CN104917297A - Electric ship power grid monitoring protection device and endurance monitoring method - Google Patents

Abstract

The invention discloses an electric ship power grid monitoring protection device comprising multiple switching power supplies, a direct-current transmitter, a signal processing unit, a PPU device, a reinforced all-in-one machine, an alarm unit, and a control unit. The direct-current transmitter acquires the voltage and current of a direct-current power grid in real time. The signal processing unit transmits voltage signals, current signals and power parameters of the direct-current power grid to the reinforced all-in-one machine. The PPU device acquires the effective values of the three-phase voltage and current of an alternating-current power grid in real time, and transmits the data to the reinforced all-in-one machine. The reinforced all-in-one machine processes and displays the data, and sends an alarm signal to the alarm unit. The control unit controls the work of power supply uninterrupted conversion and current limiting protection devices so as to realize power off of branch circuits and current overload protection. The invention further provides a power grid endurance monitoring method. By adopting the device and the method, safe and stable operation of the whole ship power grid can be ensured.

Description

Electric ship power system monitor protective device and continuation of the journey method for supervising

Technical field

The invention belongs to electric network synthetic monitoring field, particularly relate to a kind of electric ship power system monitor protective device and continuation of the journey method for supervising.

Background technology

Along with the continuous expansion of electric ship electrical network scale, electric network state monitoring and operation maintenance workload increase day by day, utilize informationization, digitlization, networking, intelligentized means carry out full ship operation of power networks condition monitoring, the emergent demand manipulating power-off is very urgent.

Existing most of electric ship mains supply, distribution, power consumption equipment, can only monitor separately, manipulate at each intra-zone, such as direct current monitoring system, exchange a monitoring system, can not with higher level or other external systems interconnected, reduce the utilization ratio of electric energy, add the management difficulty of system; And existing power supply, distribution, power consumption equipment are comparatively simple, function ratio is more single, has occurred the leak of a lot of monitoring and manipulation, has brought threat to the safety of full ship electrical network.

Therefore; we are in the urgent need to a kind of electric ship power system monitor protective device and method; these apparatus and method can the full ship direct current of Real-Time Monitoring, AC network operation conditions, and realizes voltage decompression or electric current and to transfinite protection, guarantees full ship power grid security, stable operation.

Summary of the invention

The object of the present invention is to provide a kind of can simultaneously to the direct current on naval vessel with exchange the electric ship power system monitor protective device and method monitored, guarantee full ship power grid security, stable operation.

The present invention is achieved in that

A kind of electric ship power system monitor protective device, it comprises multi-channel switch power, direct current transmitter, signal processing unit, PPU device, reinforces all-in-one, alarm unit, control unit;

Described multi-channel switch power input single-phase interchange 200V, exports the power supply that 15V is used for direct current transmitter, exports the power supply that 24V is used for signal processing unit, PPU device, reinforcing all-in-one, alarm unit, control unit;

Described direct current transmitter comprises voltage transmitter and current transducer, for the voltage and current of Real-time Collection direct current network;

The voltage and current analog signal of the direct current network of voltage transmitter and current transducer collection is converted to digital signal by described signal processing unit, and calculate the power parameter of direct current network, the voltage signal of direct current network, current signal, power parameter are passed to the reinforcing main frame reinforcing all-in-one by CAN;

The described three-phase voltage of PPU device Real-time Collection AC network and the effective value of electric current, and calculate frequency and the power parameter of AC network, the voltage of AC network, electric current, frequency and power are passed to the reinforcing main frame reinforcing all-in-one by CAN;

The reinforcing main frame of described reinforcing all-in-one receives and the data of processing signals processing unit and the transmission of PPU device, and these data is shown over the display; When abnormal parameters (branch road dead electricity or the overcurrent protection) of direct current network, reinforcing main frame sends to alarm unit to report to the police alarm signal, control unit controls the continuous electrical switching device of power supply, current-limiting protection device work, realizes branch road dead electricity, overcurrent protection;

Described reinforcing all-in-one, alarm unit, control unit are placed in casing.

