The invention discloses an intelligent power module and an air conditioner. The intelligent power module comprises a high-voltage side driving circuit, a low-voltage side driving circuit, a dead zonegeneration interlocking circuit and a bootstrap circuit, the bootstrap circuit comprises a bootstrap control unit, an N-MOS transistor and a bootstrap resistor, a positive electrode input terminal ofthe bootstrap control unit is connected with a positive terminal of a power supply, a negative electrode input terminal of the bootstrap control unit is connected with a negative terminal of the powersupply, a first controlled terminal of the bootstrap control unit is connected with a first output terminal of the dead zone generation interlocking circuit, a second controlled terminal of the bootstrap control unit is connected with a second output terminal of the dead zone generation interlocking circuit, an output terminal of the bootstrap control unit is connected with a grid electrodes of the N-MOS transistor, a source electrode and the grid electrode of the N-MOS transistor are in short circuit connection, a drain electrode of the N-MOS transistor is connected with a first terminal ofthe bootstrap resistor, and a second terminal of the bootstrap resistor is connected with a high-voltage side output terminal. According to the intelligent power module and the air conditioner, problems that the bootstrap circuit formed by discrete devices is not good for the layout of a PCB and increases the area of an electric control board are solved.

Intelligent power module and air conditioner

The invention relates to a novel topological structure voltage source type inverter and an adjusting method. The structure is a star-like topological structure and is formed by connecting a three-phase bridge type inverter in series at a neutral point of cascaded inverters connected in a star shape. Compared with the conventional cascaded inverters connected in the star shape, the novel topological structure theoretically has a function of completely compensating negative sequence current; and compared with the conventional three-phase bridge type inverter, the novel topological structure can realize extended application under high voltage level without using a device cascade or MMC (Multilevel Converter) structure. In the novel topological structure, a direct current side of the three-phase bridge type inverter can be connected with a direct current network, energy storage equipment or a power grid through a current transformer; the inverter can be widely applied to the fields of flexible direct current power transmission, new energy connection, high voltage frequency converter and the like; and the application prospect of the voltage source type inverter in the corresponding field is expanded. The novel topological structure has good generalization performance based on mature unit cascade and three-phase inverter structure and control technology.

Novel topological structure voltage source type inverter and adjusting method

The invention relates to a permanent magnet synchronous motor and discloses a motor start-up smooth transition control method to solve the dead start under the condition of heavy loading The method comprises the positioning stage, asynchronous drag stage, transitory stage for speed close-loop of position sensorless and control stage for speed close-loop of position sensorless In the transitory stage for speed close-loop of position sensorless,the changes of target frequency are controlled: if the difference value of actual frequency and target frequency exceeds the set value, the target frequency is controlled for reduction; and if the difference value of actual frequency and target frequency is less than the set value, the target frequency keeps the same The method is applicable to the startup control of freezer compressor

Motor start-up smooth transition control method

The invention discloses an air conditioner, a method and a device for controlling the starting of the compressor of the air conditioner The starting process of the compressor comprises an open-loop operation stage and a closed-loop operation stage The method comprises the following steps of when the compressor meets the switching condition from the open-loop operation stage to the closed-loop operation stage, controlling an open-loop starting given current to gradually and smoothly decrease to zero so as to acquire an open-loop current smooth transition time; during the open-loop current smooth transition time, according to the open-loop starting given current and the output current of a speed ring, acquiring the direct-axis given current of the compressor and the quadrature-axis given current of the compressor; according to the acquired direct-axis given current of the compressor and the acquired quadrature-axis given current of the compressor, conducting the vector control for the compressor Based on the method, the direct-axis given current of the compressor and the quadrature-axis given current of the compressor are enabled to continuously change at the moment of the switching operation Therefore, the switching impact is reduced Meanwhile, the failed starting of the compressor caused by the sudden switching between the direct-axis given current and the quadrature-axis given current, or the vigorous shaking of the compressor during the switching process between the direct-axis given current and the quadrature-axis given current, can be effectively avoided

Air conditioner, method and device for controlling starting of compressor of air conditioner

The invention provides a controllable charging load used for charging pile detection. The controllable charging load used for charging pile detection comprises a direct current transformer and a powerbattery pack which is cascaded with the direct current transformer; the direct current transformer comprises a boost converter and a buck converter which are cascaded with each other; and an alternating current controller used for controlling an input voltage and an input current of the direct current transformer is arranged on the direct current transformer. According to the controllable charging load used for charging pile detection, the voltage and the current of the direct current transformer can be controlled through the alternating current controller so that various charging modes, suchas constant voltage, constant current, constant power and constant resistance, of the whole charging load can be controlled; the controllable charging load is integrally convenient and fast to use and is beneficial for actual application. The invention provides a vehicle for charging pile detection, and the vehicle also has the beneficial effects and does not need be repeated here.

