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 discloses a control method for non-disturbance switching between power frequency and variable frequency of a high-voltage inverter. The control method comprises the steps that: a PLC issues a control command to a DSP of a system; phase locking and frequency locking are performed on a power frequency grid voltage, so as to obtain frequency f and phase position theta of the grid voltage; the phase sequence of the inverter is adjusted to be identical with that of the grid voltage; the phase position of the inverter is adjusted to be identical with that of the grid voltage; an amplitude value of the inverter is adjusted to be identical with that of the grid voltage; phase locking success and amplitude modulation success signals are sent to the PLC, and a switching action is started. The non-disturbance switching control method can effectively extract the grid frequency f and the grid phase position theta, avoids the problem of switching failure caused by overtime phase locking or large frequency and phase position fluctuations, has the function of adjusting the phase sequence of the inverter to be identical with that of the grid voltage, can avoid phase dislocation of phase position output without phase position correction, adds phase position compensation in phase position adjustment, and can avoid the influence of voltage sampling and filtering links.

Control method for non-disturbance switching between power frequency and variable frequency of high-voltage inverter

The invention discloses an intelligent power module and an air-conditioner with the same. The intelligent power module comprises a metal substrate, an insulating layer, a power device and control device, and an insulated plastic package, wherein a first surface and a second surface opposite to each other are arranged on the metal substrate, a thermal insulation groove recessed to the first surface is arranged on the second surface; the insulating layer is arranged on the first surface, and a circuit wiring layer is arranged on the insulating layer; the power device and the control device are respectively arranged on the insulating layer and electrically connected with the circuit wiring layer; the thermal insulation groove is arranged surrounding the control device at the periphery of the orthographic projection of the first surface and is located at the outside of the control device; the insulated plastic package wraps the metal substrate, the power device and the control device. According to the intelligent power module disclosed by the embodiment of the invention, the thermal insulation groove is arranged on the metal substrate, the operation is simple, the heat conduction on the control device by the power device can be reduced, thereby ensuring that the intelligent power module can normally at the ideal temperature, and the use reliability of the intelligent power module is promoted.

Intelligent power module and air-conditioner with the same

The invention discloses a hybrid fault current controller based on a unified power flow controller (UPFC). The unified power flow controller comprises a Tsh parallel transformer, a Tse series transformer, a capacitor C1, a parallel side current converter and a series side current converter, wherein the parallel side current converter and the series side current converter are connected back to back, and the capacitor C1 and an energy storage device are separately connected with a direct current side bus in parallel; the Tsh parallel transformer is connected with the front end of the parallel side current converter, and the Tse series transformer is connected with the front end of the series side current converter; the neutral point of the Tsh parallel transformer is connected with a groundresistor R1, and the neutral point of the Tse series transformer is connected with a ground resistor R2; and a current limiting circuit is serially connected with the output end of the Tse series transformer. According to the hybrid fault current controller provided by the invention, the fault current level of the circuit is always kept within a reasonable range, and the fault current limiting level and the intelligent degree of the hybrid fault current controlled based on UPFC are greatly increased.

Hybrid fault current controller based on unified power flow controller

The invention discloses a control method and a device for switching power grid driving of an escalator into variable frequency driving. The method comprises the following steps: disconnecting a driving motor of the escalator with a power grid; sampling the two-phase current of a motor stator after disconnection time reaches a preset first time; computing the output voltage target value of an inverter unit through a following logic algorithm, and determining the frequency target value of the inverter unit; gradually transiting the output voltage of the inverter unit to the output voltage target value according to the output voltage target value and the frequency target value, so as to drive the motor and accomplish the switching of the escalator from power grid driving into variable frequency driving. According to the method, when switching is performed, the driving motor of the escalator is actively disconnected from the power grid, the current rotate speed of the motor is rapidly tracked, the switching from power grid driving into variable frequency driving is accomplished, the method is simple and practical, during switching, the current of the motor stator is stable, overcurrent cannot occur, the escalator is smooth in transition, and the method has good engineering practice value.