By such scheme, described alarm unit comprises alarm unit plate, buzzer, mute button, when reinforcing host supervision to current overload, power overload and/or branch road dead electricity, reinforce main frame by the alarm unit plate transmission alarm command of I/O mouth to alarm unit, reinforce the display display alarm of all-in-one and dodge ruddiness, the buzzer work of alarm unit; When pressing mute button, buzzer quits work; Described reinforcing main frame store alarms record.

By such scheme, described control unit also includes band the distant of protective cover and cuts action button.

The continuous electrical switching device of described power supply and current-limiting protection device are realized by four transistors, be specially the continuous electrical switching device of power supply and comprise the first power supply and second source, the positive pole of described first power supply is connected with the first transistor, the first diode, the first inductance, current transducer successively and is connected with one end of load afterwards, and the negative pole of the first power supply is connected with transistor seconds, the second diode, the second inductance successively and is connected with the other end of load afterwards; The positive pole of described second source is connected with third transistor, the 3rd diode, the first inductance successively, and the negative pole of second source is connected with the 4th transistor, the 4th diode, the second inductance successively, and the 4th diode is connected with the first inductance by the 5th diode; Described first power supply and second source are parallel with voltage transmitter respectively; Described the first transistor, the first diode, the first inductance, third transistor, the 3rd diode, the first inductance composition current-limiting protection device.

During normal power supply, the first transistor, transistor seconds conducting, third transistor, the 4th transistor not conducting, device output end current flows through the first transistor, the first diode and the first inductance and arrives load;

(1) power supply not power-off conversion portion

The unexpected dead electricity of first power supply or voltage drop very large time, when voltage transmitter detects that voltage difference reaches specified value, control unit controls the first transistor, transistor seconds turns off, third transistor, the 4th transistor turns, and device automatically switches to second source and powers;

After the first power up normal power supply, through time delay in 5 seconds, control unit controls third transistor, the 4th transistor turns off, and the first transistor, transistor seconds conducting, return to the first Power supply;

(2) current-limiting protection part

During output short circuit, when current transducer detects that electric current reaches specified value, control unit controls the first transistor or third transistor works in limited current state, and short circuit current is limited in specified value.

If device output short trouble exists at the appointed time always, then after exceeding schedule time, control unit controls the first transistor or third transistor turns off, and keeps blocking state; If device output short trouble is eliminated at the appointed time, control unit controls the first transistor or third transistor recovers conducting state immediately.

The present invention also provides a kind of method utilizing electric ship power system monitor protective device to carry out the monitoring of power supply continuation of the journey in real time, and the method comprises the steps:

In step one, transducer real-time acquisition time t, the charge/discharge current of full ship lithium battery group, is designated as I respectively _i, i=1,2 ..., N (N=t*f, wherein f is sensor frequency);

Step 2, consult the electrochemical properties of lithium battery, during note initial time, the capacity of lithium battery is Q ₀, calculate t lithium battery group residual capacity Q _t, that is:

$Q_t=Q_0+{\∫}_0^t{I}_{i}dt---\left(1\right)$

The voltage of step 3, transducer Real-time Collection t full ship M block lithium battery, is designated as U respectively _i, i=1,2 ..., M;

The group voltage U of step 4, calculating t full ship M block lithium battery _t, that is:

$U_t=\underset{i=1}{\overset{M}{\Σ}}{U}_i---\left(2\right)$

Step 5, calculating t lithium battery group residue utilisable energy W, that is:

W＝Q _t*U _t

Step 6, transducer Real-time Collection full ship subsidiary engine power consumption instantaneous value, propulsion electric machine input power instantaneous value, be designated as P respectively ₁, P ₂;

Step 7, unit of account period of time T full ship subsidiary engine power consumption average value P _a, propulsion electric machine input power average value P _b, that is:

