Weak-power control circuit for photovoltaic motor driver and method

Abstract

The invention discloses a weak-power control circuit for a photovoltaic motor driver. The circuit comprises an MCU, a photovoltaic assembly, a Boost circuit, a three-phase inverse circuit, an input current sensor, a bus capacitor, an input voltage detection circuit, a bus voltage detection circuit, a motor, a bus energy storage circuit, an energy storage super-capacitor slow-starting and leakage circuit and an energy storage super-capacitor voltage detection circuit. The invention further discloses a control method of the weak-power control circuit for the photovoltaic motor driver at the sametime. According to the weak-power control circuit for the photovoltaic motor driver, normal work of the driver at extremely-low input power can be achieved, continuous MPPT control over the photovoltaic assembly at the low light condition is achieved, the running time of the driver is prolonged, and the assembly energy is sufficiently used; meanwhile, by means of the technical scheme, the motor starting power of the driver at low input power can be remarkably improved, the starting failure of the motor is avoided, and the control performance of the motor is improved.

Description

technical field [0001] The invention relates to a motor driver, in particular to a photovoltaic motor driver weak power control circuit and method. Background technique [0002] At present, in the field of photovoltaic motor drive, the photovoltaic motor driver adjusts the output frequency, speed or torque of the driver according to the output power of the photovoltaic module. When the light is sufficient, the driver works at the maximum power point of the module through MPPT regulation. When the driver is used to drive motor loads such as water pumps and air-conditioning compressors, the minimum power to maintain the normal operation of the motor is relatively high; when the light is weak, the driver cannot perform MPPT normally because the output power of the photovoltaic module is lower than the maintenance power of the motor load. Adjust and stop the output, and the driven motor stops running. However, at this time, the photovoltaic module can still provide electric en...

AI Technical Summary

Problems solved by technology

The principle of this invention is to add a set of charging circuit, power storage device and output circuit on the basis of the control circuit to improve the utilization rate of solar energy. Therefore, the circuit of this scheme is complex, bulky and costly; Continuous MPPT control of the drive cannot be achieved during the entire working cycle

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