1328 results about "Secondary loop" patented technology

A secondary loop temperature control circuit for a temperature-controlled region in a compartment of a refrigerator is shown. The secondary loop temperature control circuit has a reservoir, configured to have a medium flow there through. A first heat exchanger is in flow communication with the reservoir and is configured to have the medium flow there through. The first heat exchanger is in thermal communication with the temperature-controlled region.

An HVAC system for heating and cooling a passenger compartment of a vehicle is provided. A first heat exchanger transfers heat between a primary loop and a secondary loop. The primary loop is a reversible loop and uses high pressure refrigerant. A compressor pressurizes the refrigerant. A second heat exchanger selectively transfers heat energy to and from the passenger compartment. The secondary loop is a low pressure liquid coolant loop that passes through the first heat exchanger. A pump moves fluid through the secondary loop. A third heat exchanger transfers heat to and from an external medium from the fluid passing through the secondary loop. A secondary heat source adds heat to the secondary loop during a heating mode. A bypass means selectively bypasses the secondary heat source during a cooling mode.

A capillary pump two phase heat transport system that combines the most favorable characteristics of a capillary pump loop (CPL) with the robustness and reliability of a loop heat pipe (LHP). Like a CPL, the hybrid loop has plural parallel evaporators, plural parallel condensers, and a back pressure flow regulator. Unlike CPLs, however, the hybrid system incorporates elements that form a secondary loop, which is essentially a LHP that is co-joined with a CPL to form an inseparable whole. Although secondary to the basic thermal management of the system thermal bus, the LHP secondary loop portion of the system provides for important operational functions that maintain healthy, robust and reliable operation. The LHP secondary loop portion provides a function of fluid management during start-up, steady state operation, and heat sink/heat source temperature and power cycling.

The disclosed protection method for internal fault of large power transformer comprises: the protector samples the secondary current of current transformers on power transformer sides to obtain current instantaneous value and calculate complex number form of electric values by Fourier algorithm, corrects phase of connection form, and balances amplitude of transformation ratio; then, it calculates the complex number form of negative sequence current according to three-phase ac complex form, and computes negative sequence differential current and break current as the negative sequence differential protection principle to decide asymmetric inside and outside fault and drop out all breakers. This invention also contains exactly the negative sequence differential rate breaking feature and protection criterion, the adjusting means for protection values, the positive sequence current breaking criterion, and the block function for error action protection.

The invention relates to an electric secondary AC circuit detection method which comprises the following steps: before a power plant machine set is started, a low-voltage short-circuit point or a short-circuit bogie is input; three-phase 380 V voltage is added at the high-voltage side of a booster station to form a circuit by means of the impedance of a transformer and a generator; current amplitude and phase are measured through a current detecting apparatus to check polarity and transformation ratio in advance; all current protective directions such as generator differential motion are measured. When a neutral point is not connected, a short-circuit point is made at a high plant transformer low-voltage side, and the three-phase 380 V voltage is added at the neutral point of the generator, thereby realizing overall checkup of a generator AC circuit; then, the three-phase 380 V voltage is converted into one-phase voltage or two-phase voltage to carry out overall checkup of a zero sequence circuit. The detection method can check all CT and PT circuits of a generation-transformer group before power transmission; moreover, all protection directions of the generation-transformer group are checked in advance, thereby saving time and fuel oil along with economical efficiency, environmental protection and safety. The electric secondary AC circuit detection method can check secondary circuits such as the transformer and the bus differential protection of a transformer substation.

An implantable device, such as an infuser device for bidirectional hydraulically controlling a medical artificial sphincter, enhances power transfer characteristics to a secondary coil thereby allowing implantation to greater physical depths and/or enclosing the secondary coil within a housing of the infuser device. The enhanced power transfer is achieved with multiple coils that are longitudinally aligned and physical and electrical parallel to form the secondary loop of a transcutaneous energy transfer system (TET) instead of a single coil. It better optimizes the power transfer from a parallel tuned tank circuit primary coil to an implanted secondary series tuned tank circuit coil.

The invention belongs to the technical field of power systems and discloses a system for monitoring a secondary circuit model on line in real time based on a protection device. The system comprises a network communication module, a model resolution module, a graph generation module, a model storage module and a real-time comparison module, wherein the model resolution model is connected with the graph generation module and the model storage module and outputs a substation configuration description (SCD) static model and a resolved configured IED description (CID) on-line model respectively; the real-time comparison module is connected with the network communication module and the model storage module, receives a generic object oriented substation event (GOOSE) real-time model, a verified SCD static model and a resolved CID on-line model, compares and outputs a comparison result to the network communication module, and the comparison result is uploaded to a background system to realize real-time on-line monitoring. By the system, a phenomenon that a virtual terminal and a secondary circuit of the protection device make mistakes due to SCD file modification, CID configuration errors, secondary circuit real-time connection obstacles corresponding to GOOSE messages and the like can be timely found, so that operational risks of a substation are reduced.