$P_A=\frac{{\∫}_0^T{P}_{1}dt}{T}---\left(3\right)$

$P_B=\frac{{\∫}_0^T{P}_{2}dt}{T}---\left(4\right)$

Step 8, the instantaneous speed of a ship or plane of transducer Real-time Collection, be designated as S ₁;

Step 9, unit of account period of time T average speed value S _a, that is:

$S_A=\frac{{\∫}_0^T{S}_{1}dt}{T}---\left(5\right)$

Step 10, according to formula (1) ~ (5), calculate lithium battery power supply endurance:

$\begin{array}{ccc}L=\frac{W}{P_A+P_B}\&times;S_A& nmile& W\&GreaterEqual;0\\ L=0& & W<0\end{array}---\left(6\right)$

Step 11, when boats and ships power in real time endurance be less than set point time, reinforce main frame send alarm signal to alarm unit, the buzzer work of alarm unit;

Step 12, when voltage decompression or electric current transfinite; reinforce main frame and send alarm signal to alarm unit; the buzzer work of alarm unit, and control the continuous electrical switching device of power supply, current-limiting protection device work by control unit, realize branch road dead electricity, overcurrent protection.

Real-time power supply endurance predicated error is less than 5%.

Described reinforcing all-in-one is by reinforcing main frame (overlapping software and hardware system containing man-machine interface computer, task process computer two) and display forms.Described signal processing unit forms primarily of analog-to-digital conversion module, single-chip microcomputer and CAN controller, the analog signal such as voltage, electric current of voltage transmitter and current transducer Real-time Collection direct current network is converted to digital signal by described signal processing unit, and rated output parameter, send the data to reinforcing main frame by CAN; Described reinforcing main frame completes process, the display of electrical network parameter and sends alarm signal, failure diagnosis etc., reinforces main frame and receives the data that in CAN, signal processing unit and PPU device send, and these data shown over the display; When abnormal parameters (branch road dead electricity or the overcurrent protection) of direct current network, reinforcing main frame sends to alarm unit to report to the police alarm signal, control unit controls power supply not power-off conversion, current-limiting protection device work, realizes branch road dead electricity, overcurrent protection; Control unit is established and is distantly cut action button 1, and for electrical network circuit breaker provides breaking signal, distant action button of cutting is only for use in case of emergency, and distant action button of cutting establishes protective cover, prevents behaviour by mistake; When current overload, power overload and/or branch road dead electricity, reinforce main frame and send alarm signal by I/O mouth to alarm unit, the corresponding column of display reddens light, by Phototube Coupling by Signal transmissions to alarm board, alarm board relay drives buzzer work, when pressing mute button, by Phototube Coupling by noise reduction Signal transmissions to alarm board, buzzer quits work, and can inquire about corresponding warning message in alarm logging.

The beneficial effect that the present invention compared with prior art has is:

(1) improve the real-time of full ship electric network state monitoring;

(2) carry out when exceeding set point reporting to the police at voltage, current parameters, failure diagnosis, when endurance is less than set point alarm, in case of emergency disconnect electrical network circuit breaker and carry out power-off, guarantee full ship power grid security, stable, run efficiently;

(3) use CAN total digitalization communication, there is the features such as precision is high, antijamming capability is strong;

(4) functions of the equipments modularization, is convenient to increase interface unit, is convenient to care and maintenance;

(5) there is informationization, digitlization, networking, intelligentized feature, formed there is electric network state monitoring, failure diagnosis and automatically protect, the real-time integrated management functions such as endurance is predicted, power quality analysis of powering;

(6) volume little, be convenient to install, alleviate labour intensity.

Accompanying drawing explanation

Fig. 1 is the structural representation of electric ship power system monitor protective device of the present invention;

Fig. 2 is the general principle figure of the continuous electrical switching device of power supply, current-limiting protection device work.

