A resonant DC-DC converter may include an input for inputting a DC supply voltage, an output for providing a DC voltage to a load, an output rectifier to convert the converter voltage into a DC voltage, a resonant half-bridge inverter comprising two switches in series with a first serial resonant circuit to adjust the output current of the converter, and a second serial resonant circuit to block DC current in the converter and provide current continuity within the converter. The resonance of the first serial resonant circuit is measured after every start of the converter and each measurement defines the switching frequency of the half-bridge inverter. The switches of the half-bridge inverter wherein the driving of the half-bridge inverter includes a key gap during operation thereof. The resonance frequency of the second serial resonant circuit is at least slightly above the switching frequency of the half-bridge inverter.

The present invention relates to a system and method for the monitoring and detection of insulation degradation in electric systems. The system comprises a controller for an electric motor (3), including input circuitry (2a) for connecting the controller to a power supply (1), power conversion circuitry (2b) for providing a power output for the electric motor (3), and sensing circuitry (2c) for monitoring a current inside the controller that is representative of a return leakage current from the electric motor to the motor controller. A condition of the insulation may be determined based on the monitored current.

A power converter includes: a converter including four switching elements in full bridge configuration, the converter converting alternating-current power supplied from an alternating-current power supply into direct-current power; a reactor provided between the alternating-current power supply and the converter; a smoothing capacitor connected between direct-current terminals of the converter; an alternating-current voltage detector detecting an alternating-current voltage output from the alternating-current power supply; an alternating current detector detecting a current flowing through the reactor; and a control circuitry controlling a switching operation of the switching elements. The control circuitry controls the switching elements such that a potential fluctuation due to the switching operation is reduced between a P terminal of the converter and an L terminal of the alternating-current power supply, or between a G terminal of the converter and an N terminal of the alternating-current power supply.

The invention relates to a two-way electrical power distribution network including: a high electrical power distribution bus; medium voltage electrical power feed lines; low voltage distribution lines, wherein the low voltage distribution lines are connected to load(s) and/or source(s); and, medium voltage electrical power regulating apparatus including: a DC contactor having DC terminals; a transmission network connector connected to the medium voltage electrical power feed line including: live terminal(s) connected to live connection(s) and a neutral terminal connected to a neutral of the medium voltage electrical power feed line; switches connected to the DC contactor; and electronic controlling devices coupled to the switches and control the switches to independently regulate electrical power on each of the live connection and the neutral connection of the medium voltage electrical power feed line to thereby maintain a voltage in the electrical power distribution bus during different load and source conditions.

The invention comprises an apparatus, comprising an inductor, the inductor comprising: an inductor core; a first winding section comprising a first cast shape and a second winding section comprising the first cast shape, the first winding section mechanically joined to the second winding section to form a winding, the winding forming a wound shape about the inductor core. Optionally and preferably, a third winding section, comprising a second cast shape, mechanically joins the first winding section to the second winding section and a mechanical connector and/or an aluminum weld join the first winding section to the third winding section.

Methods and apparatus for active EMI cancellation in a switch mode power supply are provided herein. For example, an apparatus comprises an active EMI cancellation circuit coupled to a switch mode power supply circuit comprising an isolation transformer, wherein the active EMI cancellation circuit is positioned such that current flow through an EMI coupling capacitor substantially matches displacement current flow through a primary-to-secondary interwinding capacitance of the isolation transformer.

A bridge circuit includes a first leg and a second leg arranged in parallel between the first node and the third node. A clamp circuit includes a third leg including a first bidirectional switch disposed between a fourth node that is a midpoint of the first leg and a fifth node that is a midpoint of the second leg. A first reactor is connected with the fourth node and a sixth node, and a second reactor is connected with a fifth node and a seventh node. A fourth leg includes a second bidirectional switch disposed between the second node and the fourth node or the fifth node.

An anti-power environment suppression circuit includes: a power input terminal configured to receive an alternating current input from an external power source; a power output terminal configured to output the alternating current that has undergone anti-interference processing; a live wire, a neutral wire and a ground wire that are coupled in parallel between the power input terminal and the power output terminal; and a common-mode suppression sub-circuit coupled in the ground wire. The common-mode suppression sub-circuit is further coupled to the live wire and the neutral wire, and the common-mode suppression sub-circuit is configured to suppress common-mode interference between the ground wire and the live wire, and suppress common-mode interference between the ground wire and the neutral wire, so as to perform the anti-interference processing on the input alternating current.

A three-level inverter includes controllable switch components T1 to T6. Each of the controllable switch components includes a parallel connected junction capacitor and an anti-parallel connected diode. A first terminal of T1 is connected to a positive direct current bus, a second terminal of T4 is connected to a negative direct current bus, a second terminal of T1 is connected to first terminals of T2 and T5. A controller is configured to: in a positive half cycle, control T3 to be conducted after T1 is conducted, and control T3 to be disconnected before T1 is conducted next time; and in a negative half cycle, control T2 to be conducted after T4 is conducted, and control T2 to be disconnected before T4 is conducted next time. The three-level inverter can balance voltages of the controllable switch components.

The disclosure describes techniques to filter unwanted noise from feedback signals of an electrical machine. An electrical machine may receive AC power from an inverter and circuitry in the inverter may cause noise on the AC power signals to the electrical machine. The noise may couple to sensors for the electrical machine and cause noise in the sensor output signals. The sensor output signals may provide feedback for a closed loop control system for the electrical machine and noise may impact the closed loop operation. Also, the noise in the feedback signals may cause electromagnetic compatibility (EMC) issues, either by direct radiated emissions or by coupling to other circuits in the vehicle wiring harness as the feedback signals travel from the electrical machine. The techniques of this disclosure may include filter circuitry located near or inside the electrical machine that filters out the unwanted noise in the feedback signals.