The invention provides an automatic detection system and method of a secondary virtual loop of an intelligent transformer station. The automatic detection system comprises an automatic test system and virtual terminal simulated output subsystems, wherein the virtual terminal simulated output subsystems are disposed in secondary intelligent electronic devices. According to communication links and virtual terminal loop information in an SCD file, the automatic test system sends a test control command to spacing-layer and process-layer devices via the GOOSE internet to drive virtual terminal simulated output of the devices, response to test excitation of the devices is obtained from the MMS internet and the GOOSE internet to automatically determine a test result, and the correctness of the virtual loop is verified. According to the system and method of the invention, whether virtual terminals of point-to-point and networking ports of the devices are correctly connected can be determined needless of dismounting fibers among the devices, changing configuration of the virtual terminals or adding external testers, the debugging-verifying efficiency and correctness of the secondary virtual loop are improved, and stable and reliable operation of the secondary system of the intelligent transformer station is ensured.

The invention provides a secondary circuit closed loop monitoring system based on a GOOSE input end mapping mechanism in the technical field of power systems. The secondary circuit closed loop monitoring system comprises a network communication module, a model analyzing module, a pattern generating module, a real-time comparing module and a data storage module. The model analyzing module analyzes SCD files from the network communication module, outputs an obtained static model of an IED device virtual terminal/virtual circuit to the pattern generating module, maps a GOOSE message feature value and a GOOSE input terminal to mapping definitions of a corresponding MMS model object, and outputs the mapping definitions to the real-time comparing module. According to an IED device standard drawing template prestored in the data storage module and the static model of an IED device virtual terminal/virtual circuit in the model analyzing module, by means of a template matching technology, the pattern generating module carries out matching on the IED device standard drawing template to generate an IED device secondary circuit diagram, and output the IED device secondary circuit diagram to the data storage module for visual display. According to the system, abnormal conditions of a secondary circuit and abnormal situations of a GOOSE control block, a dataset, goIDs and other key content can be found timely according to abnormality of a GOOSE message. Secondary circuit closed loop monitoring based on the GOOSE input end mapping mechanism is achieved, and reliable technical guarantee is provided for safe operation of an intelligent substation.

The invention discloses a quality control device and a method for resistance spot welding based on electrode displacement, which belongs to the technical field of welding. 380V alternating current power supply is added to the input end of a primary loop; under the controllable trigger of an anti-parallel thyristor; the alternating current voltage is reduced by a transformer and the welding energy is switched to a secondary loop; the heavy current acquired from the secondary loop welds workpieces; a spot welding part of the workpiece generates heat expansion and the expansion capacity is measured by an electrode displacement sensing device; a spot welding quality controller collects the displacement measured value of the electrode displacement sensing device and processes the numerical value to acquire the estimation of splashing prevention judgment and nugget size, thus acquiring a welding current control voltage signal and transmitting the signal to a trigger driving circuit; the trigger driving circuit sends trigger pulse to the anti-parallel thyristor to control a conduction angle of the thyristor, thus effectively regulating the welding current and controlling the welding quality. Therefore, the device can solve the real-time monitoring and control problem of the quality of the resistance spot welding well.

A digital control circuitry for a MEMS gyroscope is provided. The digital control circuitry comprises a digital primary loop circuitry configured to process a digitized primary signal, a digital secondary loop circuitry configured to process a digitized secondary signal and a digital phase shifting filter circuitry configured to generate two phase shifted demodulation signals from the digitized primary signal. The digital secondary loop is configured to demodulate the digitized secondary signal using the two phase shifted demodulation signals.

The invention discloses a secondary loop panoramic state monitoring system for an operating mechanism of a circuit breaker in the technical field of power systems. The system comprises a communication module, a control module, a sensor module, a switch-on processing module and a trip processing module. The system can perform on-line monitoring per se on the integrity of an operating loop, a monitoring loop and loop elements in various working states of the circuit breaker such as switch-off, switch-on and the like, realizes state monitoring of trip and switch-on loops in a full state, and has active defense function. Compared with the prior art, the system simplifies the tripping and closing operation loops, improves the integral reliability of the system, provides necessary conditions for state overhauling of the intelligent circuit breaker, ensures safe operation of the high-voltage circuit breaker, and improves the power supply reliability of the power system.