In figure: 1, casing, 2, multi-channel switch power, 3, direct current transmitter, 4, voltage transmitter, 5, current transducer, 6, signal processing unit, 7, PPU device, 8, reinforce all-in-one, 9, main frame is reinforced, 10, display, 11, alarm unit, 12, control unit.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described further.

See Fig. 1, a kind of electric ship power system monitor protective device, it comprises multi-channel switch power 2, direct current transmitter 3, signal processing unit 6, PPU device 7, reinforces all-in-one 8, alarm unit 11, control unit 12; Reinforce all-in-one 8 to form primarily of reinforcing main frame 9 and display 10;

Described multi-channel switch power 2 input single-phase interchange 200V, exports the power supply that 15V is used for direct current transmitter 3, exports the power supply that 24V is used for signal processing unit 6, PPU device 7, reinforcing all-in-one 8, alarm unit 11, control unit 12;

Described direct current transmitter 3 comprises voltage transmitter 4 and current transducer 5, for the voltage and current of Real-time Collection direct current network;

The voltage and current analog signal of the direct current network that voltage transmitter 4 and current transducer 5 gather is converted to digital signal by described signal processing unit 6, and calculate the power parameter of direct current network, the voltage signal of direct current network, current signal, power parameter are passed to the reinforcing main frame 9 reinforcing all-in-one 8 by CAN;

The described three-phase voltage of PPU device 7 Real-time Collection AC network and the effective value of electric current, and calculate frequency and the power parameter of AC network, the voltage of AC network, electric current, frequency and power are passed to the reinforcing main frame 9 reinforcing all-in-one 8 by CAN;

The reinforcing main frame 9 of described reinforcing all-in-one 8 receives and the data of processing signals processing unit 6 and PPU device 7 transmission, and these data is shown on display 10; When abnormal parameters (branch road dead electricity or the overcurrent protection) of direct current network, reinforcing main frame 9 sends to alarm unit 11 to report to the police by alarm signal, control unit controls the continuous electrical switching device of power supply, current-limiting protection device work, realizes branch road dead electricity, overcurrent protection;

Described reinforcing all-in-one 8, alarm unit 11, control unit 12 are placed in casing 1.

In the present invention, described alarm unit 11 comprises alarm unit plate, buzzer, mute button, when reinforcing main frame 9 and monitoring current overload, power overload and/or branch road dead electricity, reinforce main frame 9 by the alarm unit plate transmission alarm command of I/O mouth to alarm unit 11, reinforce display 10 display alarm of all-in-one 8 and dodge ruddiness, the buzzer work of alarm unit 11; When pressing mute button, buzzer quits work; Described reinforcing main frame 9 store alarms record.

Conveniently operate, described control unit 12 also includes band the distant of protective cover and cuts action button.

Fig. 2 is the general principle figure of the continuous electrical switching device of power supply, current-limiting protection device, and specific works process is as follows:

During normal power supply, transistor IGBT 1, IGBT2 conducting, transistor IGBT 3, IGBT4 not conducting, device output end current flows through transistor IGBT 1, diode D ₁and inductance L ₁arrive load;

(1) power supply not power-off conversion portion

The unexpected dead electricity of power supply E1 or voltage drop very large time, when voltage transmitter detects that voltage difference reaches specified value, control unit control transistor IGBT 1, IGBT2 turn off, transistor IGBT 3, IGBT4 conducting, device automatically switches to power supply E2 and powers;

After power supply E1 recovers normal power supply, through time delay in 5 seconds, control unit controls transistor IGBT 3, IGBT4 turns off, and transistor IGBT 1, IGBT2 conducting, return to power supply E1 and power;

(2) current-limiting protection part

During output short circuit, when current transducer detects that electric current reaches specified value, control unit controls transistor IGBT 1 or transistor IGBT 3 works in limited current state, and short circuit current is limited in specified value.

