摘要:
The step-up converter includes the plurality of converting units, each having the reactor and the semiconductor element part having electronic parts such as the transistor and the diodes. The ECU performs changeover control of increase or decrease of the number of drive phases of the converting units, based on the output condition from the fuel cell, the temperature condition of the reactor, and the temperature condition of the semiconductor element part.
摘要:
A fuel cell system capable of carrying out a proper current limiting even when decreasing a cell voltage through, e.g., a rapid warm-up is provided. When a rapid warm-up is started, an acceptable cell-voltage value setting part sets a acceptable lowest-cell-voltage value in accordance with the operation state of a fuel cell. Meanwhile, a target cell-voltage value setting part sets an initial value for a target lowest-cell-voltage value. The target cell-voltage value setting part then compares a lowest cell voltage detected by a cell monitor with the set target lowest-cell-voltage value, and judges whether or not the lowest cell voltage is near the target lowest-cell-voltage value continuously for a given time period. If the result of the judgment is positive, the target cell-voltage value setting part updates the target lowest-cell-voltage value with a value obtained by decreasing the target lowest-cell-voltage value only by an update width.
摘要:
A voltage boost converter includes: a main voltage boost portion that has a first switch and a first coil, and that raises output voltage of a direct-current power source by using counter electromotive force of the coil caused by the switch performing a switching action on the coil; and a subsidiary voltage boost portion which has a capacitor that adjusts potential difference between two poles of the switch by amount of electricity stored, and which reduces switching loss of the switch by adjusting the amount of electricity in the capacitor during the switching action, and which has a second switch and a second coil. The second coil is formed by winding a wire around at least a portion of a core formed of a magnetic body. The core is provided with a gap formed of a non-magnetic body. A core region formed of a magnetic body is adjacent to the gap.
摘要:
A voltage conversion circuit apparatus that adjusts a timing skew between the switching control of the first switching element and the switching control of the second switching element includes: a skew storage portion that stores a timing skew between the switching controls of the first and second switching elements after the voltage conversion circuit apparatus is manufactured; and a timing adjustment portion that corrects the stored timing skew and thereby adjusts the timing relation between a first pulse signal and a second pulse signal so as to bring within a permissible range the timing skew that occurs when the switching controls of the first and second switching elements are performed by using the first pulse signal and the second pulse signal.
摘要:
Output voltage of a fuel cell 2 is decreased by a converter 51 to conduct an activation treatment to catalyst of the fuel cell 2, while measuring reduction current by a current sensor 2a while scanning output voltage of the fuel cell 2 over a certain range by the converter 51 as measurement of cyclic voltammetry under the condition that supply of oxidation gas to the fuel cell 2 is stopped from a compressor 31, and this measurement value is integrated by a control device 6. The control device 6 finds a charge amount of electrode catalyst of the fuel cell 2 based on this integration value, decides whether this charge amount is smaller or not than a degradation decision value, and displays this decision result on a display 55. A decision can be made precisely as to whether the electrode catalyst of the fuel cell is degraded or not.
摘要:
An object is to miniaturize booster coils used in a vehicle-mounted booster converter. In the design method for a vehicle-mounted multi-phase converter including multiple booster coils and a switching circuit for generating an induced electromotive force at each booster coil by switching of current flowing to each booster coil for applying an output voltage, based on an input voltage and the induced electromotive force generated at each booster coil, to a vehicle drive circuit, a coupling factor indicating the extent by which the induced electromotive force in one of multiple booster coils contributes to the voltage between terminals of another booster coil is determined on the basis of a relationship between the coupling factor and current ripple component of each booster coil.
摘要:
A fuel cell system is configured to have: a voltage superimposing unit that superimposes a predetermined AC signal on an output voltage of a fuel cell; a unit that detects an output voltage value of a battery device, the output voltage value varying as the fuel cell output voltage value on which the AC signal has been superimposed varies; a battery device voltage comparison unit that compares the detected battery device output voltage value with a predetermined threshold voltage; and a measurement permission determination unit that determines whether the AC impedance measurement is permitted or not based on whether or not the battery device output voltage value exceeds the threshold voltage. The fuel cell system can protect the battery device in the impedance measurement of the fuel cell based on an AC impedance method.
摘要:
Disclosed is a fuel cell system including a fuel cell which generates a power, and control means for decreasing the amount of a reactant gas to be supplied to the fuel cell to an amount smaller than that during normal power generation to realize low-efficiency power generation of the fuel cell. The control means sets the voltage lower limit value of the fuel cell so that the amount of an anode gas (pumping hydrogen) to be formed in a cathode of the fuel cell during the low-efficiency power generation is a predetermined amount or less.
摘要:
There is disclosed a fuel cell system capable of stably operating auxiliary devices driven at a high voltage and the like, even in a case where a poisoned electrode catalyst is recovered or a fuel cell is warmed up. On detecting that the electrode catalyst is poisoned, a controller derives a target operation point which is sufficient for recovering an activity of the poisoned electrode catalyst. Then, shift of the operation point from a usual operation point to a low-efficiency operation point is realized so that an output power is held to be constant.
摘要:
There is disclosed a fuel cell system in which a poisoned electrode catalyst can be recovered while meeting a demand for an output power. When a controller detects that an electrode catalyst is poisoned, the controller derives a target operation point adequate for recovering a function of the poisoned electrode catalyst to realize shift of an operation point so that the output power is kept constant. Specifically, a fuel cell voltage is controlled using a DC/DC converter, and an amount of an oxidizing gas to be fed from an oxidizing gas supply source is adjusted, thereby controlling a fuel cell current.