two levels of power transformation (direct-current (DC)-high-frequency alternating-current (HFAC)-low frequency alternating current (LFAC)) and has the advantages of bi-directional power flow, low voltage stress on a switch device, good spectrum characteristics on the front end of the filter, small size of the output filter, high power density and capability of realizing the high-frequency electrical isolation between the alternating-current load and the direct-current power supply.

The invention provides a high-frequency isolation-type five-level inverter. The high-frequency isolation-type five-level inverter consists of an input direct-current power supply unit, voltage-dividing capacitors, a high-frequency isolation-type five-level conversion unit, a high-frequency isolation transformer, a cyclic wave converter, an output filter and an output alternating-current load, wherein on the basis of a full-bridge inverter, four capacitors are connected to two ends of an input direct-current voltage source in parallel to divide the voltage, so that five levels of Ui/2, Ui/4, 0, minus Ui/4, minus Ui/2 can be generated on the front end of the transformer, the five levels also can be sensed by a transformer side edge, the voltage stress on a switch tube can be reduced, and the waveform quality of the output voltage can be improved. The inverter has two levels of power transformation (direct current (DC)-high frequency alternating current (HFAC)-low frequency alternating current (LFAC)) and has the advantages of bi-directional power flow, low voltage stress on a switch device, good voltage spectrum characteristics on the front end of the output filter, small size of the output filter, low voltage stress on the switch tube and capability for electrically isolating the alternating-current load and the direct-current power supply in a high-frequency manner. The inverter can be applied to the application field with higher voltage and large power.

The invention provides a matrix type motor driving system based on bidirectional wireless electric energy transmission. In the system, an energy transmission mode adopts coupling coil type wireless electric energy transmission, and a signal transmission mode adopts a wireless communication technology. According to the invention, one-step power conversion from high-frequency alternating current tolow-frequency alternating current is realized by utilizing a direct matrix converter, so that a direct-current bus capacitor with high failure rate is removed, and the number of power conversion stages is reduced so as to substantially improve the reliability and the power density; two-way power transmission capacity is achieved through coordination control of converters in a vehicle body and wheels, so that braking energy is fed back to a battery side so as to improve the energy utilization efficiency; and the application range of the designed matrix type motor driving system based on bidirectional wireless power transmission is not limited to hub motors, and the matrix type motor driving system based on bidirectional wireless power transmission also has important reference value for special industrial applications with wireless requirements, such as joint driving motors of robots.

The invention provides a high-frequency isolated type three-level inverter based on a push-pull converter. The high-frequency isolated type three-level inverter is composed of an input direct-current power source unit, an input filter, a push-pull three-level inversion unit, a high-frequency transformer, a frequency converter, an output filter and an output alternating current load which are connected in sequence. The input direct-current power source unit is connected with one end of the input filter. The other end of the input filter is connected with one end of the push-pull three-level inversion unit. The other end of the push-pull three-level inversion unit is connected with a primary winding of the high-frequency transformer. A secondary winding of the high-frequency transformer is connected with the input end of the frequency converter. The output end of the frequency converter is connected with the input end of the output filter. The output end of the output filter is connected with the output alternating current load. The high-frequency isolated type three-level inverter has the advantages that the number of levels of power conversion is small, few power switch elements exist, voltage stress of a power switch tube is low, bidirectional power current and high-frequency electric isolation are achieved, and the voltage spectral characteristic of the front end of the output filter is good.

The invention discloses a two-stage non-isolation photovoltaic grid-connected inverter. The two-stage non-isolation photovoltaic grid-connected inverter comprises a first direct current bus capacitor, a second direct current bus capacitor, a direct current power conversion circuit, and a full bridge power conversion circuit, the first direct current bus capacitor is connected with a photovoltaic assembly string and an input terminal of the direct current power conversion circuit in sequence, the second direct current bus capacitor is connected with an output terminal of the direct current power conversion circuit, the first direct current bus capacitor and the second direct current bus capacitor are connected in series and then connected with an input terminal of the full bridge power conversion circuit, and an output terminal of the full bridge power conversion circuit is externally connected with a power grid. The invention also discloses a control method thereof. According to the two-stage non-isolation photovoltaic grid-connected inverter and the control method thereof, the voltage stress of the direct current bus capacitors is reduced, only a part of power passes through the direct current power conversion circuit, the power conversion stage number is small, and the power loss is small; double-buck topology is employed, hidden risks of gating of bridge arms can be prevented, and the reliability is high; freewheeling is realized via an independent diode, a power switch tube can employ an MOSFET, and the conversion efficiency of the grid-connected inverter can be improved.

The invention discloses a two-stage non-isolated full-bridge grid-connected inverter, which comprises a first direct-current bus capacitor, a second direct-current bus capacitor, a direct-current power conversion circuit, a first power switch tube, a second power switch tube, a third power switch tube, a fourth power switch tube, a fifth power switch tube, a sixth power switch tube, a first power diode, a second power diode, a third power diode, a fourth power diode, a first filter inductor, a second filter inductor and a filter capacitor, wherein the power switch tubes and the power diodes have a plurality of structures and connection modes. The two-stage non-isolated full-bridge grid-connected inverter has the characteristic that a series form is adopted by partial power switch tubes and power diodes, so that the voltage stress of a power device is only equal to the voltage of the first direct-current bus capacitor or the voltage of the second direct-current bus capacitor. The voltage stress of the power switch tubes and the power diodes is reduced, so that the cost is reduced; the efficiency is improved; and the problems in the prior art are solved.

