JP2012019645A5 - - Google Patents

Description

In a preferred embodiment of the present invention, the pulse signal generation means is configured such that when a current flows from the connection point of the bridge to the three-phase power system, the main switch on the positive side of the bridge is opened. During on- switching to switch to the conducting state, and when switching off the main switch on the positive side of the bridge from the conducting state to the open state when current flows from the three-phase power system to the connection point of the bridge A pulse signal for controlling the auxiliary circuit is generated so that the connection point of the bridge and the connection point of the bridge of the phase fixed to the negative potential are connected to each other through the reactor.

When the switching elements S7 to S9 are turned on, the output lines of the respective phases and the auxiliary circuits 22u, 22v, and 22w of the respective phases are brought into conduction, and when the two or more switching elements are turned on, the switching elements A resonance circuit is formed by the reactor and the resonance capacitor. An auxiliary circuit pulse signal P ′ (described later) output from the control circuit 3 is input to the base terminals of the switching elements S7 to S9. Each of the switching elements S7 to S9 can be switched between an on state and an off state based on each auxiliary circuit pulse signal P ′ . In the present embodiment, the switching element is turned off when the auxiliary circuit pulse signal P ′ is at a low level, and the switching element is turned on when the auxiliary circuit pulse signal P ′ is at a high level. For example, when the switching elements S7 and S8 are turned on, the U-phase output line and the V-phase output line are connected by the resonance reactor L7 and the resonance reactor L8 connected in series. In this case, a resonance circuit is formed by the resonance capacitors C1, C2, C4, or C5 and the resonance reactors L7 and L8 connected in series.

The auxiliary circuit 22 forms a resonance circuit based on the auxiliary circuit pulse signal P ′ input from the control circuit 3 and causes a resonance current to flow, thereby discharging the resonance capacitors C1 to C6 and switching elements S1 to S6. The terminal voltage (voltage between the emitter terminal and the collector terminal of the switching element) is set to zero. Thereby, switching of each switching element S1-S6 turns into zero voltage switching, and soft switching can be implement | achieved.

In the same figure, when the U phase is switched in case 1-2, that is, when the direction of the output current of the U phase is a positive direction (direction toward the system B side), the on-switching (positive side switching element) S1 is in the off state and switching element S4 on the negative electrode side is switched from the on state to switching element S1 in the on state and switching element S4 is switched to the off state). The switching elements S4, S5, and S6 on the negative electrode side of FIG. The case where the V phase is the negative electrode stationary phase (that is, the switching element S5 is fixed in the on state) will be described.

At the beginning of the period t1, the high level period of the PWM signal Pw becomes very short and the interval between the rising edge and the falling edge becomes narrow. However, since it is not necessary to perform a resonance operation at the time of rising, the auxiliary circuit 22 is only at the time of falling. Can be controlled.

Note that the high level period of the PWM signal Pu becomes very short after the period t4, and the interval between the rising edge and the falling edge becomes narrow. However, since it is not necessary to perform a resonance operation at the time of rising, the auxiliary circuit 22 is only at the time of falling. Can be controlled.

Claims (1)

The pulse signal generation means, when current is flowing from the connection point of the bridge to the three-phase power system, at the time of on switching to switch the main switch on the positive side of the bridge from an open state to a conductive state, and wherein in the case where the three-phase power system current is flowing to the connection point of the bridge, when off switching for switching the main switch on the positive electrode side of the bridge from the conducting state to the open state, the connection point of the bridge and the negative electrode side Generating a pulse signal for controlling the auxiliary circuit so as to connect the connection point of the phase bridge fixed to the potential of the auxiliary circuit to each other via the reactor;
The inverter device according to claim 1 or 2.