traditional fuel cell vehicles with the DC / DC converter and the post-stage DC / AC converter with the regulation, realize the wide scope of multi-method exchange motor speed control,http://www.gridtieinverter.de/, the maximum output current of the DC / DC converter for fuel cell with power restraint, in order to maintain the fuel cell, while a voltage regulator regulating system line; the DC / AC converter to play the role of the power conversion master, on the system bus to electrical energy is changed to electrical energy suitable for motor running, while gripping the motor the operation, to form a model of two energy change.
traditional hard Boost topology boost switch conduction is large due to the topology boost factor than the verge, so switch conduction time is too long to switch cut-off time is too short, resulting in the loss and temperature rise is too large, prejudice to applicable limits the regulator scale. However often taken inverter installed facing due to the boost chopper circuit rated participate Boost, added system cost down conversion effectiveness; any cause of control failures or electromagnetic annoyance level of inverter tube straight through the destruction of the switch tube ; in order to prevent the switch from pipe straight to participate in the death zone affect the output current waveform, there is the problem of the large number of harmonics.
individual, two-stage efficiency is lower than the single-stage system. The new Z-source network can be applied a strange passive network buck conversion efficacy, but also insist on a single-level structure and high potency, have a good discussion. Z-source network pass-through time when the input voltage of the fuel cell is low, the introduction of work in boost mode; without adding direct time when the input voltage is higher, the Z-source network operating in buck mode. Thus, the proposed Z-source inverter network can be well adapted to the wide scope of the automotive fuel cell output voltage changes. Take Z-source capacitor voltage closed-loop control, solid given the fair, so that the voltage and the output voltage of the DC bus to adhere firmly to the capacitor voltage value.
traditional Z-source inverter, there are some disadvantages, by introducing a higher functions of the new Z-source inverter, the Z-source inverter in the traditional structure basically function more perfect, more satisfaction in fuel some requests cell vehicles with high discuss the value with use value. Its restraint can through the use of the voltage space vector modulation scheme, the longitudinal zero vector is applied to the role of the conventional zero vector interval, may simultaneously achieve gripping of the DC voltage does not affect the conditions of the effective output voltage vector relative sinusoidal pulse width modulation and other measures show the upper hand. However, the the traditional SVPWM way north to condition, helpless direct use of the Z-source inverter. To solve this problem, this paper given implementation. The new high-performance Z-source inverter topology structure, absolute in the traditional Z-source structure, a DC voltage side switch,power inverter, so the switch to master their be enunciated,Grid tie inverter.
1 Z source inverter
11 traditional Z-source inverter topology and working principle
voltage three-phase Z-source inverter main circuit topology shown in Figure 1.
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