Patent classifications
H02H7/1227
Drive circuit, liquid crystal drive controller, and liquid crystal display device
A gate driver IC includes a first diode, a second diode, a first comparator, a second comparator, and a judgement circuit. The first comparator compares a first potential difference between both ends of the first diode and a first threshold. The second comparator compares a second potential difference between both ends of the second diode and a second threshold. Based on comparison results of the first comparator and the second comparator, the judgement circuit determines occurrence of disconnection.
Overvoltage protection circuit
An overvoltage protection circuit which can be applied to a motor controller is provided. The overvoltage protection circuit comprises a voltage controller, a comparator, and a switching circuit so as to prevent damage to a driving circuit. The driving circuit is configured to supply a driving current to a motor coil.
Electromagnetic induction type wireless power supply system and load sudden-change protection circuit thereof
A power supply system includes a wireless power supply end and a wireless receiving end. The wireless receiving end includes a resonant receiving component and a rectifying and voltage-stabilizing component that is connected to the resonant receiving component to output a voltage-stabilized power supply (VCC). A load sudden-change protection circuit includes an overvoltage protection component and an under-voltage protection component that are each respectively connected to the voltage-stabilized power supply and a load. The overvoltage protection component turns on the load when the voltage of the voltage-stabilized power supply is higher than a first preset voltage due to sudden turn-off of the load. The under-voltage protection component turns off the load when the voltage of the voltage-stabilized power supply is lower than a second preset voltage due to sudden turn-on of the load.
Motor drive
A motor drive includes a rectifier bridge, which rectifier bridge is connected to an DC link, which is connected to an inverter bridge having phase outputs configured to be connected to an elevator motor, as well as a drive control controlling the semiconductor switches of the inverter bridge. The inverter bridge has upper semiconductor switches of the upper side connected to plus of the DC link and lower semiconductor switches of the lower side connected to minus of the DC link, the upper semiconductor switches are semiconductor switches without desaturation- and/or over-current protection whereas the lower semiconductor switches comprise a desaturation- and/or over-current protection, or vice versa. The drive control includes an earth fault control circuit which is configured to establish an earth fault test, in which each single semiconductor switch comprising a desaturation- and/or over-current protection is switched through, only one at a time, over a test time period, whereby the earth fault control circuit is configured to enable start of the motor drive only if the earth fault test has not lead to a tripping of the desaturation- and/or over-current protection of one of the semiconductor switches.
Protection and control of wireless power systems
One general aspect includes methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for fault protection of a bidirectional wireless power transfer system. The method includes the actions of detecting, by control circuitry of a wireless power transfer device, a fault for the bidirectional wireless power transfer system. Identifying an operating personality of the wireless power transfer device and a hardware configuration of the wireless power transfer device. Identifying, in response to detecting the fault and based on the operating personality and the hardware configuration, protection operations for protecting the wireless power transfer device from the fault. Controlling operations of the wireless power transfer device according to the protection operations. Other implementations of this aspect include corresponding systems, circuitry, controllers, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.
MOTOR DRIVE DEVICE, BLOWER, COMPRESSOR, AND AIR CONDITIONER
A motor drive device includes a reactor, a converter circuit, a capacitor, an inverter circuit, and overcurrent determination units. The converter circuit converts a first AC voltage output from an AC power supply into a DC voltage. The capacitor smooths a second voltage on the DC side of the converter circuit. The inverter circuit converts DC power stored in the capacitor into AC power. One of the overcurrent determination units determines overcurrent based on a detected value of the first AC current, flowing between the AC power supply and the converter circuit. Another overcurrent determination unit determines overcurrent based on a detected value of the second DC current, flowing between the converter circuit and the capacitor. The converter and inverter circuits stop operating when the determination result of one of the overcurrent determination units indicates an overcurrent.
In-mold lid closing apparatus
An in-mold lid closing apparatus includes a lid engagement member, a first actuation assembly connected to a first portion of the lid engagement member, a second actuation assembly connected to a second opposing portion of the lid engagement member, and a controller disposed in electrical communication with the first actuation assembly and the second actuation assembly. The controller is configured to transmit a first drive signal to the first actuation assembly and a second drive signal to the second actuation assembly to drive one of a linear position and a rotational position of the lid engagement member and to adjust at least one of the first drive signal and the second drive signal based upon a first feedback signal received from the first actuation assembly and a second feedback signal received from the second actuation assembly.
Protection coordination technique for power converters
A control unit of an electrical system is described. The control unit causes some of the switches in a power converter of the electrical system to not be shut down and not conducting upon detection of a fault current caused by a line-to-line fault. Instead, the control unit causes at least one of the switches to be switched-on and conducting to allow the some of the fault current to flow through the at least one switch, before activating a protection device that creates an open circuit and breaks the fault.
Electric protection systems and methods
Electrical protection systems and methods, of which an exemplary method comprises: measuring a voltage and an electric current in an electric link; calculating, repeatedly, from the measured values of current, a first moving average and a second moving average, the second moving average being calculated over a duration longer than the first moving average; comparing the measured voltage value with a predefined voltage threshold value; comparing the current value of the first moving average with the current value of the second moving average; and identifying a condition of trigger of the protection device when the measured voltage value is lower than the predefined voltage threshold value for a duration longer than a predefined duration threshold and when the current value of the first moving average is higher than the current value of the second moving average.
System and method for protection during inverter shutdown in distributed power installations
A protection method in a distributed power system including of DC power sources and multiple power modules which include inputs coupled to the DC power sources. The power modules include outputs coupled in series with one or more other power modules to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the string and produces output power. When the inverter stops production of the output power, each of the power modules is shut down and thereby the power input to the inverter is ceased.