Solid-state circuit breaker and breaking method for solid-state circuit breaker
A solid-state circuit breaker and breaking method are disclosed. In an embodiment, the solid-state circuit breaker includes a semiconductor switch; a controller, connected to the semiconductor switch; and an energy absorber, connected in parallel with the semiconductor switch. The controller is configured to obtain an equivalent inductance of a circuit of the solid-state circuit breaker upon a fault occurring in a line. Further, upon the equivalent inductance being greater than an inductance estimated value, the controller is configured to set a second current fault threshold. Finally, upon a fault current of the line reaching the second current fault threshold, the semiconductor switch is controlled to execute a closing operation.
1. A solid-state circuit breaker, comprising:
a semiconductor switch;
a controller, connected to the semiconductor switch; and
an energy absorber, connected in parallel with the semiconductor switch,
wherein the controller is configured to obtain an equivalent inductance of a circuit of the solid-state circuit breaker upon a fault occurring in a line,
wherein, upon the equivalent inductance being greater than an inductance estimated value, the controller is configured to set a second current fault threshold; and
wherein, upon a fault current of the line reaching the second current fault threshold, the semiconductor switch is controlled to execute a closing operation.
2. The solid-state circuit breaker of claim 1 , wherein the semiconductor switch is a CMOS switch including,
a first NMOS transistor and a second NMOS transistor, a source of the first NMOS transistor and a source of the second NMOS transistor being connected together,
wherein the controller is separately connected to gates of the first NMOS transistor and the second NMOS transistor.
3. The solid-state circuit breaker of claim 2 , wherein the equivalent inductance is:
L
practicalseries
=
V
bus
di
dt
|
t
=
t
0
wherein V bus is a voltage of the line, i is a measured value of a line current, and t 0 is the time point when the fault occurs in the line.
4. The solid-state circuit breaker of claim 3 , wherein the second current fault threshold is:
I
newthrehold
=
Δ
T
×
V
clamp
-
V
bus
L
practicalseries
wherein V clamp is a clamping voltage, and ΔT is a fault disappearance time.
5. The solid-state circuit breaker of claim 4 , wherein an initial current fault threshold of the line is:
I
oldthrehold
=
V
clamp
-
V
bus
L
practicalseries
wherein I newthrehold <I oldthrehold .
6. The solid-state circuit breaker of claim 5 , wherein energy consumed by the energy absorber is:
E
TVS
=
∫
t
1
t
2
P
TVS
(
τ
)
d
τ
=
1
2
×
V
clamp
×
Δ
T
wherein P TVS (τ) is the instantaneous power at time point τ, E TVS <½×I oldthrehold ×V clamp ×ΔT.
7. The solid-state circuit breaker of claim 1 , wherein the energy absorber is a transient voltage suppression diode.
8. A breaking method for a solid-state circuit breaker, the solid-state circuit breaker including a semiconductor switch, a controller, connected to the semiconductor switch, an energy absorber, connected in parallel with the semiconductor switch, the breaking method comprising:
obtaining, via the controller, an equivalent inductance of a circuit of the solid-state circuit breaker upon a fault occurring in a line;
setting, via the controller, a second current fault threshold upon the equivalent inductance being greater than an inductance estimated value; and
controlling, upon a fault current of the line reaching the second current fault threshold, the semiconductor switch to execute a closing operation.
9. The breaking method for a solid-state circuit breaker of claim 8 , wherein the semiconductor switch is a CMOS switch including a first NMOS transistor and a second NMOS transistor; respective sources of the first NMOS transistor and the second NMOS transistor being connected together, is the controller being separately connected to respective gates of the first NMOS transistor and the second NMOS transistor.
10. The breaking method for a solid-state circuit breaker of claim 9 , wherein the equivalent inductance is:
L
practicalseries
=
V
bus
di
dt
|
t
=
t
0
wherein V bus is a voltage of the line, i is a measured value of a line current, and t 0 is the time point when the fault occurs in the line.
11. The breaking method for a solid-state circuit breaker of claim 10 , wherein the second current fault threshold is:
I
newthrehold
=
Δ
T
×
V
clamp
-
V
bus
L
practicalseries
wherein V clamp is a clamping voltage, and ΔT is a fault disappearance time.
12. The breaking method for a solid-state circuit breaker of claim 11 , wherein an initial current fault threshold of the line is:
I
oldthrehold
=
V
clamp
-
V
bus
L
practicalseries
wherein I newthrehold <I oldthrehold .
13. The breaking method for a solid-state circuit breaker of claim 12 , wherein energy consumed by the energy absorber is:
E
TVS
=
∫
t
1
t
2
P
TVS
(
τ
)
d
τ
=
1
2
×
V
clamp
×
Δ
T
wherein P TVS (τ) is the instantaneous power at time point τ,
wherein E TVS <½×I oldthrehold ×V clamp ×ΔT.
14. The breaking method for a solid-state circuit breaker of claim 8 , wherein the energy absorber is a transient voltage suppression diode.