Abstract:
A controller that controls ON/OFF of switching elements and opening/closing of an opening/closing unit based on currents detected by current detectors. The controller includes a fault detector that detects whether any of the switching elements has a short-circuit fault and outputs a signal indicating a detection result, an ON/OFF controller that sets one of the switching elements that constitutes a phase other than a first phase that involves the short-circuit fault to an ON operation state and outputs a signal for opening the opening/closing unit, and an opening/closing controller that opens an opening/closing unit connected to a third phase other than the first phase and the second phase in which one of the switching elements is set to the ON operation state by the ON/OFF controller.
Abstract:
A correction-term adder 1 compares a maximum value max(V*) with an absolute value of a minimum value min(V*). The correction-term adder 1 selects a signal 1−max(V*) when the maximum value max(V*) is larger than the absolute value of the minimum value min(V*), on the other hand, selects a signal −1−min(V*) when the absolute value of the minimum value min(V*) is larger than the maximum value max(V*). Thereby, a signal of correction amount α is calculated. Moreover, the correction-term adder 1 produces a triangular-wave-shaped signal k(max(V*)+min(V*)) by multiplying a gain k by an addition signal max(V*)+min(V*) of the maximum value max(V*) and the minimum value min(V*). This triangular-wave-shaped signal k(max(V*)+min(V*)) is synchronized with the correction amount α. The correction-term adder 1 produces a correction amount β by selecting smaller one in absolute value between the triangular-wave-shaped signal k(max(V*)+min(V*)) and the correction amount α, and adds the correction amount β to the voltage command values V*U, V*V, V*W.
Abstract:
The present techniques include methods and systems for operating an inverter to maintain a lifespan of the inverter. In some embodiments, the switching frequency and/or the output current of the inverter may be changed such that stress may be reduced on the inverter bond wires of the inverter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the inverter and determining whether the operating conditions result in aging the inverter to a point which reduces the inverter lifespan below a desired lifespan. If the operating conditions reduce the inverter lifespan below the desired lifespan, the switching frequency may be reduced to a lower or minimum switching frequency of the inverter and/or the output current of the inverter may be reduced to a maximum output current at the minimum switching frequency.
Abstract:
According to an embodiment of the present invention, a method of controlling a grid side converter of a wind turbine is provided, wherein an output of the grid side converter is connected or connectable via a power line to an input of a grid transformer, the method comprising: determining a converter volt-sec occurring at the output of the grid side converter based on a converter voltage occurring at the output of the grid side converter; determining a volt-sec error between the determined converter volt-sec and a converter volt-sec reference, wherein the converter volt-sec reference is determined based on active power reference, reactive power reference, line current and a line voltage occurring at the input of the grid transformer (or at wind turbine terminals); and controlling, based on the determined volt-sec error, the grid side converter such that the volt-sec error is partly or fully compensated. The method is capable of supporting the demanded power quality even during abnormal voltage conditions, and is easy to realize. The method can seamlessly transit from linear to non-linear region of converter operation.
Abstract:
A circuit for filtering narrow pulse and compensating wide pulse, including a signal shaping circuit, a filter circuit, and a pulse width compensating circuit. The signal shaping circuit processes an input signal and transmits the input signal to the filter circuit. The filter circuit filters off narrow pulses of the input signal. The pulse width compensating circuit compensates the wide pulses of the input signal and outputs an output signal.
Abstract:
A method of damping harmonic output of an inverter is provided. The method may receive output phase signals from sensors disposed at an output of the inverter and on an associated electrical grid, filter the output phase signals using a low pass filter configured to extract a fundamental component from the output phase signals, isolate harmonics from the output phase signals based on the extracted fundamental component, and subtract the harmonics from the output phase signals.
Abstract:
A Multi-Tile Power Management Integrated Circuit (MTPMIC) includes tiles including an MCU/ADC tile and a power manager tile. The power manager tile includes a set of Configurable Switching Power Supply Pulse Width Modulator (CSPSPWM) components. These components, in combination with other circuitry external to the integrated circuit, are configurable to form a selected one of a number of different switching power supply circuits. Upon power up, an internal regulator supplies power to the CSPSPWM. The CSPSPWM then controls the power supply to begin switching in a low frequency start-up mode. The CSPSPWM determines during start-up the current sensing method based on circuitry external to the integrated circuit. A supply voltage generated is then supplied via a conductor of a standardized bus to a processor in the MCU/ADC tile. The processor begins executing instructions, and as a result writes across the standardized bus to configure the various tiles of the MTPMIC.
Abstract:
There are provided an apparatus and a method for controlling the power quality of a power generation system. According to the present invention, there is provided an apparatus for controlling the power quality of a power generation system including a DC/AC inverter converting DC voltage into AC voltage and supplying inverter current to a grid, including: a grid voltage phase follower generating a grid signal; a fundamental extractor extracting a magnitude of a fundamental wave of a load current introduced into a non-linear load connected between the DC/AC inverter and the grid; a first calculator subtracting a preset current compensation value from the magnitude of the fundamental wave from the fundamental extractor; and a second calculator generating an inverter current instruction value for the DC/AC inverter by using the output value of the first calculator and the grid signal and the load current from the grid voltage phase follower.
Abstract:
A controller 40 performs a control operation in a cycle based on a carrier frequency fc of a carrier, specifically, at timings corresponding to the peaks and troughs of the carrier signal. Moreover, in the case where the carrier frequency fc is switched, a disturbance estimation part forming the controller 40 updates control constants that are used for disturbance estimation and are dependent on the control operation cycle, in a control operation performed one cycle after a control operation immediately after the switching of the carrier frequency fc.
Abstract:
A means of providing solar powered electricity for day and nighttime use supported in part by power from the grid to allow a small generator to electrify the home or business with a small generator operating with much larger capacity. Excess solar energy is provided to the power company as needed.