If device output short trouble exists at the appointed time always, then after exceeding schedule time, control unit controls transistor IGBT 1 or transistor IGBT 3 turns off, and keeps blocking state; If device output short trouble is eliminated at the appointed time, control unit controls transistor IGBT 1 or transistor IGBT 3 recovers conducting state immediately.

The step of operation electric ship power system monitor protective device is:

1) use before should check input ac power power whether normal, each switch be all placed in pass or stop position;

2) transfer switch is placed in power supply, casing power source indicator light is bright, and reinforce all-in-one start, equipment is started working, if transfer switch can be forwarded to another road and powers by dead electricity in running;

3), after reinforcing all-in-one start, reinforce main frame self-inspection, after startup, enter software interface; The switching of each page can be carried out by the button on panel; When occurring reporting to the police, buzzer rings, corresponding display interface bar flicker; Carry out noise reduction by mute button, can warning message be inquired about by the alarm logging page;

4) control unit automatic remote control interchange, the continuous electrical switching device of DC power supply and current-limiting protection device realize protecting;

5) when in emergency circumstances needing remote control to disconnect electrical network circuit breaker, to open on panel the corresponding distant protective cover cutting button, connect and distantly cut action button.

The present invention also provides a kind of method utilizing electric ship power system monitor protective device to carry out the monitoring of power supply continuation of the journey in real time, and the method comprises the steps:

In step one, transducer real-time acquisition time t, the charge/discharge current of full ship lithium battery group, is designated as I respectively _i, i=1,2 ..., N (N=t*f, wherein f is sensor frequency);

Step 2, consult the electrochemical properties of lithium battery, during note initial time, the capacity of lithium battery is Q ₀, calculate t lithium battery group residual capacity Q _t, that is:

$Q_t=Q_0+{\&Integral;}_0^t{I}_{i}dt---\left(1\right)$

The voltage of step 3, transducer Real-time Collection t full ship M block lithium battery, is designated as U respectively _i, i=1,2 ..., M;

The group voltage U of step 4, calculating t full ship M block lithium battery _t, that is:

$U_t=\underset{i=1}{\overset{M}{\&Sigma;}}{U}_i---\left(2\right)$

Step 5, calculating t lithium battery group residue utilisable energy W, that is:

W＝Q _t*U _t

Step 6, transducer Real-time Collection full ship subsidiary engine power consumption instantaneous value, propulsion electric machine input power instantaneous value, be designated as P respectively ₁, P ₂;

Step 7, unit of account period of time T full ship subsidiary engine power consumption average value P _a, propulsion electric machine input power average value P _b, that is:

$P_A=\frac{{\&Integral;}_0^T{P}_{1}dt}{T}---\left(3\right)$

$P_B=\frac{{\&Integral;}_0^T{P}_{2}dt}{T}---\left(4\right)$

Step 8, the instantaneous speed of a ship or plane of transducer Real-time Collection, be designated as S ₁;

Step 9, unit of account period of time T average speed value S _a, that is:

$S_A=\frac{{\&Integral;}_0^T{S}_{1}dt}{T}---\left(5\right)$

Step 10, according to formula (1) ~ (5), calculate lithium battery power supply endurance:

$\begin{array}{ccc}L=\frac{W}{P_A+P_B}\&times;S_A& nmile& W\&GreaterEqual;0\\ L=0& & W<0\end{array}---\left(6\right)$

Step 11, when boats and ships power in real time endurance be less than set point time, reinforce main frame send alarm signal to alarm unit, the buzzer work of alarm unit;

Step 12, when voltage decompression or electric current transfinite; reinforce main frame and send alarm signal to alarm unit; the buzzer work of alarm unit, and control the continuous electrical switching device of power supply, current-limiting protection device work by control unit, realize branch road dead electricity, overcurrent protection.

This endurance predicated error of powering in real time is less than 5%.

