In one form, a capacitor voltage limiter (240), comprises a supply node (244), a pass element (242) having a first current electrode coupled to the supply node (244), a control electrode, and a second current electrode. The second current electrode is adapted to be coupled to an external storage capacitor (250). Additionally, the capacitor voltage limiter includes an amplifier having a non-inverting input for receiving a reference voltage, and an inverting input coupled to the second current electrode of the pass element (242). The amplifier includes an output coupled to the control electrode of the pass element (242). The capacitor voltage limiter also includes a rectifier (241) having an input coupled to the second current electrode of the pass element (242), and an output coupled to the first current electrode of the pass element (242).

A secondary battery, a wireless charging circuit connected to the secondary battery, an outer casing member that has an outer shape equivalent to an outer shape of a universal battery and accommodates the secondary battery and the wireless changing circuit, and a positive terminal and a negative terminal that are electrically connected to the secondary battery and are provided at positions corresponding to positions of a positive terminal and a negative terminal, respectively, of the universal battery, are provided. The wireless charging circuit includes a power reception protecting circuit that stops power reception at a rectifier circuit in a case where a received voltage exceeds a predetermined voltage range.

A secondary battery, a wireless charging circuit connected to the secondary battery, an outer casing member that has an outer shape equivalent to an outer shape of a universal battery and accommodates the secondary battery and the wireless changing circuit, and a positive terminal and a negative terminal that are electrically connected to the secondary battery and are provided at positions corresponding to positions of a positive terminal and a negative terminal, respectively, of the universal battery, are provided. The wireless charging circuit includes a power reception protecting circuit that stops power reception at a rectifier circuit in a case where a received voltage exceeds a predetermined voltage range.

A capacitive power supply circuit including, between first and second terminals of application of an AC input voltage, a distributed capacitive structure including a plurality of elementary capacitive units, each including a current limiter series-connected with a capacitor between first and second terminals of the unit and a voltage limiter connected in parallel with the capacitor, the elementary capacitive units being series-coupled by their first and second terminals.

A BMU (management apparatus) of a secondary battery (energy storage device) includes a management part that operates by power supplied from the secondary battery, and a capacitor (backup power source) that supplies power to the management part when a voltage of the secondary battery decreases.

A BMU (management apparatus) of a secondary battery (energy storage device) includes a management part that operates by power supplied from the secondary battery, and a capacitor (backup power source) that supplies power to the management part when a voltage of the secondary battery decreases.

The invention relates to a grounding fault protection method for a high-voltage capacitor of a direct-current filter. The method comprises the following steps of acquiring a head end voltage u and an unbalanced current i.sub.T2 of a direct-current filter, and acquiring a discrete head end voltage and unbalanced current sequence; calculating a virtual capacitance C.sub.zd; determining a protection setting value C.sub.set according to the bridge arm capacitance of the high-voltage capacitor, and when the virtual capacitance C.sub.zd is larger than the protection setting value C.sub.set, protecting and judging to be an internal fault; otherwise, protecting and judging to be an external fault.

The invention relates to a grounding fault protection method for a high-voltage capacitor of a direct-current filter. The method comprises the following steps of acquiring a head end voltage u and an unbalanced current i.sub.T2 of a direct-current filter, and acquiring a discrete head end voltage and unbalanced current sequence; calculating a virtual capacitance C.sub.zd; determining a protection setting value C.sub.set according to the bridge arm capacitance of the high-voltage capacitor, and when the virtual capacitance C.sub.zd is larger than the protection setting value C.sub.set, protecting and judging to be an internal fault; otherwise, protecting and judging to be an external fault.

A surge suppression device has a resistive element, a capacitor electrically connected to the resistive element, a terminal electrically connected to the opposite side of the resistive element to the side connected to the capacitor, a fixing metal bracket to be fixed to a fixing target, and a mold resin to mold the resistive element, the terminal and the fixing metal bracket. The capacitor is located away from the mold resin.

A surge suppression device has a resistive element, a capacitor electrically connected to the resistive element, a terminal electrically connected to the opposite side of the resistive element to the side connected to the capacitor, a fixing metal bracket to be fixed to a fixing target, and a mold resin to mold the resistive element, the terminal and the fixing metal bracket. The capacitor is located away from the mold resin.