The present disclosure relates to an emergency lighting circuit, an emergency start control method thereof and an emergency lighting system. When an emergency start condition is met, matching can be performed in a preset dimming database according to type information of load lighting equipment connected to a current emergency lighting circuit to obtain a dimming parameter value matching a power value required by the load lighting equipment, and finally, the load lighting equipment is directly controlled to start with the dimming parameter value. Through the above solution, when emergency lighting is started, there is no need to spend time in regulating power of the load lighting equipment, and a corresponding power value can be ensured when the load lighting equipment is started, which is highly reliable in emergency lighting start.

The present disclosure relates to an emergency lighting circuit, a control method thereof and an emergency lighting system. Normal lighting is monitored by detecting whether a charging management apparatus in the emergency lighting circuit has electric energy input. When the charging management apparatus has no electric energy input, emergency lighting may be started, and power transmitted to load lighting equipment is switched to an emergency battery apparatus through a power supply switching apparatus, which is processed by a boost inverter to provide appropriate electric energy for the load lighting equipment. A power detection apparatus detects an input-terminal power signal of the boost inverter, and regulates power of the load lighting equipment based on the input-terminal power signal. Operating power of the load lighting equipment is regulated based on the input-terminal power signal of the boost inverter. An input-terminal voltage of the boost inverter is a DC low voltage and easy to detect. Moreover, in the solution, high voltage and current are not required to be isolated for power detection, which effectively reduces detection costs and is highly reliable in power detection.

A vehicle power system including a fuel cell auxiliary power unit for providing clean, efficient power to a vehicle. The system generally includes a fuel cell with a first DC output and a heat output, a pressure vessel adapted to contain and provide pressurized hydrogen to the fuel cell, an electrical storage unit with a DC input coupled to the first DC output of the fuel cell. The electrical storage unit also has a second DC output. An inverter is coupled to the second DC output of the electrical storage unit to receive power, the inverter having a first AC output. The system can provide heat, AC power, and DC power to the vehicle.

A dual-input power supply has two power paths that connect a server to electrical Each power path has a first stage that comprises a power-factor correction circuit. The power paths share a common second stage that comprises a dc/dc converter. The first stages of the power paths collectively defining a pair of first stages that is disposed either within a package that is off the motherboard or without a package and on the motherboard. Similarly, the second stage is disposed either within a package that is off the motherboard or without a package and on the motherboard.

A ground fault detection apparatus is used to detect a ground fault of a three-phase UPS apparatus. The UPS apparatus includes a first filter circuit, an AC/DC conversion circuit, a DC bus, a DC/AC conversion circuit, and a second filter circuit coupled in sequence. The ground fault detection apparatus includes a detection circuit having a first detection end and a second detection end. The first detection end is coupled to the first filter circuit and the second filter circuit, and the second detection end is coupled to an equipment grounding point. The equipment grounding point is coupled to a neutral point of a three-phase power source, and the three-phase power source is coupled to the first filter circuit. The detection circuit indicates whether the UPS apparatus has a ground fault and a location where the ground fault occurs according to a detection voltage between the first detection end and the second detection end.

A power switching circuit including a first DC/DC converter having a first input configured to receive a first input DC voltage, a second DC/DC converter having a first input configured to receive a second input DC voltage, a DC/AC inverter having a first input coupled to the output of the first DC/DC converter and a second input coupled to the output of the second DC/DC converter, the DC/AC inverter including n (n>2) switching legs, and at least one controller coupled to the first DC/DC converter, the second DC/DC converter, and the DC/AC inverter, the at least one controller configured to operate the DC/AC inverter to provide n AC signals to at least one load coupled to the DC/AC inverter by operating two of the n switching legs in a static state and n−2 of the n switching legs in a transition state.

An elevator includes an elevator motor; a motor drive for the elevator motor having a frequency converter including a rectifier bridge, an inverter bridge and a DC link in between, which frequency converter is controlled via a controller, the rectifier bridge being connected to AC mains via three feed lines including chokes, and the rectifier bridge being realised via controllable semiconductor switches; a contactor being located between the feed lines and AC mains; and a backup power supply at least for emergency drive operation. An emergency control is associated with the motor drive, which emergency control is configured to perform an automatic emergency drive. The emergency control is connected to a manual drive circuit having a manual drive switch for a manual rescue drive. The elevator includes a motion sensor connected to the emergency control, whereby the emergency control is configured to activate a brake and/or gripping device of the elevator in case the car speed during a manual rescue drive exceeds a predetermined threshold value.

An uninterruptible power supply includes a plurality of vacuum circuit breakers and a bypass circuit connected in series between a commercial AC power supply and a load, a control device that turns on both of the plurality of vacuum circuit breakers and the bypass circuit when the commercial AC power supply is normal and turns off a vacuum circuit breaker different from a vacuum circuit breaker turned off on the occurrence of previous power failure of the plurality of vacuum circuit breakers and turns off the bypass circuit when the commercial AC power supply fails, and a power converter that converts DC power of a battery into AC power and supplies AC power to the load when the commercial AC power supply fails.

A method for operation of UPS modules connected in parallel is provided. The method includes: in a case that a UPS system is constructed based on multiple UPS modules connected in parallel, sleeping, based on a system load rate, a predetermined number of UPS modules to control the UPS system to operate at a predetermined efficiency level; controlling UPS modules not being slept in the UPS system to enter into a main-inverter power supply mode or a main-bypass common mode to perform reactive power and harmonic compensation; and waking up the slept UPS modules when the system load rate drops by a predetermined value due to a sudden addition of a load. The UPS modules can be slept or waked up intelligently based on the system load rate in the dynamic online mode, ensuring that the UPS system operates around highest efficiency.

A method for operation of UPS modules connected in parallel is provided. The method includes: in a case that a UPS system is constructed based on multiple UPS modules connected in parallel, sleeping, based on a system load rate, a predetermined number of UPS modules to control the UPS system to operate at a predetermined efficiency level; controlling UPS modules not being slept in the UPS system to enter into a main-inverter power supply mode or a main-bypass common mode to perform reactive power and harmonic compensation; and waking up the slept UPS modules when the system load rate drops by a predetermined value due to a sudden addition of a load. The UPS modules can be slept or waked up intelligently based on the system load rate in the dynamic online mode, ensuring that the UPS system operates around highest efficiency.