A chiller-condenser is disposed downstream of a condenser and a chiller-evaporator is disposed downstream of the chiller-condenser. A main three-way valve is disposed between the compressor and the condenser for directing flow from the compressor to the condenser in the air-conditioning mode and for directing flow from the compressor through a by-pass line to the chiller-condenser in the heat pump mode. A heat pump (HP) expansion device shown as an orifice tube expands the refrigerant in the heat pump mode and an by-pass valve is disposed between the chiller-condenser and the chiller-evaporator for directing flow from the chiller-condenser through the heat pump expansion device and to the chiller-evaporator in the heat pump mode. An air-conditioning (A/C) expansion device shown as orifice tube is disposed downstream of the condenser and upstream of the by-pass line for expanding the refrigerant in the air-conditioning mode.

A system for providing supplemental or auxiliary heat to a crude oil separator is provided. The system includes a primary circuit carrying a fluid heated by a solar panel and a secondary circuit carrying a fluid heated by heat exchangers engaged with the primary circuit. The secondary circuit includes heat exchangers engaging the separator to provide auxiliary heat. The system may also include a source of off-grid electrical energy, such as a wind turbine and/or photoelectric cell.

The invention discloses an integrated passenger compartment heat pump air conditioner for a pure electric vehicle and a tri-electric heat management system. The integrated passenger compartment heat pump air conditioner comprises a three-heat-exchanger heat pump air conditioning system, a battery heat management system and a motor electric-control heat management system, wherein a heat pump air conditioning system of a passenger compartment is a novel three-heat-exchanger heat pump air conditioning system; the battery heat management system and the heat pump air conditioning system exchange heat to define a secondary loop; the battery heat management system is regulated by an electronic expansion valve, and different temperature-control needs are realized through an electronic water pump,so that different mode functions are realized through switching of a three-way valve. A heat management function of the tri-electric heat management system is controlled by two three-way valves, fivesolenoid valves and one one-way valve. During electric-motor heat dissipation, the motor independently dissipates heat through a low-temperature water tank, and also can be connected with a battery inseries and then can co-dissipate heat through the low-temperature tank. The whole vehicle heat management system of the electric vehicle integrates functions of passenger compartment heat management,battery heat management and motor electric-control heat management, and can realize heat management needs of full-range working conditions.

The invention provides a system and a method for detecting the state of a secondary circuit of a current transformer for metering. The detection system comprises a high frequency voltage signal generation unit, an oscillation and resonance detection unit and a current detection unit which are serially connected between the current transformer for metering and an electric energy meter. The detection method detects the state of the secondary circuit by steps of measuring a practical current value, comparing the practical current value with a measured current value obtained by the electric energy meter, measuring an oscillation frequency value, comparing the oscillation frequency value with an oscillation frequency standard value, inputting high frequency voltage to the secondary circuit and detecting the practical high frequency voltage value of the secondary circuit. The detection system can be independently installed in the secondary circuit, is simple and reliable in structure, and can timely detect required data of the state of the secondary circuit of a detected current transformer. The detection method is more reliable, achieves real-time detection of the state of the secondary circuit of the detected current transformer, and provides a reliable data source for identification of the normal operation state and the open circuit state and analysis of the state of the secondary circuit.

Air conditioning units, systems, and methods that control temperature and humidity within a space in a building, for example, using a recovery wheel, a desiccant-based or passive dehumidification wheel, a primary cooling coil; and a secondary direct-expansion refrigeration circuit that includes a secondary circuit compressor, a secondary circuit evaporator coil, and a secondary circuit condenser coil. In various embodiments, the system forms a supply airstream that passes outdoor air first through the recovery wheel, then through the primary cooling coil, then through the secondary circuit evaporator coil, then through the dehumidification wheel, and then to the space. Further, in many embodiments, the system forms an exhaust airstream that passes return air from the space first through the secondary circuit condenser coil, then through the dehumidification wheel, and then through the recovery wheel. In some embodiments, various quantities of heat and moisture are transferred between the two airstreams.

A phase-locked loop (PLL) keeps tracking a reference clock when a frequency offset is introduced. The PLL has primary and secondary PLL loops. A digital-to-analog converter (DAC) generates a current that is passed through an offset resistor to generate an offset voltage. An op amp is inserted in the primary loop between a filter capacitor and a voltage-controlled oscillator (VCO). The offset resistor is coupled between the inverting input of the op amp and the op amp's output. When the DAC offset occurs, the voltage to the VCO and the frequency of the primary loop change and the primary loop loses tracking of the reference clock. The secondary loop keeps tracking the reference clock during the DAC offset while the primary loop is open. Then the output clock of the secondary loop is applied as the feedback clock to the phase comparator of the primary loop.