电力系统中性点运行方式: (1)直接接地:主要用于110KV及以上系统,其优点是经济性好,但供电可靠性差。 (2)不直接接地(经消弧线圈接地、经高电阻接地、不接地):主要用于110KV以下系统,有时10KV为提高可靠性也采用,优点是供电可靠性较高,但造价高

Ohm's law states that voltage across many types of conducting materials is directly proportional to the current flowing through the material. U= Ri or R= i R--resis tance()( linear resistor) The resistor is a passive element that cannot deliver power or store energy

One of the main uses of Thevenin's and Norton's theorems is the replacement of a large part of network very simple equivalent

The displacement current flowing internally between the capacitor plates is exactly equal to the conduction current flowing in the capacitor leads

Let=R3 and The result we have found for two /R =k, we have inputs may be extended to any v2=-k(v1+3) number of inputs

UB =A(DA-UB) =cons tant The inverting OP-AMP circuit

Equation is satisfied when=. The maximum power is=

Let us first define a linear element as passive element that has a linear voltage-current relationship

We select one node as a reference node and then define a voltage between each remaining node and the reference node

2.1引言 2.2基本编码方法 2.3图像编码标准 2.4语音编码标准