The invention discloses a forward five-level inverter, comprising an input direct current power supply, a voltage dividing capacitor, a forward five-level conversion unit, a cycle converter, an output filter and an output alternating current load. Through change of the type of the cycle converter, a circuit topology family of a half-wave rectification forward five-level inverter and a full-wave rectification forward five-level inverter is obtained. The forward five-level inverter provided by the invention has the advantages of few power conversion stages, bidirectional power flow, good output filter front-end voltage spectral characteristic and the like, the conversion efficiency and the power density are improved, the size and the weight are reduced, the voltage stress of a switching device can be reduced, and high-frequency electrical isolation of the alternating current load from the direct current power supply is realized.

The invention provides a high-frequency isolated type boost three-level inverting circuit which is composed of a Boost inverting circuit and a flyback type energy feedback circuit. The Boost inverting circuit is composed of an input direct-current power supply unit, an input filter, a high-frequency inverter, a high-frequency transformer, a frequency converter, an output filtering capacitor and an output alternating-current load which are sequentially connected. A Boost converter can only increase the voltage and can not decrease the voltage, so that the output voltage can not be decreased, and the voltage can not meet the requirement for the output sine waveform. In order to ensure the quality of the output sine waveform in the period and solve the problem of the orientation of reactive energy of the output filtering capacitor and the load, the high-frequency electrical isolation flyback type converter energy feedback circuit is added between the output load and an input power supply. The inverter has the advantages that the number of power conversion stages is small, the number of power switching devices is small, input ripple waves are small, the voltage stress of a power switching tube is low, the dual-directional power stream and high-frequency electrical isolation are achieved, and the spectrum characteristic of the voltage at the front end of the output filter is good.

The invention provides a three-phase alternating current-alternating current (AC-AC) direct frequency converter and a control method thereof. The three-phase AC-AC direct frequency converter comprises a three-phase power supply, a filter, a main circuit and a buffer circuit, and is characterized in that the power supply is sequentially connected with the filter and the main circuit, and the main circuit is connected with the buffer circuit. The control method for the three-phase AC-AC direct frequency converter comprises a sinusoidal pulse width modulation (SPWM) control mode and a hysteresis current control mode. The converter is simple in topology structure; and the control method is simple, practical and high in reliability, and comprises a few power conversion stages.

The invention discloses a current source type three-level AC/AC converter. The current source type three-level AC/AC converter is formed by an input alternating current power supply, a voltage-dividing capacitor, a high-frequency isolation type three-level conversion unit, a frequency converter, an output filter and an output alternating current load which are connected in sequence. According to the converter, on the basis of a traditional AC/AC converter, the two ends of the input alternating current power supply are in parallel connection with two capacitance partial voltages, the front end of the converter can generate three levels including U, U/2 and -Uo/n (n=N2/N1= ), voltage stress of a switch tube is reduced, and output voltage waveform quality is improved. The current source type three-level AC/AC converter has the advantages that voltage stress of a switch device is small, front end voltage spectral characteristics of the output filter are good, the size of the output filter is small, and an alternating current load and alternating current power supply high-frequency electrical isolation can be achieved; and the current source type three-level AC/AC converter can be applied to the application occasions with high voltage and high power and is wide in application prospect.

The invention provides a high-frequency isolation three-level inverter. The high-frequency isolation three-level inverter comprises an input direct-current power supply, a voltage dividing capacitor, a high-frequency isolation Buck-Boost type three-level conversion unit, a cycle converter, an output filter and an output alternating-current load which are connected with one another. According to the converter, on the basis of a traditional full-bridge high-frequency isolation Buck-Boost type inverter, two capacitors are connected to the two ends of an input direct-current voltage source in parallel for voltage division, so that three levels can be generated at the front end of a transformer, the voltage stress of a switching tube is reduced, and the application range of the high-frequency isolation Buck-Boost type inverter is widened. The high-frequency isolation three-level inverter has the advantages of two-stage power conversion (direct current (DC)-high frequency alternating current (HFAC)-low frequency alternating current (LFAC), bidirectional power flow, low voltage stress of a switching device, good voltage spectrum characteristic at the front end of the output filter, small size of the output filter, relatively high power density, capability of realizing high-frequency electrical isolation of an alternating current load and a direct current power supply, suitability for a micro-grid and the like.

The invention discloses a multi-port converter for electric automobile cluster charging and discharging and a control method of the multi-port converter. The multi-port converter is characterized in that the multi-port converter is totally provided with n ports; (n-1) ports from the first port to the (n-1)th port in the n ports are respectively used for being connected with an electric automobile battery; and the n-th port in the n ports is used for being connected with a direct current bus in a direct current micro grid. The control method of the multi-port converter is characterized in that the duty ratio of each switch tube is obtained through calculation; driving pulses corresponding to each switch tube are formed by utilizing the duty ratio obtained through calculation for controlling the on-off state of each switch tube; and the discharging control and the charging control on the electric automobile battery are further realized. The multi-port converter and the control method are used for electric automobile cluster charging and discharging control, and the interaction function between an electric automobile and an electric network is fully achieved.