Attached example:

Described real-time power supply continuation of the journey method for supervising, comprises the steps:

The charge/discharge current of full ship lithium battery group in step one, transducer Real-time Collection 2 hours, transducer times of collection N=120, is recorded in table 1;

The charge/discharge current record sheet of the full ship lithium battery group of table 1

Step 2, consult the electrochemical properties of lithium battery, during note initial time, the capacity of lithium battery is 6000Ah, calculates the 2 little group of lithium battery constantly residual capacity Q _t, unit is ampere-hour (Ah), that is:

$Q_t=Q_0+{\&Integral;}_0^t{I}_{i}dt=5863.6Ah$

The voltage of the little full ship 100 pieces of lithium batteries constantly of step 3, transducer Real-time Collection 2, is designated as U respectively _i, i=1,2 ..., M, unit is volt (V), is recorded in table 2;

The graphic voltmeter of the little full ship 100 pieces of lithium batteries constantly of table 22

The group voltage U of step 4, the calculating full ship of t 100 pieces of lithium batteries _t, that is:

$U_t=\underset{i=1}{\overset{M}{\&Sigma;}}{U}_i=389.8V$

Step 5, calculating t lithium battery group residue utilisable energy W, that is:

W＝Q _t*U _t＝2285.6kWh

In step 6, transducer Real-time Collection unit period T, (for unit period of time T gets 0.1 hour in this example, namely 6 minutes) full ship subsidiary engine power consumption instantaneous value, propulsion electric machine input power instantaneous value, is designated as P respectively ₁, P ₂, unit is kilowatt (kW), is recorded in table 3;

Table 3 full ship subsidiary engine power consumption instantaneous value, propulsion electric machine input power instantaneous value record sheet

Step 7, unit of account period of time T full ship subsidiary engine power consumption average value P _a, propulsion electric machine input power average value P _b, unit is kilowatt (kW), that is:

$P_A=\frac{{\&Integral;}_0^{0.1}{P}_{1}dt}{0.1}=38.41kW$

$P_B=\frac{{\&Integral;}_0^{0.1}{P}_{2}dt}{0.1}=27.145kW$

Step 8, the instantaneous speed of a ship or plane of transducer Real-time Collection, unit is joint (Kn), is recorded in table 4;

The instantaneous flight speed record table of table 4

Step 9, unit of account period of time T average speed value S _a, unit is joint (Kn):

$S_A=\frac{{\&Integral;}_0^{0.1}{S}_{1}dt}{0.1}=13.533Kn$

Step 10, according to formula (4) ~ (7), calculate lithium battery power supply endurance, unit be nautical mile (nmile), that is:

$\begin{array}{cc}{L}_1=\frac{W}{P_A+P_B}\&times;S_A=471.83nmile& W\&GreaterEqual;0\\ L_1=0& W<0\end{array}$

Step 11, when boats and ships power in real time endurance be less than set point time, reinforce main frame send alarm signal to alarm unit, the buzzer work of alarm unit;

Step 12, when voltage decompression or electric current transfinite, reinforce main frame send alarm signal to alarm unit, the buzzer work of alarm unit.

Claims (4)

1. an electric ship power system monitor protective device, is characterized in that: it comprises multi-channel switch power, direct current transmitter, signal processing unit, PPU device, reinforces all-in-one, alarm unit, control unit;

Described multi-channel switch power input single-phase interchange 200V, exports the power supply that 15V is used for direct current transmitter, exports the power supply that 24V is used for signal processing unit, PPU device, reinforcing all-in-one, alarm unit, control unit;

Described direct current transmitter comprises voltage transmitter and current transducer, for the voltage and current of Real-time Collection direct current network;

The voltage and current analog signal of the direct current network of voltage transmitter and current transducer collection is converted to digital signal by described signal processing unit, and calculate the power parameter of direct current network, the voltage signal of direct current network, current signal, power parameter are passed to the reinforcing main frame reinforcing all-in-one by CAN;