Controllable charging load used for charging pile detection and vehicle

The invention discloses an asynchronous motor parameter offline identification method comprising a stator resistor identification step including selecting two random phases of an asynchronous motor to serve as two tested phases, injecting a DC signal to windings of the two tested phases, and executing a one-time single phase DC test; the method also comprises the following steps: adjusting a test current value of the injected DC signal, collecting a phase current value and a corresponding phase voltage value of one tested phase at different test current values, thus obtaining a plurality of data points formed by phase current values and phase voltage values; carrying out curve fitting according to the collected data points so as to obtain a fitting relation curve between the phase current value and the phase voltage value, thus identifying a stator resistance Rs value according to a gradient of the fitting relation curve The asynchronous motor parameter offline identification method is simple in identification process, high in identification result precision, and small in identification error

Asynchronous motor parameter offline identification method

An intelligent power module includes a rectifying circuit for connecting with a corresponding external AC power source to convert a first AC power transmitted from the external AC power source into afirst DC power; An inverter circuit connected to the rectifier circuit for converting the first direct current into a second alternating current; A control circuit and a driving circuit are connectedbetween the inverter circuit and the control circuit for driving the inverter circuit to operate under the control of the control circuit. As the intelligent pow module controls the circuit, rectifiercircuit, the inverter circuit and the driving circuit are integrated in the whole module, Compared with the existing intelligent power module, the intelligent power module has a higher integration level, which simplifies the hardware circuit design, helps to shorten the development cycle and reduce the volume of the system. Users only need to build a simple peripheral circuit to complete the development of the variable frequency drive system.

Intelligent power module

The invention discloses a cascaded high voltage frequency converter controlling method. The method comprises the steps that two basic converting chains are adopted by each phase of the cascaded high voltage frequency converter. The basic converting chain comprises an H-bridge power unit and an equalizing reactor. A three-phase voltage is input by a phase-shifting transformer, after the voltage is reduced through the phase-shifting transformer and provides power for the H-bridge power unit of the frequency converter, the H-bridge power unit outputs single phase alternating current voltage after rectifying, filtering and inverting, changes a series-parallel connection way and an output way of each basic converting chain by changing an opening and closing state of multi-position shifting switch combination, and achieves output of rated capacity of different voltage levels. A plurality of the H-bridge power units are connected in series to form the smallest basic converting chain, the series-parallel connection combination and shifting of star and triangle of the plurality of the basic converting chains are controlled through the shifting of the multi-position shifting switch, and full-size output of the transformers of various voltage levels is achieved. The method is simple in structure and multipurpose by using one machine.

Cascaded high voltage frequency converter controlling method

The invention discloses a cascaded high-voltage inverter. The high-voltage inverter comprises a phase-shifting transformer, an inverter and a multi-position selector switch assembly, wherein the inverter is connected with the phase-shifting transformer, and the multi-position selector switch assembly is connected with the inverter; each phase of the inverter further comprises two basic converting chains, and each basic converting chain comprises an H bridge power unit and a sharing reactor; a three-phase voltage is input into the phase-shifting transformer, and supplied as power to the H bridge power unit of the inverter after being reduced through the phase-shifting transformer; the H bridge power unit outputs a single-phase alternating voltage through rectification, filtration and inversion; and the serial and parallel connection mode and output mode of each basic converting chain can be changed by changing the on-off state of the multi-position selector switch assembly. According to the cascaded high-voltage inverter, a plurality of H bridge power units are serially connected to form minimum basic converting chains, and the serial and parallel connection combinations and star/triangular conversion of a plurality of basic converting chains are controlled by shifting a multi-position switch, so that full capacity output of various voltage-level converters can be realized, and the inverter is simple in structure and multi-purpose.

Cascaded high-voltage inverter

The invention discloses a multi-winding motor temperature-rise test system and a control method thereof. The system comprises a multi-winding motor with more than two sets of armature windings, more than two sets of variable-frequency test power supplies, and a switch cabinet. The variable-frequency test power supplies and the armature windings are matched in number. The armature windings are respectively driven by the corresponding variable-frequency test power supplies in such a manner that one or several armature windings are driven to run in the motoring state while one or several other armature windings are driven to run in the power-generating state. The switch cabinet is arranged between the variable-frequency test power supplies and the power grid and is used for isolating the variable-frequency test power supplies from the power grid and protecting the temperature-rise test system. According to the invention, the single-unit temperature-rise test on dual-winding motors of different models is enabled. Therefore, the adoption of complicated coupling and pairing tools for two motors is avoided. Meanwhile, the number of test matching devices is reduced. At the same time, the related loss is reduced. Most time and most cost are saved.

Li Jia

Papers

Asynchronous motor parameter offline identification method

Intelligent power module

Cascaded high voltage frequency converter controlling method

Cascaded high-voltage inverter

Multi-winding motor temperature-rise test system and control method thereof