Control method and method for switching power grid driving of escalator into variable frequency driving

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 high-voltage variable frequency and power frequency switching method, which comprises the steps of 1) connecting a high-voltage frequency converter to a load motor, starting the high-voltage frequency converter so as to supply power to the load motor, and getting into a variable-frequency power supply mode; 2) switching the variable-frequency power supply mode into a power-frequency power supply mode, connecting a power-frequency power grid to the load motor, blocking pulses of the high-voltage frequency converter, disconnecting the high-voltage frequency converter after the pulses are blocked, and supplying power to the load motor by the power-frequency power grid and the high-voltage frequency converter simultaneously after the power-frequency power grid is connected and before the pulses are blocked; and 3) switching the power-frequency power supply mode into a variable-frequency power supply mode, starting the high-voltage frequency converter, connecting the high-voltage frequency converter to the load motor when running to the power frequency, disconnecting connection between the power-frequency power grid and the load motor, supplying power to the load motor by the power-frequency power grid and the high-voltage frequency converter simultaneously after the high-voltage frequency converter is connected and before the power-frequency power grid is disconnected, and returning back to the step 2). The method disclosed by the invention has the advantages of simple implementation method, stable system operation, and ability of realizing two-way switching between the power frequency and the variable frequency without power loss switching time.

High-voltage variable frequency and power frequency switching method

The invention discloses a multi-load variable-frequency speed control system and a method thereof. The system comprises a frequency converter device and a multi-load control unit; the frequency converter device and the multi-load control unit are mutually connected; the frequency converter device is used for executing frequency conversion and speed control; and the multi-load control unit is used for controlling multiple sets of loads. The frequency converter devices are connected to a high-voltage power supply by a first circuit breaker QF1. The multi-load control unit includes a controller and a plurality of changer-over switch branch circuits connected with the controller. An output terminal of each changer-over switch branch circuit is connected with one set of loads and an input terminal is divided into two paths; one path is connected with the high-voltage power supply by a circuit breaker and the other path is connected with one frequency converter device by a variable-frequency change-over switch. According to the method, all change-over switch branch circuits are controlled by the controller to realize multi-load variable-frequency soft starting. With the system and method, multi-load variable-frequency soft starting and variable-frequency regulation can be realized. Moreover, advantages of simple structure and principle, simple and convenient operation, low needed cost, little influence on power grid, and high extendibility and the like are realized.

Multi-load variable-frequency speed control system and method thereof

The invention discloses a motor thyristor soft-starting control method and an application thereof. During the soft-starting process of a motor, a rising rate of a starting current of the motor is subjected to segmented control according to time periods by adopting a closed-loop control method before a current output by a soft-starting device to the motor reaches a set constant value. When a power grid generator is a synchronous motor, the motor thyristor soft-starting control method is applied and can effectively solve the technical problem that a motor protection device on a high-voltage switch cabinet warns about overvoltage faults because a soft-starting control method of the existing thyristor soft-starting control device is likely to cause increased exciting current and overhigh voltage output of the motor end. When the motor thyristor soft-starting control method is applied to a high-power or super-power motor soft-starting control system, the technical problems of under-compensation or over-compensation of the system which easily occur in the prior art can be solved.

Motor thyristor soft-starting control method and application thereof

The utility model discloses an electric wire netting short circuit current limiting device, including thyristor module and current limiting reactor module, thyristor module and current limiting reactor module parallel connection, the current limiting reactor module includes current limiting reactor, when electric wire netting normal operating, thyristor module switches on, when the electric wire netting took place the short circuit, thyristor module turn -offed and the current limiting reactor module inserts. The utility model discloses can restrain electric wire netting short -circuit current, and have that simple structure, required with low costs, response speed are fast, advantages such as loss and harmonic pollute little, safe and reliable.

Lei Li

Papers

Intelligent power module

High-voltage variable frequency and power frequency switching method

Multi-load variable-frequency speed control system and method thereof

Motor thyristor soft-starting control method and application thereof

Electric wire netting short circuit current limiting device