Summary of the invention
For the deficiencies in the prior art, the invention provides one and seal in capacitive high voltage DC circuit breaker and control method thereof, the present invention realizes mechanical switch and does not play electric arc, realize thick-less vane, use lightning arrester that energy is released, thus realize extinguish fast electric arc, disengagement failure electric current.
The object of the invention is to adopt following technical proposals to realize:
The invention provides one and seal in capacitive high voltage DC circuit breaker, described circuit breaker comprises the DC circuit breaker unit of series connection, each described DC circuit breaker unit comprises change over switch in parallel, change-over circuit and energy consumer, and its improvements are, described change over switch adopts mechanical switch; Described change-over circuit adopts capacitance-resistance branch road, and described energy consumer adopts lightning arrester; Described high voltage DC breaker is connected with control circuit, described control circuit for control mechanical switch shutoff, control capacitance-resistance branch road and realize fault current transfer, and the energy suppressing mechanical switch both end voltage and control lightning arrester is released.
Wherein, described capacitance-resistance branch road comprises capacitor and the resistance of series connection; Described capacitor and resistor coupled in parallel are at mechanical switch two ends.
Wherein, described resistance and diodes in parallel.
Wherein, the capacitor being connected in parallel on mechanical switch two ends, when mechanical switch disconnects, makes mechanical switch both end voltage all the time lower than its corresponding arcing voltage opening distance, realizes disconnecting without arc of mechanical switch;
Described resistance be used for suppression capacitor after mechanical switch separating brake and DC circuit breaker is installed electric power system reactance between resonance; Diode is used for short-circuit resistance when fault current transfers to capacitance-resistance branch road, and eliminates the vibration between capacitor and system reactance; Lightning arrester is for limiting high voltage DC breaker both end voltage.
Wherein, described mechanical switch can realize disconnecting without arc fast.
Wherein, described control circuit adopts controller.
Wherein, described energy consumer or employing adjustable resistance.
The one that the present invention is based on another object provides seals in capacitive high voltage DC circuit breaker control method, and its improvements are, described control method comprises the steps:
(1) mechanical switch detects fault current, and in T1 moment action, is transferred to by fault current in capacitance-resistance branch road;
(2) described fault current is the capacitor charging in capacitance-resistance branch road, and control circuit controls mechanical switch and disconnects, and before mechanical switch disconnects the T2 moment, the charging voltage at capacitor two ends is all the time lower than the arcing voltage between mechanical switch fracture;
(3), when described capacitor voltage at both ends reaches lightning arrestor movement voltage, control lightning arrestor movement at T3 moment control circuit, energy is released from lightning arrester.
Wherein, described T1 is 1ms after fault occurs, and described T2 and T1 differs 2ms, and described T3 and T2 differs 1ms.
Compared with the prior art, the beneficial effect that the present invention reaches is:
1, provided by the inventionly seal in capacitive high voltage DC circuit breaker and control method thereof, fast shut-off fault current demand can be met, the thick-less vane of mechanical switch can be realized, the simple to operation and complete function of control method.
2, the present invention's speed of utilizing voltage on capacitor to rise is lower than mechanical switch medium recovery ltage rate all the time, thus realize mechanical switch and do not play electric arc, realize thick-less vane, and there is no resonant tank in this topology, avoid auxiliary branch capacitor and inductor resonance.
3, Topology Structure Design two fracture of the present invention, shortens each fracture stroke distances, breaker actuation speed can be made to double, thus realize extinguish fast electric arc, disengagement failure electric current during the action simultaneously of two fractures.
4, provided by the inventionly seal in capacitive high voltage DC circuit breaker fast response time, topological structure is simple, saves cost.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.
The invention provides one and seal in capacitive high voltage direct-current breaker topology structure as shown in Figure 2, circuit breaker comprises the DC circuit breaker unit of series connection, each described DC circuit breaker unit comprises change over switch in parallel, change-over circuit and energy consumer, and change over switch of the present invention adopts mechanical switch; Change-over circuit adopts capacitance-resistance branch road, and capacitance-resistance branch road comprises capacitor and the resistance of series connection; Capacitor and resistor coupled in parallel at mechanical switch two ends, resistance and diodes in parallel.Energy consumer adopts lightning arrester or adjustable resistance; High voltage DC breaker is connected with control circuit, control circuit for control mechanical switch shutoff, control capacitance-resistance branch road and realize fault current transfer, and the energy suppressing mechanical switch both end voltage and control lightning arrester is released.Mechanical switch realizes turning on and off by the electromagnetic pulse that control circuit sends.Control circuit adopts controller.
The effect being connected in parallel on the high-voltage capacitor at mechanical switch two ends in this structure is when mechanical switch disconnects, and makes mechanical switch both end voltage all the time lower than its corresponding arcing voltage opening distance, thus realizes disconnecting without arc of mechanical switch.The selection of capacitor will consider the peak value of the fracture voltage that mechanical switch can bear and system failure electric current simultaneously, capacitor is selected too small, then can not meet voltage request, select excessive, then can not meet current requirements, therefore the selection of capacitor needs balanced voltage and electric current.Occurrence needs to obtain according to DC circuit breaker institute power application system value.The effect of resistance is the resonance suppressed after mechanical switch separating brake between electric capacity and system reactance.The effect of diode is fault current short-circuit resistance vibration eliminated between electric capacity and system reactance when transferring to capacitance-resistance branch road.The effect in lightning arrester loop is limiting circuit breaker both end voltage.
Present invention also offers the control method sealing in capacitive high voltage DC circuit breaker, specifically comprise the steps:
1, when fault occurs, mechanical switch detects fault current, T1 moment action, and transfer fault current is in capacitance-resistance loop.
2, fault current transfers to capacitance-resistance branch road, and be the capacitor charging in capacitance-resistance branch road, control circuit controls mechanical switch and disconnects, before mechanical switch thorough opening time, namely before the T2 moment, the charging voltage at capacitor two ends all the time lower than the arcing voltage between mechanical switch fracture, thus realizes mechanical switch and disconnects without arc.
3, when capacitor voltage at both ends reaches lightning arrestor movement voltage, i.e. the T3 moment, control circuit controls lightning arrestor movement, and energy is released from lightning arrester branch road.High voltage DC breaker Control timing sequence as shown in Figure 3.
Described T1 is that 1ms, T2 and T1 differ 2ms, T3 and T2 difference 1ms after fault occurs.
Whole process implementation mechanical switch disconnects without arc fast and fault current excises, and reaches the application target of high voltage DC breaker.
Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment to invention has been detailed description, those of ordinary skill in the field are to be understood that: still can modify to the specific embodiment of the present invention or equivalent replacement, and not departing from any amendment of spirit and scope of the invention or equivalent replacement, it all should be encompassed in the middle of right of the present invention.