The described three-phase voltage of PPU device Real-time Collection AC network and the effective value of electric current, and calculate frequency and the power parameter of AC network, the voltage of AC network, electric current, frequency and power are passed to the reinforcing main frame reinforcing all-in-one by CAN;

The reinforcing main frame of described reinforcing all-in-one receives and the data of processing signals processing unit and the transmission of PPU device, and these data is shown over the display; When the abnormal parameters of direct current network, reinforce main frame and send to alarm unit to report to the police alarm signal, control unit controls the continuous electrical switching device of power supply, current-limiting protection device work, realizes branch road dead electricity, overcurrent protection;

Described reinforcing all-in-one, alarm unit, control unit are placed in casing.

2. electric ship power system monitor protective device as claimed in claim 1, it is characterized in that: described alarm unit comprises alarm unit plate, buzzer, mute button, when reinforcing host supervision to current overload, power overload or branch road dead electricity, reinforce main frame by the alarm unit plate transmission alarm command of I/O mouth to alarm unit, reinforce the display display alarm of all-in-one and dodge ruddiness, the buzzer work of alarm unit; When pressing mute button, buzzer quits work; Described reinforcing main frame store alarms record.

3. electric ship power system monitor protective device as claimed in claim 1, is characterized in that: described control unit also includes band the distant of protective cover and cuts action button.

4. adopt the electric ship power system monitor protective device of the arbitrary claim of above-mentioned 1-3 to carry out a method for the monitoring of power supply continuation of the journey in real time, it is characterized in that comprising the steps:

In step one, transducer real-time acquisition time t, the charge/discharge current of full ship lithium battery group, is designated as I respectively _i, i=1,2 ..., N (N=t*f, wherein f is sensor frequency);

Step 2, consult the electrochemical properties of lithium battery, during note initial time, the capacity of lithium battery is Q ₀, calculate t lithium battery group residual capacity Q _t, that is:

$Q_t=Q_0+{\&Integral;}_0^t{I}_{i}dt---\left(1\right)$

The voltage of step 3, transducer Real-time Collection t full ship M block lithium battery, is designated as U respectively _i, i=1,2 ..., M;

The group voltage U of step 4, calculating t full ship M block lithium battery _t, that is:

$U_t=\underset{i=1}{\overset{M}{\&Sigma;}}{U}_i---\left(2\right)$

Step 5, calculating t lithium battery group residue utilisable energy W, that is:

W＝Q _t*U _t

Step 6, transducer Real-time Collection full ship subsidiary engine power consumption instantaneous value, propulsion electric machine input power instantaneous value, be designated as P respectively ₁, P ₂;

Step 7, unit of account period of time T full ship subsidiary engine power consumption average value P _a, propulsion electric machine input power average value P _b, that is:

$P_A=\frac{{\&Integral;}_0^T{P}_{1}dt}{T}---\left(3\right)$

$P_B=\frac{{\&Integral;}_0^T{P}_{2}dt}{T}---\left(4\right)$

Step 8, the instantaneous speed of a ship or plane of transducer Real-time Collection, be designated as S ₁;

Step 9, unit of account period of time T average speed value S _a, that is:

$S_A=\frac{{\&Integral;}_0^T{S}_{1}dt}{T}---\left(5\right)$

Step 10, according to formula (1) ~ (5), calculate lithium battery power supply endurance:

$\begin{array}{ccc}L=\frac{W}{P_A+P_B}\&times;S_A& nmile& W\&GreaterEqual;0\\ L=0& & W<0\end{array}---\left(6\right)$

Step 11, when boats and ships power in real time endurance be less than set point time, reinforce main frame send alarm signal to alarm unit, the buzzer work of alarm unit;

Step 12, when voltage decompression or electric current transfinite; reinforce main frame and send alarm signal to alarm unit; the buzzer work of alarm unit, control unit controls the continuous electrical switching device of power supply, current-limiting protection device work, realizes branch road dead electricity, overcurrent protection.